Horticultural oils are among the safest of pesticides. Lack of product identification through the label makes it difficult for the field user to know what product was actually used in experimental studies. A minimum standard for product identification is suggested. Phytotoxicity, while relatively uncommon, continues to cause fears on the part of nurserymen and spray contractors. Factors that must be taken into account before spraying oil include dosage, timing with regard to plant phenological development and climatic conditions, and an awareness of sensitive plant species. A list of sensitive plants is given. A new expression of pesticide resistance through the thickening of the test of certain armored scales was observed.
Author notes
Presented at the Interstate Ornamental Plant Management Conference, University of Maryland, February 20, 1985.
2Professor of Entomology.