Search Results (359)

In recent years, the cultivated area of hazelnuts in Chile has increased significantly. Along with this rapid expansion, biotic constraints that affect the optimal development of the crop have been identified. Among these, bacterial blight disease caused by Xanthomonas arboricola pv. corylina has been particularly relevant. This pathogen has a global distribution and is present in all hazelnut-producing countries. In the spring of 2023, hazelnut orchards were sampled from the Maule to Biobío Regions of Chile. The Chilean isolates recovered from hazelnut tissues showing symptoms of bacterial blight were characterized by their ability to grow on different semi-selective media, their carbohydrate utilization profiles, hypersensitivity response in tobacco plants, and biochemical tests. Additionally, the isolates were identified based on the 16S rRNA gene and multilocus sequence analysis (MLSA) on the rpoD, gyrB, and atpD genes. The results showed that the X. arboricola pv. corylina Chilean isolates differed from previously reported isolates in other geographic areas as they are capable of metabolizing sorbitol and mannitol. Using MLSA and average nucleotide identity (ANI) comparison, these isolates were grouped into four and five phylogenetic clades, respectively, representing a significant difference from what has been reported in similar international studies. Full article

‘Hainan Qingyou’ (Citrus maxima) Pomelo is one of the predominant local cultivars cultivated in Hainan Province, renowned for its high economic value and strong market competitiveness. However, during cultivation, it was observed that the fruit quality of ‘Hainan Qingyou’ grafted onto a ‘Sanhong’ interstock deteriorated, predominantly manifesting as vesicle granulation. This study was therefore conducted to investigate this phenomenon using ‘Sanhong’ Honey Pomelo as the interstock. Fruit quality indicators were measured, and pulp transcriptomic analysis was performed during the expansion and maturation stages. The results indicated that fruits grafted onto ‘Sanhong’ interstock (SHZ) exhibited increased peel thickness, yellower peel, reduced edible rate, higher pulp firmness, decreased total soluble solids (TSS), increased total acid content, and reduced total antioxidant capacity at maturity, all contributing to diminished fruit quality. Additionally, SHZ fruit accumulated higher lignin content in the pulp, leading to vesicle granulation, which severely compromised marketability. Transcriptomic analysis identified 42 structural genes involved in lignin biosynthesis in ‘Hainan Qingyou’ pulp, including 5 PAL, 2 C4H, 2 4CL, 6 CAD, 15 PER, 2 HCT, 1 C3′H, 1 CCoAOMT, 1 CCR, 1 COMT, 2 CSE, and 1 F5H genes. Most of these genes were highly expressed in SHZ fruit at maturity, with expression levels significantly higher than those in fruit grafted onto ‘Hainan Qingyou’ interstock (QYZ). The interstock also affected hormone signaling pathways. Weighted gene co-expression network analysis (WGCNA) identified transcription factors such as MYB, MIKC, ERF, and bZIP as key regulators involved in pulp lignin biosynthesis. This study provides insights into the effects of rootstocks on citrus fruit quality and offers valuable information for cultivar improvement in pomelo orchards. Full article

The production of apples plays a crucial role in global agriculture. In 2023, the world production of these fruits amounted to nearly 150 million tonnes, cultivated on 6.6 million ha. Today’s horticulture faces the difficult challenge of maintaining high productivity while simultaneously reducing negative environmental impact. Traditional methods based on chemical pesticides encounter increasing problems, such as biodiversity loss, toxic residues in food, development of pest resistance, and disrupted balance of ecosystems. Integrated Pest Management (IPM) responds to these challenges by combining biological and agrotechnical methods with selective use of chemicals. Biopesticides are a crucial component of IPM, and they include antagonist microorganisms, substances of natural origin, and other biological methods of control, which represent effective alternatives to conventional measures. Their development is driven by consumer requirements concerning food safety, as well as by the need to protect the environment. The aim of this article is to highlight current problems in apple production, describe microorganisms and natural substances used as biopesticides used for the protection of apple orchards, as well as present the characteristics of modern technologies used for biocontrol in apple orchards. Full article

