Managing the Imminent Danger of Rice Blast (<i>Pyricularia oryzae</i> Cav.) and Sheath Blight (<i>Rhizoctonia solani</i> Kühn) Disease: A Critical Review Article

Abstract

Rice is one of the most important crop planted on earth. It provide food and employment for thousands of persons daily through out the world. In Guyana the rice industry is one of the largest user of agricultural lands and contributies more than 20% to the country gross domestic product (GDP). The rice crop is known to suffer from several biotic and abiotic factors. Of which rice blast (P. oryzae) and sheath blight (R. solani) disease identified as two of the most devastating disease affecting the rice cultivation in Guyana. In this context, the present critical review article entitled 'Managing the imminent danger of Rice Blast (Pyricularia oryzae Cav.) and Sheath Blight (Rhizoctonia solani Kühn) Disease' was taken up to look at the most practical disease management approaches available and can be utilized to mitigate the imminent threat pose by the rice blast and sheath blight disease. The review will focus on: disease resistant screening and understand the genotype and environment interactions; study the expression pattern of proteins in resistant and susceptible genotypes against blast pathogen (P. oryzae); examine the efficacy of botanicals, biocontrol agents and new generation fungicides against blast and sheath blight disease under different conditions. This will form a foundation for the exploration of the various disease management stratigies for blast and sheath blight disease.

Population structures of Pyricularia oryzae Cavara in South Sulawesi

“…Blast disease is cosmopolitan, which means it affects rice plants all over the world. Blast disease(P. oryzae) can infect 1,285 million ha of rice fields in Indonesia, accounting for 12% of total rice field areas [5]. This fungus appears because susceptible varieties of the pathogen exist, and it is also influenced by environmental factors and farming practices that use excessive nitrogen fertilizers, as well as high rainfall and humidity [6].…”

“…If the distribution of the dominant P. oryzae race in that area is known, blast disease control will be more effective by using resistant varieties adapted to that race. Because blast pathogenic races have different virulence depending on location and growing season, the dominance of blast pathogenic races in one region allows rice varieties to be resistant in one region but susceptible in another [14]. As a result, monitoring disease severity and the dynamics of P. oryzae population race structures is critical for the breeding and rational distribution of resistant rice varieties.…”