Chemicals for the Management of Paddy Blast Disease

Blast disease of rice caused by Magnaporthe oryzae has remained to be the biggest threat for rice production across the world. Several strategies such as cultural, biological, host plant resistance, chemical and integration of different strategies have been developed to manage this devastating disease in farm situations. Poor bio-efficacy of biocontrol agents, limited availability of resistant cultivars in desired varieties and continuous evolution of pathotypes have forced the rice farmers to depend much on fungicides for minimising the yield losses caused by blast disease. Several molecules with the diverse mode of action have been developed and registered against blast disease since the 1960s, and the work is being carried out continuously in search of better molecules. Compared to the fungicides developed in the 1970s, present-day fungicides are better in terms of higher efficacy and lower environmental impacts. In this chapter, we attempt to summarise all the chemicals developed and recommended for the management of paddy blast. This chapter also includes some of the novel chemicals which interfere with the infection process without causing any toxicity to the pathogen, and also those that trigger resistances in rice plants against blast disease.