EFFECTS OF CALCIUM SUPPLEMENTATION ON GROWTH, YIELD AND NUTRIENT CONTENT OF TWO RICE CULTIVARS UNDER DIFFERENT SALINE CONDITIONS

Abstract

A pot culture experiment was conducted from January to June, 2015 at the net house of the Department of Agricultural Chemistry, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh to study the effect of supplemental calcium (Ca) for amelioration of salinity and improve the growth of rice. The three factorial experiment composed of Factor A: two selected rice varieties (Binadhan-8 and BRRI dhan29). Factor B: 4 salinity levels (0, 4, 8 and 12 dSm4) and Factor C: 3 levels of Ca supplement (0, 5 and 10 mM). Due to varietal effect; highest panicle length (24.34 cm), 1000-grain weight (20.09 g) and grain yield hill4 (22.74 g) were found in Binadhan-8. Plant height, number of total tiller hill', panicle length, number of spikelet panicle4, number of filled grains panicle', root thy weight, shoot dry weight, total dry weight, 1000-grain weight and grain yield hilP' increased up to 4 dSm4 and then decreased afterwards. 1000-grain weight and grain yield bill4 increased with increasing calcium (Ca) supplement while non-effective tiller hill4 and unfilled grains panicle4 decreased. With the increase of salinity, parameters showed negative trend in most of the cases in both varieties. Reduction of yield (from control salinity) at highest salinity level is higher in BRRI dhan29 (26.51 to 8.109 g hilP') than Binadhan-8 (25.78 to 11.28 g hill4). As the Ca level increased. 1000-grain weight and grain yield hill' increased but non-effective tiller bill4 and unfilled grains panicle' decreased in both varieties. At every salinity level, 1000-grain weight and grain yield hilN increased with the increase of Ca while non-effective tiller hill4 and unfilled grains panicle" decreased. Interaction of variety, salinity and calcium significantly affected all the parameters studied. Each of the variety showed significant reduction in growth and yield parameters including 1000-grain weight and grain yield hill' due to higher salinity level (except at 4 dSnr') while Ca supplementation had significant positive effects on these parameters at every salinity level. Binadhan-8 showed highest yield (13.48 g hilP') in maximum salinity level with 10 mM calcium (Ca) supplementation compared to BRRI dhan29 (10.11 g hill-'). In each variety, at every salinity level, K and Ca content in shoot increased with increasing calcium (Ca) supplement while Na content decreased. But Binadhan-8 showed higher K (1.52%) and lower Na (1.29%) content in highest salinity level with 10 mM calcium (Ca) supplement compared to BRRI dhan29 (0.73% K and 2.45% Na, respectively).