A rearrangement of the Harris et al. equation was used to determine a precise and economical field plan for conducting a randomized complete block muscadine grape cv. and selection trial. An increase in the number of replications decreased the magnitude of the yield differences that are detectable as being significant to a greater extent than did an increase in plot size or number of clones being tested. Relatively little precision was gained by increasing the plot size from 1 to 2 vines and almost nothing was gained by increasing the plot size further to 3 or 4 vines. Muscadine grape yield trials can be conducted most efficiently by using 1-vine plots and 5 or more replications.
Received for publication April 3, 1972. Paper No. 3689 of the Journal Series of the North Carolina State University Agricultural Experiment Station, Raleigh.
Associate Professor, Department of Horticultural Science.