Abstract

Fusarium wilt caused by Fusarium oxysporium f. sp lycopersici is the most serious diseases attacking tomato plants. The objectives of the study were to determine the effects of three types of compost as resistance inducers in tomato plants against F. oxysporium f.sp. lycopersici and to provide new strategies to control the wilt disease of tomatoes. The results demonstrate that different types and rates of compost resulted in significant decreases in percentages of infection and disease severity, compared with those of the control. Compost 2 rate 2 gave the highest reduction of disease by 73.3%, while compost 3. rate 3 gave the highest of disease severity by 78.4% whereas, treatment with the fungicide Topsin M resulted in the lowest reduction, by 46.6 and 45.4%, respectively. Compost 2 rate 2 proved to be the superior treatment as it increased total phenols by 57.9% relative to the untreated control. Compost 1 rate 2 was the best treatment and increased total chlorophyll and carotenoids (5.8 and 4 mg, respectively) in fresh leaves relative to the control. Different types and rates of compost significantly increased the activity of tyrosine ammonia lyase (TAL), peroxidase (POX), polyphenol oxidase (PPO), alkaline phosphatase (ALP) and acid phosphatase (ACP) as defense enzymes against pathogen. These results suggest that broad bean straw compost at rate 10 ton/feddan might have contributed to restriction of invasion of F. oxysporium f.sp.lycopersici in tomato plants, since they are safe, low cost and effective against the disease.

Key words: Fusarium oxysporum f.sp. lycopersici, composts, tomato plants, induced resistance, fungicide, fusarium wilt.