Garlic as a Biocontrol Agent for Sorghum Ergot

Abstract

Ergot (Claviceps sorghi) is a serious limiting factor to the production of sorghum (Sorghum bicolor), specially when its flowering coincides with rains and low temperature (20-22 deg C). In an attempt to control this disease, we tested the efficacy of garlic extracts during 1991-1993 in Andhra Pradesh, India. Crude garlic extract (9%) was the most effective, providing complete inhibition of conidial germination. Prophylactic spray containing 12% of crude garlic extract gave 98-100% control under greenhouse conditions. Under field conditions, the spray gave about 90% ergot control during the post-rainy seasons (February-March) or during non-rainy days of the rainy season. During the rainy season, sprays were less effective. The extract at a concentration of more than 12% was toxic. However, a concentration of 12% and below was non-toxic to pollen germination. Being non-toxic to humans, the extract can be effectively used as an environment friendly method for the control of thisdisease. However, the feasibility of its use is still to be determined.