Tamanho de parcela e número de repetições para avaliação de caracteres vegetativos em centeio

The objectives of this work were to determine the optimum plot size (Xo) and number of repetitions to evaluate the fresh and dry matter of rye (Secale cereale L.), and to investigate the variation of Xo between two cultivars and five sowing times. Thirty uniformity trials were conducted. Each trial with dimensions of 6 × 4 m was divided into 24 basic experimental units (BEU) of 1 × 1 m. Fresh and dry matter of rye were evaluated in the 720 BEU. The Xo was determined by the method of maximum curvature of the coefficient of variation model. The number of repetitions was determined in scenarios formed by combinations of treatments, experimental designs, and levels of precision. The optimal plot sizes to evaluate fresh and dry matter of rye are, respectively, 3.43 and 3.82 m2. Six repetitions are sufficient to evaluate fresh and dry matter in completely randomized and randomized block design with up to 50 treatments and make it possible to obtain a least significant difference less than or equal to 20% of the experiment mean.