Year: 2015
Type: article
Abstract: Testing new chemistries and monitoring the efficacy of existing compounds is extremely important because the CPB has the ability to develop resistance to chemical insecticides. The experiment was conducted at Presque Isle, ME, in 2014 and replicated four times. Experimental design was a randomized complete block, with plots being four rows wide (12 ft) and 50-ft long. A 10-ft space was left fallow between blocks, and a 6-ft space was left fallow between plots within blocks. The crop was planted on 28 May using machine-cut “Kennebec” potato seed. A two-row potato planter (John Deere 216) applying 1,100 lb of 14-14-14 fertilizer per acre was used to form open furrows. The seed was hand placed at 12-inch spacing. The rows were mechanically covered, placing the seed piece approximately 3 inches below the surface. Foliar insecticide applications were made with a modified Century boom sprayer affixed with eight Turbo Twinjet nozzles delivering 40-gpa at 35-psi pressure with a 12 ft wide spray pattern, boom height of 20–24 inches and tractor speed 3 mph. The crop was treated with Bravo ZN at 5–7-d intervals throughout the season for late blight control based on recommendations from the University of Maine Cooperative Extension. Numbers of insects were counted weekly on 20 plants selected randomly from the center two rows of each plot. When dates of count and application were the same, counts were made prior to applications of the insecticide. Analyses of variance were conducted following transformation of the data using log 10 ( X + 1), and means were compared using Fisher’s LSD test. Means followed by the same letter do not significantly differ from each other ( P > 0.05). The soil was classified as Caribou Loam, pH 5.0. The total monthly rainfall for June, July, and August was, respectively, 3.55, 5.31, and 1.28 inches and the mean temperature was 63.25, 69.47, and 65.53°F. Colorado potato beetle populations were low prior to the first application, possibly due to low winter temperatures. There was no difference between insect responses to chemical treatments following the first application ( Table 1 ). After the second application, Blackhawk showed the best control, followed by DPX-KN128 applied at the high rate. Avaunt applied at the high rate displayed the same level of control as Admire Pro. AzaGuard and the low rates of DPX-KN128 and Avaunt did not affect CPB populations compared with the untreated check ( Table 1 ). However, all chemicals did reduce the amount of damage done to the foliage ( Table 2 ). There were no significant effects on yields, but the untreated check had the lowest numeric value for the weight of harvested tubers ( Table 2 ). Means in a column followed by the same letter are not significantly different (LSD, P > 0.05). Means in a column followed by the same letter are not significantly different (LSD, P > 0.05). No phytotoxicity symptoms were observed following any of the insecticide treatment applications.
Source: Arthropod management tests
DOI: 10.1093/amt/tsv059
Authors: Aaron M. Buzza, Andrei Alyokhin
Institution: University of Maine
Language: English
Subfield: Insect Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: gold
Estimated APC paid: $300
OpenAlex ID: W2916415884