Optimum plot size for field experiments in sesame

This work aimed to determine the appropriate plot size for field experiments in sesame. We performed a complete randomized block design experiment, using 14 sesame varieties and four replicates. The plots were composed of four rows of 0.8 m long, spaced 0.6 m apart, and 0.1 m between plants. The useful plot area (0.72 m2), which was the two central rows, was divided into 12 basic units with one plant (0.06 m2) each. The measures of sesame production were taken from the useful plot area. The appropriate size of the experimental plot was estimated using the intraclass correlation coefficient method and calculated the detectable difference between treatments. The optimum plot size for evaluation of sesame seed yield was 0.18 m2 (useful area), taking into account the one-row border on the sides. Gains in experimental precision (12%) were occurred with increments in plot size up to eight basic units (0.48 m2), using five replicates and four or more varieties. The increase in the number of replicates and plot size was more efficient than the increase in varieties number to increase the experimental precision