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  • Author or Editor: Hilary F. Goonewardene x
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Abstract

E11-24, E14-32, and E36-7 apple (Malus domestica Borkh) were found to be resistant in greenhouse test to apple scab, [Venturia inaequalis (Cke.) Wint.j and to have field immunity to this disease. Field and laboratory resistance to codling moth (Laspyresia pomonella L.) also was found in E11-24 and E14-32, whereas E36-7 was found to have field, laboratory, or greenhouse resistance to plum curculio [Conotrachelus nenuphar (Herbst)] and European red mite [Panony-chus ulmi (Koch)], E11-24, E14-32, and E36-7 are being released as advanced lines of germplasm by the ARS/USDA to interested apple fruit breeders. The scientific disease and insect names mentioned in this release are as reported in refs. 3 and 4.

Open Access

Abstract

E7-47, E7-54, E29-56, and E31-10 apples (Malus × domestica Borkh) were found resistant to apple scab, [Venturia inaequalis (Cke.) Wint.] in greenhouse tests and in the field. Field and laboratory resistance to red-banded leafroller [Argyrotaenia velutinana (Walker) in E7-47, European red mite [Panonychus ulmi (Koch)] in E7-54, apple maggot [Rhagoletis pomonella (Walsh)j in E29-56, and to codling moth (Laspyresia pomonella L.) in E31-10 were also found. E31-10 was also found to have resistance to European red mite in the field and greenhouse. E7-47, E7-54, E29-56, and E31-10 have been released as advanced pest- and disease-resistant germplasm lines by the ARS/USDA to interested apple breeders for use in breeding programs. The scientific names of diseases and insects mentioned in this release are as reported by the USDA (1960) and Sutherland (1978).

Open Access

Abstract

Twenty-eight apple selections exhibiting different levels of powdery mildew resistance, based on greenhouse and field ratings from other investigations at other locations, were evaluated as grafts in the greenhouse for European red mite survival and development. Although we found selections HAR5T8, HAR8T140, HCR9T48, HCR14T149, OR48T70, and TSR14T146 to have a significantly (P = 0.05, 80 df) higher powdery mildew rating than NY55140-19, at one or more European red mite counts the other 22 selections did not show similar differences. Only selection HAR5T142 had significantly higher (P = 0.05, 80 df) mite counts relative to HCR21T200. The absence of a relationship between powdery mildew and European red mite infestations in apple was demonstrated through the lack of significant correlation between the levels of infestation by these 2 pests.

Open Access

Abstract

Significant differences in mean leaf hair density values were found between strains of ‘Delicious’ apple (Malus domestica Borkh.) within locations (states). There were also location differences among strains common to more than one location (state). Ranking of strains according to the amount of pubescence present appeared relatively consistent between states.

Open Access

Abstract

“No choice” procedures were established to complement “free choice” procedures for determining resistance of apple fruit to 4 insect pests. ‘Starking Delicious’ was more resistant to damage by apple maggot, Rhagoletis pomonella (Walsh) than ‘Jonathan’ or ‘Golden Delicious’. There were no differences in damage to ‘Jonathan.’ ‘Golden Delicious’ and ‘Starking Delicious’ by plum curculio, Conotrachelus nenuphar (Herbst) or redbanded leafroller, Argyrotaenia velutinana (Walker). The resistance of some apple scab resistant selections to these insects and codling moth, Laspeyresia pomonella (L.) previously determined in a “free choice” test was confirmed in this “no choice” test.

Open Access

Abstract

Methods of evaluating resistance of apple fruit to 4 insect pests were established by modifying existing rearing procedures. When ‘Jonathan’ was used as the check cultivar and an adjustment was made for variation between trays among checks, it was possible to separate selections that were significantly more resistant from randomly selected samples of apple genotypes. We found 9.7 22.9, 32.3, and 17.0% of the selections tested against the codling moth, Laspeyresia pomonella (L.), plum curculio, Conotrachelus nenuphar (Herbst), apple maggot, Rhagoletis pomonella (Walsh), and redbanded leafroller, Argyrotaenia velutinana (Walker), respectively, had significantly less damage than the check.

Open Access

Abstract

Selections of apple (Malus domestica Borkh.) from the cooperative breeding program for disease resistance were evaluated in 3 tests for resistance to the European red mite. Field-collected detached leaves used to determine infestations of motile mites throughout the growing season, dormant twigs used to determine overwintering eggs, and in situ examination of artificially infested leaves of greenhouse-growing whip grafts indicated good sources of resistance. Selections with less hairy leaves supported fewer mites than selections with an abundance of hairs. Selection PRI 1677-2, 1957-1, 2023-1, 2175-7 and 2175-25 show consistently good resistance to the European red mite warranting their use in vegetative propagation or use as parents in breeding for resistance.

Open Access