Abstract

A field experiment was ocnducted to investigate the efficacy of a few growth regulators / botanicals / chemicals on alleviating low irradiance stress in rice (Oryza sativa L.) High LAI, increased accumulation of chlorophylls, higher soluble protein content and higher NRase activity were evident in the treated plants resulting in increased biomass accumulation. Increased number of spikelets and reduciton in spikelet sterility contributed to higher yield. Brassinosteroid treatment recorded highest yield (4.76 t ha-1) followed by salicylic acid (4.62 t ha-1), coconut water (4.40 1 ha -1) and diammonium phosphate (4.32 t ha-1) as against the lowest of 3.46 t ha-1 in control.

Keywords: Rice, Low irradiance, Growth regulators. Botanicals, Brassinosteriod, Stress alleviation, Photosynthesis, Yield.