Horticulturae

16 pages, 4416 KiB

Open AccessEditor’s ChoiceArticle

Leaf Volatiles and Relevant Gene Expression as the Specific Characteristics in Citrus depressa Accession Discrimination

by Shu-Yen Lin, Yung-Yu Liao and Po-An Chen

Horticulturae 2022, 8(9), 773; https://doi.org/10.3390/horticulturae8090773 - 26 Aug 2022

Cited by 2 | Viewed by 1904

Abstract

Citrus depressa Hayata is the native and widespread citrus species in Taiwan. The notable character is that C. depressa has a distinct aroma different from local citrus. The ex situ germplasm of scions from different collection regions has variant leaf shapes and [...] Read more.

Citrus depressa Hayata is the native and widespread citrus species in Taiwan. The notable character is that C. depressa has a distinct aroma different from local citrus. The ex situ germplasm of scions from different collection regions has variant leaf shapes and different odor characteristics. Establishing volatile biomarkers for classifying the local C. depressa is beneficial to commercial development. Volatile organic compounds (VOCs) of fresh leaves from seven C. depressa accessions which were collected from different locations in Taiwan were extracted by headspace solid-phase microextraction and analyzed by GC-MS. The volatile compositions from each season showed the diversity, and linalool, of which the average relative content is 52.7%, was the most volatile component in any season. The other main VOCs of leaves of C. depressa were γ-terpinene, limonene, β-ocimene, and α-terpineol. The result of linear discriminant analysis by VOC markers shows that there are two main different types which are (1) accessions from the central and the east of Taiwan and (2) accessions which are closer to C. depressa in Okinawa, Japan. Five major VOC-related synthase genes were selected and the gene expression was used to classify the varieties. The clustering result is the same with VOC-based discrimination. Our results reveal leaf volatile profiling is capable of being the discrimination markers, and the possibility for constructing molecular markers is directly related to characteristics from secondary metabolites phenotyping. Full article

(This article belongs to the Section Genetics, Genomics, Breeding, and Biotechnology (G2B2))

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16 pages, 3035 KiB

Open AccessEditor’s ChoiceArticle

Inheritance of Apple (Malus × domestica (L.) Borkh) Resistance against Apple Scab (Venturia inaequalis (Cooke) Wint.) in Hybrid Breeding Material Obtained by Gene Pyramiding

by Kristīne Zelmene, Katrīna Kārkliņa, Laila Ikase and Gunārs Lācis

Horticulturae 2022, 8(9), 772; https://doi.org/10.3390/horticulturae8090772 - 26 Aug 2022

Cited by 10 | Viewed by 2444

Abstract

Apple scab caused by the pathogenic fungus Venturia inaequalis causes significant damage to apples. The creation of apple-scab resistant varieties is considered an alternative to pesticide-based management. To evaluate R gene inheritance, 862 apple hybrid samples were analyzed and divided into populations depending [...] Read more.

Apple scab caused by the pathogenic fungus Venturia inaequalis causes significant damage to apples. The creation of apple-scab resistant varieties is considered an alternative to pesticide-based management. To evaluate R gene inheritance, 862 apple hybrid samples were analyzed and divided into populations depending on the resistance genes (Rvi6 and Rvi5) present in the parents’ genotypes and their combinations. The field evaluation was carried out in 2016–2018 using the international VINQUEST scab evaluation methodology, but the genes were identified using specific scab resistance-gene molecular markers. Parent plants were genotyped using 22 SSR markers. The study determined that the field resistance of apple scab is influenced not only by the resistance genes present in the genotype but also by the genetic background of the apple cultivar, the tree’s general health status and resistance to other diseases. It was found that the apple scab resistance genes Rvi6 (Vf) and Rvi5 (Vm) are inherited according to Mendelian laws, and when both genes are pyramided in offspring, they are inherited as separate genes. In general, the inheritance of both genes in the offspring is not a determining factor for apple field resistance, as field resistance to scab is influenced by a combination of several factors. Full article

(This article belongs to the Section Genetics, Genomics, Breeding, and Biotechnology (G2B2))

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15 pages, 4484 KiB

Open AccessEditor’s ChoiceReview

Precooling and Cold Storage Methods for Fruits and Vegetables in Sub-Saharan Africa—A Review

by Edna Makule, Noel Dimoso and Savvas A. Tassou

Horticulturae 2022, 8(9), 776; https://doi.org/10.3390/horticulturae8090776 - 26 Aug 2022

Cited by 27 | Viewed by 12761

Abstract

Fruits and vegetables, known for their large nutrient potential, are more susceptible to high postharvest loss than other crops. Factors such as perishability, poor post-production handling and storage and processing infrastructures, increase the magnitude of food losses. The postharvest loss of fruits and [...] Read more.

Fruits and vegetables, known for their large nutrient potential, are more susceptible to high postharvest loss than other crops. Factors such as perishability, poor post-production handling and storage and processing infrastructures, increase the magnitude of food losses. The postharvest loss of fruits and vegetables in Sub-Saharan Africa ranges from 30% to 50%. One key strategy to overcome such losses is through cold chain integration in value chains. However, most developing countries currently lack the basic infrastructure and management skills needed to support the development of integrated cold chains, particularly in rural areas, where up to 60% of overall food losses occur on the farm and in ‘first-mile’ distribution. Storage of highly perishable produce in a controlled environment with respect to temperature and relative humidity leads to quality and quantity preservation. This contributes to increases in food and nutrition security, household incomes and environmental protection. This review addresses the need for adopting and strengthening measures for the precooling and cold storage of fruits and vegetables to improve their value chains. A range of precooling and cold storage methods, their suitability, energy demands and the constraints on storage and distribution are discussed and recommendations are made on how to improve their accessibility for small-scale farmers in rural communities. Full article

(This article belongs to the Section Postharvest Biology, Quality, Safety, and Technology)

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24 pages, 1793 KiB

Open AccessEditor’s ChoiceArticle

Antimicrobial Multiresistant Phenotypes of Genetically Diverse Pseudomonas spp. Isolates Associated with Tomato Plants in Chilean Orchards

by Pamela Córdova, Juan Pablo Rivera-González, Victoria Rojas-Martínez, Pablo Villarreal, Alan Zamorano, Nicola Fiore, Daniel San Martín, Francisca Vera, Eduardo Gálvez, Jaime Romero, Jaime Barrueto, Carolina Ilabaca-Díaz and Gastón Higuera

Horticulturae 2022, 8(8), 750; https://doi.org/10.3390/horticulturae8080750 - 19 Aug 2022

Cited by 1 | Viewed by 2409

Abstract

Tomatoes are susceptible to bacterial diseases, mainly related to some Pseudomonas syringae pathovars. Many Pseudomonas species are considered innocuous, but some have shown the ability to opportunistically infect tomato plants. Antimicrobial compounds have been used to control pathogenic organisms, and this can lead [...] Read more.

Tomatoes are susceptible to bacterial diseases, mainly related to some Pseudomonas syringae pathovars. Many Pseudomonas species are considered innocuous, but some have shown the ability to opportunistically infect tomato plants. Antimicrobial compounds have been used to control pathogenic organisms, and this can lead to environmental selection of phenotypically resistant bacteria. We assessed the diversity of Pseudomonas species associated with tomato plants from Chilean orchards and analyzed antimicrobial resistance among the isolated strains. A total of 64 Pseudomonas isolates (P. syringae, P. viridiflava, P. fluorescens, P. koreensis, P. gessardii, and P. azotoformans) were evaluated for their phenotypic resistance to seven antimicrobial compounds, including copper, streptomycin, and five other antibiotics typically not used in agriculture. The results showed that 95%, 86%, 70%, 53%, 45%, and 1.6% of the isolates were resistant to rifampin, ampicillin, copper, chloramphenicol, streptomycin, and tetracycline, respectively, with no isolates being resistant to gentamicin. A total of 96.9% of Pseudomonas isolates exhibited a multiresistant phenotype to at least two of the antimicrobials tested. The most frequent multiresistance phenotype was Cu-Str-Amp-Cm-Rif (23.4%). The presence of Pseudomonas strains tolerant to conventional bactericides, metals, and other antimicrobials makes these bacteria an emerging threat to the agriculture industry and to human health. Full article

(This article belongs to the Special Issue Bacterial Diseases in Horticulture: Advances in the Study of Pathogens, Interaction with the Host, Diagnosis and Sustainable Control)

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18 pages, 2533 KiB

Open AccessEditor’s ChoiceArticle

Cleaning of Tomato brown rugose fruit virus (ToBRFV) from Contaminated Clothing of Greenhouse Employees

by Jens Ehlers, Shaheen Nourinejhad Zarghani, Bärbel Kroschewski, Carmen Büttner and Martina Bandte

Horticulturae 2022, 8(8), 751; https://doi.org/10.3390/horticulturae8080751 - 19 Aug 2022

Cited by 12 | Viewed by 4651

Abstract

The highly infectious Tomato brown rugose fruit virus (ToBRFV) is a new viral threat to tomato production worldwide. In production, the very easy mechanical transmissibility combined with the high resistance in vitro is of great concern. We tested: (i) whether household cleaning products, [...] Read more.

The highly infectious Tomato brown rugose fruit virus (ToBRFV) is a new viral threat to tomato production worldwide. In production, the very easy mechanical transmissibility combined with the high resistance in vitro is of great concern. We tested: (i) whether household cleaning products, commercial agricultural detergents, and an authorized plant protectant are suitable for cleaning contaminated clothing, and (ii) whether infectious viruses remain in the resulting cleaning water. The evaluation of the sanitation effect was performed using bioassays, by counting ToBRFV-associated necrotic local lesions on Nicotiana tabacum cv. Xanthi NN. For this purpose, leaves were mechanically inoculated with treated fabrics and cleaning solutions which would normally be discharged to the sewer system. The detergents Fadex H⁺ (FH) and Menno Hortisept Clean Plus, as well as the disinfectant Menno Florades (MF), led to an almost complete removal of ToBRFV from contaminated fabrics, corresponding to a reduction in local lesions by 99.94–99.96%. In contrast, common household cleaning products (Spee ActivGel (SAG), Vanish Oxi Action Gel (VO) did not effectively remove the pathogen from the fabric, where the reduction was 45.1% and 89.7%, respectively. In particular, cleaning solutions after the use of household cleaners were highly contaminated with ToBRFV. After a 16-h treatment with the disinfectant MF, infectious ToBRFV was no longer present in VO, FH, and MF cleaning solutions, as demonstrated by extensive bioassays. Full article

(This article belongs to the Special Issue Innovative System for Disinfection in Greenhouses)

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21 pages, 5455 KiB

Open AccessEditor’s ChoiceReview

Bio-Circular Perspective of Citrus Fruit Loss Caused by Pathogens: Occurrences, Active Ingredient Recovery and Applications

by Pattarapol Khamsaw, Jiraporn Sangta, Pirawan Chaiwan, Pornchai Rachtanapun, Sasithorn Sirilun, Korawan Sringarm, Sarinthip Thanakkasaranee and Sarana Rose Sommano

Horticulturae 2022, 8(8), 748; https://doi.org/10.3390/horticulturae8080748 - 18 Aug 2022

Cited by 10 | Viewed by 3661

Abstract

The Sustainable Development Goals (SDGs) contribute to the improvement of production and consumption systems, hence, assisting in the eradication of hunger and poverty. As a result, there is growing global interest in the direction of economic development to create a zero-waste economy or [...] Read more.

The Sustainable Development Goals (SDGs) contribute to the improvement of production and consumption systems, hence, assisting in the eradication of hunger and poverty. As a result, there is growing global interest in the direction of economic development to create a zero-waste economy or circular economy. Citrus fruits are a major fruit crop, with annual global production surpassing 100 million tons, while orange and tangerine production alone account for more than half of the overall production. During pre- and postharvest stages of citrus fruit production, it is estimated that more than 20% of fruit biomass is lost, due, primarily, to biotic stresses. This review emphasizes causes of fruit losses by pathogenic caused diseases and proposes a bio-circular perspective in the production of citrus fruits. Due to substantial changes in fruit characteristics and environmental conditions, some of the most economically significant pathogens infect fruits in the field during the growing season and remain dormant or inactive until they resume growth after harvest. Peel biomass is the most significant by-product in citrus fruit production. This biomass is enriched with the value-adding essential oils and polysaccharides. For the complete bio-circular economy, these active ingredients can be utilized as citrus postharvest coating materials based upon their functional properties. The overall outreach of the approach not only reduces the amount of agricultural by-products and develops new applications for the pomology industry, it also promotes bio-circular green economic, which is in line with the SDGs for the citrus fruit industry. Full article

(This article belongs to the Topic New Trends in Agri-Food Sector: Environmental, Economic and Social Perspectives)

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13 pages, 2043 KiB

Open AccessEditor’s ChoiceArticle

Metabolite Analysis of Lettuce in Response to Sulfur Nutrition

by Jung-Sung Chung, Hyeong-Cheol Kim, Su-Min Yun, Hyun-Jin Kim, Cheol-Soo Kim and Jeung-Joo Lee

Horticulturae 2022, 8(8), 734; https://doi.org/10.3390/horticulturae8080734 - 16 Aug 2022

Cited by 7 | Viewed by 2050

Abstract

Sulfur is an essential nutrient required for plant growth and metabolism, and plays an important role in relieving stress. Nutrient deficiency is one of the main factors that negatively affect crop growth, quality, and yield. This study aimed to evaluate the effect of [...] Read more.

