How to define the sample size

How to define the sample size

This section presents some documents concerning sampling size.

In this folder

In a 3-year field study, Premier rabbiteye blueberry plants were sampled at three hierarchical levels (leaf, shoot, and bush) to assess severity of Septoria leaf spot (caused by Septoria albopunctata) and incidence of defoliation.
Knowledge of the distribution of diseased plant units (such as leaves, plants, or roots) or of the relationship between the variance and mean incidence is essential to efficiently sample for diseased plant units. Cluster sampling, consisting of N sampling units of n individuals each, is needed to determine whether the binomial or beta-binomial distribution describes the data or to estimate parameters of the binary power law for disease incidence.
A sound assessment of phoma stem canker symptoms is needed to develop epidemiological, agronomical and physiological studies on the pathosystem.
N-Index is a program which allows calculating the minimum size of a sample, when knowing the coefficient of variation of the index you want to obtain.

Modification date : 13 June 2023 | Publication date : 21 April 2023 | Redactor : IPM network