Effects of Insecticides, with and Without Vapam, on Thrips Injury and Peanut Growth and Yield, 1994

Abstract

Abstract Efficacy of selected insecticides, with and without fumigation with Vapam, was evaluated against TT injury and for effects on growth and yield of Virginia-type peanut in Suffolk, VA. Peanuts were planted 9 May with 36-inch row spacing. Granular insecticides were applied into the seed furrow (IF) at planting with a tractor-mounted Noble granular applicator. Liquids were applied using a CO2 pressurized tractor-mounted sprayer calibrated to deliver 5 gal/acre at 24 psi through 1 SS8001E flat fan nozzle per row mounted just above planter disks and turned parallel to row direction. Vapam (metam-sodium) at the rate of 10 gal per acre was applied two weeks before planting 6 to 8 inches below the soil surface with a single chisel shank centered over each in front of a Tilrowvator with Virginia-type bedshapers. Beds were 24 inches wide and 4 inches tall. A randomized complete block experimental design was used with 4 replicates; plots were 4 rows by 30 ft. Treatments were evaluated by determining plant injury based on a 0-10 scale where 0 = no TT injured leaves and 10 = 100 percent injured leaves. Flower, peg and plant canopy measurements were taken in the 2 center rows of each plot. Flowers were counted on 6 or 80 row feet (depending on the sample date); pegs were counted on 2 or 6 row feet (depending on the sample date); and terminal leader height and lateral branch width were measured on five randomly selected plants. Yield was based on digging, combining, drying and weighing peanuts from the 2 center rows (60 row ft) of each plot. Data were analyzed using ANOVA and LSD procedures.