Growth characteristics, yield attributes, grain yield and quality of rice hybrids as influenced by nitrogen fertilization

An investigation was conducted during the kharif, 2008 to study the effect of nitrogen fertilization on production potential and quality characters of rice genotypes. Among the cultivars tested hybrids PA6201, PHB-71 recorded significantly higher LAI, dry-matter production values at all the growth stages when compared to variety Rajavadlu. Hybrids also showed their superiority in case of yield attributes and yield. These two hybrids PA6201, PHB-71 recorded 19.84%, 15.61% of yield advantage respectively over the variety Rajavadlu. The increased levels of nitrogen from 0 to 225 kg N/ha significantly improved the growth characteristics and yield attributes of rice cultivars, in turn it resulted in higher grain and straw yield with higher levels of nitrogen. The interaction effect between rice cultivars and nitrogen levels on grain yield found to be significant. Among the rice hybrids tested, PA6201 recorded highest grain yield at 225 kg N ha⁻¹ followed by PHB-71. In case of quality characteristics significantly more head rice recovery (63.63%) and amylose content (24.43%) were recorded by PA6201 over PHB-71 which in turn registered significantly greater than that of Rajavadlu. 225 kg N ha⁻¹ recorded appreciable higher values of quality characteristics such as head rice recovery and amylose content over 150 kg N ha⁻¹, 75 kg N ha⁻¹ and Control.