Sulfur is an essential nutrient required for plant growth and metabolism, and plays an important role in relieving stress. Nutrient deficiency is one of the main factors that negatively affect crop growth, quality, and yield. This study aimed to evaluate the effect of sulfur nutrients on the growth and metabolites of lettuce after treatment with two different sulfur concentrations (16 μM and 2 mM) in spray hydroponics. The fresh weight, chlorophyll, and carotenoid content of lettuce leaves were analyzed. Root morphology was examined using the WinRHIZO program. Metabolites were comparatively evaluated with the help of LC-MS and GC-MS. The fresh weight, chlorophyll, and carotenoid contents of lettuce were higher in the high concentration sulfur treatment group than in the low concentration sulfur treatment group. In the characteristics analysis of the lettuce roots, treatment with a high concentration of sulfur had a more positive effect on the lettuce root development than treatment with a low concentration of sulfur. Moreover, mass-based metabolomics analysis showed that the lettuce metabolites content was significantly different according to low- and high-concentration sulfur treatments. Therefore, this study highlights the importance of sulfur nutrient content in lettuce growth and metabolites. Full article

(This article belongs to the Topic Plants Nutrients)

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18 pages, 1103 KiB

Open AccessEditor’s ChoiceArticle

Effects of Plasticulture and Conservation Tillage on Nematode Assemblage and Their Relationships with Nitrous Oxide Emission following a Winter Cover Cropping and Vegetable Production System

by Koon-Hui Wang, Philip Waisen, Roshan Paudel, Guihua Chen, Susan Lynn Fricke Meyer and Cerruti R. R. Hooks

Horticulturae 2022, 8(8), 728; https://doi.org/10.3390/horticulturae8080728 - 14 Aug 2022

Viewed by 1901

Abstract

Agriculture production emits significant amounts of nitrous oxide (N₂O), a greenhouse gas with high global warming potential. The objectives of this study were to examine whether different husbandry practices (tillage and plasticulture) following winter cover cropping would influence soil food web [...] Read more.

Agriculture production emits significant amounts of nitrous oxide (N₂O), a greenhouse gas with high global warming potential. The objectives of this study were to examine whether different husbandry practices (tillage and plasticulture) following winter cover cropping would influence soil food web structure and whether a change in the soil community could help mitigate N₂O emission in vegetable plantings. Three consecutive field trials were conducted. A winter cover crop mix of forage radish (Raphanus sativus), crimson clover (Trifolium incarnatum) and cereal rye (Secale cereale) were planted in all plots. Winter cover crop was terminated by flail mowing followed by (1) conventional till without surface residues [Bare Ground (BG)], (2) conventional till with black plastic mulch (BP) without surface residues, (3) strip-till (ST) with partial surface residues, or (4) no-till (NT) with surface residues. The cash crop planted subsequently were eggplant (Solanum melongena) in 2012 and 2014 and sweet corn (Zea mays) in 2013. The soil food web structure was consistently disturbed in the BP compared to other treatments as indicated by a reduction in the abundance of predatory nematodes in 2012 and 2014, and nematode maturity index in 2013 in BP. Changes in soil food web structure in the conservation tillage (NT or ST) treatments based on the weight abundance of nematode community analysis were not consistent and did not improve over the 3-year study; but were consistently improved based on functional metabolic footprint calculation at termination of cover crops of 2013 and 2014. None-the-less, the N₂O emissions increased as the abundance of fungivorous nematodes increased during all three trials. It was also found that improved soil food web structure [higher abundance of omnivorous in 2012 or predatory nematodes in 2013 and 2014, and structure index (SI) in all 3 years] reduced N₂O emissions. These findings suggested that proper soil husbandry practices following winter cover cropping could mitigate N₂O emissions over time. Full article

(This article belongs to the Special Issue Advancements in Soil Health)

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16 pages, 3248 KiB

Open AccessEditor’s ChoiceArticle

In Search of Antifungals from the Plant World: The Potential of Saponins and Brassica Species against Verticillium dahliae Kleb.

by Caterina Morcia, Isabella Piazza, Roberta Ghizzoni, Stefano Delbono, Barbara Felici, Simona Baima, Federico Scossa, Elisa Biazzi, Aldo Tava, Valeria Terzi and Franca Finocchiaro

Horticulturae 2022, 8(8), 729; https://doi.org/10.3390/horticulturae8080729 - 14 Aug 2022

Cited by 1 | Viewed by 1983

Abstract

Control methods alternative to synthetic pesticides are among the priorities for both organic and conventional farming systems. Plants are potential sources of compounds with antimicrobial properties. In this study, the antifungal potentialities of saponins derived from Medicago species and oat grains and of [...] Read more.

Control methods alternative to synthetic pesticides are among the priorities for both organic and conventional farming systems. Plants are potential sources of compounds with antimicrobial properties. In this study, the antifungal potentialities of saponins derived from Medicago species and oat grains and of brassica sprouts have been explored for the control of Verticillium dahliae, a widely distributed fungal pathogen that causes vascular wilt disease on over 200 plant species. All the tested plant extracts showed antifungal properties. Such compounds, able to reduce mycelium growth and conidia formation, deserve deeper in vivo evaluation, even in combination with a delivery system. Full article

(This article belongs to the Special Issue Sustainable Control Strategies of Plant Pathogens in Horticulture)

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29 pages, 2017 KiB

Open AccessEditor’s ChoiceReview

Emerging Technologies for Prolonging Fresh-Cut Fruits’ Quality and Safety during Storage

by Rey David Iturralde-García, Francisco Javier Cinco-Moroyoqui, Oliviert Martínez-Cruz, Saúl Ruiz-Cruz, Francisco Javier Wong-Corral, Jesús Borboa-Flores, Yaeel Isbeth Cornejo-Ramírez, Ariadna Thalia Bernal-Mercado and Carmen Lizette Del-Toro-Sánchez

Horticulturae 2022, 8(8), 731; https://doi.org/10.3390/horticulturae8080731 - 14 Aug 2022

Cited by 20 | Viewed by 9069

Abstract

Fresh-cut fruits have been in great demand by consumers owing to the convenience of buying them in shopping centers as ready-to-eat products, and various advantages, such as the fact that they are healthy and fresh products. However, their shelf lives are brief due [...] Read more.

Fresh-cut fruits have been in great demand by consumers owing to the convenience of buying them in shopping centers as ready-to-eat products, and various advantages, such as the fact that they are healthy and fresh products. However, their shelf lives are brief due to their physiological changes and maturation. Therefore, this review includes information from the physicochemical, microbiological, nutritional, and sensory points of view on the deterioration mechanisms of fresh-cut fruits. In addition, updated information is presented on the different emerging technologies, such as active packaging (edible films, coatings, and modified atmospheres), natural preservatives (antioxidants and antimicrobials), and physical treatments (high hydrostatic pressure, UV-C radiation, and ozone). The benefits and disadvantages of each of these technologies and the ease of their applications are discussed. Having alternatives to preserve fresh-cut fruit is essential both for the consumer and the merchant, since the consumer could then obtain a high-quality product maintaining all its properties without causing any damage, and the merchant would receive economic benefits by having more time to sell the product. Full article

(This article belongs to the Special Issue Fruits Quality and Sensory Analysis)

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15 pages, 2924 KiB

Open AccessEditor’s ChoiceArticle

Effect of a Radical Mutation in Plastidic Starch Phosphorylase PHO1a on Potato Growth and Cold Stress Response

by Anna V. Nezhdanova, Gleb I. Efremov, Maria A. Slugina, Anastasia M. Kamionskaya, Elena Z. Kochieva and Anna V. Shchennikova

Horticulturae 2022, 8(8), 730; https://doi.org/10.3390/horticulturae8080730 - 14 Aug 2022

Cited by 1 | Viewed by 1746

Abstract

The plant response to stresses includes changes in starch metabolism regulated by a complex catalytic network, in which plastidic starch phosphorylase PHO1a is one of the key players. In this study, we used the CRISPR-Cas9 system to edit the PHO1a gene in four [...] Read more.

The plant response to stresses includes changes in starch metabolism regulated by a complex catalytic network, in which plastidic starch phosphorylase PHO1a is one of the key players. In this study, we used the CRISPR-Cas9 system to edit the PHO1a gene in four potato (Solanum tuberosum L.) cultivars, which resulted in the introduction of a radical mutation, G261V, into the PHO1a functional domain. The mutants had altered morphology and differed from wild-type plants in starch content in the roots and leaves. Exposure to cold stress revealed the differential response of parental and transgenic plants in terms of starch content and the expression of genes coding for β-amylases, amylase inhibitors, and stress-responsive MADS-domain transcription factors. These results suggest that the G261V mutation causes changes in the functional activity of PHO1a, which in turn affect the coordinated operation of starch catabolism enzymes both under normal and cold stress conditions, possibly through differential expression of MADS-domain transcription factors. Our results highlight a critical regulatory role of PHO1a in starch metabolism, root and shoot development, and stress response in potatoes. Full article

(This article belongs to the Special Issue Horticultural Plants Pathology and Advances in Disease Management)

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18 pages, 7123 KiB

Open AccessEditor’s ChoiceArticle

Balance of Carotenoid Synthesis and Degradation Contributes to the Color Difference between Chinese Narcissus and Its Yellow-Tepal Mutant

by Yiming Zhang, Yi Zhou, Yijing Wu, Junhuo Cai, Yiqiang Zhang, Jincai Shen, Shibin Wu, Wenjie Liu, Ming Cai, Tangren Cheng and Qixiang Zhang

Horticulturae 2022, 8(8), 727; https://doi.org/10.3390/horticulturae8080727 - 12 Aug 2022

Cited by 4 | Viewed by 1798

Abstract

Chinese narcissus (Narcissus tazetta var. chinensis) was introduced to China 1300–1400 years ago, and has grown naturally in southeastern China. It is a popular Chinese traditional potted flower and a well-known flowering bulb cultivated worldwide with only two white-tepal triploid cultivars, [...] Read more.

Chinese narcissus (Narcissus tazetta var. chinensis) was introduced to China 1300–1400 years ago, and has grown naturally in southeastern China. It is a popular Chinese traditional potted flower and a well-known flowering bulb cultivated worldwide with only two white-tepal triploid cultivars, ‘Jinzhan Yintai’ and ‘Yulinglong’. Recently, a mutant with yellow tepals was observed and promptly became popular. To clarify the key pigment for color difference and its molecular mechanism of accumulation, we conducted pigment metabolite analysis and comparative transcriptome analysis on ‘Jinzhan Yintai’ and the yellow-flowered mutant. The results showed that there was no significant difference in total flavonoid content between the mutant and ‘Jinzhan Yintai’, whereas the total carotenoid content of the mutant was more than 10-fold higher than that of ‘Jinzhan Yintai’. Based on the RNA-sequencing results, sixty-four unigenes, corresponding to 29 enzymes associated with the carotenoid biosynthesis pathway, were analyzed in detail. A comparative KEGG pathway enrichment analysis, in conjunction with quantitative real-time PCR data, revealed the opposite gene expression mode of the carotenoid biosynthesis pathway. Compared with ‘Jinzhan Yintai ’, PSY and PDS were up-regulated in the three mid-flowering stages of the mutant, whereas NCED genes were strongly down-regulated, which likely contributed to carotenoid accumulation in chromoplasts of the tepals in the mutant. Full article

(This article belongs to the Section Floriculture, Nursery and Landscape, and Turf)

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12 pages, 3507 KiB

Open AccessEditor’s ChoiceArticle

Lipidomics Analysis of Tea Leaves Cultured in Hydroponics Reveals That High Nitrogen Application Decreases Tea Plant Resistance to Ultraviolet Radiation

by Sijia Du, Meiya Liu, Fang Dong, Chuan Yue, Jianyun Ruan, Hongli Cao and Qunfeng Zhang

Horticulturae 2022, 8(8), 724; https://doi.org/10.3390/horticulturae8080724 - 11 Aug 2022

Cited by 1 | Viewed by 1708

Abstract

Lipid composition in tea leaves is significantly affected by ultraviolet (UV) radiation and nitrogen levels. Here, to reveal the response of lipids in tea plants (Camellia sinensis L.) to the interaction between nitrogen and UV radiation, we treated tea plants with three [...] Read more.

