Influence of irrigation schedule and nutrient-management practice on dry matter accumulation and grain yield of quality protein maize (Zea mays) in new alluvial zone of West Bengal

A 2-year field experiment was conducted during the winter (rabi) season of 2017-18 and 2018-19 at Kalyani Nadia, West Bengal, to study the response of ‘HQPM1’ quality protein maize (Zea mays L.) to irrigation schedule and nutrient-management practice. Three irrigation schedules, viz. irrigation water: cumulative pan evaporation or (IW : CPE) of 0.5 (I₁), 0.75 (I₂) and 1.0 (I₃) constituted main plots and 4 nutrient management practices, viz. control (N₁), 100% recommended dose of fertilizer (120 kg N, 60 kg P₂O₅ and 60 kg K₂O/ha) (N₂), 75% RDF+ 2 t/ha vermicompost (N₃) and 75% RDF + 2 t/ha vermicompost + 25 kg/ha ZnSO₄ (N₄), subplots a split plot design with 3 replications. The results revealed that interaction of an IW : CPE 1.0 and 75% RDF + 2 t/ha vermicompost + 25 kg/ ha ZnSO₄ (I₃N₄) excelled the other treatment combinations in terms of total dry-matter accumulation (1,509.8 g/m²), grain yield (6.76 t/ha), net returns (76,886 /ha) and B : C ratio (2.50). The interaction effect of irrigation regimes and nutrient-management practices on stress degree-days and number of stress-days was insignificant. Both stress degree-days (SDD) and numbers of stress days were significantly and negatively correlated to dry-matter accumulation and grain yield and they showed a polynomial relationship with SDD. Therefore, an interaction of IW : CPE 1.0 and 75% RDF + 2 t/ha vermicompost + 25 kg/ha ZnSO₄ (I₃N₄) can be recommended to the farmers for recording less moisture stress condition and improving dry-matter accumulation, grain yield and benefit: cost ratio of quality protein maize in new alluvial zone of West Bengal.