VARIETAL RESPONSE OF RICE GENOTYPES TO DIFFERENT LEVELS OF PHOSPHORUS

Abstract

A field experiment was conducted during kharif 2015 at the research farm of the ICAR–Indian Institute of Rice Research, Hyderabad, to evaluate the response of 30 rice genotypes to four phosphorus levels, viz., P0 (control), P20, P40 and P60. The experiment was conducted in a randomized block design with three replications. Significant variation was observed among genotypes and phosphorus levels for plant height, effective tillers, panicle length, test weight, grain yield and straw yield. Mean plant height increased from 59.72 cm under P0 to 76.29 cm under P40 and P60, while effective tillers increased from 4.34 to 9.56. Mean panicle length increased from 17.72 cm under P0 to 21.76 cm under P60, and test weight increased from 24.11 to 30.70 g. Grain yield increased from 1.34 t ha-1 under P0 to 3.52 t ha-1 under P60, while straw yield increased from 1.63 to 4.24 t ha-1. Among the genotypes, INH12013, PA6444 and DRRH3 recorded higher grain yields under P60, with 5.5, 5.0 and 4.7 t ha-1, respectively. INH12013 also recorded the highest straw yield (6.60 t ha-1) under P60. IET24003 and TRIGUNA recorded comparatively longer panicles, whereas INH10001, PR133 and INH12013 showed higher test weight under different P levels. The results demonstrated substantial genotypic variation in response to phosphorus application and indicated the potential for identifying rice genotypes with superior performance under improved phosphorus availability.