Lipid composition in tea leaves is significantly affected by ultraviolet (UV) radiation and nitrogen levels. Here, to reveal the response of lipids in tea plants (Camellia sinensis L.) to the interaction between nitrogen and UV radiation, we treated tea plants with three gradients of UV radiation under two nitrogen levels by the hydroponic method. Lipidomics results show that ultraviolet radiation can decrease neutral lipid (TAG) and increase membrane lipids (including PC, PE, and PG) under hydroponic conditions, indicating that tea plants could survive UV radiation by decomposing TAG to avoid damaging cells. In addition, the accumulation of phospholipids and galactolipids may be related to avoiding UV damage and enhancing photosynthesis in tea plants under UV radiation. Furthermore, the response of lipid components to UV radiation in tea plants under low nitrogen conditions is significantly lower than that under high nitrogen conditions, which suggests that excessive nitrogen application may reduce the resistance of tea plants to UV radiation. This study provides a theoretical basis for optimizing cultivation measures based on tea UV resistance. Full article

(This article belongs to the Special Issue Advances in Tea Plant Biology and Tea Quality Regulation)

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12 pages, 2339 KiB

Open AccessEditor’s ChoiceArticle

Effect of UV-B Irradiation on Bioactive Compounds of Red Perilla (Perilla frutescens (L.) Britton) Cultivated in a Plant Factory with Artificial Light

by Hideo Yoshida, Kanae Shimada, Shoko Hikosaka and Eiji Goto

Horticulturae 2022, 8(8), 725; https://doi.org/10.3390/horticulturae8080725 - 11 Aug 2022

Cited by 4 | Viewed by 1908

Abstract

In this study, we investigated the effect of UV-B irradiation 3 days prior to harvest, on the accumulation of rosmarinic acid (RA) and anthocyanin, and the expression of genes related to phenylpropanoid and flavonoid biosynthetic pathways, in red perilla (Perilla frutescens L.). [...] Read more.

In this study, we investigated the effect of UV-B irradiation 3 days prior to harvest, on the accumulation of rosmarinic acid (RA) and anthocyanin, and the expression of genes related to phenylpropanoid and flavonoid biosynthetic pathways, in red perilla (Perilla frutescens L.). In experiment 1, seedlings at 60 days after sowing (DAS) were subjected to UV-B irradiation at 0 (control), 6, and 10 W m⁻² under a 16 h light period; while in experiment 2, seedlings at 45 DAS were subjected to UV-B irradiation at 0 (control), 4 W m⁻² at continuous irradiation, and 6 W m⁻² at 16 h irradiation. UV irradiation of 10 W m⁻² for 16 h negatively affected leaf color, while irradiation at 6 W m⁻² enhanced RA biosynthesis and antioxidant capacity. Continuous UV-B irradiation of 4 W m⁻² increased the RA concentration by 92% compared to the control; however, this effect was smaller than that of UV-B irradiation at 6 W m⁻² for 16 h, 141% higher than that of the control and had a lower antioxidant capacity against UV-mediated ROS overproduction during the dark period. Results demonstrate that 6 W m⁻² of UV-B irradiation for 16 h is suitable for enhancing the RA concentration and content of red perilla. Full article

(This article belongs to the Special Issue Indoor Farming and Artificial Cultivation)

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23 pages, 7889 KiB

Open AccessEditor’s ChoiceArticle

Comparison of Waterlogging Tolerance of Three Peach Rootstock Seedlings Based on Physiological, Anatomical and Ultra-Structural Changes

by Fangjie Xu, Huaqing Cai, Xianan Zhang, Mingshen Su, Huijuan Zhou, Xiongwei Li, Minghao Zhang, Yang Hu, Chao Gu, Jihong Du and Zhengwen Ye

Horticulturae 2022, 8(8), 720; https://doi.org/10.3390/horticulturae8080720 - 10 Aug 2022

Cited by 4 | Viewed by 2128

Abstract

Peach (Prunus persica (L.) Batsch) is a typical shallow-rooted fruit plant with a high respiratory intensity and oxygen demand, which makes it highly susceptible to oxygen-deficient soil conditions resulting from waterlogging. Rootstock waterlogging resistance is essential to the performance of cultivated peaches [...] Read more.

Peach (Prunus persica (L.) Batsch) is a typical shallow-rooted fruit plant with a high respiratory intensity and oxygen demand, which makes it highly susceptible to oxygen-deficient soil conditions resulting from waterlogging. Rootstock waterlogging resistance is essential to the performance of cultivated peaches under waterlogging stress. In comparison to Prunus persica var. persica (‘Maotao’, M) and Prunus davidiana (Carr.) C. de Vos (‘Shantao’, S), Prunus persica f. Hossu (‘Hossu’, H) exhibited superior leaf photosynthetic electron transfer efficiency, a higher rate of mycorrhizal fungi infection in both fine roots and mesophyll palisade cells, as well as earlier air cavity formation in both leaf midvein and fine roots under waterlogging stress. Furthermore, under non-waterlogging conditions, Hossu had greater leaf superoxide dismutase (SOD) activity, higher proline content, and a greater content of starch granules in the pith and xylem ray cells of stems and roots than rootstocks M and S. As a result, Hossu’s tolerance to waterlogging may be due to its higher photosynthetic efficiency, improved tissue oxygen permeability, higher energy metabolism, and increased intracellular mycorrhizal fungus infection rates in both root parenchyma cells and mesophyll palisade cells. Full article

(This article belongs to the Special Issue Advanced Studies in Fruit Trees under Water Stress)

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12 pages, 2534 KiB

Open AccessEditor’s ChoiceArticle

The Occurrence of Clubroot in Colombia and Its Relationship with Climate and Agronomic Practices

by Andrea Botero-Ramírez, Fabián Leonardo Padilla-Huertas, Stephen E. Strelkov and Celsa García-Dominguez

Horticulturae 2022, 8(8), 711; https://doi.org/10.3390/horticulturae8080711 - 8 Aug 2022

Cited by 1 | Viewed by 1558

Abstract

Clubroot, caused by Plasmodiophora brassicae, is a major disease of cruciferous crops in Colombia. Limited information is available, however, regarding its distribution or epidemiology in this country. The objectives of this study were to determine the occurrence of clubroot in the main [...] Read more.

Clubroot, caused by Plasmodiophora brassicae, is a major disease of cruciferous crops in Colombia. Limited information is available, however, regarding its distribution or epidemiology in this country. The objectives of this study were to determine the occurrence of clubroot in the main regions of Colombia where cruciferous crops are grown, and to examine the relationship between pathogen inoculum density and the likelihood of field infestation with crop management practices and climatic information. In total, 127 fields were surveyed across eight departments, the pathogen inoculum density was estimated, climatic information was obtained, and farmers were surveyed on their crop management practices. More than half (53.7%) of the fields visited were found to be clubroot-infested and pathogen DNA was detected in 91.3% of the surveyed fields. The only department where clubroot symptoms were not observed was Nariño. In infested fields, P. brassicae inoculum density varied between 3 × 10² and 1 × 10⁶ resting spores per gram of soil, with the highest inoculum density observed in Norte de Santander. All other departments had comparable spore loads. Inoculum density positively affected the likelihood of infestation of a field, and both spore loads and infestations were positively affected by the average temperature. Full article

(This article belongs to the Special Issue Soil-Borne Obligate Parasite of Brassicaceae)

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21 pages, 1980 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Nutrient Content with Different Fertilizer Management and Influence on Yield and Fruit Quality in Apple cv. Gala

by Mariana Mota, Maria João Martins, Gonçalo Policarpo, Layanne Sprey, Mafalda Pastaneira, Patrícia Almeida, Anabela Maurício, Cristina Rosa, João Faria, Miguel B. Martins, Miguel L. de Sousa, Ricardo Santos, Rui M. de Sousa, Anabela B. da Silva, Henrique Ribeiro and Cristina M. Oliveira

Horticulturae 2022, 8(8), 713; https://doi.org/10.3390/horticulturae8080713 - 8 Aug 2022

Cited by 11 | Viewed by 2881

Abstract

Assessing a plant’s nutritional status and fertilizer rates and types that can optimize fruit quality and yield are critical in intensive apple orchards. The aim of this work was to identify correlations between nutrients in the different organs that allow the early diagnosis [...] Read more.

Assessing a plant’s nutritional status and fertilizer rates and types that can optimize fruit quality and yield are critical in intensive apple orchards. The aim of this work was to identify correlations between nutrients in the different organs that allow the early diagnosis of the nutritional status and to assess the impact on the optimal nutrient content in apple leaves, as well as in the yield and quality of chemical and organic fertilization. Five orchards of ‘Gala’ were fertilized with different levels of NPK over a period of four years. Macro and micronutrients of buds, flowers, 45 and 90–110 days after full bloom (DAFB) leaves and 60 DAFB and 15 days before harvest (DBH) fruits were determined. Boron was the only element for which strong correlations, 0.7 < r < 0.9, were observed between all organ pairs. The fertilization treatments did not affect the nutrient concentrations in the leaves of 90–110 DAFB other than P, Ca and Mg and did not affect the macronutrients in the fruit. In one of the five orchards, the yield increased by 26% with double fertilization compared to standard fertilization and, for the other four orchards, the impact depended on the year. Fruit size was more related to crop load than to fertilization and TSS and firmness were not affected by the type or amount of fertilizers. Replacing part of the chemical fertilizer with organic materials did not affect productivity or fruit quality. Full article

(This article belongs to the Special Issue Strategies in Fruit Trees and Vegetables to Increase Nutrient Use Efficiency)

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14 pages, 1351 KiB

Open AccessEditor’s ChoiceArticle

Compost Composition and Application Rate Have a Greater Impact on Spinach Yield and Soil Fertility Benefits Than Feedstock Origin

by Alicia J. Kelley, David N. Campbell, Ann C. Wilkie and Gabriel Maltais-Landry

Horticulturae 2022, 8(8), 688; https://doi.org/10.3390/horticulturae8080688 - 29 Jul 2022

Cited by 8 | Viewed by 2322

Abstract

Rapid urbanization results in the accumulation of food wastes that can be composted and diverted from landfills. Previous lab incubations demonstrated that food-based composts can increase soil N relative to manure-based composts, but these benefits were not tested within a crop system. We [...] Read more.

Rapid urbanization results in the accumulation of food wastes that can be composted and diverted from landfills. Previous lab incubations demonstrated that food-based composts can increase soil N relative to manure-based composts, but these benefits were not tested within a crop system. We assessed soil fertility and yield of spinach (Spinacia oleracea L.) grown in two different soils in a greenhouse, comparing two food- and two manure-based composts added at the recommended N rate (101 kg N ha⁻¹). We quantified soil N mineralization and resin-extractable phosphorus, spinach biomass (root and shoot), and crop nutrient concentrations and accumulation. Nitrogen mineralization generally peaked four weeks after application, and one food-based compost (but no manure-based composts) increased soil phosphorus at harvest compared to an unamended control. One manure-based compost and one food-based compost produced a higher yield and greater nitrogen, phosphorus, and potassium accumulation than the unamended control, whereas only the food-based compost increased spinach phosphorus and potassium concentrations. There was a positive relationship between yield and compost inputs of potassium and plant-available nitrogen (especially nitrate), suggesting that potassium inputs may also explain differences observed among composts. Our results suggest that food-based compost provides more nutrients than composts made from cow manure fiber. Full article

(This article belongs to the Topic Soil Fertility and Plant Nutrition for Sustainable Agriculture)

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14 pages, 1274 KiB

Open AccessEditor’s ChoiceArticle

Onion Plant Size Measurements as Predictors for Onion Bulb Size

by Seyed Shahabeddin Nourbakhsh and Christopher S. Cramer

Horticulturae 2022, 8(8), 682; https://doi.org/10.3390/horticulturae8080682 - 27 Jul 2022

Cited by 3 | Viewed by 4190

Abstract

Onion is a biennial plant that produces a bulb. The larger the onion bulb, the more valuable it becomes. Therefore, it is important to study bulb weight and plant size components affecting it. For this study, four New Mexico State Univ. breeding lines [...] Read more.

Onion is a biennial plant that produces a bulb. The larger the onion bulb, the more valuable it becomes. Therefore, it is important to study bulb weight and plant size components affecting it. For this study, four New Mexico State Univ. breeding lines and two commercial cultivars, ‘Rumba’ and ‘Stockton Early Yellow’, were selected. These breeding lines and cultivars were evaluated for plant height, leaf number and sheath diameter, at five different dates two weeks apart throughout the growing season, and for bulb weight upon harvest. The experiment was designed as a randomized complete block design with three blocks each containing four replications. Plant size components were all positively correlated with each other and with bulb weight with correlation coefficients above 0.50. NMSU breeding lines also exhibited greater average bulb weights than commercial cultivars. Sheath diameter proved to be the best predictor of bulb size, showing strong positive correlations with bulb weight at around 12 weeks after transplanting, and positive correlations are observed as early as 6–8 weeks after transplanting. Full article

(This article belongs to the Special Issue Advances in Allium Breeding and Genetics)

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12 pages, 1084 KiB

Open AccessEditor’s ChoiceArticle

Effects of Supplemental UV-A LEDs on the Nutritional Quality of Lettuce: Accumulation of Protein and Other Essential Nutrients

by Myungjin Lee, Jungkwun Kim, Myung-Min Oh, Jin-Hui Lee and Channa B. Rajashekar

Horticulturae 2022, 8(8), 680; https://doi.org/10.3390/horticulturae8080680 - 26 Jul 2022

Cited by 6 | Viewed by 1799

Abstract

Light plays an important role in influencing the nutritional quality of food crops, especially with regard to the health-promoting phytochemicals. However, its role in affecting the nutritional quality with regard to the essential nutrients is not well understood. In this study, the effects [...] Read more.

