Chemical, Biological and Cultural Control

Four uniform fungicide trials were planted in Michigan during 3 – 8 Oct 2005. The sites were at the Plant Pathology Farm, East Lansing MI, (inoculated with Fusarium graminearum and mist-irrigated); Bean and Beet Farm, Saginaw, MI (inoculated/not-irrigated); Sanilac, Sanilac County, MI and at Williamston, Ingham County, MI (not-inoculated/not-irrigated). Caledonia wheat, treated with Thiram 42S (thiram 42%, 2.0 fl. oz./cwt), was planted at the rate of 24 seeds/ft of row at each site. Head scab developed at all sites but only severe deterioration was measured at the East Lansing (inoculated) site resulting in high DON levels and low yields and test weights. Scab levels across the state were low in 2006. Very little Fusarium developed at the other three sites and DON levels were negligible. At the East Lansing location, measurable precipitation occurred on only eight days from the period encompassing the first application of fungicide through harvest. Frequent irrigation kept the heads almost continuously wet during early grain maturation. Powdery mildew was evident but only developed to 6.6% foliar area affected by Feekes 10.5.2 in the non-treated control and there were no significant differences among treatments. Stagnospora leaf blotch also developed and by Feekes 10.5.2 the non-treated control had about 5.5% of the foliage affected. Folicur 3.6F (4.0 fl oz) and Caramba 90SL (13.5 fl oz) had significantly less Stagnospora leaf blotch than the non-treated control but were not different from any other treatments. Daily mist irrigation favored FHB development in spite of moderately cool temperatures during and one week following anthesis. Fusarium head blight developed in the trial however there were no differences in incidence or severity among any treatments or the non-treated control. There were no differences in green leaf area (%) remaining at Feekes 11.1 among any treatments or the non-treated control. Only Caramba 90SL (13.5 fl oz) had significantly higher yield than the non-treated control and was also significantly higher than Topguard 1.04SC (14.0 fl oz). No other treatments had significantly higher yield than the non-treated control. Based on analysis of variance, no treatments were significantly different in terms of test weight, percentage damaged kernels, 1000 grain weight or DON levels (3.9-7.0 ppm). At the Bean and Beet Farm, there were no significant differences among treatments for powdery mildew or Stagnospora leaf blotch (disease ratings were very low), FHB severity, FHB incidence or FHB index. There were no significant differences among the treatments for yield, test weight, 1000 grain weight, FDK or DON levels (0.2-0.4 ppm). At the Sanilac location, leaf rust was evaluated for severity and incidence. All treatments significantly reduced leaf rust compared to the control, but were not significantly different from each other. Powdery mildew and Stagnospora leaf blotch were rated. There were some differences among treatments in 1000 grain weights at Sanilac, but no differences in test weights or yield. DON levels for all treatments were 0 ppm. At the Williamston location, there were no significant differences among treatments for powdery mildew or Stagnospora leaf blotch Fusarium head blight severity and incidence was significantly lower for Prosaro (6.5 fl oz), compared to the untreated control, but not significantly different from other treatments. The Fusarium head blight index was significantly lower than the control for all treatments except Tilt and one of