Correlation analysis on growth and straw yield of rice (Oryza sativa l.) varieties grown under influence of three post emergence herbicides in Aliero Sudan savannah zone of Nigeria

Background: Rice is an important crop for resource poor farmers across Africa and Asia. The crop is susceptible to weeds that severely reduce yields, because of their competition with the crop for moisture, nutrients, sunlight and space. Methodology: The trial was conducted in the screen house of Teaching and Research Farm of Kebbi State University of Science and Technology Aliero located at Jega during the rainy season of 2018/2019 to evaluate three selected post emergence herbicides for weed control on rice (Oryza sativa L.) in Sudan Savanna zone of Nigeria. Treatments consisted of two rice varieties (Faro 44 and Faro 52), three herbicides namely BRACER, BRACERPLUS and NOMINEEGOLD. Each of the herbicides were applied at three levels; BRACER 250ml/ha, 275ml/ha and 300ml/ha, BRACERPLUS 129ml/ha, 142ml/ha and 155ml/ha NOMINEEGOLD 200ml/ha, 300ml/ha and 400ml/ha; with  hand weeding at 4 and 8WAS` and weedy check as control. Ten kilogram (10kg) of the soil was measured and filled into each of the sixty-six pots that were placed equidistant to one another in the screen house. Results: The correlation coefficient values showed highly significant relationship. Crop dry matter or straw yield showed positive correlation with number of leaves at 10 weeks after sowing (WAS) (r=0.4228), leaf area index at 10 WAS (r=0.4796). Similarly positive correlation exists with the leaf area at 10 WAS (r=0.2218). Weed dry matter at 10 WAS showed positive correlation to weed dry matter at 6WAS(r = 0.0778), Weed density at 6 WAS, was negatively correlated to weed control efficiency (r = -0.0693) and leaf area at 10 WAS ( r = -0.2216). Conclusion: The correlation obtained between the straw yield and other crop growth parameters were significant and positive while the correlation between the straw yield and weed parameters were significant but negative this indicates that the relationship between crop growth parameters and those of weeds were not positive but negative.