ISA Certified Arborist Practice Exam

Cultivars that are resistant to pests and diseases are specifically selected and bred to possess genetic traits that enable them to handle and prevent attacks from such problems. Chlorosis, organic fertilization, and mycorrhizae are not related to disease resistance and would not be selected for this purpose. Chlorosis is a condition related to lack of chlorophyll in plants, organic fertilization is a method of providing nutrients to plants through organic matter, and mycorrhizae are symbiotic fungi that help plants uptake nutrients. These options would not be considered when selecting a cultivar for disease or pest resistance.