Use of plant extracts for controlling rice blast and bacterial leaf blight disease

Abstract

Effectiveness of crude extracts from Eupatorium spp. and Curcuma spp. as an alternative method to chemical control were studied. These kinds of plant extracts were tested in the laboratory for their potential to inhibit the mycelial of rice blast disease fungus and cells of bacterial leaf blight which showed 100 percent inhibition. The field experiment was conducted in Phatthalung Rice Research Center in Amphur Muang, Phatthalung during wet season 2004-2006. The experiment was designed as RCB (randomized complete block design) with 5 replications and 4 treatments. The treatments were 1) foliar-sprayed with crude extract from Eupatorium spp. 2) foliar-sprayed with crude extract from Curcuma spp. 3) foliar-sprayed with fungicide benomyl and copper hydroxide for bacterial leaf blight and 4) foliar-sprayed with water as a check. Leb Nok Pattani, Chiang PTL and Chainat 1 rice varieties were sprayed at seedling and tillering stages at 60 l/rai (375 l/ha). The results of experiments indicated that crude extract from Eupatorium spp. could control rice blast disease and crude extracts from Eupatorium spp. and Curcuma spp. could not control rice bacterial leaf blight disease.