The flat peach, an important commercial crop in the 143rd Regiment of Shihezi, China, is overwintered using plastic film mulching. Flat peaches are cultivated to boost the local temperate rural economy. The development of accurate maps of the spatial distribution of flat peach plantations is crucial for the intelligent management of economic orchards. This study evaluated the performance of pixel-based and object-based random forest algorithms for mapping flat peaches using the GF-1 image acquired during the overwintering period. A total of 45 variables, including spectral bands, vegetation indices, and texture, were used as input features. To assess the importance of different features on classification accuracy, the five different sets of variables (5, 15, 25, and 35 input variables and all 45 variables) were classified using pixel/object-based classification methods. Results of the feature optimization suggested that vegetation indices played a key role in the study, and the mean and variance of Gray-Level Co-occurrence Matrix (GLCM) texture features were important variables for distinguishing flat peach orchards. The object-based classification method was superior to the pixel-based classification method with statistically significant differences. The optimal performance was achieved by the object-based method using 25 input variables, with an overall accuracy of 94.47% and a Kappa coefficient of 0.9273. Furthermore, there were no statistically significant differences between the image-derived flat peach cultivated area and the statistical yearbook data. The result indicated that high-resolution images based on the overwintering period can successfully achieve the mapping of flat peach planting areas, which will provide a useful reference for temperate lands with similar agricultural management. Full article

In the Mediterranean basin, olive cultivation occupies the largest share of agricultural land, due to the region’s favorable soil and climatic conditions. However, the intensification of farming systems has had negative environmental impacts, for which diversified approaches such as agroforestry offer a potential solution. The objective of the present study was to determine the growth of barley, triticale, and pea as cover crops, as well as the respective intercrops in olive orchards and their productivity. The results showed that the intercropping of pea with barley and triticale had the highest yields in dry biomass compared to the other treatments, while barley monoculture recorded the highest yield in terms of grain. The findings demonstrated that intercropping enhances resource-use efficiency, particularly in terms of land productivity, Radiation-Use Efficiency, and Water-Use Efficiency. However, competitive dynamics varied significantly between species and across years, with pea often exhibiting dominance in biomass production, while cereals showed trade-offs in seed yield components due to shading and interspecific competition. These findings can be used for sustainable intensification strategies, ensuring higher productivity while minimizing external inputs in climate-vulnerable regions. Full article

‘Pera’ sweet orange is a key variety for the Brazilian citrus industry, but orchards rely on a limited number of clonal selections, which restricts adaptability and productivity across diverse environments. This study assessed the agronomic performance of 13 ‘Pera’ selections grafted on Rangpur lime, cultivated under rainfed conditions in subtropical Brazil. From 2002 to 2010, trees were assessed for vegetative growth, cumulative yield, alternate bearing, and fruit quality. Market-specific performance indices were calculated to determine suitability for fresh fruit or juice processing. Substantial genotypic variation was observed across traits, particularly during early orchard stage. Selections such as ‘Morretes’, ‘Seleção 11’, ‘Seleção 27’, ‘Seleção 37’, and ‘IPR 153’ demonstrated high cumulative yield, stable productivity, and favorable canopy traits, supporting their use in both conventional and high-density systems. ‘IPR 153’ combined compact growth with high yield efficiency and excellent fruit quality, while ‘Morretes’ had the highest juice content and broad market adaptability. In contrast, ‘IPR 159’ showed low vigor and yield under rainfed conditions. The results emphasize the value of regionally targeted clonal selection to improve orchard performance and market alignment. The identification of dual-purpose genotypes offers a pathway to diversify citrus production and improve profitability under subtropical growing conditions. Full article

