Evaluation of soil- and foliar-applied Propulse to manage root-knot nematode in cotton in Arkansas, 2018

摘要

Propulse contains the nematicide, fluopyram, which was evaluated for suppression of Meloidogyne incognita on a susceptible cotton cultivar. The trial was conducted in a field with a history of southern root-knot nematode (RKN) near Manila, AR. The cotton cultivar was planted on 9 May at a seeding rate of 48,000 seed/A in a field of Routon-Dundee-Crevasse complex loamy sand previously cropped in cotton. Weeds were controlled in plots based on recommendations by the University of Arkansas Cooperative Extension Service. This study was furrow irrigated. Plots consisted of two, 45-ft-long rows spaced 38-in. apart and separated by a 6ft fallow alley. Soil applied nematicide (Velum Total and Propulse) and insecticide (Admire Pro) were applied in-furrow through a 0.6-in-diam. poly tubing using a pressurized sprayer to deliver 5.0 gal/A. Foliar treatments were broadcast 68 DAP (2nd wk of bloom) through flat-fan nozzles (Tee-Jet 80015VS) spaced 38-in. apart using a compressed air pressured hand held sprayer.The sprayer was calibrated to deliver 19 gal/A. All seed were treated with base fungicide and Gaucho 600 F (0.375 mg ai/seed). The experiment was arranged in a randomized complete block design with four replications per treatment. Stand counts and vigorwere evaluated on 7 Jun. Stand counts were based on seedling population per plot and vigor was assessed on a 5-point scale (1-5) with 5 = most vigorous seedlings. Soil samples were collected within each block at planting and harvest. Soil samples were acomposite of 10 core samples taken 8 to 10 in. deep with a 0.75-in.-diam. soil probe. Second-stage juveniles (J2) were collected with a Baermann ring system and enumerated using a stereoscope. To determine nematode infection, ten roots were arbitrarilysampled from one row of each plot on 11 Jul and galls per root system recorded. Plots were harvested 18 Oct with a cotton harvester equipped with a weigh system. Data were subjected to ANOVA using ARM Software (Version 9.0) and mean separation with TukeyHSD at P = 0.05.