Slow blasting resistance and rice cultivar heterogeneity in the management of blast (Pyricularia grisea)

Slow blasting resistance studies revealed seven genotypes; HPR 1062, HPR 1064, HPR 1001, HPR 1155, HPR 1009, HPR 977 and HPR 917 as slow blasters based on low values of ‘r’ and ‘AUDPC’. Crop heterogeneity studies conducted on different combinations of resistant (RP 2421), moderately resistant (IR 64) and susceptible cv (Himalaya 2216) showed leaf and neck blast severity significantly reduced in susceptible cv Himalaya 2216 when grown in combination with cultivars RP-2421 and IR 64. Whereas, among mixtures of cultivars, minimum leaf and neck blast was observed in cultivar mixture of IR 64 and RP 2421 planted in the ratio of 1:4 in both the years.