Corky split vein (CSV) is a common physiological disease in citrus that can result from multiple types of stresses. Preliminary field investigation found that more severe CSV in citrus cultivated in orchards lacking both boron (B) and other photosynthesis-related nutrients, including manganese (Mn). In this study, two-year-old ‘Newhall’ navel orange seedlings were treated with control (CK), B deficiency (BD), Mn deficiency (MnD), and combined B and Mn deficiency (BD + MnD). After 31 weeks, typical CSV symptoms appeared on old leaves (OLs) and secondary new leaves (SLs) in BD, while BD + MnD symptoms were more severe. BD and BD + MnD significantly reduced B concentrations in all leaf types, but there were no significant differences between them. Except for OLs in MnD, the net photosynthetic rate (P_n) of all leaf types significantly decreased in all treatments, with BD + MnD showing significantly lower P_n values than BD. Compared with BD, BD + MnD significantly increased minimal fluorescence (F_o) of all leaves at the later stage and significantly decreased Y(II) of new leaves. BD significantly increased sucrose and starch contents in all type leaves, while the OL starch content was significantly higher in BD + MnD than that in BD. BD + MnD significantly decreased the enzyme activities of Rubisco, TK, and FBA in OLs, FBPase and NI in PLs, and Rubisco in SLs compared with BD, while the activities of NI and AI in OLs and SS in SLs were significantly increased. BD + MnD significantly enhanced lignin concentrations and the expression of key lignin synthesis genes in leaves compared with BD. In conclusion, Mn deficiency exacerbates B-deficiency-induced CSV not only by intensifying photosynthetic dysfunction and carbohydrate accumulation but also by promoting lignin biosynthesis. These findings highlight the synergistic nature of B and Mn deficiencies in impairing leaf function and structure, providing new insights into the physiological and molecular mechanisms underlying CSV development. Full article

Oil content is a critical component of yield production in Mediterranean olive orchards, but it has received limited attention in modeling olive cultivation under extreme weather conditions. To address this gap, statistical and regression models based on multiple oil content measurements from field trials conducted with representative olive cultivars in the Guadalquivir basin (southern Iberian Peninsula), together with the latest future climate projections from the Coupled Model Intercomparison Project Phase 6 (CMIP6) for the Iberian Peninsula, were integrated to improve the modeling of its behavior under future climate conditions. Temperature was the most influential factor affecting the olive oil accumulation pattern. Summer temperature was negatively correlated with the onset of oil accumulation, the accumulation rate, and the maximum oil content (MOC), while it was positively correlated with the date at which MOC was reached. When these relationships were combined with CMIP6 climate projections, inland southern Spain emerge as one of the most affected areas in the Iberian Peninsula. In the near future period (2040–2069), projected climate warning is expected to result in an earlier onset of oil accumulation, delays of up to 33 days in reaching MOC, and reductions in MOC of up to 17.5 percentage points, corresponding to an average olive oil yield loss of up to 30.3%, considering only the olive oil yield loss associated with the reduction in MOC. These changes vary in intensity depending on the location, cultivar, climate period and the greenhouse gas emission scenario considered. This study confirms the critical importance of temperature in olive oil production, highlights the need to incorporate functions that account for the effects of rising temperature on MOC, and emphasizes the identification of adaptation measures to cope with increasing temperatures and more frequent heat waves. Full article

The adaptability of several Italian olive cultivars to high-density cultivation was evaluated from 2020 to 2024 in central Italy by assessing their agronomic behavior, with the aim of identifying which Italian olive cultivars can combine high productivity and suitability for intensive mechanization—through high- and very high-density planting systems—allowing biodiversity valorization. The cultivars were Borgiona, Don Carlo, FS17, Gentile di Anghiari, Gentile di Montone, Giulia, Leccio del Corno, Maurino, Moraiolo, Pendolino, Piantone di Falerone, and Piantone di Mogliano. The international cultivar Arbequina was used as a reference. The olive orchard was planted in 2015, at a tree spacing of 5 m × 2 m (1000 trees/ha). Arbequina was found to have limited vigor and high production efficiency, as reported in other works, therefore confirming its suitability for high-density and super-high-density cultivation. Some cultivars, such as Leccio del Corno, Maurino, FS17, Piantone di Mogliano, and Piantone di Falerone, had a production and yield efficiency that was not different from or even higher than Arbequina. Other cultivars found to be promising were Don Carlo and Gentile di Anghiari, which had a slightly lower productive performance than Arbequina. Overall, the results are encouraging and suggest that some of these cultivars may be suitable candidates for high- and super-high-density olive orchards. This suitability is further supported by their favorable fruit characteristics, which appear to facilitate efficient mechanical harvesting. However, additional data is necessary to enable a more comprehensive assessment of these cultivars, particularly their capacity to maintain canopy dimensions compatible with straddle harvester operation, while maintaining a stable vegetative–reproductive balance over time. Full article

