R. N. Story

EVALUATION OF PREPLANT AND LAYBY INSECTICIDES FOR CONTROL OF SOIL INSECTS IN SWEET POTATOES, 2009

Trials were conducted at the LSU AgCenter Sweet Potato Research Station, Chase, LA in 2008, to evaluate the efficacy of pre-plant and lay-by insecticides for control of soil insects. All pre-plant insecticide treatments were applied the day preceding transplanting. Sweet potato transplants were planted at a rate of 1 plant/ft in plots of 3 rows (centered on 42 inches) × 25 ft on 12 June. Treatments were arranged in a RCB design and replicated four times. Pre-plant insecticides were applied as a band along the row center, and the beds were disked immediately after application. A CO2-pressurized backpack sprayer was used (30 lb psi) with two nozzles (Tee-Jet 8002vs) calibrated to deliver 15 gpa. Lay-by insecticides were applied with the same equipment, 4 wk after planting as a band along the row center, and the beds were disked immediately following application. At harvest, roots from the middle row were dug and 25 roots per plot were chosen at random and evaluated for insect damage after washing. Total insect damage (cucumber beetle, white grub, sugarcane beetle) and sugarcane beetle only damage are reported. All data were subjected to ANOVA and means separated according to LSD (P > 0.05).

EVALUATION OF INSECTICIDES FOR CONTROL OF CUCUMBER BEETLES AND WHITE GRUBS IN SWEET POTATOES, 2007

Field trials were conducted during 2007 in 3 grower fields to determine the efficacy of insecticides used as lay-by applications for control of cucumber beetles and white grubs on sweet potato. Growers typically apply a single preplant, soil incorporated insecticide followed by a series of post-plant foliar applications of insecticides targeting cucumber beetle adults and lepidopterans. The objective of this study was to determine the value of a lay-by application made 4-6 weeks after planting. The lay-by applications were used as stand-alone treatments and in conjunction with preplant and foliar spray applications. The lay-by treatments were: Lorsban 4E (4 pt), Capture 2EC (9.6 and 19.2 fl oz), Admire 2E (24 fl oz), and Mach II 2SC (1 gal).

EVALUATION OF INSECTICIDES FOR CONTROL OF SWEETPOTATO WEEVILS IN STORAGE: EFFECT OF PARTIAL ROOT COVERAGE, 2002

Sweetpotato roots were treated with three insecticides (Imidan 5% dust, Cryolite 50% dust, Capture 2EC) and four levels of root surface area coverage: (1, 4, 16, cm2 area and 0.5 root). Individual roots were treated by cutting a square of the appropriate size (1, 4, 16, cm2 area) out of Parafilm, wrapping the root with the film, and then applying the dust by hand to the exposed surface area. With the Capture 2EC, a hand held manual applicator with a single nozzle was used to apply the liquid and wet the surface of the root (0.0003% solution of active ingredient). Individual roots were held in 1 qt paper cartons, 10 weevils placed in the carton, and mortality counts taken at 1 wk intervals. A control consisting of untreated roots was included. Six replications were used at each treatment level.