SOME ASPECTS OF A RYANIA-GLYODIN SPRAY SCHEDULE IN BRITISH COLUMBIA APPLE ORCHARDS: I. ENTOMOLOGICAL, HORTICULTURAL, AND ECONOMIC ASPECTS

Publisher Website
Google Scholar
Abstract
In apple orchards at Summerland, B.C., four applications of 100 per cent ryania at 48 lb. per acre per application, with glyodin as the fungicide, gave control of light infestations of the codling moth, Carpocapsa pomonella (L.), similar to that from four sprays of 50 per cent DDT at 12 lb. per acre, with lime-sulphur, ferbam, and wettable sulphur. In a heavily-infested orchard, ryania was inferior to DDT. The ryania-glyodin schedule also controlled the woolly apple aphid, Eriosoma lanigerum (Hausm.), and the apple aphid, Aphis pomi DeG. It had little detrimental effect on predacious mites. Except for the apple rust mite, Vasates schlechtendali (Nal.), phytophagous mites were usually not so troublesome where the modified schedule was used.Packing-house records showed that the ryania-glyodin schedule reduced the size and lowered the grade of McIntosh, Newtown, and Delicious apples, and reduced the size of Red Delicious. Grade of Red Delicious was better with the modified than with the standard schedule. The 1954 applications of the modified schedule evidently reduced the size of the 1955 crops on all varieties; most seriously affected were McIntosh with 76.2 per cent reduction and Delicious with 53.7 per cent.