Beneficial effect of Achromobacter insolitus MB20 and manures in reducing Pythium aphanidermatum disease in cucumber

Abstract

Abstract The increased global livestock production, such as chickens, cows, goats, and rabbits causes increased animal waste in both liquid and solid forms. The utilization of animal manures are considered as a beneficial way to minimize the livestock waste problems. Application of manure is advantageous to the soil nutrient balance, soil structure and moisture-holding capacity, and facilitates environmental protection. A combination of biocontrol agent of Achromobacter insolitus MB20 and manures was studied as alternative to chemical fungicides to protect crop from diseases without damaging the environment and human health. The chemical fungicides cannot be used continously and do not represent a sustainable method control. Result showed that an application of A. insolitus alone reduced cucumber damping-off as high as 60%, and in combination of A. insolitus with chicken manure was 80%, goat manure 70%, cow manure and rabbit urine 65%. The in vitro test indicated that A. insolitus inhibited P. aphanidermatum growth by 28%. This antagonist bacterium also produced extracellular enzyme of protease and cellulase with proteolytic index (PI) value was 1.4 and cellulolytic index (CI) value was 1.7. An application of A. insolitus with chicken manure resulted the best combination and the most effective in reducing of cucumber damping-off.