Control of Spider Mites on Celery, 1989

Plots were established in the portion of a celery field near Mission, Tex. which had not been harvested because of high spider mite densities and associated damage. Each plot consisted of 2 beds (4 rows) on 40 inch centers by 15 ft. Plots were arranged in a randomized complete block design with 3 replications. All acaricides were applied on 12 Dec and 20 Dec, 1988, using a CO2-pressurized backpack sprayer calibrated to deliver 69.5 gal/acre (2 flat-fan nozzles/bed; 40 psi). Acaricide treatments were evaluated by counting the number of motile adult mites on the underside of 5 randomly selected trifoliates/plot. A visual rating technique was also used with a 1 (lowest) to 5 (highest) rating, based on the relative abundance of spider mites, assigned to each of 15 randomly selected trifoliates/plot.