EFFECT OF PLANT SPACING AND GENOTYPE ON GROWTH, YIELD, AND YIELD-RELATED TRAITS OF RICE VARIETIES

Plant spacing and genotype have an impact on rice productivity. From June to November 2019, a field experiment was conducted at Rampur, Chitwan, Nepal, to assess the effects of plant spacing and genotype on growth and yield traits of rice. Twelve treatments were laid out in a split-plot design with three replications, consisting of four rice genotypes (OR, Sabitri, Sunaulo Sugandha, and Sugandhit-1) in sub-plots and three plant spacings (20 cm × 15 cm, 20 cm × 20 cm, and 20 cm × 30 cm) in main-plots. Plant height at harvest was found to be similar among all spacings, whereas the tallest plant height (106.21 cm) was found in Sugandhit-1. Leaf area index, at 75 DAT (days after transplanting), was found the highest (3.50) at the spacing of 20 cm × 15 cm and Sabitri (3.56), followed by Sugandhit-1 (3.37). At the spacing of 20 cm × 15 cm, the highest values of no. of effective tillers per m2 (240.87) and spike sterility percentage (22.92%) were found. Sugandhit-1 had the longest panicle length (29.04 cm), the heaviest panicle weight (5.83 g), and the highest number of grains per panicle (171.38) as compared to other genotypes. Similarly, the spacing of 20 cm × 20 cm resulted in the highest grain yield (5.31 t ha-1) and biological yield (11.05 t ha-1). Sugandhit-1 produced the highest grain yield (5.52 t ha-1) and biological yield (11.15 t ha-1) followed by Sabitri (grain yield; 5.39 t ha-1 and biological yield; 10.95 t ha-1). The interaction effect of spacing of 20 cm × 20 cm and genotype namely Sugandhit-1 resulted in the highest grain yield (6.65 t ha-1), which was similar to the interaction effect of spacing 20 cm × 20 cm and genotype namely Sabitri (6.08 t ha-1). As a result, spacing of 20 cm × 20 cm and genotypes such as Sugandhit-1 and Sabitri are found to be best-suited genotypes for maximizing rice production in Chitwan and similar environments.