Plot size related to numbers of treatments and replications, and experimental precision in dwarf pigeon pea

ABSTRACT The aim of this study was to determine the optimum plot size to evaluate the fresh matter of aerial part of dwarf pigeon pea (Cajanus cajan (L.) Millsp), cultivar IAPAR 43 (Aratã), in scenarios formed by combinations of numbers of treatments, number of replications, and precision levels. The fresh matter of aerial part was weighed on basic experimental units of 1 m × 1 m in three uniformity trials with size of 24 m × 12 m (288 m2 in each trial). The soil heterogeneity index of Smith was estimated. Also, the optimum plot size was determined by Hatheway’s method in scenarios formed by combinations of i treatments (i = 5, 10, 15, and 20), r replications (r = 3, 4, 5, 6, 7 8, 9, and 10), and d precision levels (d = 5%, 10%, 15%, 20%, 25%, and 30%). In experiments designed on randomized block design with 5 to 20 treatments and four replications, plots with 9 m2 were enough to identify significant differences among treatments regarding the fresh matter of aerial part in dwarf pigeon pea at 5% probability of 30% of the experiment overall mean.

摘要 本研究旨在确定用于评估矮型木豆（Cajanus cajan (L.) Millsp）品种IAPAR 43（阿拉塔）地上部鲜重的最优小区面积，试验设置由处理数、重复数与精度水平组合而成的多类场景。试验在3个面积为24 m × 12 m（单个试验面积288 m²）的一致性试验中，以1 m × 1 m的单元作为基本试验单元，称量其地上部鲜重。研究估算了史密斯土壤异质性指数，并通过哈思韦法，在处理数i（i=5、10、15、20）、重复数r（r=3、4、5、6、7、8、9、10）和精度水平d（d=5%、10%、15%、20%、25%、30%）组合的场景中确定最优小区面积。在处理数为5至20、重复数为4的随机区组设计试验中，当以试验总均值的30%作为精度判定基准时，采用9 m²的小区即可在5%显著性概率水平下识别矮型木豆地上部鲜重的处理间显著差异。