Nursery Potted Vegetable Phytotoxicity Evaluations, California, 1979-80

Phytotoxicity resulting from one application of selected insecticides (one insecticide/vegetable) to several potted vegetables was determined. The following materials were evaluated: Lannate 1.8L, Orthene 75S, Pirimor 50W, Pramex 2E, SPB-1382 2E, Vydate 2L. Compounds were chosen based on their ability to control many pests commonly found on potted vegetables and due to a lack of information necessary for their labeling on these crops in a nursery. Applications were made in Jan, March, July or Aug and several plots designs were employed (Table 1). Materials were applied until run-off with a hand gun operating from a 2.5 gpm (9.5 litres per min) piston pump at 125 psi. Plants were sprayed outdoors at all locations and then transferred to raised benches within greenhouses at UCR and onto black plastic sheets located at ground level under shade at cooperating nurseries. The soil at all locations was based on a University of California mixture with a pH of ca 7.4. Following the date of spray application, data on phytotoxicity were recorded weekly for 4 weeks. Damage was evaluated based on the overall appearance of the plants compared to an untreated control: 0-no damage; 1-slight damage, no effect on marketability; 2-moderate damage, marketability reduced; 3-heavy damage, unmarketable. An evaluation of phytoroxic effects was made on plant growth if this occurred after the insecticide applications. Observations on phytotoxicity were made by at least 2 individuals on each date and where possible, only the innermost plants within replicates were evaluated.