Interrelationship and cause effect analysis among panicle yield attributing traits in lowland Traditional Rice

Sa？etak Yield component analysis provides a framework for identifying potentially useful traits for yield improvement. A field experiment was conducted for two consecutive years to evaluate the forty four low land traditional rice cultivars for twenty three panicle yield and its attributing traits during kharif season at the Zonal Adaptive Research Station, Krishnagar, Nadia, West Bengal, India. Significant varietal differences were observed for all the characters. Among the panicle yield attributing traits, number of primary branches per panicle, number of grains on primary branches panicle-1, number of spikelets on primary branches panicle-1, grain length, grain breadth, grain thickness, kernel breadth, kernel thickness, 100 grain weight, 100 kernel weight correlated significantly and positively with panicle yield both at the genotypic and phenotypic levels. Results of path analysis showed that the direct positive effect on panicle yield was greatest for number of spikelets on secondary branches panicle-1 (0.998) which is followed by number of grains on secondary branches panicle-1 (0.948), grain length (0.755), and number of spikelets on primary branches panicle-1 (0.625), grain thickness (0.392) and fertility % of spikelets on primary branches panicle-1 (0.378). Few characters like number of primary branches panicle-1, number of spikelets panicle-1, by number of grains on primary branches panicle-1 and grain breadth showed negative direct effect on panicle yield even though the genotypic correlation coefficients on panicle yield were positive. The study revealed that the direct selection of the above said traits might be rewarding for panicle yield improvement since they revealed a true relationship with the panicle yield