الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Botrytis cinerea is a foliar pathogen under natural conditions but survives in soil as a saprophyte or on infected plant debris and can cause systemic infection through roots. The risk of grey mold disease can be minimized by using fungicides, but the problem of adequately protecting plants against the fungus by using fungicides has been complicated by the development of fungicidal resistance and/or adverse effects on growth and productivity of the host plant. Therefore, the present study aimed to replace the undesirable and unsafe chemical control by other safe, effective, persistent, economic and natural options for grey mold disease control. The evaluated antagonistic fungi were Trichoderma harzianum, Trichoderma hamatum, Trichoderma viride, Gliocladium roseum and Gliocladium vireins. Chitosan was tested at three concentrations 0.1, 0.2 and 0.3%. It was noticed that all treatments significantly reduced grey mold incidence in cucumber plants comparing with untreated plants. Among all tested antagonists, Trichoderma harzianum and chitosan 0.3% were better than others in inhibiting disease incidence and improving plant defense against the pathogen. Chitosan treatments did not show antimicrobial activity against Botrytis cinerea isolates in vitro, however, when it used as a foliar spray on greenhouse it showed a highly significant control level of grey mold disease. According to the obtained results from the current study, it could be suggested that the application of antagonistic fungi and chitosan might be an easily applied, safely and cost effective alternative control method to chemical control of grey mold of cucumber. Inspite of B. cinerea infection reduced growth parameters, yield component, photosynthetic pigments, total phenol, carbohydrates, peroxidase enzyme and other metabolic activities of cucumber, a significant increase in the previous parameters was observed in cucumber plants treated with these bioagents. Also a significant decrease in disease incidence and disease severity was observed in the treated plants.