Influence of plant extracts and microbioagents on physiological traits of faba bean infected with Botrytis fabae

摘要

Laboratory and greenhouse experiments were conducted to assess the efficacy of Eucalyptus citriodora, Ipomoea carnea, Cuminum cyminum, Allium sativum and Hyoscyamus muticus leaf extracts, and Streptomyces exfloliatus (S) and Trichoderma harzianum (7) for controlling Botrytis fabae causing chocolate spot disease of faba bean. Laboratory study supported the use of E. citriodora (Ex 1) and I. carnea (Ex 2) extracts than the others for controlling the growth of B. fabae. S + T was the best for inhibiting spore germination followed by Ex 1 + Ex 2 after 8 h of testing, whereas Ex 1 + Ex 2 produced the lowest percent of germination after 16 h. After 4 days, the inhibiting order of the growth of B. fabae was S + T > Ex 1 + Ex 2 > T > Ex 2 > Ex 1 = S. Greenhouse experiments showed the highest activities of peroxidase, catalase and pectinase in the infected plants. These activities were markedly reduced in healthy plants and widely changed by the biocontrol treatments. Applying biocontrol agents to the infected plants increased minerals (N, P, K and Mg), and both Chl biosynthesis and the photosynthetic activity, which in turn led to accumulation of metabolites. This served the plant to resist the detrimental effects of B. fabae on the plant growth and yield. In this concern, the efficiency of test biocontrol agents seemed to be in the order: T + S > Ex 1 + Ex 2 > T > S > Ex 2 > Ex.