Performance of Four Aman Rice Varieties Under Different Phosphorus Levels in The Tidal Saline Condition of Satkhira District

Abstract

An experiment was conducted during aman season from June to December 2008 in a shrimp farm of the village Chhotokupot in Shyamnagor upazila of Satkhira District to evaluate the response of two high yielding and two local rice varieties to phosphorus. The soil was low in phosphorus, medium in nitrogen and high in organic matter. The experiment was laid out in a factorial Randomized Complete Block Design (Factorial) with three replications. Four aman rice varieties viz, V₁= BR 23, V₂ =BRRI dhan 41, V₃= Kalo dhan and V₄= Patnai dhan with four levels of phosphorus viz., P₁ = 0 kg P₂O₅ ha⁻¹, P₂ = 30 kg P₂O₅ ha⁻¹, P₃ = 60kg P₂O₅ ha⁻¹ and P₄ = 90 kg P₂O₅ ha⁻¹ used in the present study. Among the four varieties, BRRI dhan 41 produced highest panicle length (25.10 cm), total grain per panicles (113.50), filled grain per panicles (95.72), highest grain yield (3.59 t ha⁻¹) and highest harvest index (45.55 %). The results revealed that the effect of phosphorus was differed significantly. Among the four treatments, application of 90 kg P₂O₅ ha⁻¹ produced tallest plant (105.98 cm), total tiller per hill (15.65), maximum dry matter (428.93 g / m²), highest effective tiller hill⁻¹ (11.66), highest panicle length (24.60 cm), total grain per panicles (105.40), filled grain per panicles (82.95), thousand grain weight (24.21 g), the highest grain yield (3.65 t ha⁻¹), straw yield (4.64 t ha⁻¹), biological yield (8.29 t ha⁻¹) and highest harvest index (44.13 %). The interaction effect of variety and phosphorus was varied significantly for effective tiller hill⁻¹, panicle length, total grain per panicles, filled grain per panicles, grain yield. The highest effective tiller hill⁻¹ (14.20) was recorded from local patnai dhan and 90 kg P₂O₅ ha⁻¹ treatment combination. The highest panicle length (25.73 cm) and total grain per panicles (116.40), filled grain per panicles (99.37) and highest grain yield (3.76 t ha⁻¹) was recorded from BRRI dhan 41 and 90 kg P₂O₅ ha⁻¹ treatment combination. The interaction effect of variety and phosphorus was not varied significantly for plant height, total tiller per hill, dry matter m⁻², 1000 grain weight, straw yield, biological yield and harvest index. The highest plant height (113.40cm) and dry matter (439.98 g m⁻²) were recorded from patnai dhan and 90 kg P₂O₅ ha⁻¹ treatment combination. The highest total tiller per hill (19.60), straw yield (5.11 t ha⁻¹) and biological yield (8.40 t ha⁻¹) were recorded from kalo dhan and 60 kg P₂O₅ ha⁻¹ treatment combination. The highest harvest index (45.88 %) was obtained from BRRI dhan 41 and 90 kg P₂O₅ ha⁻¹ treatment combination. From the present study it may be concluded that local kalo dhan performed better in case of growth characters and BRRI dhan 41 performed better in case of yield and yield attribute characters. 90 kg P₂O₅/ha application performed better in both cases i,e growth and yield and yield attribute characters but economically 60 kg P₂O₅/ha application was better because they were statistically similar to all parameters in both cases. So, BRRI dhan 41 can be selected for cultivation in the tidal saline condition in the shrims farms in the aman season. 60 kg P₂O₅/ha was found suitable as optimum dose for economic view point for the cultivation of the selected varieties.