Sample size for evaluation of eggplant and gilo seedlings

Abstract

In horticultural nurseries, it is important to determine the number of plants to be evaluated to obtain reliable inferences about seedling growth. The objective of this study was to determine the sample size required to estimate the mean of quality traits of eggplant and gilo seedlings. The seedlings of both vegetables were produced in expanded polystyrene trays using (8×16) 128 cells each and 40 cm 3 high. At 45 days after sowing, the following traits were evaluated in each seedling of the two crops: leaf number; total leaf area; fresh matter mass of shoot, roots and the total of fresh matter mass of shoot and roots, and Dickson quality index. Measures of central tendency and variability were calculated; the normality of the sample data was tested, and the sample size was calculated. The sample size required is different among the different traits of eggplant and gilo seedlings, and the same trait is different between the two crops. The sample size to evaluate seedlings for an estimation error of 10% of the estimated mean and at a confidence level of 95% is 32 and 26 for eggplant and gilo, respectively.