Can attack of a plant by one organism induce resistance to subsequent attack by a different organism? In a study of this question, individually potted cotton (Gossypium) plants were randomly allocated to two groups. Each plant in one group received an infestation of spider mites (Tetranychus); the other group were kept as controls. After 2 weeks the mites were removed, and all plants were inoculated with Verticillium, a fungus that causes wilt disease. The accompanying table shows the numbers of plants that developed symptoms of wilt disease. Do the data provide sufficient evidence to conclude that infestation with mites induces resistance to wilt disease? Use a chi-square test against a directional alternative following the five steps (a-e) in Exercise 10.2.4. Let α = 0.01.

Transcribed Image Text:

Treatment Mites No mites Response Wilt disease 11 No wilt disease 15 26 17 Total 21