Agriculture

1643 KiB

Open AccessArticle

Low Soil Phosphorus Availability Increases Acid Phosphatases Activities and Affects P Partitioning in Nodules, Seeds and Rhizosphere of Phaseolus vulgaris

by Adnane Bargaz, Mustapha Faghire, Neila Abdi, Mohamed Farissi, Bouaziz Sifi, Jean-Jacques Drevon, Mohamed Cherkaoui Ikbal and Cherki Ghoulam

Agriculture 2012, 2(2), 139-153; https://doi.org/10.3390/agriculture2020139 - 13 Jun 2012

Cited by 30 | Viewed by 9614

Abstract

The effect of phosphorus (P) deficiency on phosphatases activities in N₂-fixing legumes has been widely studied in hydroponic culture. However, the response of acid phosphatase (APase) and phytase in rhizosphere, nodules and seeds of Phaseolus vulgaris to low soil’s P-availability is not yet fully understood. In this study, six genotypes of N₂-fixing P. vulgaris were grown under contrasting soil P-availabilities; i.e., low (4.3 mg P kg⁻¹) and sufficient (16.7 mg P kg⁻¹) in the Haouz region of Morocco. At flowering and maturity stages, plants were harvested and analyzed for their phosphatases activities, growth and P content. Results show that, low P decreased nodulation, growth, P uptake and N accumulation in all the genotypes, but to a greater extent in the sensitive recombinant inbreed line 147. In addition, while seed P content was slightly reduced under low P soil; a higher P was noticed in the Flamingo and Contender large seeded-beans (6.15 to 7.11 mg g⁻¹). In these latter genotypes, high APase and phytase activities in seeds and nodules were associated with a significant decline in rhizosphere’s available P. APase activity was mainly stimulated in nodules, whereas phytase activity was highly induced in seeds (77%). In conclusion, the variations of APase and phytase activities in nodules and seeds depend on genotype and can greatly influence the internal utilization of P, which might result in low P soil tolerance in N₂-fixing legumes. Full article

(This article belongs to the Special Issue Soil Biology and Its Importance in Soil Fertility)

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835 KiB

Open AccessReview

Photosynthesis and Yellow Vine Syndrome of American Cranberry

by Harvey J. M. Hou

Agriculture 2012, 2(2), 125-138; https://doi.org/10.3390/agriculture2020125 - 7 Jun 2012

Viewed by 8170

Abstract

The American cranberry (Vaccinium macrocarpon Ait.) contains rich antioxidants and has significant health benefits in fighting a variety of human diseases. In the past ten years, cranberry growers have reported yellow vine syndrome, which is associated with reduced photosynthetic performance, in the cranberry bogs. It has been found that the yellow vine syndrome of cranberry is associated with nutritional imbalance; it might be an issue for cranberry quality and food security as well as the crop production. This review evaluates the present state of knowledge of yellow vine syndrome, together with recent advances that are resulting from an improved mechanistic understanding and a possible solution that will be of considerable value to cranberry growers. This review also includes results from the author’s own laboratory. Water stress, nutritional imbalance, and photoinhibition are the likely reasons for producing yellow vine of cranberry. Future endeavors should be placed on the combination of genetic, biochemical, and biophysical techniques at the molecular level and plant physiology at the field and greenhouse level. This may provide specific information in order to understand the molecular details of yellow vine of cranberry as well as a tool for guiding future breeding efforts and management practices. Full article

(This article belongs to the Special Issue The Impact of Plant Disease on Food Security)

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378 KiB

Open AccessArticle

Use of Biofungicides for Controlling Plant Diseases to Improve Food Availability

by Antonieta De Cal, Inmaculada Larena, Belén Guijarro and Paloma Melgarejo

Agriculture 2012, 2(2), 109-124; https://doi.org/10.3390/agriculture2020109 - 21 May 2012

Cited by 20 | Viewed by 11511

Abstract

Biological control of fungal plant pathogens can improve global food availability, one of the three pillars of food security, by reducing crop losses, particularly for low-income farmers. However, the interrelationships of many environmental variables can result in multiple interactions among the organisms and their environment, several of which might contribute to effective biological control. Here, we present an advanced survey of the nature and practice of biological control when it is used to control brown rot in stone fruit. Specifically, we describe the population dynamics of Penicillium frequentans and Epicoccum nigrum and their efficacy as biocontrol agents against brown rot disease under field conditions. The size of P. frequentans population after an application of a P. frequentans conidial formulation during the crop season is bigger than that of E. nigrum following the application of an E. nigrum conidial formulation. Moreover, applications of a P. frequentans conidial formulation during the crop season also caused a higher reduction in the number of Monilinia spp. conidia on the fruit surface than that found after applications of an E. nigrum formulation during the growing season. Full article

(This article belongs to the Special Issue The Impact of Plant Disease on Food Security)

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908 KiB

Open AccessReview

Earthworm Populations in Savannas of the Orinoco Basin. A Review of Studies in Long-Term Agricultural-Managed and Protected Ecosystems

by Danilo López-Hernández

Agriculture 2012, 2(2), 87-108; https://doi.org/10.3390/agriculture2020087 - 10 Apr 2012

Cited by 8 | Viewed by 8735

Abstract

Earthworm biomass and production in savannas are limited by seasonal precipitation and the lack of organic and nutrient resources; I hypothesize that after a long-term protection of savanna from fire and agricultural activities drastic changes in the physical and chemical characteristics of the soil occur with a concomitant increase in earthworm abundance and activities. Similar changes might occur after a long-term fertilization of savannas with manure. This review article considers the earthworm communities and other soil quality indices in Trachypogon savannas of the Orinoco Basin in an organic agricultural forestal savanna (OAFS) amended with compost over forty years in Puerto Ayacucho, Venezuela, and in an Experimental Station long-term protected (PS) from fire and cattle raising from more than four decades in Central Llanos, Venezuela, comparison is made with results from similar savannas. Long-term additions of organic manure or a long protection have induced significant changes in the soil physical and chemical properties of the natural savanna (NS) soils that induce a significant increase in the density and biomass of earthworm populations. On the other hand, the protection of the savanna promotes an improvement in the physical and chemical properties of the soil, which favors an increase in the density and biomass of earthworms in the PS compared with the NS subjected to recurrent burning and grazing. The results emphasize the importance of appropriate organic matter management and the relevance of earthworms in such agroecosystems. Full article

(This article belongs to the Special Issue Soil Biology and Its Importance in Soil Fertility)

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Agriculture, Volume 2, Issue 2 (June 2012) – 4 articles , Pages 87-153

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