Suppression of Adult Sweetpotato Whitefly (SPWF) and Spread of Tomato Mottle Geminivirus (TMOV) in Staked Tomato, Spring, 1993

Abstract

Abstract Greenhouse grown seedlings were transplanted into sandy soil on 8 Mar into single rows on raised beds 36 inches wide on 6 ft centers and subsurface irrigated. Beds were fertilized with a bottom mix of 5-16-8 at 508 lb/acre and top mix of 19-0-30 in 2 bands 9 inches from centerline at 952 lbs/acre, fumigated with 300 lb/acre of 66% methyl bromide and 33% chloropicrin and covered with white-faced polyethylene mulch. Crop was sprayed weekly with Manzate 200 Df at 24 oz/acre and Kocide 100 DF at 3 lb/acre for disease control. Experimental design was randomized complete block with 4 replications, each 3 rows wide by 240 ft long, divided into 10 plots 24 ft long for 9 treatments and an unsprayed check. Spray applications from 6 Apr to 21 May were made with a tractor-mounted hydraulic boom sprayer driven by a diaphragm pump and fitted with four drop lines. Albuz ATR Lilac nozzles were used for the application of JMS Stylet oil at 400 psi (2 times per week) and Albuz ATR Red nozzles at 200 psi for all other treatments (once per week except for New Day detergent at 2 times per week). TMoV-symptomatic greenhouse raised tomato plants that had been exposed to infected whitefly were interplanted into each row of each plot on 12 Mar. An adjacent field of fall-planted collards provided additional whiteflies. Whiteflies were sampled by placing an oil/detergent coated black 10 × 13 inch aluminum pie pan under the plant and striking the plant to dislodge the whiteflies. Nine plants were sampled weekly 24 h after each spray in each plot (3 in each row) through 28 Apr and 3 plants per plot (1 per row) were sampled subsequently.