Light plays an important role in influencing the nutritional quality of food crops, especially with regard to the health-promoting phytochemicals. However, its role in affecting the nutritional quality with regard to the essential nutrients is not well understood. In this study, the effects of preharvest UV-A treatment on the nutritional quality of lettuce (Lactuca sativa, cv. red-leaf ‘New Red Fire’ and green-leaf ‘Two Star’) in relation to the essential nutrients and health-promoting phytochemicals were explored. Lettuce plants were grown in a growth chamber and were subjected to supplemental UV-A LEDs (peak wavelength 375 nm) for a brief period (3–6 days) prior to harvest. UV-A LEDs were equipped with lenses to control the light dispersion. Many growth indices such as shoot fresh mass, leaf area, and leaf number were unaffected by supplemental UV-A in both varieties while shoot dry mass decreased in response to a 6-day UV-A treatment compared to the control. Leaf chlorophyll and carotenoid concentrations increased significantly in green-leaf lettuce after 3 or 6 days of UV-A treatment, but only after 3 days of UV-A treatment in red-leaf lettuce compared to the control. Leaf protein concentration increased significantly in both lettuce varieties along with a number of essential nutrients such as phosphorus, potassium, calcium, manganese, and sulfur in response to supplemental UV-A. Supplemental UV-A increased the accumulation of protein by approximately 48% in green-leaf lettuce and 31% in red-leaf lettuce compared to the control plants. Moreover, in addition to the above essential nutrients, green-leaf lettuce accumulated higher amounts of magnesium, copper, and zinc compared to the control plants, indicating that green-leaf lettuce was more responsive to preharvest supplemental UV-A treatment than red-leaf lettuce. However, the accumulation of total phenolic compounds and flavonoids in both varieties was lower under supplemental UV-A. Furthermore, the use of LED lenses did not have a consistent impact on most of the plant responses studied. Overall, the results indicate that a brief preharvest exposure of both red- and green-leaf lettuce varieties to UV-A increased their nutritional quality by enhancing the accumulation of protein and other major essential nutrients. Full article

(This article belongs to the Section Vegetable Production Systems)

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14 pages, 4602 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Maintaining Canopy Density under Summer Stress Conditions Retains PSII Efficiency and Modulates Must Quality in Cabernet Franc

by Michele Faralli, Roberto Zanzotti and Massimo Bertamini

Horticulturae 2022, 8(8), 679; https://doi.org/10.3390/horticulturae8080679 - 26 Jul 2022

Cited by 3 | Viewed by 1505

Abstract

Shoot topping and other summer grapevine management practices are considered crucial for producing high-quality wine. However, in recent years, climate change is increasing the need to reassess these strategies, as excessive radiation and high temperatures can negatively impact canopy functionality and berry quality. [...] Read more.

Shoot topping and other summer grapevine management practices are considered crucial for producing high-quality wine. However, in recent years, climate change is increasing the need to reassess these strategies, as excessive radiation and high temperatures can negatively impact canopy functionality and berry quality. Indeed, it has been hypothesized that limiting summer vegetative pruning may protect the bunch, via shading, and the leaf by maintaining a more favorable environment for leaf functionality (e.g., lower VPD, reduced high light stress) owing to a denser canopy. In this work, a series of canopy manipulation treatments (shoot topping vs. long-shoot bundling; secondary shoot trimming vs. untrimmed) were tested in a replicated factorial block design over two seasons in field-grown grapevine plants (cv. Cabernet Franc grafted in SO₄). Overall, treatments in which secondary shoot removal and/or shoot topping were not applied produced a higher canopy area, increased pruning wood and leaf layers, and had a higher F_v/F_m on warm days when compared to pruned canopies. These were associated with a year-dependent modulation of quality parameters of the must in which long-shoot bundling treatment, overall, produced the highest polyphenol and anthocyanin contents and must acidity. Our data provide evidence of a potential usefulness of preserving dense canopies under high temperature – high irradiance conditions with desirable effects on leaf photosynthesis and must quality when long-shoot bundling was applied. Full article

(This article belongs to the Section Viticulture)

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7 pages, 16456 KiB

Open AccessEditor’s ChoiceArticle

Pruning Quality Effects on Desiccation Cone Installation and Wood Necrotization in Three Grapevine Cultivars in France

by Emilie Bruez, Céline Cholet, Massimo Giudici, Marco Simonit, Tommasso Martignon, Mathilde Boisseau, Sandrine Weingartner, Xavier Poitou, Patrice Rey and Laurence Geny-Denis

Horticulturae 2022, 8(8), 681; https://doi.org/10.3390/horticulturae8080681 - 26 Jul 2022

Cited by 7 | Viewed by 2055

Abstract

Pruning experimental studies have been performed in different vineyards, in France, USA and Australia. This article investigates and models the effects of pruning quality on the installation of desiccation cones and wood necrotization. Two different modalities of pruning, short and high pruning, were [...] Read more.

Pruning experimental studies have been performed in different vineyards, in France, USA and Australia. This article investigates and models the effects of pruning quality on the installation of desiccation cones and wood necrotization. Two different modalities of pruning, short and high pruning, were performed at the same period each year on three cultivars in Bordeaux (Cabernet Sauvignon and Sauvignon Blanc) and Charente (Ugni Blanc) wine regions. In the short typ of pruning, the diaphragm was damaged but, in the high one, a 2–3 cm woody length was left immediately above the diaphragm. None of the three cultivars showed any correlation between necrosis length and spur diameter (R² < 0.1925). Analysis of the Ugni Blanc, 8 months after pruning, showed significantly more necrosis length (>60%) than either Cabernet Sauvignon (31–41%) or Sauvignon Blanc (25–55%). Desiccation cone necrotization rates also varied with the vintage, particularly for Ugni Blanc. 4 or 8 months after pruning, the newly-installed desiccation cones could then be analysed. High pruning stopped the desiccation cones at the diaphragm, which ensured that the sap flow path remained unaffected. Full article

(This article belongs to the Special Issue New Advances in Grapevine Trunk Diseases)

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28 pages, 5354 KiB

Open AccessEditor’s ChoiceReview

An Academic and Technical Overview on Plant Micropropagation Challenges

by Neama Abdalla, Hassan El-Ramady, Mayada K. Seliem, Mohammed E. El-Mahrouk, Naglaa Taha, Yousry Bayoumi, Tarek A. Shalaby and Judit Dobránszki

Horticulturae 2022, 8(8), 677; https://doi.org/10.3390/horticulturae8080677 - 25 Jul 2022

Cited by 33 | Viewed by 16822

Abstract

The production of micropropagated plants in plant-tissue-culture laboratories and nurseries is the most important method for propagation of many economic plants. Micropropagation based on tissue-culture technology involves large-scale propagation, as it allows multiplication of a huge number of true-to-type propagules in a very [...] Read more.

The production of micropropagated plants in plant-tissue-culture laboratories and nurseries is the most important method for propagation of many economic plants. Micropropagation based on tissue-culture technology involves large-scale propagation, as it allows multiplication of a huge number of true-to-type propagules in a very short time and in a very limited space, as well as all year round, regardless of the climate. However, applying plant-tissue-culture techniques for the commercial propagation of plants may face a lot of obstacles or troubles that could result from technical, biological, physiological, and/or genetical reasons, or due to overproduction or the lack of facilities and professional technicians, as shown in the current study. Moreover, several disorders and abnormalities are discussed in the present review. This study aims to show the most serious problems and obstacles of plant micropropagation, and their solutions from both scientific and technical sides. This review, as a first report, includes different challenges in plant micropropagation (i.e., contamination, delay of subculture, burned plantlets, browning, in vitro rooting difficulty, somaclonal variations, hyperhydricity, shoot tip necrosis, albino plantlets, recalcitrance, shoot abnormalities, in vitro habituation) in one paper. Most of these problems are related to scientific and/or technical reasons, and they could be avoided by following the micropropagation protocol suitable for each plant species. The others are dominant in plant-tissue-culture laboratories, in which facilities are often incomplete, or due to poor infrastructure and scarce funds. Full article

(This article belongs to the Special Issue Plant Tissue and Organ Cultures for Crop Improvement in Omics Era)

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20 pages, 1413 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Potency of Titanium Dioxide Nanoparticles, Sodium Hydrogen Sulfide and Salicylic Acid in Ameliorating the Depressive Effects of Water Deficit on Periwinkle Ornamental Quality

by Nahid Zomorrodi, Abdolhossein Rezaei Nejad, Sadegh Mousavi-Fard, Hassan Feizi, Georgios Tsaniklidis and Dimitrios Fanourakis

Horticulturae 2022, 8(8), 675; https://doi.org/10.3390/horticulturae8080675 - 24 Jul 2022

Cited by 12 | Viewed by 2159

Abstract

In this study, the optimal concentration of sodium hydrosulfide (NaSH), salicylic acid (SA), and titanium dioxide nanoparticles (TiO₂NPs), and their relative effectiveness on alleviating the adverse effects of water deficit on ornamental quality, were investigated in periwinkle. Plants were cultivated under [...] Read more.

In this study, the optimal concentration of sodium hydrosulfide (NaSH), salicylic acid (SA), and titanium dioxide nanoparticles (TiO₂NPs), and their relative effectiveness on alleviating the adverse effects of water deficit on ornamental quality, were investigated in periwinkle. Plants were cultivated under three water deficit levels (80, 50, and 20% available water content) and received two foliar applications of TiO₂NPs (0, 0.5 and 1 mM), NaSH (0.5 and 1 mM), or SA (1 and 2 mM). Water deficit deteriorated ornamental quality, amplified the risk of buckling (lower stem strength) and suppressed longevity. It decreased both light interception (leaf area) and carbon assimilation. Besides impaired hydration status, water-stressed plants underwent oxidative damage as indicated by reduced chlorophyll content, elevated membrane degradation, and lipid peroxidation. Spray treatments improved all traits, besides stem strength and proline content. Additionally, they enhanced carotenoid content and the activities of catalase and peroxidase. Their relative effectiveness (TiO₂NPs > NaSH > SA) and optimal concentration (i.e., 0.5 mM (TiO₂NPs, NaSH), and 1 mM (SA)) was independent of water deficit level. In conclusion, this study provides practices for improved ornamental quality and longevity independently of water availability, with their positive effect being stronger under irregular or limited water supply. Full article

(This article belongs to the Section Floriculture, Nursery and Landscape, and Turf)

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17 pages, 3158 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Bark Extract of Uncaria tomentosa L. for the Control of Strawberry Phytopathogens

by Eva Sánchez-Hernández, Pablo Martín-Ramos, Jesús Martín-Gil, Alberto Santiago-Aliste, Salvador Hernández-Navarro, Rui Oliveira and Vicente González-García

Horticulturae 2022, 8(8), 672; https://doi.org/10.3390/horticulturae8080672 - 23 Jul 2022

Cited by 16 | Viewed by 2798

Abstract

Gray mold (Botrytis cinerea Pers.), crown and fruit rot (Phytophthora cactorum (Lebert and Cohn) J.Schröt), and verticillium wilt (Verticillium dahliae Kleb.) are among the main diseases that affect the strawberry crop. In the study presented herein, the bark extract of [...] Read more.

Gray mold (Botrytis cinerea Pers.), crown and fruit rot (Phytophthora cactorum (Lebert and Cohn) J.Schröt), and verticillium wilt (Verticillium dahliae Kleb.) are among the main diseases that affect the strawberry crop. In the study presented herein, the bark extract of Uncaria tomentosa (Willd. ex Schult.) DC, popularly known as “cat’s claw”, has been evaluated for its capability to act as a sustainable control method. The bioactive compounds present in the aqueous ammonia extract were characterized by gas chromatography–mass spectroscopy, and the antimicrobial activity of the extract—alone and in combination with chitosan oligomers (COS)—was assessed in vitro and as a coating for postharvest treatment during storage. Octyl isobutyrate (30.7%), 19α methyl-2-oxoformosanan-16-carboxylate (9.3%), tetrahydro-2-methyl-thiophene (4.7%), and α-methyl manofuranoside (4.4%) were identified as the main phytoconstituents. The results of in vitro growth inhibition tests showed that, upon conjugation of the bark extract with COS, complete inhibition was reached at concentrations in the 39–93.75 μg∙mL⁻¹ range, depending on the pathogen. Concerning the effect of the treatment as a coating to prolong the storage life and control decay during post-harvest storage, high protection was observed at a concentration of 1000 μg∙mL⁻¹. Because of this effectiveness, higher than that attained with conventional synthetic fungicides, the bark extracts of cat’s claw may hold promise for strawberry crop protection. Full article

(This article belongs to the Special Issue Bioactivity, Phytochemical and Nutritional Composition of Natural Products)

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16 pages, 4864 KiB

Open AccessEditor’s ChoiceArticle

Multi-Band-Image Based Detection of Apple Surface Defect Using Machine Vision and Deep Learning

by Yan Tang, Hongyi Bai, Laijun Sun, Yu Wang, Jingli Hou, Yonglong Huo and Rui Min

Horticulturae 2022, 8(7), 666; https://doi.org/10.3390/horticulturae8070666 - 21 Jul 2022

Cited by 7 | Viewed by 2196

Abstract

Accurate surface defect extraction of apples is critical for their quality inspection and marketing purposes. Using multi-band images, this study proposes a detection method for apple surface defects with a combination of machine vision and deep learning. Five single bands, 460, 522, 660, [...] Read more.

