A successful infection is indicated by the appearance of smut balls in rice panicle, which usually takes about 20 days after the infection to occur. Rice false smut disease causes yield loss and reduces grain quality. The yield losses have been attributed to not only the smut ball incidence but also the chaffiness and reduction in 1000- grain weight [8], and the rice grain quality is reduced much by fungal contamination. Thus, the smut balls must be removed before rice sale in many countries as the rice grains that are contaminated with spores of U. virens cannot be parboiled, and the resulting product is discolored and toxic to humans and live stock.