Control of the Sweetpotato Whitefly in Cantaloupe with Adjuvants, Endosulfan and Amitraz, 1991

Abstract

Abstract Cantaloupe was seeded into Sunshine Mix® potting mixture in 10 cm pots on 9 Apr in a greenhouse heavily infested with SPWF. Plants were transferred on 6 May into spray chambers (25 cm X 30 cm PVC cylinders) in a randomized complete block design with eight treatments and-six replicates. Plants were irrigated daily using drip tubes to avoid wetting of foliage. Adults were counted on the second or third expanded leaf from the growing point 24 hours prior to treatment. Plants were sprayed to runoff (3 seconds/31 ml/plant, ca. 100 gal/acre) using a C02 backpack sprayer with two TX-4 hollow cone spray tips (Spraying Systems Co.) positioned 5 to 10 cm from the plant canopy (one above and one below) at 60 psi. Treatment applications were made on 7 and 13 May. Untreated plants were inter-spaced between treated plants for an added source of SPWF adult re-infestation. SPWF adults were counted on the second or third expanded leaf on treated plants at 24 and 72 hours after the first application and at 24 hours after the second application. Immature SPWF (including eggs and all stages of nymphs) were sampled on one 2.1 cm diameter leaf disk/plant and numbers were recorded by instar on the oldest of second oldest leaf at 72 hours after the first and second applications.