Efficacy of Chitosan and Salicylic acid for Controlling Gray mold Caused by Botrytis cinerea on Greenhouse Tomato

Application of Chitosan (CH) and salicylic acid (SA) in controlling the fungus Botrytis cinerea that causes gray mold on tomato fruits is a successful safe alternative approach to chemical pesticides. were applied as Pre-harvest treatment at concentration 2000 mg/l 250 mg/L under field conditions three different ripening stages Turning, Pink, Light Red determine best stage for application. The was determined enhancing plant defenses against pathogen studying effect factors levels some enzymes related induction resistance, such peroxidase enzyme POD PAL enzyme. application SA CH had significant increasing activity level both enzymes, with revealed an increase treated plants fruit maturity (Turning, red), where 17.33, 16.72 15.5 min /gm. enzyme, it recorded 12.27, 12.12, 12.1 min/gm fresh weight, affected which 32.27, 31.53, 31.87 mg/gm stages, respectively. did not differ extending shelf life reducing losses depending rate healthy end storage period 25°C. mg-1/L differed significantly from other concentrations inhibiting pathogenic fungus, well salicyac superior its effectiveness compared concentrations. However, chitosan biofilm formation B. cinerea, displayed average absorption degree 0.53 (OD), while affect fungal formation, 1.2 (OD) control treatment.