Overview on the Chemical Control of Rice Blast Disease

Abstract

Rice blast disease is the most serious and damaging of all the plant diseases in rice production in such temperate and humid climate like that of Japan, which resulted in the development of many excellent chemicals for this particular disease, e.g., blasticidin S, kasugamycin, iprobenphos (IBP), edifenphos (EDDP), isoprothiolane, ferimzone, and metominostrobin. These chemicals mostly act on the growth of M. oryzae by exhibiting specific fungicidal effects on the pathogen. The wide use of these site specific chemicals sometimes causes development of resistance in the pathogens. In fact, resistance against kasugamycin and organophosphorus thiolate fungicides were recognized in the field where they were too intensively used. Solutions to the problem were contrived for the effective use of the chemicals at hand, such as application of mixtures with different action mechanisms or their use in rotation. While all modern fungicides are developed through extensive safety evaluation, there is a deep public concern about their side effects on non-target organisms and on the environment.