RESPONSE OF RICE VARIETIES AGAINST THE INFECTION OF CERCOSPORA ORYZAE MIYAKE UNDER CONTROLLED ENVIRONMENTAL CONDITIONS

Abstract

Research trials on commercially important rice varieties were conducted to assess their response against the narrow brown leaf spot (NBLS) disease at the research area of Plant Pathology Department, University of Agriculture, Faisalabad, Pakistan during the year 2018 and repeated in 2019. For the sake of experimentation, Rice Research Institute Kala Shah Kaku (RRIKSK) Sheikhupura provided the germplasm of ten rice varieties that farmers frequently used for cultivation. The seeds of rice varieties were sown in pots with a completely randomized design under controlled environmental conditions. The lower, middle, and flag leaves of five plants from each replication were tagged, and the percent severity of narrow brown leaf spot disease was recorded and analyzed by statistical computer software GenStat (10th Edition). The means of percent disease severity on different rice varieties were compared by Fisher’s protected least significant difference test at a 5% significance level. The simple main effects of rice varieties and years on the development of narrow brown leaf spot disease were significant, but their interactions were non-significant. The disease severities were enhanced during the year 2019 as compared to 2018 on the same rice varieties. Minimum disease severity was detected on the plants of rice variety Basmati-515 (1.67%) and maximum on rice variety PK1121 (81.00%). The second-highest level of susceptibility was found in the variety KSK-133 (67%) and ranked as very highly (VHS) susceptible. The variety B-Ksn (43.67%) was found highly susceptible. The varieties B-Chb (21.17%) and KSK-434 (22.50%) were statistically at par and found mildly resistant. Different rice varieties have different genetic response against the NBLS disease development. So, evaluating rice varieties against the infection of narrow brown leaf spot disease is the need of time for breeders for their breeding programs. The cultivation of resistant rice varieties is cost-effective for farmers regarding disease management.