Effect of strobilurin fungicides on grain yield, moisture content and DON levels of soft winter wheat, 2009

摘要

Field research was conducted to measure the effect of various strobilurin fungicide products on grain yield, grain moisture, disease severity deoxynivalenol (DON) levels using three soft white winter wheat cultivars (Coral, Crystal, and D8006) and twosoft red winter wheat cultivars (Red Ruby and Hopewell). The wheat was planted on 25 Sep 08 at a rate of 1.8 M seeds/A into minimum tilled, Parkhill loam soil that was previously planted to dry beans. Three replications were created within a randomizedsplit-plot design. Plots were 8.3 ft wide by 35 ft long. Fungicide treatments were applied to all five varieties on 20 May 09 at Feekes growth stage (FGS) 8 (flag leaf tip emergence) or on 5 Jun 09 at FGS 10.5 (full heading) at rates calculated to deliver a strobilurin fungicide product at either 0.065 or 0.130 lb a.i./A. For comparison, there was one treatment using a triazole-based product (Folicur 3.6F) and an untreated control. All fungicides were applied using a tractor mounted boom sprayer, Twinjet nozzles (TJ60-8002), 12 gpa of water, a nonionic surfactant and 35 psi. The center 5.3 by 34 ft area of each plot was harvested on 27 Jul 09 using a small plot combine. DON levels were determined by the University of Minnesota DON Testing Laboratory. The statistical analysis was performed by the Statistical Consulting Center, Michigan State University. Where the treatment effects were found to be statistically significant, mean comparisons were conducted using t-tests (p<0.05). Because of unequal variances in fungicide treatments, mean separations were derived based on the results of individual t-tests. The interaction between fungicide treatments and cultivars was not statistically significant (p<0.05), therefore the treatments were compared acrossall cultivars.