Optimum plot size for experiments on rubber tree nurseries

Abstract

This research was carried out to obtain information on the plot size for experiments with rubber tree (Hevea spp.) nurseries. The data were obtained from an experiment testing twelve spacings, but only those belonging to the six best spacings were considered. The optimum plot size was determined by the methodology that uses the intraclass coefficient of correlation. Based on both variables plant height and stem diameter, the authors were led to recommend for plots with a complete guard row 3 test rows with 9 to 15 plants, or 4 test rows with 16 to 20 plants. These numbers multiplied by 4 or 5 give the total numbers of test plants per plot, among which are selected the competitive plants to be measured. In this study were taken in consideration plots with one or a double guard row. Other options according to the researcher interest are offered.