Accurate surface defect extraction of apples is critical for their quality inspection and marketing purposes. Using multi-band images, this study proposes a detection method for apple surface defects with a combination of machine vision and deep learning. Five single bands, 460, 522, 660, 762, and 842 nm, were selected within the visible and near-infrared. By using a near-infrared industrial camera with optical filters, five single-band images of an apple could be obtained. To achieve higher accuracy of defect extraction, an improved U-Net was designed based on the original U-Net network structure. More specially, the partial original convolutions were replaced by dilated convolutions with different dilated rates, and an attention mechanism was added. The loss function was also redesigned during the training process. Then the traditional algorithm, the trained U-Net and the trained improved U-Net were used to extract defects of apples in the test set. Following that, the performances of the three methods were compared with that of the manual extraction. The results show that the near-infrared band is better than the visible band for defects with insignificant features. Additionally, the improved U-Net is better than the U-Net and the traditional algorithm for small defects and defects with irregular edges. On the test set, for single-band images at 762 nm, the improved U-Net had the best defect extraction with an mIoU (mean intersection over union) and mF1-score of 91% and 95%, respectively. Full article

(This article belongs to the Special Issue Innovative Nondestructive Techniques to Improve Quality Measurement of Fruits and Vegetables)

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18 pages, 1312 KiB

Open AccessEditor’s ChoiceArticle

The Emotional Experience of Flowers: Zoomed In, Zoomed Out and Painted

by Jacqueline Urakami, Ephrat Huss, Mitsue Nagamine, Johanna Czamanski-Cohen and Michele Zaccai

Horticulturae 2022, 8(7), 668; https://doi.org/10.3390/horticulturae8070668 - 21 Jul 2022

Viewed by 3660

Abstract

People have an ancient and strong bond to flowers, which are known to have a positive effect on the mood. During the COVID-19 pandemic, sales of ornamental plants increased, and many turned to gardening, possibly as a way to cope with ubiquitous increases [...] Read more.

People have an ancient and strong bond to flowers, which are known to have a positive effect on the mood. During the COVID-19 pandemic, sales of ornamental plants increased, and many turned to gardening, possibly as a way to cope with ubiquitous increases in negative mood following lockdowns and social isolation. The nature of the special bond between humans and flowers requires additional elucidation. To this means, we conducted a comprehensive online mixed methods study, surveying 253 individuals (ages 18–83) from diverse ethnic backgrounds and continents, regarding their thoughts and feelings towards photos of flowers, nature scenes and flower drawings. We found that looking at pictures and drawings of flowers, as well as nature scenes induced positive emotions, and participants reported a variety of positive responses to the images. More specifically, we found associations of flowers with femininity, and connotations to particular flowers that were affected by geographical location. While nature scene photos induced positive reactions, flower photos were preferred, denying a mere substitution of nature by flowers and vice versa. Drawings of flowers elicited less positive emotions than photos, as people related more to the art than to the flower itself. Our study reveals the importance of ornamental flowers and nature in our life and well-being, and as such their cultivation and promotion are essential. Full article

(This article belongs to the Section Floriculture, Nursery and Landscape, and Turf)

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12 pages, 257 KiB

Open AccessEditor’s ChoiceReview

Effects of Potassium Deficiency on the Growth of Tea (Camelia sinensis) and Strategies for Optimizing Potassium Levels in Soil: A Critical Review

by Wei Huang, Minyao Lin, Jinmei Liao, Ansheng Li, Wugyan Tsewang, Xuan Chen, Binmei Sun, Shaoqun Liu and Peng Zheng

Horticulturae 2022, 8(7), 660; https://doi.org/10.3390/horticulturae8070660 - 20 Jul 2022

Cited by 9 | Viewed by 3579

Abstract

Potassium is among the three essential macronutrients for tea plants, along with nitrogen and phosphorous, and plays important roles in growth and stress response. Potassium is absorbed by plants in larger amounts than any other mineral element except nitrogen and, in some cases, [...] Read more.

Potassium is among the three essential macronutrients for tea plants, along with nitrogen and phosphorous, and plays important roles in growth and stress response. Potassium is absorbed by plants in larger amounts than any other mineral element except nitrogen and, in some cases, calcium. At present, more than 59% of China’s tea gardens are in a state of potassium deficiency, which negatively affects tea quality and yield. This paper reviews the effects of potassium deficiency on tea plant growth and stress response, details factors affecting potassium supply and demand in tea gardens, examines the interactions between potassium and other elements in soils, and provides strategies for optimizing potassium levels in soils. Potassium is positively correlated with the elements nitrogen, copper, and zinc. Sufficient potassium dramatically improves the yield and quality of tea: it accelerates metabolism, promotes synthesis of catechins, and strengthens biotic and abiotic resistance by activating and regulating different enzymes. Moderate application of potassium fertilizers, along with potassium-solubilizing bacteria, can regulate the ratio of different forms of potassium and increase available potassium in soils of tea gardens. We suggest that research on potassium occurring in soils and its interaction with other elements be strengthened, so as to improve the efficient use of potassium fertilizers in tea gardens and maintain the balance of elements in soils. Full article

(This article belongs to the Section Plant Nutrition)

10 pages, 2410 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Iodine Enhances the Nutritional Value but Not the Tolerance of Lettuce to NaCl

by Giuseppe Maglione, Ermenegilda Vitale, Giulia Costanzo, Franca Polimeno, Carmen Arena and Luca Vitale

Horticulturae 2022, 8(7), 662; https://doi.org/10.3390/horticulturae8070662 - 20 Jul 2022

Cited by 7 | Viewed by 1616

Abstract

Positive stress or essential and nonessential elements can improve nutritive values (biofortification) of edible plants. In the present study, we evaluate (i) the effect of moderate salinity on lettuce biofortification, evaluated as nutritional bioactive compound accumulation, and (ii) the role of iodine in [...] Read more.

Positive stress or essential and nonessential elements can improve nutritive values (biofortification) of edible plants. In the present study, we evaluate (i) the effect of moderate salinity on lettuce biofortification, evaluated as nutritional bioactive compound accumulation, and (ii) the role of iodine in enhancing salt tolerance by increasing photorespiration and the content of antioxidants in lettuce. Physiological (gas exchange and chlorophyll fluorescence emission) and biochemical (photosynthetic pigment and bioactive compound) analyses were performed on lettuce plants grown under moderate salinity (50 mM NaCl alone or 50 mM NaCl in combination with iodine, KIO₃). Our results show that NaCl + iodine treatment improves the nutritional value of lettuce in terms of bioactive compounds acting as antioxidants. More specifically, iodine enhances the accumulation of photosynthetic pigments and polyphenols, such as anthocyanins, under salt but does not improve the salt tolerance. Our findings indicate that iodine application under moderate salinity could be a valid strategy in plant biofortification by improving nutritional bioactive compound accumulation, thus exercising functional effects on human health. Full article

(This article belongs to the Special Issue Horticultural Plants Facing Stressful Conditions - Ways of Stress Mitigation)

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15 pages, 1459 KiB

Open AccessFeature PaperEditor’s ChoiceReview

The SSR Null Allele Problem, and Its Consequences in Pedigree Reconstruction and Population Genetic Studies in Viticulture

by Gizella Jahnke, József Smidla, Tamás Deák, Róbert Oláh, Barna Árpád Szőke and Diána Ágnes Nyitrainé Sárdy

Horticulturae 2022, 8(7), 658; https://doi.org/10.3390/horticulturae8070658 - 19 Jul 2022

Cited by 3 | Viewed by 2724

Abstract

Null alleles are alleles that are recessive to codominant markers without any effect on the phenotype. In SSR assays, there are several reasons for the lack of amplification at a locus: the primer does not bind well, longer fragments do not amplify due [...] Read more.

Null alleles are alleles that are recessive to codominant markers without any effect on the phenotype. In SSR assays, there are several reasons for the lack of amplification at a locus: the primer does not bind well, longer fragments do not amplify due to imperfections in the PCR reaction, or the amount of DNA in the sample is insufficient. In microsatellite studies, null alleles are mostly used in pedigree analysis and population genetics calculations such as diversity estimation. Null alleles in pedigree analysis can cause rejection of the true parent; if not recognized while in population genetics they distort the results in underestimating diversity. In this review, the effects caused by null-alleles in viticultural research and its possible solutions were summarized. Full article

(This article belongs to the Section Viticulture)

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12 pages, 1551 KiB

Open AccessEditor’s ChoiceArticle

Response of Common Ice Plant (Mesembryanthemum crystallinum L.) to Photoperiod/Daily Light Integral in Vertical Hydroponic Production

by Jiaqi Xia and Neil Mattson

Horticulturae 2022, 8(7), 653; https://doi.org/10.3390/horticulturae8070653 - 19 Jul 2022

Cited by 4 | Viewed by 2867

Abstract

Common ice plant (Mesembryanthemum crystallinum L.) is a novel edible plant with a succulent and savory flavor emerging as new crop for greenhouse and plant factory growers. Currently very limited information is available on the response of ice plant to photoperiod and [...] Read more.

Common ice plant (Mesembryanthemum crystallinum L.) is a novel edible plant with a succulent and savory flavor emerging as new crop for greenhouse and plant factory growers. Currently very limited information is available on the response of ice plant to photoperiod and to daily light integral (DLI). The objective of this study was to determine the impact of photoperiod/DLI on the growth of ice plant for indoor vertical production. Four-week old seedlings of ice plant were transplanted into vertical hydroponic systems and given five photoperiod/DLI treatments: 8/6.3, 12/9.5, 16/12.7, 20/15.8, and 24/19.0 h/mol·m⁻²·d⁻¹. Sequential destructive harvests to determine plant growth occurred 14, 21, and 28 days after lighting treatments began. Plants performed better with increasing photoperiod/DLI from 8 h/6.3 mol·m⁻²·d⁻¹ to 20 h/15.8 mol·m⁻²·d⁻¹. By day 28, shoot fresh weight increased from 160 g to 639 g as the photoperiod/DLI increased from 8 h/6.3 mol·m⁻²·d⁻¹ to 20 h/15.8 mol·m⁻²·d⁻¹. The continuous lighting treatment, 24 h/19 mol·m⁻²·d⁻¹, showed a negative effect on the plant fresh weight (FW) and dry weight (DW). Light treatment did not have obvious effects on shoot:root ratio and macronutrient uptake except that potassium (K) uptake decreased slightly with increased photoperiod/DLI. Plants receiving higher photoperiod/DLI showed the same number of leaves (indicating the same development stage) but had smaller, thicker, and darker green leaves compared to lower photoperiod/DLI treatments. Leaf water content was not affected by light treatment up to 20 h/15.8 mol·m⁻²·d⁻¹ but decreased at 24 h/19 mol·m⁻²·d⁻¹. Further research is needed to separate the physiological response of increasing/continuous photoperiod from the response of increasing DLI. Full article

(This article belongs to the Special Issue Controlled Environment Horticulture: Latest Advances and Future Prospects)

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13 pages, 1854 KiB

Open AccessEditor’s ChoiceArticle

Elicitor Activity of Curdlan and Its Potential Application in Protection of Hass Avocado Plants against Phytophthora cinnamomi Rands

by Nathalie Guarnizo, Andree Álvarez, Diego Oliveros, Oveimar Barbosa, Jordi Eras Joli, María Bianney Bermúdez-Cardona and Walter Murillo-Arango

Horticulturae 2022, 8(7), 646; https://doi.org/10.3390/horticulturae8070646 - 16 Jul 2022

Cited by 4 | Viewed by 1808

Abstract

Phytophthora cinnamomi causes one of the most important diseases in avocado crop and its chemical management represents 25% of the production cost per year. Induction of plant defense responses by elicitors is a promising strategy that is compatible with sustainable agriculture. This study [...] Read more.

