. Annual report - Entomological Society of Ontario. Entomological Society of Ontario; Insect pests; Insects. ENTOMOLOGICAL SOCIETY 53. OIL SPRAYING PEAR TREES Maximum and minimum temperatures at Vineland Station before, during and after oil spraying. Heavy perpendiculars. . dates of spraying. To me it has been most reassuring to find that six successive applications'of an oil spray, 3 Yz times the strength of what we recommend, have been responsible for no commercial loss, and that an oil spray, approximately seven times the strength of what the pear grower uses, has so far caused no fatal or
. Annual report - Entomological Society of Ontario. Entomological Society of Ontario; Insect pests; Insects. ENTOMOLOGICAL SOCIETY 53. OIL SPRAYING PEAR TREES Maximum and minimum temperatures at Vineland Station before, during and after oil spraying. Heavy perpendiculars. . dates of spraying. To me it has been most reassuring to find that six successive applications'of an oil spray, 3 Yz times the strength of what we recommend, have been responsible for no commercial loss, and that an oil spray, approximately seven times the strength of what the pear grower uses, has so far caused no fatal or permanent injury. It has been stated that oil sprays are likely to injure dormant trees if freezing temperatures follow immediately after the application. This most assuredly has not been our experience. During the past eight years the temperature dropped to 28°F in 1924; 26°F. in 1925 20°F. in 1926, 28°F. in 1927, 23°F. m 1928, 23 F. in 1929 25°F. in 1930 and 28°F. in 1931, after some oil spraying had been done without giving rise to any damage. In order to give some idea of what tempera- ture conditions are like at the time oil spraying for psylla is done, we have pre- pared a chart showing, for the period 1924-1931, the maximum and minimum temperatures recorded at Vineland Station and the dates of spraying an orchard situated about three miles from Vineland Station. It should be mentioned that none of the spraying took place when the temperature was very near at or below freezing. This of course means that on some days only one or two tanks ol oil spray would be put on around the warmer part of the day. Oil Sprays and Fire-Blight :—It is an interesting fact that, since the gen- eral adoption of oil sprays, fire blight has been of minor importance in pear orchards Personally I am in no position even to express an opinion as to whethei this is merely a coincidence, or whether the oil has actually had a restraining effect on the disease. There is no experimental eviden
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectinsects, bookyear1872