Saline–alkali soils in southern Xinjiang present significant challenges for sustainable jujube cultivation, necessitating innovative fertilization strategies to improve soil health and enhance fruit quality. This study investigated the synergistic effects of biochar–nitrogen (N) co-application on soil amelioration and the improvement of jujube quality in saline–alkali jujube orchards. A field experiment was conducted using different biochar application rates (0, BC1, BC2) combined with various N fertilizer types (conventional nitrogen N1, N2, UI-N (urease inhibitor), and NI-N (nitrification inhibitor)), which systematically analyzed soil physicochemical properties, nutrient dynamics, enzyme activities, microbial community structure, and jujube fruit yield and quality parameters. The BC1 biochar application rate emerged as the optimal threshold for soil carbon and N sequestration, with BC1 + N2 treatment achieving the highest total carbon and total nitrogen concentrations, representing increases of 12.4% and 21.42%, respectively, compared to controls. Biochar–N co-application significantly enhanced soil available nutrients, with BC1 + UI-N treatment producing the greatest soil organic matter increase within the BC1 group (9.20–14.51% enhancement). Notably, the treatments modulated soil microelement profiles, suppressing potentially toxic Cu and Mn while enhancing the availability of beneficial Mg and Fe. Soil enzyme activities responded differently, with urease and sucrase activities reaching maximum levels under BC2 + N1 and BC1 + UI-N treatments, respectively. Microbial community analysis revealed that biochar–N combinations significantly restructured both bacterial and fungal communities, with BC1 + NI-N treatment demonstrating superior bacterial α-diversity across all indices. Soil enzyme activities exhibited distinct response patterns, with urease and sucrase activities reaching their peak under the BC2 + N1 and BC1 + UI-N treatments, respectively. Moreover, the co-application of biochar (BC1) with N fertilizer significantly improved fruit performance, increasing per-tree yield by 24.23% and fruit vitamin C content by 16.47%, compared to the control. This study demonstrates that moderate biochar application (BC1) combined with urease inhibitor- enhanced N fertilizer (UI-N) represents an optimal fertilization strategy for saline–alkali jujube orchards, achieving simultaneous soil amelioration and fruit quality enhancement through coordinated regulation of soil–microbe–plant interactions. The established quantitative relationships provide a scientific foundation for the implementation of precision agriculture in arid saline–alkali regions, offering significant implications for sustainable specialty fruit production and soil health restoration in environmentally challenged agricultural systems. Full article

Although substantial research has been conducted on pecan cultivation, studies that account for variability in farm scale, from small to large commercial operations, are still needed. To address this gap, the primary objective of the present study was to quantify and compare groundwater recharge rates and crop yield in pecan orchards utilizing different irrigation systems. This investigation employed in-orchard water budget measurements combined with analytical water balance models to facilitate comparative analysis between orchard sizes. The study tested the hypothesis that groundwater recharge rates vary significantly with farm scale, with larger commercial orchards exhibiting higher recharge rates than their small-scale counterparts. Analysis of 2021–2023 irrigation data revealed significant variability in deep percolation (DP) as a percentage of total water applied (TWA) across orchard sites, ranging from 0% to 52%, with P1 exhibiting the highest recharge and yield, while P2 had the lowest due to limited irrigation. ANOVA revealed significant differences in DP and yield among sites, with P1 outperforming the others. CWP averaged 0.33 kg/m³ but varied considerably by site (0.12–0.42 kg/m³). The results showed significant variability in DP, highlighting its dependence on management practices. These findings emphasize the critical role of site-specific irrigation strategies in optimizing productivity. Full article

English walnut (Juglans regia) is a species that is highly valued for the quality of its wood and the nutritional and nutraceutical properties of its fruit. A severe dieback of J. regia trees was observed recently in orchards located in three geographically distinct areas of Tuscany, central Italy. Symptoms included root and collar rot, necrosis of the under-bark tissue, bleeding cankers, stunted growth, and crown dieback. Four Phytophthora species were obtained from 239 isolates found on symptomatic J. regia individuals. They were identified, on the basis of macro-morphological (colony shape and texture), micro-morphometric (shape and size of oogonia, antheridia, oospores, sporangia, and chlamydospores) and molecular (ITS sequencing) characters, as P. gonapodyides, P. cactorum, P. citricola, and P. plurivora. Among these species, P. plurivora was the species isolated with overwhelming frequency from symptomatic tissue and rhizosphere soil, suggesting it to be the putative etiological agent. Pathogenicity assays were conducted on 20 cm long detached J. regia branches for a definitive establishment of disease causation. Severe symptoms (extended necroses) were exhibited by branches infected with P. plurivora, proving its pathogenicity and high virulence on this host. The other Phytophtora species produced negligible necroses around the inoculation site. P. plurivora was recovered from all the investigated orchards, providing evidence that it is quite widespread. This study highlights the growing threat posed by the polyphagous P. plurivora to walnut cultivation and the sustainable business it fuels in Europe, underscoring the need for integrated management strategies to mitigate its economic and ecological impacts. Full article

