Wireworm and Flea Beetle Control on Floe-Cured Tobacco with Soil-Applied Insecticides, 1982

Abstract

Abstract Tests were conducted on commercially grown tobacco in four locations. Plots consisted of 0.020 or 0.025 acre of tobacco in four rows separated laterally by a vacant fifth row and on the ends by a 16 to 20-ft turn alley. Treatments were arranged in a randomized complete block design replicated three times. Broadcast treatments were applied 14 Apr., 19 Apr., 22 Apr. and 3 May in Tests 1 to 4 respectively. Broadcast spray treatments were applied with a tractor-mounted sprayer at 35 lb/in2 through 8004 flat fan nozzles delivering ca. 25 gal finished spray per acre. Granular materials were broadcast using two tractor-mounted, electrically driven granular applicators. Broadcast treatments were incorporated by discing twice in opposite directions. Transplant water treatments were applied using the farmers’ tractor-drawn transplanters (225, 175, 320, 200 gal/acre in Tests 1 to 4, respectively). Transplant dates were 21 Apr., 29 Apr., 4 May, and 5 May (Tests 1 to 4, respectively). Twenty additional plants were set in the middle rows of each plot at transplanting using hand setters. These (or adjacent mechanically set plants in the case of transplant water treatments) were removed 15 to 20 days later and evaluated for wireworm damage on the following scale: 0, no damage; 1, external feeding not reaching pith; 2, feeding reaching pith but less than 0.5 in. vertical tunneling; 3, stem tunneled over 0.5 in. In test 2, ten alternate plants (from a random start) in the middle two rows were checked for flea beetles and rated for flea beetle damage (1, light to 3, heavy). After harvest and curing, tobacco from each plot was weighed and given a standard federal grade. Grades were converted to a quality index and weighted averages calculated. Analyses of variance tests were conducted on all variables and means were separated using the Waller-Duncan K ratio t test (K ratio = 100). For analysis, flea beetle numbers were transformed to the square root of N + 0.5; damage ratings were converted to a proportion of the highest possible rating and subjected to an arc sine transformation.