5300
MOHAMED SAIED ALI HASSAN KHALIL
NEW APPROACHES FOR CONTROLLING POSTHARVEST DISEASES OF GREEN BEAN PODS
Green bean plants - White rot disease - Essential oils - potassium sorbate – sodium benzoate -salicylic - sorbic acids -chitosan
Green bean (Phaseolus vulgaris L.) is considered one of the most important leguminous crops cultivated in Egypt for both local consumption and exportation. White rot disease caused by Sclerotinia sclerotiorum is the most important disease attack green beans pods under pre, post-harvest and storage conditions. Pathogenicity tests indicated that all isolates of S. sclerotiorum caused highest infection in green bean pods. Under laboratory conditions, complete inhibition of linear growth of S. sclerotiorum was obtained with Black seeds, citronella, oils, potassium sorbate sodium benzoate, salicylic and ascorbic acids at 0.25 %. While, Citral and Lemongrass at 0.5 %. At concentration of 4.0 g/L of chitosan completely inhibited the linear growth of pathogenic fungus. Pre-harvest spraying of bean plants under field conditions with citral, black seed oils , potassium sorbate , ascorbic acids and sorbic acids gave less percentage of white rot disease incidence and severity of green bean bods under different storage conditions. Postharvest experiments, indicated that ascorbic acid was the most effective treatment among the tested acids where it achieved better reducing the disease incidence and severity on green bean pods at two degrees (at 5±1and 20±1°C) followed by salicylic acids after storage green bean pods at 20±1°C.While, potassium sorbate recorded 74.20% reduction ratio in disease incidence and reduced disease severity by 81.47%. Green bean pods treated with Black seed and Lemon grass oils after harvest were the most effective treatments which reduced the disease incidence and severity of S. sclerotiorum during storage at two degree (5±1°C and 20+1oC). Thyme oil was the most suppressive treatment against white rot of green bean pods which reduced the disease incidence and severity by 75.93 and 76.70% respectively. Moreover, combined treatments between chitosan and ascorbic acid, salicylic acid, potassium sorbate, sodium benzoate, black seeds and lemon grass resulted in reducing white rot incidence and severity of green bean pods under different conditions.
2017
Ph.d
Suez Canal
Agriculture