Phytophthora cinnamomi causes one of the most important diseases in avocado crop and its chemical management represents 25% of the production cost per year. Induction of plant defense responses by elicitors is a promising strategy that is compatible with sustainable agriculture. This study aimed to evaluate the effect of curdlan application on the induction of defense responses in avocado plants against P. cinnamomi. The trials were conducted under greenhouse conditions, and curdlan leaf spraying was performed one day before the inoculation of the pathogen. The results showed that the application of elicitor significantly increased the protection of avocado plants against P. cinnamomi, decreasing the injury and wilting. The Curd + Phy treatment improved the defenses of plants by increasing the enzymes peroxidase (POD) and polyphenol oxidase (PPO) in the first 3 h after inoculation and increasing the enzymes superoxide dismutase (SOD) and phenylalanine ammonium lyase (PAL) 144 h after inoculation (p < 0.05). Also, chlorophyll and carotenoid content increased or remained stable in Curd + Phy treatment. Therefore, these results suggest that curdlan increases the protection against P. cinnamomi and its protection could be due to an increase in the activity of the enzymes related to the phenylpropanoid pathway as well as the effect on chlorophyll and carotenoids. Full article

(This article belongs to the Special Issue Pathogens and Disease Control of Fruit Trees)

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16 pages, 2278 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Characterizing the Spatial Uniformity of Light Intensity and Spectrum for Indoor Crop Production

by László Balázs, Zoltán Dombi, László Csambalik and László Sipos

Horticulturae 2022, 8(7), 644; https://doi.org/10.3390/horticulturae8070644 - 15 Jul 2022

Cited by 11 | Viewed by 2372

Abstract

Maintaining uniform photon irradiance distribution above the plant canopy is a fundamental goal in controlled environment agriculture (CEA). Spatial variation in photon irradiance below the light saturation point will drive differences in individual plant development, decreasing the economic value of the crop. Plant [...] Read more.

Maintaining uniform photon irradiance distribution above the plant canopy is a fundamental goal in controlled environment agriculture (CEA). Spatial variation in photon irradiance below the light saturation point will drive differences in individual plant development, decreasing the economic value of the crop. Plant growth is also affected by the spectral composition of light. So far, little attention has been paid to the quantification of the spatial variability in horticultural lighting applications. This work provides a methodology to benchmark and compare lighting installations used in indoor cultivation facilities. We measured the photon irradiance distributions underneath two typical grow light installations using a 10 × 10 measurement grid with 100 mm spacing. We calculated photon irradiance values for each grid point for 100 nm-wide blue, green, red and far-red wavebands covering the 400–800 nm range. We showed that the generally used uniformity metric defined as the minimum to average ratio of PPFD is not appropriate for the characterization of light uniformity in horticultural lighting applications. Instead, we propose to normalize photon irradiance to the maximum, analyze the histograms constructed from relative photon irradiance values and consider the light response of the cultivated crop while comparing the performance of CEA grow systems. Full article

(This article belongs to the Special Issue Innovative Technologies and Production Strategies for Sustainable Controlled Environment Horticulture)

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16 pages, 2316 KiB

Open AccessEditor’s ChoiceArticle

Root Morphological and Physiological Adaptations to Low Phosphate Enhance Phosphorus Efficiency at Melon (Cucumis melo L.) Seedling Stage

by Pengli Li, Jinyang Weng, Asad Rehman and Qingliang Niu

Horticulturae 2022, 8(7), 636; https://doi.org/10.3390/horticulturae8070636 - 14 Jul 2022

Cited by 5 | Viewed by 2115

Abstract

The high phosphorus (P) acquisition ability of crops can reduce their dependence on artificial inorganic phosphate (Pi) supplementation under Pi-limited conditions. Melon (Cucumis melo L.) is vulnerable to Pi deficiency. This study was carried out to explore the morphological and physiological responses [...] Read more.

The high phosphorus (P) acquisition ability of crops can reduce their dependence on artificial inorganic phosphate (Pi) supplementation under Pi-limited conditions. Melon (Cucumis melo L.) is vulnerable to Pi deficiency. This study was carried out to explore the morphological and physiological responses of melon to low-Pi stress under a hydroponic system. The results show that low-Pi stress significantly disturbed nutrient homeostasis, reduced P content, and resulted in iron accumulation in melon seedlings and brown iron plaque formation on the root surface. A nutrient pool of P and Fe formed on the roots to forage for more Pi under low-Pi conditions. Severe long-term low-Pi stress promoted primary root elongation and inhibited lateral root growth, which increased the longitudinal absorption zone of the roots. The decrease in P content of the roots upregulated the expression of the acid phosphatase (APase) gene and increased APase activity. The high-affinity phosphate transporter (Pht1) genes were also upregulated significantly. These morphological and physiological responses significantly increased Pi uptake rate and P utilization efficiency at the melon seedling stage. These findings will be useful for screening low-Pi-tolerant varieties and sustaining melon production in P-limited environments. Full article

(This article belongs to the Topic Physiological and Molecular Characterization of Crop Tolerance to Abiotic Stresses)

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21 pages, 892 KiB

Open AccessEditor’s ChoiceArticle

Growth and Mineral Relations of Beta vulgaris var. cicla and Beta vulgaris ssp. maritima Cultivated Hydroponically with Diluted Seawater and Low Nitrogen Level in the Nutrient Solution

by Martina Puccinelli, Giulia Carmassi, Luca Botrini, Antonio Bindi, Lorenzo Rossi, Juan Francisco Fierro-Sañudo, Alberto Pardossi and Luca Incrocci

Horticulturae 2022, 8(7), 638; https://doi.org/10.3390/horticulturae8070638 - 14 Jul 2022

Cited by 7 | Viewed by 2588

Abstract

There is an increasing interest in the use of seawater in horticulture. The objective of this study was to evaluate Beta vulgaris var. cicla (Swiss chard) and its wild ancestor B. vulgaris spp. maritima (sea beet) as potential crop species for seawater hydroponics [...] Read more.

There is an increasing interest in the use of seawater in horticulture. The objective of this study was to evaluate Beta vulgaris var. cicla (Swiss chard) and its wild ancestor B. vulgaris spp. maritima (sea beet) as potential crop species for seawater hydroponics or aquaponics. Both species were grown in a floating system for leaf production with recurrent harvests. The nutrient solutions contained different concentrations of nitrate (1 and 10 mM) and a synthetic sea salt (0 and 10 g L⁻¹), in a factorial design, where the saline solution with a low nitrate level intended to mimic the typical nutritional conditions of saltwater aquaponics. In both species, increasing the salinity or reducing the N level in the nutrient solution reduced the crop yield and total dry biomass. In both Swiss chard and sea beet, the use of saline water resulted in a lower leaf concentration of K, Ca, Cu, and Mn, and a greater content of Na and Cl. In Swiss chard, an increase in Na and Cl and a decrease in K leaf content were found in successive harvests. On average, sea beet showed a higher leaf production and accumulation of nitrate than Swiss chard. Full article

(This article belongs to the Collection Biosaline Agriculture)

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17 pages, 3481 KiB

Open AccessEditor’s ChoiceArticle

Effects of Shading Nets on Reactive Oxygen Species Accumulation, Photosynthetic Changes, and Associated Physiochemical Attributes in Promoting Cold-Induced Damage in Camellia sinensis (L.) Kuntze

by Shah Zaman, Jiazhi Shen, Shuangshuang Wang, Yu Wang, Zhaotang Ding, Dapeng Song, Hui Wang, Shibo Ding, Xu Pang and Mengqi Wang

Horticulturae 2022, 8(7), 637; https://doi.org/10.3390/horticulturae8070637 - 14 Jul 2022

Cited by 6 | Viewed by 1853

Abstract

Climate change and extreme weather affect tea growing. A competitive tea market needs quick, short-term solutions. This study evaluates the effects of various shade nets under mild and extreme cold stress on tea leaf physiology, photosynthetic alterations, antioxidant activities, and physiochemical characteristics. Tea [...] Read more.

Climate change and extreme weather affect tea growing. A competitive tea market needs quick, short-term solutions. This study evaluates the effects of various shade nets under mild and extreme cold stress on tea leaf physiology, photosynthetic alterations, antioxidant activities, and physiochemical characteristics. Tea plants were treated with SD0 (0% non-shading), SD1 (30% shading), SD2 (60% shading), and SD3 (75% shading). The 30%, 60%, and 75% shade nets shielded tea leaves from cold damage and reduced leaf injury during mild and extreme cold conditions compared with SD0% non-shading. Shading regulates photochemical capacity and efficiency and optimizes chlorophyll a and b, chlorophyll, and carotenoid contents. Moreover, carbon and nitrogen increased during mild cold and decreased in extreme cold conditions. Shading promoted antioxidant activity and physiochemical attributes. In fact, under 60% of shade, superoxide dismutase, peroxidase, catalase, and ω-3 alpha-linolenic acid were improved compared with SD0% non-shading during both mild and extreme cold conditions. From these findings, we hypothesized that the effect of different shades played an important role in the protection of tea leaves and alleviated the defense mechanism for “Zhong Cha 102” during exposure to a cold environment. Full article

(This article belongs to the Special Issue The Effects of Shade on Crops: From Greenhouse to Agrivoltaic)

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20 pages, 2591 KiB

Open AccessEditor’s ChoiceReview

Fusarium Dry Rot of Garlic Bulbs Caused by Fusarium proliferatum: A Review

by Laura Gálvez and Daniel Palmero

Horticulturae 2022, 8(7), 628; https://doi.org/10.3390/horticulturae8070628 - 12 Jul 2022

Cited by 14 | Viewed by 8614

Abstract

Fusarium dry rot (FDR) is a postharvest disease of garlic crops causing yield losses worldwide. Fusarium proliferatum has been identified as the main species causing the disease. Symptoms begin as small brown lesions with a dehydrated appearance that can progress to cover the [...] Read more.

Fusarium dry rot (FDR) is a postharvest disease of garlic crops causing yield losses worldwide. Fusarium proliferatum has been identified as the main species causing the disease. Symptoms begin as small brown lesions with a dehydrated appearance that can progress to cover the entire clove during the storage period. Symptoms on growing plants cause brown lesions on the basal plates and roots, and sometimes damping-off is observed. F. proliferatum is a polyphagous pathogen with a wide range of hosts. This pathogen colonizes garlic roots, remaining as a latent pathogen, and develops rot during storage. The pathogen can overwinter in the soil, infested crop residues, and weeds. The fungus can also persist on garlic cloves, acting as primary inoculum in the field and contributing to the long-distance spread. Using healthy plant material, rotating crops, burying crop residues, avoiding bulb injury during harvest and subsequent handling, and providing appropriate postharvest environmental conditions are crucial factors that greatly influence the disease severity. Choosing a suitable non-host crop to achieve truly effective rotation is sometimes difficult. Chemical control in the form of seed treatments or field spraying of the crop has a limited effect on controlling FDR. Field applications of biological control agents have shown some efficacy, but conditions to optimize their activity must be determined. Moreover, different soil management strategies to reduce soil inoculum must be also studied. Full article

(This article belongs to the Section Plant Pathology and Disease Management (PPDM))

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12 pages, 1455 KiB

Open AccessEditor’s ChoiceArticle

Oligosaccharins Used Together with Tebuconazole Enhances Resistance of Kiwifruit against Soft Rot Disease and Improves Its Yield and Quality

by Qiuping Wang, Youhua Long, Qiang Ai, Yue Su and Yang Lei

Horticulturae 2022, 8(7), 624; https://doi.org/10.3390/horticulturae8070624 - 11 Jul 2022

Cited by 4 | Viewed by 1507

Abstract

Botryosphaeria dothidea is one of the most frequent pathogens of soft rot disease in kiwifruit. The aim of this study was to investigate the role of oligosaccharins used together with tebuconazole to control soft rot and their influences on kiwifruit’s disease resistance, growth [...] Read more.

Botryosphaeria dothidea is one of the most frequent pathogens of soft rot disease in kiwifruit. The aim of this study was to investigate the role of oligosaccharins used together with tebuconazole to control soft rot and their influences on kiwifruit’s disease resistance, growth and quality. The results show that tebuconazole displayed a toxicity against B. dothidea RF-1 with 0.87 mg kg⁻¹ of EC₅₀ value. Oligosaccharins used together with tebuconazole effectively managed soft rot with 84.83% of the field management effect by spraying tebuconazole + oligosaccharins (0.5:0.5, m/v) as a 5000-fold dilution liquid, which significantly (p < 0.01) exceeded the 72.05%, 52.59%, 62.17% and 33.52% effect of tebuconazole 2500-, oligosaccharins 2500-, tebuconazole 5000- and oligosaccharins 5000-fold liquids, respectively. Simultaneously, co-application of tebuconazole and oligosaccharins was more effective for enhancing the resistance, growth and quality of kiwifruit compared with tebuconazole or oligosaccharins alone. This work highlights that oligosaccharins used together with tebuconazole can be proposed as a practicable measure for managing kiwifruit soft rot and reducing the application of chemical synthetic fungicides. Full article

(This article belongs to the Section Plant Pathology and Disease Management (PPDM))

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10 pages, 569 KiB

Open AccessEditor’s ChoiceReview

Human Health Benefits through Daily Consumption of Jerusalem Artichoke (Helianthus tuberosus L.) Tubers

by Angela Méndez-Yáñez, Patricio Ramos and Luis Morales-Quintana

Horticulturae 2022, 8(7), 620; https://doi.org/10.3390/horticulturae8070620 - 8 Jul 2022

Cited by 2 | Viewed by 5966

Abstract

“Let food be thy medicine and medicine be thy food”, is one of the most famous phrases attributed to Hippocrates, the father of medicine. Scientific research on superfoods has increased in the last six years. These foods have nutritional and pharmacological properties, such [...] Read more.

