Determining suitable sample size for some characteristics in wet rice experiments

Abstract

This article was written based on of three field rice experiments conducted at Gialam, Hanoi and Hatay Province in two years, 2004 and 2005 with 4 different rice genotypes, viz. Nep 87-2, Bac Thom No7 (BTS7), LT2, and N46. Sample size depends on the  nature and variability of characteristics under  investigation and research conditions. 30 random individual measurements were taken on each characteristic to estimate the coefficient variation that in turn was used to calculate the sample size with different significance levels and acceptable standard errors. The results showed that with the commom significance level (P=0.05) and standard error of 10%, the sampling size should be 3 hills for measuring of plant height, 30 hills for tiller number, leaf area and dry matter, 3 panicles for measuring panicle neck length and 10 panicles for counting seed numbers per panicle