GROWTH, YIELD COMPONENTS, AND YIELD ASSCOCIATIONS IN RICE GROWN ON LOWLAND SWAMP

Knowledge on trait associations plays an important role in determining the effectiveness of a selection program
for improving rice yield performances. This study was conducted to estimate the correlation among growth, yield
components, and grain yield of rice grown on inland swamp environment. Experiment was laid on inland swamp
area with > 50 cm peat thickness. Five rice varieties, comprising four local Bengkulu rice varieties (Hanafi,
Harum Curup, Batubara, and Lubuk Durian) and a released variety (Inpara 3) were evaluated in a randomized
block design with three replications. Data were collected for plant height, leaf area, relative growth rate, net
assimilation rate, total tiller and productive tiller numbers, panicle length, grain number panicle-1, and grain yield plant-1. No significant difference was found among the varieties for all observed trait. Grain yield plant-1 had strong positive correlation (r > 0.60) with leaf area, total tiller and productive tiller numbers, moderate positive correlation (0.36 < r < 0.39) with plant height, relative growth rate, and panicle length, but weak negative correlation (r = -0.26) with net assimilation rate. Path analysis revealed that the highest positive direct effect on grain yield plant-1 was exhibited by productive tiller number (p = 0.54), followed by grain number panicle-1 (p =
0.43) and relative growth rate (p = 0.37). Present findings suggested that rice grain yield grown on lowland
swamp can be improved by indirect selection favoring higher productive tiller number and higher grain density in a panicle.