This study aims to develop a multi-dimensional framework to systematically identify optimal adjustment zones for converting orchard land into cultivated land, thereby providing a reference for spatial optimization of cultivated land within the context of integrating diverse land occupation activities into the requisition–compensation balance system. The research incorporates land quality evaluation, land-use conversion cost assessment, ecological loss analysis, and scenario-based simulations. The study demonstrates that (1) compared to the common practice of directly converting orchard land to cultivated land by only considering the slope, our multi-scenario optimization model for cultivated land reduces both economic and ecological losses. (2) For cities prioritizing ecological or economic development, selecting strategies under corresponding priority scenarios can maximize the protection of local ecological environments or maintain economic levels, thereby providing reserve resources for cultivated land optimization and adjustment. (3) Under the MMEG (EG: Ecological priority scenario) and MMEM (EM: Economic priority scenario) scenarios (MM: conversion of medium-low-grade orchard land to medium-high-grade cultivated land), the area of cultivated land optimal adjustment zones is the largest. The method of comprehensively identifying cultivated land optimal adjustment zones through multi-dimensional scenario settings is more comprehensive than the conventional approach that only considers slope. This method enhances cultivated land quality more effectively and protects both the ecosystem and the economy. Full article

Bee pollination is an indispensable part of agricultural production and a crucial factor in maintaining ecosystem balance and biodiversity. Understanding foraging behavior and pollination effects is essential for the management of bee pollination. Over a two-year experiment, we evaluated the foraging behavior and pollination effects of bumblebee Bombus terrestris and Chinese honeybee Apis cerana cerana on cherries in orchards. Results showed that all bees exhibited enhanced foraging activity as daytime temperatures rose in early spring. However, the daytime foraging activity of bumblebees differs from that of Chinese honeybees. The number of bumblebees leaving the hive exhibited two peak periods, whereas Chinese honeybees showed only one peak period. Bumblebees had longer working hours and greater pollen-carrying capacity than Chinese honeybees. Undoubtedly, cherries pollinated by bees had higher yields, as indicated by a greater fruit setting rate and yield. Thus, as effective pollinators, their pollination significantly boosts production and presents a viable option for widespread use in cherry cultivation. However, the risk of biological invasion by exotic bumblebees cannot be overlooked before extensive use. Full article

Most sweet cherry varieties exhibit typical gametophytic self-incompatibility (GSI) characteristics, necessitating careful configuration of pollination trees to ensure adequate yields. This requirement increases the costs associated with orchard labor, management, and other related expenses. Consequently, cultivating and developing sweet cherry cultivars with self-compatibility can effectively address these challenges. Research into the molecular mechanisms underlying GSI formation can provide vital theoretical support and genetic resources for breeding self-compatible sweet cherries. In this study, we assessed the fruit set rates of ‘Tieton’ following both self- and cross-pollination. Additionally, we conducted a transcriptome analysis of the ‘Tieton’ style (which includes the stigma) at 0, 12, 24, and 48 h post-pollination to identify key genes involved in the self-incompatibility process of sweet cherries. The results indicated that the self-fruiting rate of ‘Tieton’ was significantly lower than that of cross-pollination. We identified a total of 8148 differentially expressed genes (DEGs) through transcriptome analysis, with KEGG pathway analysis revealing that the plant-pathogen interaction, plant hormone signal transduction, and plant MAPK signaling pathways were primarily involved in sweet cherry GSI. Furthermore, we identified 13 core transcription factors (TFs) based on their differential expression patterns, including three ERFs, three NACs, three WRKYs, two HD-ZIPs, one RAV, and one MYB. Co-expression analysis identified 132 core DEGs significantly associated with these TFs. Ultimately, this study provides initial insights into the key genes within the sweet cherry GSI network, laying a theoretical foundation and offering genetic resources for the future molecular design breeding of new self-compatible varieties. Full article