Quality control is the guaranty that experimental error is kept under acceptable levels, and the definition of the proper size and form of experimental plots ensures acurate experimental planning. This paper aims to determine the proper plot size and shape for the culture of the Italian pumpkin in protected environments. Two experiments were set in plastic green house in distinct crop seasons: either Summer-Fall or Winter-Spring season. The experiment comprised eight, 23-m long lines with 20 plants each, and fruit weight was considered the main performance parameter. Estimates of best plots size and shape were obtained by the maximum curvature, variance comparison and Hatheway methods. The plot size and shape varied according to the season and the ideal size and shape, according to the maximum curvature and Hatheway methods, to the Summer-Fall and Winter-Spring seasons, were eight plants (4 <FONT FACE=Symbol>´</FONT> 2 plot) and four plants (2 <FONT FACE=Symbol>´</FONT> 2 plot), respectively.
Curcubita pepo; protected environment; experiment planning; quality control