Estimation of Optimum Plot Size in Experimentation with Sweet Potato

Abstract

Optimum plot size determination, in any culture, is a method to increase experimental precision and maximize the information obtained in an experiment. Research of the optimal plot size for sweet potato date back to 2006, meanwhile, no previous work with the Morotí variety has been recorded. Therefore, in order to provide and/or update information regarding the adequate sizing of plots for the crop, the goal of this study was to estimate the optimum plot size in a field experiment with sweet potatoes [Ipomoea batatas (L .) Lam.]. Three methods were considered: the modified maximum curvature, the segmented linear model with plateau response, and the segmented quadratic model with plateau response. For this purpose, a uniformity trial was conducted with variety Morotí of sweet potato. The basic experimental unit was defined as one plant (0,30 m²), then eight different plot sizes were simulated and the coefficient of variation for each of the simulated sizes was determined. The results showed that the three methods estimated different optimum plot sizes, the modified maximum curvature method being the one that estimated the smaller optimum plot size. The methods based on segmented models estimated the most appropriate optimum plot sizes. Methods based on dish-segmented models estimated adequate plot sizes. It is recommended to use 13 to 16 plants (3,90 to 4,80 m²) per plot.