Estimated number of replications for evaluation of productive and morphologic characters in soybean genotypes

Abstract

Estimating the number of repetitions of data obtained from several experiments performed ingiven location is important to minimize human and financial resources and leverage the existinginformation. The objective of this research was to determine how many evaluations (replications)were necessary to predict productive and morphologic characters of soybean genotypes (Glycinemax L. Merril) and to verify its variability in the number of replications among characters. Twenty-eightsoybean genotypes were evaluated in five experiments conducted in Jaboticabal, São Paulo State,Brazil, from 2002 to 2005. Randomized blocks design with three repetitions was installed to evaluatethe following productive characters (seed yield, number of pods per plant and mass of one hundredgrains) and morphologic (plant height at maturity, height of first pod insertion, number of nodesper plant and number of branches per plant). It was performed analysis of variance, estimated therepeatability coefficient and calculated the number of repetitions necessary to predict the realvalue of the genotypes. It was found variability in the number of replications among the productiveand morphologic characters. Experiments with three replicates identify soybean genotypes withhigher 17.52% (height of first pod insertion) to 61.07% (number of nodes per plant) of real accuracy.To improve the accuracy of the evaluation of characters in soybean plants, you need to use agreater number of repetitions.