mosaic (version 0.8-3)

Mites: Mites and Wilt Disease

Description

Data from an experiment to test whether exposure to mites protects against Wilt Disease in cotton plants.

format

A data frame with 47 observations on the following variables.

• treatment

{a factor with levels mites and no mites} outcome {a factor with levels wilt and no wilt}

source

Statistics for the Life Sciences, Third Edition; Myra Samuels & Jeffrey Witmer (2003), page 409.

Details

Researchers suspected that attack of a plant by one organism induced resistance to subsequent attack by a different organism. Individually potted cotton plants were randomly allocated to two groups: infestation by spider mites or no infestation. After two weeks the mites were dutifully removed by a conscientious research assistant, and both groups were inoculated with Verticillium, a fungus that causes Wilt disease. More information can be found at https://www.causeweb.org/webinar/activity/2010-01/.

Examples

data(Mites)
tally(~ treatment + outcome, data=Mites)
tally(~ outcome | treatment, format="percent", data=Mites)