UNIFORM FUNGICIDE RESULTS ON SPRING WHEAT, ND, 2000

Marcia McMullen¹, Blaine Schatz² and John Lukach³

¹ NDSU Extension Service, Fargo; ² Carrington Research and Extension Center; ³ Langdon Research and Extension Center

            A core set of seven fungicide treatments were evaluated on hard red spring wheat for efficacy against Fusarium head blight (FHB = scab) and leaf diseases at three locations in North Dakota in 2000.  The evaluation of the fungicide treatments was part of a national effort to evaluate a uniform set of treatments across multiple states and environments.   The core set of treatments included Folicur, Tilt, Stratego, BAS 500, BAS 500 + Folicur, and Quadris + Benlate. Folicur (tebuconazole) had a Section 18 for use in ND in 2000.  Tilt (propiconazole) has a state label for heading application on wheat in ND.  Quadris (azoxystrobin) is registered for wheat in ND.  Stratego is a combination product of Tilt + trifloxystrobin (Flint) and recently received a federal label for wheat.  BAS 500 is a strobilurin fungicide and is not yet labeled for wheat in the US.   An additional fungicide, Caramba (metconazole), was included in the evaluations in ND.  Metconazole is not labeled in the US and this was the first year of testing of this product.

            The fungicide treatments were applied to Russ hard red spring wheat at Fargo and Carrington and to Grandin hard red spring wheat at Fargo and Langdon.  Treatments were applied at early flowering.  Fusarium head blight and leaf disease ratings were recorded at soft dough stage of kernel development.  Fungicide treatments were applied at 35-40 psi in 17-18 gpa, using flat fan nozzles oriented forward/backward.  Fusarium inoculum was added in the form of inoculated grain kernels to the plots in Fargo and Langdon.   Plots were mist irrigated at Fargo and Langdon, while sprinkler irrigation was used at Carrington.  Disease levels were high at all three locations.   Results of fungicide effects on disease and yield parameters are given in Table 1.

Table 1.  Effect of fungicide treatments on Fusarium head blight (FHB) and leaf diseases of spring wheat, ND, 2000 (averaged over 4 trials at 3 locations)

* FHB field severity = incidence (% tillers with scab symptoms) x head severity

** DON levels in the untreated check were 5.4 and 10.4 ppm at Fargo, 6.1 at Carrington, and 18.4 at Langdon

Uniform fungicide results on spring wheat, cont.

             Compared to the untreated check, all fungicide treatments significantly reduced leaf disease, FHB field severity, and DON levels, and significantly increased yield and test weight across locations.  Among fungicide treatments, significant differences were not observed for leaf disease, but BAS 500F and BAS 500 F + Folicur resulted in the lowest leaf disease ratings.  Caramba gave the lowest FHB field severity and DON levels, and was significantly lower for these disease scores than some of the treatments.  All fungicide treatments resulted in significant yield increases over the untreated check, ranging from 6.9 bu to 15.2 bu/acre.  Some significant differences among treatments were observed for yield and test weight.  The Caramba treatment had significantly higher yield than several treatments. The BAS 500 had a significantly higher test weight than the Tilt treatment.  Yield and quality responses with fungicide treatments were economic in these tests in 2000.