Assessing the Effects of Structural Arrangements and Seedling Densities on the Growth and Yield-contributing Parameters of Boro Rice
Chandni Khatun
Department of Agronomy and Agricultural Extension, University of Rajshahi, Rajshahi, Bangladesh.
Md. Arifur Rahman
Department of Agronomy and Agricultural Extension, University of Rajshahi, Rajshahi, Bangladesh.
Md. Mejbah Uddin *
Department of Crop Science and Technology, University of Rajshahi, Rajshahi, Bangladesh.
*Author to whom correspondence should be addressed.
Abstract
Planting geometry and the number of seedlings per hill may influence the growth and yield of transplanted Boro rice. A field experiment was conducted at the Agronomy Field Laboratory, University of Rajshahi, Bangladesh, from December 2022 to May 2023 to assess the individual and combined effects of these factors on BRRI dhan28. The experiment used a 4 × 4 factorial randomised complete block design (RCBD), comprising four structural arrangements (A1: 25 cm + 25 cm, A2: 20 cm + 30 cm, A3: 15 cm + 35 cm and A4: 10 cm + 40 cm) and four seedling densities (S1: 1 seedling hill-1, S2: 2 seedlings hill-1, S3: 3 seedlings hill-1 and S4: 4 seedlings hill-1) with 3 replications. The structural arrangement A1 (25cm+25cm) recorded the highest values for most parameters, including plant height (89.17 cm), total tillers per plant (18.80), effective tillers per plant (15.27), panicle length (22.36 cm), panicle weight (14.35 g), spikelets per panicle (184.72), grains per panicle (144.11), filled grains per panicle (124.29), grain yield (5.42 t ha⁻¹), straw yield (7.02 t ha-1), and biological yield (12.44 t ha-1). With respect to seedling density, treatment S3 (3 seedlings per hill) resulted in the highest values, including plant height (90.20 cm), number of tillers per plant (19.11), number of leaves per plant (15.50), effective tillers per plant (15.69), panicle length (23.33 cm), panicle weight (15.42 g), spikelets per panicle (196.15), grains per panicle (149.33), filled grains per panicle (130.57), grain yield (5.79 t ha-1), straw yield (7.39 t ha-1), and biological yield (13.18 t ha-1). The results showed that A1 and S3, both individually and in combination, produced the highest values for most of the measured parameters. These findings emphasise the importance of optimising both planting arrangement and seedling density for improving the growth, resource efficiency and yield potential of Boro rice. The study offers agronomists and rice farmers a potential approach to improving Boro rice productivity under the experimental conditions, namely a 25cm + 25 cm arrangement with three seedlings per hill.
Keywords: Boro rice, structural arrangement, seedling number, yield components, grain yield, resource use efficiency, sustainability