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  • Author or Editor: H. F. Goonewardene x
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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

Significant differences (P = 0.05) in fruit infestation by codling moth larvae were found when fruit of 5 apple selections, with different levels of leaf pubescence, were evaluated. No differences in entry into fruit were found when larvae were placed on the relatively glabrous upper leaf surface. Selections having a pubescent lower leaf surface had significantly (P < 0.05) reduced numbers of entries. Females allowed to oviposit freely on fruit and leaves preferred to oviposit on the glabrous upper leaf surface. In all but one selection, more eggs were laid on the leaves than on the fruit. About 70% of larval entries were found in the midsection of the fruit, with 14% and 15% occurring at the calyx and stem ends, respectively. Larval entry was increased on the side of the fruit closest to the light source. Leaf pubescence seems to be a factor in 1st brood codling moth preference of apple cultivars.

Open Access

Abstract

Selections of apple (Malus domestica Borkh.) of known parentage were exposed in a greenhouse to artificial infestations of European red mite. The clones PRI 95356, N.J. 70, PRI 123056, and PRI 159155 and ‘Vista Bella9, were the least preferred (P = 5%); mite counts per leaf and per cm2 of leaf area were highly correlated even though the leaf area varied within and between selections. There was no evidence that any parent in the pedigrees contributed to ERM resistance based on an analysis of the association of mite numbers for the 4th and 5th week after infestation and the expected frequency of genetic contribution from various parents in the pedigree.

Open Access