| Abstract: | In The Netherlands at present the research on resistance against pests is aimed at red spider mite in cucumber, glasshouse whitefly in tomato, carrot fly, aphids in lettuce. In addition projects are planned with a view to breeding resistance against Myzus persicae Sulz. in paprika, and aphids in barley. Tolerance can hardly be considered as a type of resistance, since it does not control the parasite population. Non-preference has some advantages, but does not reduce the size of the insect population and causes pests to migrate to other plants and possibly to the neighbours. Antibiosis is the more desirable type of resistance. To prevent it from being broken, antibiosis ought to be based on polygenes. Another method of prevention is to breed multiline varieties. When creating new varieties that possess certain valuable qualities in combination with a resistance based on polygenes, the breeder has to test yearly thousands of plants. Rapid methods for mass-testing for resistance are therefore urgently needed. Breeders have found high-yielding varieties, which help to feed the world population. However, the desired resistance against pests must frequently come from low-yielding varieties. To combine the indispensable high yields with resistance against pests is a time-consuming work. The process will be shortened as better screening methods become available. |
