EFFECT OF WATER STRESS ON GROWTH AND YIELD OF RICE (Oryza sativa L.)

Abstract

It is generally known that drought affects rice production in Northern Ghana, which has negative impact on productivity of rice yield and food security. Over 200 million tonnes of rice is lost annually through adverse environmental conditions such as water stress. Farmers require modern cultivar such as aerobic rice to improve crop performance in areas where there is limited and irregular rainfall pattern. In an attempt to identify drought tolerant rice variety, pot experiments were conducted at the experimental site of the University for Development Studies, Nyankpala to investigate the responses of seven exotic and two local accessions of rice under different moisture conditions during the periods, starting from December 2016 to May 2017 and January 2018 to May 2018. Nine genotypes of rice DKA 23, DKA 21, DKA-M8, GBEWAA, AGRA, UPL RI 7, IR 55419-04, IR 79913-B-179-B-4 and APO were evaluated under 100% Crop Water Requirement, 100% Crop Water Requirement-Split, 80% Crop Water Requirement and 60% Crop Water Requirement. The study was laid out in a 9 x 4 factorial experiment in Randomized Complete Block Design (RCBD) with three replications. Rice plants cultivated under 100% Crop Water Requirement and 100% Crop Water Requirement split recorded a relatively better growth parameters compared to 80% Crop Water Requirement and 60% Crop Water Requirement. Also, number of tillers, number of leaves, number of panicles, grain yield and chlorophyll content at maturity were highest with DKA 23 genotype. DKA-M8 recorded the highest Plant height, panicle length and above ground biomass. Results of the study indicated that DKA 23 was the best drought tolerant among the genotypes. Phenotypic traits such as number of tillers, number of leaves, number of panicles, total grain yield and chlorophyll content appeared to be linked with moisture stress tolerance. Also, genotype IR 55419 14 clearly showed susceptibility to soil moisture stress. DKA 23, UPL R1, APO and DKA 21 are the best genotypes for farmers to cultivate in dryland conditions under 100% crop water requirement. The study needs to be advanced under field conditions across the two agroecological zones of Northern Ghana.