Abstract

Montaser Fawzy ABDEL-MONAIM; Mohsen Abdel-Wahab ABDEL-GAID; Hanaa Aiead Haliam ARMANIOUS

Root rot and wilt in tomato caused by Rhizoctonia solani, Fusarium solani and F. oxysporum is one of the most destructive diseases. Effect of some chemical inducers viz. ethephon, hydrogen peroxide (H2O2), mannitol, salicylic acid (SA) at three different concentrations (50,100, 200 ppm) were used to treat tomato seedling by soaking into these to minimize root rot and wilt diseases incidence as well as influence of these chemicals on growth, quantity and quality parameters of tomato plants (cv. Super Strain B) e under greenhouse and field conditions were studied. All the tested chemical inducers significantly reduced root rot and wilt diseases severity either under both greenhouse and field conditions and the efficiency of these compounds increased with increasing concentrations. Mannitol was the most effective inducer for decreasing area under disease progress carve (AUDPC) followed by salicylic acid, while ethephon was recoded as the least effective for reducing AUDPC in greenhouse conditions. However, under laboratory conditions, all tested chemical inducers significantly reduced mycelial linear growth of all tomato root rot and wilt tested fungi compared with control. The highest decrease in linear growth wasobserved in ethephon at 200 ppm followed by SA at 200 ppm. Conversely, F. solani was more affected by chemical inducers than F. oxysporum and R. solani. Under field conditions, the selected chemicals significantly increased tomato growth, yield and quality. Application of mannitol at 200 ppm followed by SA at 200 was the most potent for growth, yield and quality of tomato compared with control. Therefore, tt could be suggested that application of mannitol and SA to treat seedling by soaking could be commercially used for controlling tomato root rot and wilt diseases and increased both quality and quantity of tomato since they are safe, less expensive and effective against these diseases in field conditions.