“Let food be thy medicine and medicine be thy food”, is one of the most famous phrases attributed to Hippocrates, the father of medicine. Scientific research on superfoods has increased in the last six years. These foods have nutritional and pharmacological properties, such that they can help to fight against diseases and poor nutritional status. Helianthus tuberosus L., or Jerusalem artichoke, appears to be a superfood that provides benefits to human health at the level of the digestive, gastrointestinal, and dermatological systems, being fit for patients with diabetes mellitus due to its high content of inulin and use in an optimal hypocaloric diet due to its low carbohydrate content. In fact, 5 to 15 g per day is beneficial, with evidence of a prebiotic effect. Unfortunately, its consumption and cultivation are not well known worldwide. For this reason, the present review describes the benefits of H. tuberosus in human health to promote knowledge about its nutritional benefits. Full article

(This article belongs to the Collection Nutritional Quality of Fruits and Vegetables)

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14 pages, 8843 KiB

Open AccessEditor’s ChoiceArticle

In Vitro and In Vivo Performance of Plum (Prunus domestica L.) Pollen from the Anthers Stored at Distinct Temperatures for Different Periods

by Milena Đorđević, Tatjana Vujović, Radosav Cerović, Ivana Glišić, Nebojša Milošević, Slađana Marić, Sanja Radičević, Milica Fotirić Akšić and Mekjell Meland

Horticulturae 2022, 8(7), 616; https://doi.org/10.3390/horticulturae8070616 - 7 Jul 2022

Cited by 5 | Viewed by 1957

Abstract

A study was conducted to investigate the effect of different storage periods and temperatures on pollen viability in vitro and in vivo in plum genotypes ‘Valerija’, ‘Čačanska Lepotica’ and ‘Valjevka’. In vitro pollen viability was tested at day 0 (fresh dry pollen) and [...] Read more.

A study was conducted to investigate the effect of different storage periods and temperatures on pollen viability in vitro and in vivo in plum genotypes ‘Valerija’, ‘Čačanska Lepotica’ and ‘Valjevka’. In vitro pollen viability was tested at day 0 (fresh dry pollen) and after 3, 6, 9 and 12 months of storage at four different temperatures (4, −20, −80 and −196 °C), and in vivo after 12 months of storage at distinct temperatures. In vitro germination and fluorescein diacetate (FDA) staining methods were used to test pollen viability, while aniline blue staining was used for observing in vivo pollen tube growth. Fresh pollen germination and viability ranged from 42.35 to 63.79% (‘Valjevka’ and ‘Čačanska Lepotica’, respectively) and 54.58 to 62.15%, (‘Valjevka’ and ‘Valerija’, respectively). With storage at 4 °C, pollen viability and germination decreased over the period, with the lowest value after 12 months of storage. Pollen germination and viability for the other storage temperatures (−20, −80 and −196 °C) were higher than 30% by the end of the 12 months. Pollination using pollen stored at 4 °C showed that pollen tube growth mostly ended in the lower part of the style. With the other storage temperatures, pollen tube growth was similar, ranging between 50 and 100% of the pistils with pollen tubes penetrated into the nucellus of the ovule in the genotype ‘Čačanska Lepotica’. The results of these findings will have implications for plum pollen breeding and conservation. Full article

(This article belongs to the Special Issue In Vitro Regeneration, Micropropagation and Germplasm Conservation of Horticultural Plants)

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17 pages, 6356 KiB

Open AccessEditor’s ChoiceArticle

Influence of Citrus Rootstocks on Scion Growth, Hormone Levels, and Metabolites Profile of ‘Shatangju’ Mandarin (Citrus reticulata Blanco)

by Faisal Hayat, Juan Li, Wen Liu, Caiqing Li, Wenpei Song, Shahid Iqbal, Ummara Khan, Hafiz Umer Javed, Muhammad Ahsan Altaf, Panfeng Tu, Jiezhong Chen and Jianliang Liu

Horticulturae 2022, 8(7), 608; https://doi.org/10.3390/horticulturae8070608 - 6 Jul 2022

Cited by 16 | Viewed by 2884

Abstract

Dwarfing rootstocks are a valuable genetic resource for managing high-density plantations. The selection of the appropriate scion/rootstock combination is key to improving crop performance and sustainable production in a particular environment and specific training systems. ‘Shatangju’ mandarin scion cultivar grafted onto ‘Flying Dragon’ [...] Read more.

Dwarfing rootstocks are a valuable genetic resource for managing high-density plantations. The selection of the appropriate scion/rootstock combination is key to improving crop performance and sustainable production in a particular environment and specific training systems. ‘Shatangju’ mandarin scion cultivar grafted onto ‘Flying Dragon’ rootstock tends to be dwarfing and develops short stature plants. To obtain insight into potential mechanisms underlying rootstock-induced dwarfing effects, we conducted a rootstock trial to examine the influence of 11 different rootstocks based on their growth vigor, antioxidants, and hormonal levels of the scion cultivar. The phenotypic observations revealed that size reduction in the ‘Flying Dragon’ rootstock is due to lower node number, shorter internodal length, and a reduced trunk diameter of the scion compared with more vigorous rootstocks. Antioxidant analysis showed that ‘Shatangju’ mandarin grafted onto ’Flying Dragon’ and ‘Trifoliate Orange’ rootstock had significantly lower peroxidase (POD) activity than other tested rootstocks. The hormonal analysis indicated that there were markedly lower amounts of abscisic acid (ABA) in ‘Shatangju’ mandarin grafted with ‘Flying Dragon’ rootstock. In addition, trees grafted with ‘Sour Pummelo’ and ‘Flying Dragon’ depicted minimum amounts of gibberellins (GA₂₄). Moreover, several metabolites associated with organic acids, flavonoids, amino acids, and alkaloids responded differently in plants grafted with ‘Flying Dragon’ (dwarfing) and ‘Shatang Mandarin’ (vigorous) rootstocks. This study concluded that ‘Flying Dragon’ rootstock with a strong dwarfing effect has been proposed to improve high-density cultivation methods. These findings will provide useful insights for future research associated with rootstock-mediated dwarfing mechanisms of citrus rootstocks. Full article

(This article belongs to the Special Issue New Insights into Rootstock - Scion Interactions in Horticultural Crops)

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32 pages, 518 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Postharvest Technologies of Fresh Citrus Fruit: Advances and Recent Developments for the Loss Reduction during Handling and Storage

by Maria Concetta Strano, Giuseppe Altieri, Maria Allegra, Giovanni Carlo Di Renzo, Giuliana Paterna, Attilio Matera and Francesco Genovese

Horticulturae 2022, 8(7), 612; https://doi.org/10.3390/horticulturae8070612 - 6 Jul 2022

Cited by 37 | Viewed by 11995

Abstract

Citrus spp. are spread mainly in the Mediterranean basin and represent the largest fruit source for human consumption. Postharvest losses, mainly due to diseases and metabolic disorders of fruits, can cause severe wastage, reaching 30 to 50% of the total production. Preserving quality [...] Read more.

Citrus spp. are spread mainly in the Mediterranean basin and represent the largest fruit source for human consumption. Postharvest losses, mainly due to diseases and metabolic disorders of fruits, can cause severe wastage, reaching 30 to 50% of the total production. Preserving quality and extending shelf life are essential objectives for postharvest technological innovation, determined by the proper handling, treatment, storage and transport of harvested produce. Moreover, the application of novel sustainable strategies is critical for the reduction of synthetic fungicide residues on fruit surfaces and the impact on the environment caused by waste disposal of fungicides. In this article, the current knowledge about the safest and more sustainable strategies, as well as advanced postharvest handling and storage technologies, will be critically reviewed. Full article

(This article belongs to the Special Issue Postharvest Management of Citrus Fruit)

21 pages, 2759 KiB

Open AccessEditor’s ChoiceArticle

Molecular Characterization of Tomato (Solanum lycopersicum L.) Accessions under Drought Stress

by Ibrahim Makhadmeh, Ammar A. Albalasmeh, Mohammed Ali, Samar G. Thabet, Walaa Ali Darabseh, Saied Jaradat and Ahmad M. Alqudah

Horticulturae 2022, 8(7), 600; https://doi.org/10.3390/horticulturae8070600 - 4 Jul 2022

Cited by 5 | Viewed by 2932

Abstract

Exploring the genetic diversity among plant accessions is important for conserving and managing plant genetic resources. In the current study, a collection of forty-six tomato accessions from Jordan were evaluated based on their performance and their morpho-physiological, in addition to molecularly characterizing to [...] Read more.

Exploring the genetic diversity among plant accessions is important for conserving and managing plant genetic resources. In the current study, a collection of forty-six tomato accessions from Jordan were evaluated based on their performance and their morpho-physiological, in addition to molecularly characterizing to detect genetic diversity. Tomato accessions seedlings were exposed to drought stress with 70% field capacity and 40% field capacity under field conditions in Jordan. Drought stress had significantly negatively influenced the dry root weight, fresh root weight, root growth rate, fresh shoot weight, dry shoot weight, and shoot growth rate. Moreover, proline content showed a highly significant increase of 304.2% in response to drought stress. The analysis of twenty morphological characters revealed a wide range of variations among tomato accessions. Accessions were screened with fourteen SSR primers; six primers were informative to explain the genetic diversity. Based on resolving power, primers LEct004 and LEat018 were most significant with all 46 accessions. Interestingly, polymorphic information content (PIC) values ranged from 0.00 (Asr2 marker) to 0.499 (LEct004), which confirms that the SSR markers are highly informative. Our findings provide new insights into using informative molecular markers to elucidate such wide genetic variation discovered in our collections from Afraa and Abeel (the southern part of Jordan). Interestingly, the SSR markers were associated with genes, e.g., LEat018 with ACTIN_RELATED PROTEIN gene, the LEct004 with the HOMEOBOX PROTEIN TRANSCRIPTION FACTORS gene, and Asr2 with ABA/WDS. Moreover, the AUXIN RESPONSE FACTOR8 gene was associated with the LEta014 SSR marker and the LEta020 with the THIOREDOXIN FAMILY TRP26 gene. Therefore, the genetic diversity analysis and functional annotations of the genes associated with SSR information obtained in this study provide valuable information about the most suitable genotype that can be implemented in plant breeding programs and future molecular analysis. Furthermore, evaluating the performance of the collection under different water regimes is essential to produce new tomato varieties coping with drought stress conditions. Full article

(This article belongs to the Special Issue Drought Stress in Horticultural Plants)

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16 pages, 1454 KiB

Open AccessEditor’s ChoiceArticle

Foliar Application of Selenium under Nano Silicon on Artemisia annua: Effects on Yield, Antioxidant Status, Essential Oil, Artemisinin Content and Mineral Composition

by Nadezhda Golubkina, Lidia Logvinenko, Dmitry Konovalov, Ekaterina Garsiya, Mikhail Fedotov, Andrey Alpatov, Oksana Shevchuk, Liubov Skrypnik, Agnieszka Sekara and Gianluca Caruso

Horticulturae 2022, 8(7), 597; https://doi.org/10.3390/horticulturae8070597 - 2 Jul 2022

Cited by 9 | Viewed by 2055

Abstract

The unique biological properties of A. annua have stimulated the research on its cultivation in different regions of the world. In this study, the effect of the Se and nano-Si supply on the yield, biochemical characteristics and mineral content of A. annua was [...] Read more.

The unique biological properties of A. annua have stimulated the research on its cultivation in different regions of the world. In this study, the effect of the Se and nano-Si supply on the yield, biochemical characteristics and mineral content of A. annua was investigated. Growth stimulation and a significant increase in the antioxidant status were recorded under Se and nano-Si foliar application. A decrease in the number of essential oil components and significant changes in the essential oil amount and composition led to significant phenophase shifts: nano-Si significantly stimulated eucalyptol and artemisia ketone accumulation and decreased germacrene D production, whereas Se demonstrated the opposite effect. A joint Se and nano-Si supply significantly decreased the camphor content and increased artemisia ketone and artemisinin levels by 1.3–1.5 times. Se/Si supplementation affected the macro- and microelements content, causing either a redistribution of leaves/stems elements (Al, Li and Zn) or a significant decrease in Ca, Mg, K, B, Cu, Fe and Mn concentrations in leaves, with no signs in growth inhibition or a decrease in the photosynthetic pigments content. The biofortification of A. annua with Se singly or in combination with nano-Si resulted in the synthesis of products with a Se content of as much as approximately 16% of the daily adequate Se consumption level (ACL) when using 5 g day⁻¹ as a spice, or 36% of ACL when using 50 mL of tea infusion (1:2, v/w). The results indicated a high possibility of Se and nano-Si application toward the regulation of A. annua growth, biochemical characteristics (including essential oil and artemisinin) and mineral content. Full article

(This article belongs to the Special Issue Vegetable Biofortification: Strategies, Benefits and Challenges)

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16 pages, 2531 KiB

Open AccessEditor’s ChoiceArticle

Integrated Metabolomic and Transcriptomic Analysis Reveals the Effect of Artificial Shading on Reducing the Bitter Taste of Bamboo Shoots

by Yongjian Huang, Hang Xun, Guilin Yi, Ti Li, Xi Yao and Feng Tang

Horticulturae 2022, 8(7), 594; https://doi.org/10.3390/horticulturae8070594 - 1 Jul 2022

Cited by 2 | Viewed by 2244

Abstract

Bamboo shoot is a delicious and nutritious forest vegetable. It has been found that bamboo shoots collected from low-light environments have a less bitter taste. The molecular mechanism of light in the regulation of bitter substance accumulation in bamboo shoots is still unclear. [...] Read more.

