botrytis cinerea

Diseases are a major cause of post-harvest losses depending on season, region and management practices. Chemical control is the most used but with serious consequences for human health and the environment. This forces us to carry out more exhaustive studies on botanical products. The general objective of the present study was to evaluate the effect of citrus extracts for the control of pathogens that cause post-harvest diseases in tomato fruit. The product to be evaluated is of botanical origin from citrus extracts. Doses were evaluated (0, 666, 1000, 2000, 4000, 8000 ppm). The treatments were located at a temperature of 25°C±2 and 45% relative humidity (rH). The design used corresponded to a completely random design. The least significant difference was estimated by Tukey Multiple Range test at P=0.05. The statistical tests were performed through the SAS computer program. The results indicate that the pathogens detected and identified correspond to Alternaria tenuissima; Botrytis cinerea; Cladosporium fulvum; Colletotrichum coccodes; Fusarium oxysporum; Geotrichum candidum; Rhizopus stolonifer and Stemphylium macrosporoideum. Our conclusion is that the efficient doses correspond to 666, 2000 and 8000 ppm. With the application of citrus extracts, the damage percentage of tomato fruit was reduced in relation to the control treatments. Based on the results with the application of citrus extracts, the shelf life of the tomato was lengthened.

Gray mold disease, caused by the fungus Botrytis cinerea, causes heavy losses in strawberries. The use of chemical fungicides due to the dangers for humans and the environment has caused attention to reduce their consumption and use biological methods. In this research, the effects of zinc oxide, copper, and silver nanoparticles have been synthesized from an aqueous extract of cloves, and the probiotic bacteria Lactobacillus casei by the green method was investigated on the gray mold disease of strawberries. The results showed that concentrations of 10% of zinc oxide nanoparticles synthesized from aqueous extract of cloves can completely control this pathogen on the culture medium and the fruit. Zinc and silver nanoparticles produced by Lactobacillus casei prevented 93.7% and 81% of fungal growth in the culture medium, respectively. Other treatments did not show a good inhibitory effect on the fungus. All treatments were able to prevent 100% to 50% of fungal growth after 96 hours on strawberries. The investigation of the storage characteristics showed the positive effect of the examined nanoparticles on reducing the rate of change of the physicochemical characteristics of the strawberry fruit tissue. Apparent decay was significantly reduced and samples treated with nanoparticles scored higher in sensory evaluation compared to control. Also, investigating the toxicity of nanoparticles in this experiment on the HepG2 cell line showed that Compared to the control, copper and zinc nanoparticles did not have significant toxicity on cells, but silver nanoparticles led to 25% cell death. This research provides promising results in the field of using nanoparticles for pre-harvest and post-harvest control of plant diseases.

Background information: Cultural practices play an important role on the development of pathogens (Datnoff, et al. 2007). In this context, several authors have been interested in studying the effects of mineral nutrition on the resistance of vegetables and fruits to fungi during storage, especially nitrogen.The purpose of the study: In this work we tested the effects of three contrasted regimes of nitrogen supply, with nitrate concentrations in the nutrient solutions of 2 mM (low), 10 mM (normal) and 20 mM (high) on the susceptibility of Lactuca sativa L towards Botrytis cinerea (BC87) and Sclerotinia minor (SM) during storage.Once harvested, the outerleaves of the plants derived from the three nitrogen regimes were inoculated with either Botrytis cinerea (BC87) or Sclerotinia minor (SM). Data showed that the resistance to this two pathogens increase when plants were developed under low nitrogen concentration. This resistance observed is correlated with low values in oxidative stress indicators (MDA and H2O2) and high values in total phenols.