Effect of Seaweeds on Growth and Yield of Boro Rice (Oryza sativa L.)

Abstract

Introduction: Seaweed extract, an organic bio-stimulant has emerged as a promising tool for increasing crop growth and yield without affecting soil health and environment. Aim: i) To study the efficacy of seaweed extract on growth and yield of boro rice ii) To evaluate the nutrients uptake and residual soil fertility under different treatments iii)To assess the economic viability of using the bio-stimulants in rice production. Study Design:  Seven treatments were laid out inrandomized block design with three replications. Place and Duration of the Study: Boro seasons of 2016-17 and 2017-18 at Instructional Farm of BCKV, Nadia, under new alluvial zone of West Bengal. Methods: Field experiment was carried out in boro (summer) rice (cv. Satabdi) with seven treatments viz., T1-100% RDF (120:60:60 kg/ha N, P2O5 and K2O), T2-100% RDF+ biozyme liquid @ 2.5ml/l of water (seed soaking), T3-100% RDF + biozyme liquid @ 10ml/l of water (root dipping), T4- 100% RDF+ biozyme granule @15 kg/ha (soil application at 15 and 45 DAT)+ liquid @ 625 ml/ha (foliar spray at 15 and 45 DAT), T5-75% RDF + biozyme liquid, T6-75% RDF+ biozyme granule+ liquid  and T7-75% RDF+ amaze-X granule @ 10kg/ha at 45 DAT + biozymegranule + liquid. Results: Results revealed that the maximum grain yield (4.88 t/ ha) was obtained under T7 followed by T4 and T6, however, the net return (Rs.25576/ha) and benefit-cost ratio (1.51) of T6 treatment gave maximum. Conclusion: It may be concluded that T7 treatment performed best in terms of growth and yield of Boro rice but T6 treatment gave the highest B:C ratio and net income which is supposed to be more economical to the small and marginal farmers. Therefore, integrated use of 75% RDF and biozyme soil & foliar application can be recommended for boro rice under new alluvial zone of West Bengal.