Fungicides and adjuvants in managing Fusarium head blight on spring wheat in Minnesota, 2008

摘要

On 6 May, hard red spring wheat was planted with a Hege plot drill at 1.35 million live seed/A into Hegne silty clay soil having sunflower residue present. The trial was arranged in a randomized complete block design with four replicates. Each plot was 5 ft x 25 ft with rows 6 in. apart. An application of Axial (0.66 pt/A) and Bronate Advanced (1.0 pt/A) was made 17 Jun to manage weeds. On 20 Jun, 100 lb/A of corn grain infested with Fusarium graminearum was scattered uniformly throughout the test area. Misting began on 25 Jun and continued between 4:00PM and 8:30AM each day at intervals of 2 min on and 13 min off until medium dough development when it was discontinued. Misting intervals were modified as needed to manage soil saturation. On 9 Jul, fungicide treatments at early flowering (Feekes growth stage 10.51) were applied using a backpack-type sprayer with XR Teejet flat fan 8001VS nozzles spaced 20 in. apart on a 5-ft boom, angled 60o from vertical spraying forward and backward at 20 gpa and40 psi. On 25 Jul, 50 wheat spikes/plot were rated forFusarium head blight (FHB) incidence (percent of heads with symptoms) and severity (percent of symptomatic spikelets on diseased heads). Plots were harvested 27 Aug, and grain was cleaned using a Clipper Eclipse seed sizer and conditioner.Grain subsamples of approx. 1.8 oz/plot were sent to the Univ. of Minnesota Mycotoxin Lab in St. Paul to determine deoxynivalenol (DON) content. Results were analyzed using PROC GLM in SAS, with Fisher’s Protected Least SignificantDifference (LSD) mean separations at P=0.05.