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Disease Note.

Recent Epidemics of Rice Blast in India and Egypt. A. P. K. Reddy, Directorate of Rice Research, Rajendranagar, Hyderabad 500 030, India. J. M. Bonman, International Rice Research Institute, P.O. Box 933, Manila, Philippines. Plant Dis. 71:850. Accepted for publication 11 May 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0850E.

Severe epidemics of blast caused by Pyricularia oryzae Cav. have occurred recently on rice (Oryza sativa L.) in India and Egypt. During the wet and dry seasons of 1984 and 1985, Indian Directorate of Rice Research survey teams recorded blast on 120,000 ha in the states of Andhra Pradesh, Karnataka, and Tamil Nadu. Cultivars affected were improved introduced IRSO, traditional introduced Intan, and improved locally developed NLR9672, Tellahamsa, and TKM9. Because of their susceptibility to blast, these cultivars are being replaced. Yields in these states are about 3 tfha over a harvested area of 7 million ha. State department of agriculture production figures indicated a total loss from blast of 140,000 t. In Egypt, yields exceed 5 tfha. Improved introduced Giza 173 (Reiho), grown on about one-fourth of the rice area (100,000 hal in 1984, was badly damaged by blast. Late-sown fields were totally lost. Yields from demonstration fields indicated the average loss in Giza 173 was about 50%. Locally developed Giza 171 and Giza 172, although susceptible to Egyptian races of P. oryzae, were only mildly affected. These outbreaks emphasize the need for continued research on all aspects of blast management, particularly disease resistance.