Nursery Stock Phytotoxicity Evaluations, California, 1980-81

Five insecticides were applied to selected container-grown nursery stock and phytotoxic effects were determined. The following pesticides were selected based on their ability to control many pests commonly found on nursery stock (particularly the black vine weevil, Otiorhynchussulcatus (F.), and due to a lack of information necessary for their labeling in a nursery: Supracide 2E, Knox-Out 2FM, Ficam 76W, and Furadan 4F and 10G. These insecticides were applied on the following plants, Supracide - camel ia, podocarpus, ivy; Knox-Out - camelia, podocarpus, azalea; and Furadan 4F and 10G - azalea, camel ia, pine and podocarpus. Materials were applied until run-off with a handgun operating at from a 2-1/2 gpm (9.5 liters per min) piston pump at 125 psi, except Furadan 10G which was applied to the soil of individual pots. The soil was a modified University of CA mixture with a pH of ca 7.4. Insecticides were applied at 1X, 2X and 4X concentrations where 1X = recommended label rate. The recommended rates per 100 gal water for the chemicals evaluated are: Supracide, Knox-Out, Ficam, Furadan 4F - 0.5 lb, Furadan 10G was applied at 10.0 lb ai/acre (= 1X). Insecticides were applied on Nov 17, Dec 8, May 1, Jun 8 and 29. Data on phytotoxicity were recorded on a weekly basis for 4 weeks following spray application. No phytotoxicity was detected.