Effect of nutrient levels and nutrient schedules on physiological parameters and grain yield of upland rice intercropped in coconut garden

Abstract

The experiment was conducted at Coconut Research Station, Balaramapuram with an objective to study the effect of nutrient levels and nutrient schedules on physiological parameters and grain yield of upland rice (MO 21- Prathyasa rice variety) intercropped in coconut. Field experiment was conducted in factorial randomized block design with nutrient levels as first factor and nutrient schedules as second factor in three replications. Nutrient levels had significant effect on the physiological parameters. Among the nutrient levels rested, NPK applied @ 120:30:60 recorded higher total chlorophyll (2.803 mg g-1) and chlorophyll b content (1.508 mg g-1), crop growth rate (CGR) (11.23 g m-2 day-1) and relative growth rate (RGR) (0.056 g g-1 day-1) as compared to lower nutrient level tested, NPK @ 60:30:30 kg ha-1. Nutrient schedules also had significant effect (P=0.05) on the physiological parameters viz., total chlorophyll, chlorophyll a, chlorophyll b, CGR and RGR and the treatment receiving 0.2 per cent zinc sulphate and 0.04 per cent sodium borate spray at 45 DAS recorded higher chlorophyll content, RGR and CGR. Though the higher nutrient level, NPK @ 120:30:45 kg ha-1 recorded higher values for physiological parameters, it recorded the lowest grain yield. Application of NPK @ 90:30:45 kg ha-1 recorded the highest grain yield and it was followed by NPK applied @ 70:30:35 kg ha-1. Among the nutrient schedules, N applied as three equal splits, P as basal and K in two equal splits along with foliar spray of zinc sulphate 0.2 per cent and sodium borate 0.04 per cent at 45 DAS recorded the highest grain yield (3.25 t ha-1). The study clearly revealed that excessive vegetative growth is not a desirable parameter for higher grain yield.