EFFECT OF NUMBER OF SEEDLINGS PER HILL ON SPIKELET STERILITY AND YIELD OF T. AMAN RICE VARIETIES

Abstract

An experiment was conducted at the research field of Sher-e-Bangla Agricultural University during the period from July, 2019 to November, 2019 to investigate the influence of number of seedlings per hill on spikelet sterility and yield of T. Aman rice varieties. The experiment comprised of two factors viz. Factor A: Varieties (3); i) V₁ = BRRI dhan49, ii) V₂ = BRRI Hybrid dhan 6 and iii) V₃ = Biroin; Factor B: Seedlings hill⁻¹ (4); i) S₁ = 1 seedling hill⁻¹, ii) S₂ = 2 seedlings hill⁻¹, iii) S₃ = 3 seedlings hill⁻¹ and iv) S₄ = 4 seedlings hill⁻¹. This experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. Data were collected on different aspects of growth, yield attributes and yield of rice. The result revealed that V₂ (BRRI Hybrid dhan 6) exhibited its superiority to other tested variety BRRI dhan49 and Biroin in terms of seed yield, the former out-yielded over V₁ (BRRI dhan49) by 23.54% higher yield. V₂ (BRRI Hybrid dhan 6) also showed the minimum number of noneffective

tillers hill⁻¹ (0.96), the lowest spikelets sterility (6.61%), lowest number of unfilled grains panicle⁻¹ (4.94), highest weight of 1000-grains (27.55 g), straw yield (7.29 t ha⁻¹), biological yield (13.69 t ha⁻¹) and harvest index (46.73%) than other tested varieties in this experiment. The variety V₃ (Biroin) returned with 32.01% lower yield than variety V₂ (BRRI Hybrid 6) which was numerically the lowest compare with other varieties under study. A yield advantages of 0.07 t ha⁻¹, 0.56 t ha⁻¹ and 0.90 t ha⁻¹ over S₁ (1 Seedling hill⁻¹), S₃ (3 Seedlings hill⁻¹) and S₄ (4 Seedlings hill⁻¹) treated plot, respectively was found which was possibly aided by the lowest spikelets sterility (7.33%), higher number of filled grains panicle⁻¹ (85.60), lower number of unfilled grains panicle⁻¹ (6.87), longer length of panicle (26.33 cm), higher weight of 1000-grains (22.41 g), the highest straw yield (6.91 t ha⁻¹) and biological yield (12.75 t ha⁻¹) in the S₂ (2 Seedlings hill⁻¹) treatment. Treatment S₁ (1 Seedling hill⁻¹) gave similar result with S₂ treatment in some parameters like- plant height at harvest, number of non-effective tillers hill⁻¹, number of filled grains panicle⁻¹, number of unfilled grains panicle⁻¹, spikelets sterility, panicle length, 1000-grain weight, biological yield and harvest index. Treatment S₂ (2 Seedlings hill⁻¹) had 90.82% and 61.13% lesser amount of unfilled grains panicle⁻¹ over S₄ (4 Seedlings hill⁻¹) and S₃ (3 Seedlings hill⁻¹) treatment respectively, which showed that higher number of seedlings hill⁻¹ can produce higher amount of unfilled grains panicle⁻¹, which was supported by higher spikelets sterility in S₄ (4 Seedlings hill⁻¹) and S₃ (3 Seedlings hill⁻¹) treatment (8.14% and 4.86%, respectively) in compare to treatment S₂ (2 Seedlings hill⁻¹). Interactions V₂S₂ and V₂S₁ were superior in most of the growth and yield attributing parameters along with grain yield. Interaction of V₂S₂ (BRRI Hybrid dhan 6 × 2 Seedlings hill⁻¹) performed the best in respect of yield attributing and yield parameters including grain yield. From the result of the experiment, it may be concluded that BRRI hybrid 6 planted with 2 seedlings hill⁻¹ seems promising in rice for higher yield and reducing spikelet sterility.