EFFECT OF MICRONUTRIENT ZINC ON THE PERFORMANCE OF MODERN RICE VARIETIES

Abstract

The experiment was carried out during the period from December 2020 to May 2021 at the research field of the Bangladesh Rice Research Institute, Regional Station, Sonagazi, Feni, Bangladesh. The experiment consisted of two factors: Factor A: eight Zn levels viz. T 1

(Recommended rate: N, P, K, S and Zn (monohydrate) @ 124, 22, 75, 20 and 4 kg ha ), T 2 (T 1 – 50% Zn), T 3 (T 1 – 100% Zn; T 1 but without Zn), T 4 (T 1 + 50% higher Zn; ZnSO 4 : 13.20 kg ha -1 ), T 5 (T 1 + 100% higher Zn; ZnSO 4 : 15.40 kg ha -1 ), T 6 (T 1 but Zn was applied by spraying), T 7 (Soil test based (STB) nutrient rates N, P, K, S and Zn @ 158, 24, 82, 10 and 2 kg ha -1 ) and control treatment T 8 (control/native supply of nutrient; no nutrient was applied) and Factor B: three rice varieties viz. V 1 (BRRI dhan74), V 2 (BRRI dhan84) and V 3 (BRRI dhan88). The experiment was laid out in Strip Plot Design with three replications. Among different levels of micronutrient zinc (Zn) treatments, the longest plant height (90.4 cm), maximum number of tillers m -2 (472), panicles hill -1 (11.6), and panicles m -2 (385); and highest grain yield (5.28 t ha -1 ) were recorded in the treatment T 5 + 100% higher Zn; ZnSO 4 :15.4 kg ha -1 ) and this treatment also showed highest Zn content in grain (0.136 ppm), however the highest Zn content in straw (0.403 ppm) was acquired from T 6 (T 1 but Zn was applied by spraying). Again, the treatment T 1 (Recommended rate: N, P, K, S and Zn @ 124, 22, 75, 20 and 4 kg ha -1 1 (988) and 1000-grain weight (23.4 g). Control treatment T 8 ) gave the highest number of grains hill (no nutrient was applied) gave least performance for the respected parameters. Among three rice varieties, the highest number of tillers m -2 (446) and grains hill -1 (920) were achieved by V 3 (BRRI dhan88), while the maximum number of panicles m -2 (369) and the highest mean grain yield (4.56 t ha -1 ) were produced by V 1 (BRRI dhan74). Moreover, different varieties showed nonsignificant variation on Zn content in grain and straw. Considering the combined effect of

Zn treatments and variety, the highest number of panicles m -2 (425), 100-grain weight (27.1 g) and highest grain yield (5.73 t ha -1 ) were observed in T 5 V 1 . In case of Zn content of grain and straw, the maximum (0.218 and 0.573 ppm, respectively) were found in T 5

and T 6 V 3 , respectively, whereas T 8 V 2 gave the minimum Zn content in grain and straw (0.046 and 0.088 ppm, respectively). Based on overall performances, it could be concluded that the treatment T 5 (T 1 + 100% higher Zn; ZnSO 4 : 15.40 kg ha -1 ) might be recommended for sustainable cultivation of modern rice varieties to obtain higher yield and better Zinc content.