Estimation and Utilization of Inter‐cultivar Competition in Peanuts1

Abstract

Competition among three peanut (Arachis hypogaea L.) cultivars: ‘NC 5,’ ‘NC 17,’ and ‘Florigiant,’ was measured in replicated hill and row‐plot field designs for purposes of predicting optimum proportions of the components in seed blends. The three cultivars are adapted to the Virginia‐North Carolina peanut belt, but differ in maturity and growth habit. Competition was determined by calculating the coefficients of regression for mean plant, fruit, and seed characters on numbers of competing plants or rows.Three‐year trials provided evidence of inter‐cultivar competition. Fruit yield, fruit number, and plant weight of NC 17 were found to increase (overcompensate) significantly over that of pure stands when grown in competition with Florigiant. Coefficients tended to be negative, small in magnitude, and nonsignificant when Florigiant was in competition with NC 17. NC 5 and NC 17 frequently had reduced numbers, sizes, and weights of fruit when grown in competition with each other. Overcompensation was not found when the coefficients for the regression of NC 17 performance on number of competing plants or rows of Florigiant were summed with coefficients based on reciprocal arrangements of the cultivars.Yields of cultivar blends could not be predicted using data from competition tests.