·1 all the listed nematodes may not occur in all geographic regions, or fields within a geographic region, where the crop is grown

·2 cultivars or rootstocks may have been developed or selected that have resistance or tolerance to specific nematodes

·3 there may be races of a particular nematode species that are either virulent or avirulent to a plant species

·4 you need to determine which nematodes are present in the soil before using this list to make management decisions.