Skip to contents

Cochran(1936) provided a data that comprise the number of tomato spotted wilt virus(TSWV) infected tomato plants in the field trials in Australia. The field map was divided into 160 'quadrats'. 9 tomato plants in each quadrat. then the numbers of TSWV infected tomato plants were counted in each quadrat. Number of infected plants out of 9 plants per quadrat can be treated as a binomial variable. the collection of all such responses from all 160 quadrats would form "binomial outcome data" below provided is a data set similar to Cochran plant disease incidence data. Marcus R(1984). orange trees infected with citrus tristeza virus (CTV) in an orchard in central Israel. We divided the field map into 84 "quadrats" of 4 rows x 3 columns and counted the total number (1981 + 1982) of infected trees out of a maximum of n = 12 in each quadrat

Usage

Plant_DiseaseData

Format

A data frame with 2 columns and 10 rows

Dis.plant

Diseased Plants

fre

Observed frequencies

Source

Extracted from

Hughes, G., 1993. Using the Beta-Binomial Distribution to Describe Aggregated Patterns of Disease Incidence. Phytopathology, 83(9), p.759.

Available at: doi:10.1094/Phyto-83-759 .

Examples

Plant_DiseaseData$Dis.plant      # extracting the binomial random variables
#>  [1] 0 1 2 3 4 5 6 7 8 9
sum(Plant_DiseaseData$fre)       # summing all the frequencies
#> [1] 160