Control of Dagger and Lesion Nematodes in Apple and Plum Orchards with Fenamiphos, Carbofuran, and Carbosulfan. D. A. Rosenberger, Associate Professor, Department of Plant Pathology, New York State Agricultural Experiment Station, Cornell University, Geneva 14456. F. W. Meyer, Research Assistant, Department of Plant Pathology, New York State Agricultural Experiment Station, Cornell University, Geneva 14456. Plant Dis. 72:519-522. Accepted for publication 4 January 1988. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/PD-72-0519.

The effectiveness of fenamiphos, carbofuran, and carbosulfan for controlling dagger nematodes was evaluated for 2 yr in a bearing Delicious/MM. 106 apple orchard. Carbofuran and fenamiphos were also compared over 5 yr in a newly established plum orchard. Nematicides were applied both to bare herbicide-treated ground beneath trees and to sod. When applied to bare ground, fenamiphos did not reduce Xiphinema sp. populations in either orchard but was effective against Pratylenchus sp. Conversely, carbofuran and carbosulfan applied to bare ground in the apple orchard reduced mean Xiphinema populations from 56 to fewer than two per 100 cm³ of soil but failed to control Pratylenchus. Fenamiphos and carbofuran applied to sod in the apple orchard were effective against both nematode species. Annual applications of carbofuran in the plum orchard kept Xiphinema populations below two per 100 cm³ soil in sod and below three per 100 cm³ in the herbicide strip until the fifth year, when the latter population reached 15. Carbofuran treatments suppressed apple yield during the second year but had no significant effect on total apple production over a 3-yr period.