Water–nitrogen relationships for wheat growth and productivity in late sown conditions

摘要: Abstract Field experiments were conducted on a sandy loam soil (Typic Ustochrept) to study the water–nitrogen yield relationships of late sown wheat under adequate and limited water supply conditions. The treatments comprised four levels irrigation ( I 0 , no post-sown irrigation; 1 one at CRI stage; 2 two irrigations, each crown root initiation (CRI) flowering stages; 3 irrigations given CRI, jointing, dough stages) in main plots combination three N (0, 50 100 kg N/ha) zinc as ZnSO 4 ·7H O (0 5 kg Zn/ha) sub-plots split plot design replicated times. Progressive increase from nitrogen 100 kg/ha, increased average leaf area index (LAI), crop growth rate (CGR), relative (RGR) net assimilation (NAR), attributes, biomass grain significantly p  ≤ 0.05) over control ), both seasons, respectively. Analyses by multiple regression techniques reveled that LAI estimates with uptake much higher 84% predictability than estimate based use could account for 75% variations only. Lower consumption seen result less therefore, resulting lower yields irrigation. highest gains 53.1 kg/ha-mm was obtained during 60–90 day period, period fell within maximum phase wheat, followed 28.3 6.7 kg/ha-mm 90–120 0–60 days after sowing (DAS) periods. response above ground (76.6 kg/ha-kg uptake) DAS (22.1 kg/ha-kg uptake). Additive production functions took care stage sensitivity along complete stresses induced through different applications nitrogen. rates commensurate well observed growth. For this reasons, scheduling application ought consider providing relatively quantities compared periods respectively, order provide just sufficient amounts so enhance available required optimum development wheat.