ISHS Acta Horticulturae 433: I International Symposium on Edible Alliaceae
THE ONION MAGGOT IN NEW YORK STATE: EVALUATION OF HOST PLANT RESISTANCE |
| Authors: | C.J. Eckenrode, T.W. Walters |
| Keywords: | Allium cepa, Delia antiqua, plant resistance, breeding, germplasm, evaluation |
| Abstract:
Left unchecked, the onion maggot, Delia antiqua (Meigen) can cause onion stand losses from 20 to 90% in many temperate regions. Control of this insect in New York State currently relies upon synthetic insecticides, but the onion maggot has developed resistance to several chemicals, including the products currently used. New chemicals for onion maggot control are scarce. Previous germplasm screens revealed onion maggot resistance in some Allium species, but not in the bulbing onion (A. cepa). As part of an ongoing project to develop onion maggot control methods, we screened breeding lines derived from crosses with the German cultivar Zittauer Gelb for onion maggot resistance. These lines were previously selected for white rot resistance, and it was suspected that onion maggot resistance may have a similar chemical basis. In order to evaluate the materials under appropriate conditions, screening was carried out with natural onion maggot populations within commercial fields. In three years of evaluation, most of the lines were susceptible, but several exhibited moderate resistance. Resistance was superior to the chemical check in a few cases. The resistance or susceptibility of these lines was passed on to hybrid combinations with susceptible inbreds. The prospects for development of maggot-resistant onions and the relationship to other methods of onion maggot control are discussed. | |
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