Efficacy of aqueous extract of Agavae Sisalana on rice leaf blight caused by Magnaporthe grisae Barr

A test on the efficacy of aqueous extracts of Agave sisalana roots on rice leaf blast caused by the fungus Magnaporthe grisae was conducted under controlled inoculation condition as a curative treatment and under natural infection condition as a preventive treatment. Under artificial inoculation condition, a mixture of several isolates of M. grisae obtained from infected leaf samples of is used to inoculate the plants. Rice seedlings transplanted into pots from a susceptible variety were inoculated with these isolates and treated 7 days after inoculation with the aqueous extract at different concentrations compared to the effect of a synthetic fungicide Azox 250 SC. The results showed that the aqueous extract slowed down the progression of the disease at all concentrations. However, at 14 and 21 days after the first application, the 3% and 20% concentrations did not stop the disease. A second treatment is required to limit the disease. On the other hand, the 30% and 50% concentrations control the disease. A second treatment is required. The 30% and 50% concentrations control the disease.