Evaluation of Two Biologically Active Compounds for Control of Wheat Root Rot and its Causal Pathogens

Abstract

The main aim of this study is to evaluate the efficiency of two biologically active compounds (Strom and F-760) in control of wheat root rot disease and its causal organisms. Fusarium graminearum, F oxysporum, F solani and Bipolaris sorokiniana were used as target organisms. In vitro, the two compounds showed fungicidal effect on all investigated pathogens resulted in suppression of radial growth and mycelial dry weight of them. Under greenhouse conditions, treatment of wheat grains with either Strom or F-760 before cultivation significantly reduced the percent of disease distribution as well as the mean disease rating of plants in both seedling and flowering stages. Fresh and dry weights of plants as well as water maintenance capacity were increased as the result of applying these compounds as seed dressing. Also data showed that the membrane stability of plants was injured as a result of infection with all investigated organisms, while this injury was alleviated when F-760 and Strom were applied. The K⁺ efflux and the leakage of UV-absorbing metabolites was stimulated with fungal infection. However, F-760 and Storm treatment partially retarded the stimulatory effect on leakage of K⁺ and UV-absorbing metabolites of fungal infected plants. On the other side, the fungal infection had inhibitory effects on pigment fractions (chlorophyll a, b, and carotenoids) biosynthesis in wheat leaves. This retarding effect was partially or completely alleviated as the grains were treated with the applied compounds.

Key Words:

• Biological control
• Bipolaris sorokiniana
• Fusarium spp.
• K⁺ efflux
• Membrane stability
• UV-absorbing metabolites
• Wheat root rot