Bamboo shoot is a delicious and nutritious forest vegetable. It has been found that bamboo shoots collected from low-light environments have a less bitter taste. The molecular mechanism of light in the regulation of bitter substance accumulation in bamboo shoots is still unclear. In this study, we applied a shading treatment to Pleioblastus amarus bamboo shoots in the preharvesting period. The reduction in the bitterness intensity was confirmed by a sensory test. An integrated metabolomic and transcriptomic analysis was performed on P. amarus bamboo shoots grown under shading treatment and normal growing conditions, and 56 differentially accumulated metabolites and 178 differentially expressed genes were identified. The results showed that the contents of a series of phenolic acids related to the tyrosine metabolism pathway were downregulated under shading treatment, revealing that shading decreased the accumulation of phenolic acids and further mediated the resulting bitter taste of the bamboo shoots. This work will be helpful for understanding the regulatory mechanisms governing the bitter tasting substances in bamboo shoots grown under a shading treatment and provides a reference for the use of shading treatment in cultivation practices to improve the taste of bamboo shoots. Full article

(This article belongs to the Special Issue Omics Technologies and Their Applications in Vegetable Plant Research)

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16 pages, 5407 KiB

Open AccessEditor’s ChoiceArticle

Comprehensive Evaluation of Low Temperature and Salt Tolerance in Grafted and Rootstock Seedlings Combined with Yield and Quality of Grafted Tomato

by Shijie Fu, Jiaqian Chen, Xiaolei Wu, Hongbo Gao and Guiyun Lü

Horticulturae 2022, 8(7), 595; https://doi.org/10.3390/horticulturae8070595 - 1 Jul 2022

Cited by 6 | Viewed by 2109

Abstract

Environmental stress, especially in the form of low temperatures and salinity, has becomethe main limiting factor affecting the yield and quality of tomatoes in greenhouse production in China. Grafting, as an effective and sustainable strategy for improving plant stress tolerance, is closely related [...] Read more.

Environmental stress, especially in the form of low temperatures and salinity, has becomethe main limiting factor affecting the yield and quality of tomatoes in greenhouse production in China. Grafting, as an effective and sustainable strategy for improving plant stress tolerance, is closely related to rootstock properties and scion affinity. Here, 15 commercial rootstock genotypes were collected to investigate the differences in low temperatures and salt tolerance of rootstocks and grafted tomato seedlings in parallel, as well as well as the effect of grafting on the yield and quality of tomato. The results indicated that there were differences among rootstocks, and the resistance of grafted seedlings mainly depended on the characteristics of the rootstocks. We also found that the resistance of grafted seedlings was affected by the affinity between the scion and rootstock. Genotypes 6, 7, 11, and 14 showed advantages over the other genotypes in seedling growth, based on the fresh weight of the plants, the seedling index, and the root-shoot ratio. Genotypes 2, 7, 11, and 14 had greater total root lengths and higher numbers of root tips than other genotypes. These results showed that the significant increase in growth in the grafted tomato seedlings might have been attributable to the vigorous roots of the rootstocks. Genotypes 4, 7, 11, and 13 showed advantages with respect to low temperature stress, whereas genotypes 7, 11, 12, and 13 showed advantages with respect to salt stress. The salt tolerance of grafted tomato seedlings was influenced by both scion affinity and rootstock characteristics and was decreased by grafting. The highest yields were obtained from the grafted plants of genotypes 7 and 11, whose yields were 17.2% and 14.6% higher, respectively, than those of the control group. The rootstock genotype did not affect the fruit quality parameters, such as soluble protein content, titratable acidity, and total soluble solids content, and in most cases, the lycopene and ascorbic acid contents of the fruit increased. After considering the results pertaining to the stress tolerance of rootstocks in combination with fruit yield and quality, genotypes 7 and 11 were selected as potentially suitable tomato rootstock varieties for further large-scale applications. These results provide a new perspective for the study of rootstock characteristics and an important reference for grafted tomato cultivation in greenhouse production. Full article

(This article belongs to the Special Issue Advances in Protected Vegetable Cultivation)

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21 pages, 5582 KiB

Open AccessEditor’s ChoiceArticle

A Lignin-Rich Extract of Giant Reed (Arundo donax L.) as a Possible Tool to Manage Soilborne Pathogens in Horticulture: A Preliminary Study on a Model Pathosystem

by Stefania Galletti, Stefano Cianchetta, Hillary Righini and Roberta Roberti

Horticulturae 2022, 8(7), 589; https://doi.org/10.3390/horticulturae8070589 - 30 Jun 2022

Cited by 6 | Viewed by 2083

Abstract

Finding new sustainable tools for crop protection in horticulture has become mandatory. Giant reed (Arundo donax L.) is a tall, perennial, widely diffuse lignocellulosic grass, mainly proposed for bioenergy production due to the fact of its high biomass yield and low agronomic [...] Read more.

Finding new sustainable tools for crop protection in horticulture has become mandatory. Giant reed (Arundo donax L.) is a tall, perennial, widely diffuse lignocellulosic grass, mainly proposed for bioenergy production due to the fact of its high biomass yield and low agronomic requirements. Some studies have already highlighted antimicrobial and antifungal properties of giant reed-derived compounds. This study aimed at investigating the potential of a lignin-rich giant reed extract for crop protection. The extract, obtained by dry biomass treatment with potassium hydroxide at 120 °C, followed by neutralization, was chemically characterized. A preliminary in vitro screening among several pathogenic strains of fungi and oomycetes showed a high sensitivity by most of the soilborne pathogens to the extract; thus, an experiment was performed with the model pathosystem, Pythium ultimum–zucchini in a growth substrate composed of peat or sand. The adsorption by peat and sand of most of the lignin-derived compounds contained in the extract was also observed. The extract proved to be effective in restoring the number of healthy zucchini plantlets in the substrate infected with P. ultimum compared to the untreated control. This study highlights the potential of the lignin-rich giant reed extract to sustain crop health in horticulture. Full article

(This article belongs to the Special Issue Sustainable Control Strategies of Plant Pathogens in Horticulture)

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24 pages, 5000 KiB

Open AccessEditor’s ChoiceArticle

Characteristics of Meteorological Conditions during a Severe Outbreak of Onion Downy Mildew and Metalaxyl Sensitivity of Peronospora destructor in Saga, Japan, in 2016

by Shin-ichirou Syobu and Sachiko Watanabe

Horticulturae 2022, 8(7), 578; https://doi.org/10.3390/horticulturae8070578 - 26 Jun 2022

Cited by 2 | Viewed by 2326

Abstract

In 2016, an onion downy mildew epidemic caused by Peronospora destructor severely damaged the commercial onion fields in Saga Prefecture, western Japan. To identify the factors underlying the outbreak, we investigated the symptoms of downy mildew caused by secondary infections and examined P. [...] Read more.

In 2016, an onion downy mildew epidemic caused by Peronospora destructor severely damaged the commercial onion fields in Saga Prefecture, western Japan. To identify the factors underlying the outbreak, we investigated the symptoms of downy mildew caused by secondary infections and examined P. destructor’s sensitivity to metalaxyl, the most effective traditional fungicide used against this onion pathogen, in 2016–2018. Disease symptoms developed in late March 2016, which was earlier than symptom development in 2017 and 2018. Furthermore, there were synchronous repeated disease development and favourable meteorological conditions for infection in early and late April resulting in the development of polycyclic epidemics. In field trials from 2016 to 2018, the efficacy of chlorothalonil + metalaxyl-M application ranged 18–45%, as calculated by comparing disease severity at the final stage of each treatment to that in the untreated plots. On the basis of the metalaxyl sensitivity observed in 2016, the effective concentration, which reduced germ-tube elongation in P. destructor by 50%, exceeded 200 µg ai/mL for certain strains. Our observations indicate that these characteristic meteorological conditions were major factors contributing to the severe disease outbreak in 2016. The emergence of less-metalaxyl-sensitive P. destructor strains may be an additional predisposing factor. Full article

(This article belongs to the Special Issue Horticultural Plants Pathology and Advances in Disease Management)

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19 pages, 2184 KiB

Open AccessEditor’s ChoiceArticle

Early-Summer Deficit Irrigation Increases the Dry-Matter Content and Enhances the Quality of Ambrosia™ Apples At- and Post-Harvest

by Changwen Lu

Horticulturae 2022, 8(7), 571; https://doi.org/10.3390/horticulturae8070571 - 23 Jun 2022

Cited by 1 | Viewed by 1786

Abstract

Ambrosia™ is an apple that naturally has limited post-harvest quality retention, which is accompanied by relatively low dry-matter content (DMC). This trial was proposed to improve the DMC of this apple by scheduling deficit irrigation (DI) conducted in a semi-arid orchard in the [...] Read more.

Ambrosia™ is an apple that naturally has limited post-harvest quality retention, which is accompanied by relatively low dry-matter content (DMC). This trial was proposed to improve the DMC of this apple by scheduling deficit irrigation (DI) conducted in a semi-arid orchard in the Similkameen Valley (British Columbia, Canada) in 2018 and 2019. Two irrigation regimes were implemented in the orchard: commercial irrigation (CI) and DI, which was defined as irrigation for 2/5 of the timespan of CI. Five irrigation treatments were conducted: 1—adequate irrigation (AI), which used CI for the whole season; 2—early-summer DI (ED), which used DI from 20 June to 20 July; 3—middle-summer DI (MD), which used DI from 20 July to 20 August; 4—late-summer DI (LD), which used DI from 20 August to 10 days before harvest; and 5—double-period DI (DD), which covered the interval of MD and LD. The DI treatments resulted in a significant decrease from AI −1.0 to −1.5 MPa in stem water potential (SWP), followed by subsequent recovery. Conversely, SWP did not recover, and instead reached a critical low of −2.5 MPa under continued deficit conditions (DD). This, in turn, correlated with significant differences in the DMC among the treatments. Specifically, ED resulted in a rapid and sustained increase in DMC throughout the summer. At the time of harvest, ED resulted in a five-fold increase in the proportion of fruit, with greater than 16% DMC and 15% DMC in 2018 and 2019, respectively, compared to AI. DD resulted in similar levels of DMC elevation compared to ED, but also caused irregular maturation and the increased incidence of soft scald disorder in the post-harvest period. MD and LD had variable effects on DMC, and also increased the incidence of soft scald disorder. Consequently, fruit collected from the ED resulted in the best blush color attributes, higher soluble solid content, and a significant improvement in the post-harvest retention of both fruit firmness and acidity. The ED irrigation model would be recommended as a practical way for Ambrosia™ growers in semi-arid regions to decrease water usage, and to ensure high fruit quality for superior marketing and sustainable production. Full article

(This article belongs to the Special Issue Irrigation and Water Management in Horticulture)

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15 pages, 3338 KiB

Open AccessEditor’s ChoiceArticle

Evaluation of the Storage Performance of ‘Valencia’ Oranges and Generation of Shelf-Life Prediction Models

by Abiola Owoyemi, Ron Porat, Amnon Lichter, Adi Doron-Faigenboim, Omri Jovani, Noam Koenigstein and Yael Salzer

Horticulturae 2022, 8(7), 570; https://doi.org/10.3390/horticulturae8070570 - 22 Jun 2022

Cited by 4 | Viewed by 2122

Abstract

We conducted a large-scale, high-throughput phenotyping analysis of the effects of various preharvest and postharvest features on the quality of ‘Valencia’ oranges in order to develop shelf-life prediction models. Altogether, we evaluated 10,800 oranges (~3.6 tons) harvested from three orchards at different periods [...] Read more.

We conducted a large-scale, high-throughput phenotyping analysis of the effects of various preharvest and postharvest features on the quality of ‘Valencia’ oranges in order to develop shelf-life prediction models. Altogether, we evaluated 10,800 oranges (~3.6 tons) harvested from three orchards at different periods and conducted 151,200 measurements of 14 quality parameters. The storage time was the most important feature affecting fruit quality, followed by the yield, storage temperature, humidity, and harvest time. The storage time and temperature features significantly affected (p < 0.001) all or most of the tested quality parameters, whereas the harvest time, yield, and humidity conditions significantly affected several particular quality parameters, and the selection of rootstocks had no significant effect at all. Five regression models were evaluated for their ability to predict fruit quality based on preharvest and postharvest features. Non-linear Support Vector Regression (SVR) combined with a data-balancing approach was found to be the most effective approach. It allowed the prediction of fruit-acceptance scores among the full data set, with a root mean square error (RMSE) of 0.195 and an R² of 0.884. The obtained data and models should assist in determining the potential storage times of different batches of fruit. Full article

(This article belongs to the Special Issue Postharvest Management of Citrus Fruit)

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