IMPACT OF WATER DEFICIT ON MORPHOLOGY AND YIELD ATTRIBUTES OF HYBRID AND INBRED RICE (Oryza sativa L.) VARIETIES

Abstract

The pot experiment was conducted at the Research Farm of the Department of Agricultural Botany, Sher-e-Bangla Agricultural University, during the period from November 2019 to May 2020 to study the impact of water deficit on morphology and yield attributes of hybrid and inbred rice varieties. The experiment comprised of two factors viz. Factor A: Variety (4), V₁ = BRRI dhan92, V₂ = Heera 4, V₃ = Aloron and V₄ = BRRI hybrid dhan5; factor B: Water deficit (3), T₁ = Control, T₂ = Water deficit at 45–55 days after transplanting (tillering) and T₃ = Water deficit at 85–95 days after transplanting (flowering). The result revealed that V₃ (Aloron) exhibited its superiority to other tested variety Heera 4, BRRI hybrid dhan5 and BRRI dhan92 in terms of seed yield. V₃ (Aloron) out-yielded over V₂ (Heera 4) by 5.08% and V₄ (BRRI hybrid dhan5) by 11.43% higher yield. V₃ (Aloron) also showed the tallest plant at harvest (91.60 cm), highest SPAD value (40.02), the highest number of filled grains panicle⁻¹ (157.56), lowest number of unfilled grains panicle⁻¹ (28.08), the highest weight of 1000-grains (25.30 g), higher straw yield (7.56 t ha⁻¹), the highest biological yield (14.38 t ha⁻¹) and harvest index (47.14%) than other tested varieties in this experiment. On the other hand, the variety V₁ (BRRI dhan92) returned with 17.18% lower yield than variety V₃ (Aloron) which was significantly the lowest compared to other varieties under study. Significant differences existed among different water deficit treatments with respect to yield and yield attributing parameters of rice. A yield advantages of 1.81 t ha⁻¹ and 3.63 t ha⁻¹ was observed from T₁ treatment [Control)] over T₂ [ Water deficit at 45–55 days after transplanting (tillering)] and T₃ [Water deficit at 85–95 days after transplanting (flowering)] treated pot, respectively. The higher amount of yield from T₁ treatment was possibly aided by the tallest plant at harvest (91.81 cm), highest number of tillers hill⁻¹ at harvest (11.68), highest number of leaves hill⁻¹ at harvest (78.73), maximum leaf area index (4.49), highest SPAD value (46.20), higher number of filled grains panicle⁻¹ (167.08), lowest number of unfilled grains panicle⁻¹ (28.90), highest weight of 1000-grains (28.40 g), the highest straw yield (9.23 t ha⁻¹), biological yield (17.36 t ha⁻¹) and harvest index (46.81%). It was observed that water deficit at flowering stage (85–95 days after transplanting) could be move detrimental to rice plant than water deficit at tillering stage (45–55 days after transplanting) and significantly reduced yield attributes and yield of rice. Among the interaction effects, T 2 II

V 3 was superior and comparable to T 1 V 3 in most of the growth and yield attributing parameters along with grain yield. Aloron variety seems promising for combating water deficit in rice field and produces significantly higher yield compared to other varieties.