Variation in Morpho-Agronomic Traits of Lowland Rice (Oryza Sativa) Genotypes of Assam in Response to Phosphorus Fertilization

Abstract

The present investigation was conducted with twenty-four genotypes (sub-plot) in two phosphorus doses (main plot) in a split-plot design with three replications during the Sali season (July-December) of 2017 at ICR farm, AAU. The ANOVA for 15 characters studied revealed significant variation between the phosphorus doses (0 and 20\xa0kg P2O5 ha−1) for days to heading and 50% flowering, root length and root volume per hill. A highly significant variation among the genotypes was observed for all the 15 characters. The genotype and phosphorus interaction effects were significant for panicle length, filled grains/panicle, chaffs/panicle, spikelet fertility, 1000-grain weights, root length, root dry weight and root volume. A significant advance in days to heading and 50% flowering along with an enhancement in root length and volume was registered for 20\xa0kg P2O5 ha−1. Among the 24 genotypes, only 7 genotypes, namely Herapoa, Gondhi Biroin, Pankaj, Prabhat Sali, Gheu Bora, Betguti-2 and Tulsi Bora, were categorized as high performing on the basis of total scores worked out of all the characters. Among the 3 diverse variety groups, glutinous genotypes contained the highest number of high yielding and phosphorus efficient genotypes followed by normal Sali, while the aromatic rice had only intermediate types. The genotype Herapoa proved to be highly phosphorus efficient based on mean grain yield and grain yield efficiency index (GYEI). This study proved the presence of P-efficient genotypes among the rice landraces of Assam to be used in breeding for low input or organic farming.