EFFECT OF ARSENIC ON GROWTH, YIELD AND NUTRIENTS CONTENT OF FIVE BORO RICE VARIETIES

Abstract

A pot experiment was conducted at the net house of Agro-environmental chemistry laboratory of department of Agricultural Chemistry, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during the period from December 2020 to March 2021 to study the effect of arsenic on the growth, yield and nutrients content in straw and grain of rice varieties. Five rice varieties viz. V 1 (BRRI dhan-29), V 4 (BRRI dhan-55) and V 5 ii (BR-16), V 2 (BRRI dhan-28), V 3 (BRRI hybrid dhan-5) were comprised with five arsenic treatment viz. As 0 (control; no arsenic added), As 1

soil), As 2 (10 mg As kg -1 soil), As 3 (20 mg As kg -1 soil) and As 4 (2 mg As kg (40 mg As kg soil) for the present study. The experiment was laid out in Completely Randomized Design (CRD) with four replications. Among different rice varieties, V 5 showed better performance on growth and yield contributing parameters except plant height, leaf length and number of leaves hill -1 . Maximum grain and straw yield (19.5 g hill and 24.70 g hill -1 , respectively) were obtained from V 5 variety whereas minimum grain yield (12.76 g hill -1 ) from V 2 and straw yield (13.79 g hill -1 ) from V 4 was obtained. Arsenic had significant effect on growth and yield contributing parameters of rice and it was observed that higher doses of As showed lower performance on yield and higher As content in grain and straw. In terms of treatment combinations, V 5

showed highest number of panicles hill -1 (10.25), filled grain panicle -1 (143.40), 1000 grain weight (28.63 g), grain yield hill -1 (28.60 g) and straw yield hill (41.00 g) whereas V 3 As 4 showed minimum results. In case of nutrient content, V 5 gave maximum K (0.259%) content in grain but V 5 As 4 showed maximum S content (0.197%) whereas in straw, the maximum P (0.215%), K (1.057%) and S content (0.330%) were recorded from V 1 As 0 , V 2 As 0 and V 5 As 4 , respectively. Increased doses of As adversely affected the growth and yield of rice variety. But V 1 (BR-16) up took minimum As than other varieties and As content increased with increasing doses of it. In terms of treatment combinations, V 3 As 4 gave maximum As content in straw (230 mg/kg) and this treatment combination showed no grain yield that is why the maximum As content in grain (270.00 mg/kg) was found from V 3 As 3 . In case of As uptake, V 2 , V 3 , V 4 and V 5 was increased with the increasing amount of As addition in soil but in case of variety V 1 was not that much increased like other varieties in grain and straw. So, it was found that low or no As was recommended for successful rice cultivation.