Optimum size and shape of plots based on data from a uniformity trial on Indian Mustard in Haryana

Abstract

The most obvious use of uniformity trial data is to provide information on the most suitable size and shape of plots, in which the field was planted to a single variety and harvested as small plots. Indian mustard (Brassica juncea L.) cultivar RH-749 was grown using uniform crop improvement practices during rabi season of 2013-14 at Research Farm of Oilseed section, Department of Genetics and Plant Breeding, CCSHAU, Hisar, Haryana state, India, to estimate optimum plot size and shape using yield data of the 48 m × 48 m (2304 basic units) recorded separately from each basic unit of 1 m × 1 m. The variability among plots of different sizes and shapes was determined by calculating coefficient of variation. It was observed that the coefficient of variation decreases as the plot size increases in case of both the directions i.e., when plots were elongated in N-S direction (88 per cent decrease) or elongated in E-W direction (93 per cent decrease). Further it was observed that long and narrow plots elongated in E-W direction were more useful than the compact and square plots in controlling the soil heterogeneity. Based on the maximum curvature method the optimum plot size for yield trial was estimated to be 5 m2 with rectangular shape.