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Maintaining Wheat Yield and Quality

The favorable weather conditions for wheat we have enjoyed to date and the unusually late start of harvest may mean that we will encounter more problems with shattering compared to most years. The rationale for the for this worry is twofold; first the yield potential looks very good and a portion of that yield will come in the form of (very) large kernels, secondly the later start will likely mean a slower dry down and more chances for rain and dews. The resulting repeated wetting and drying can cause the glumes, especially if the kernels are heavy, to open up. This in turn can lead to increased chances of shattering. Two varieties are probably slightly more prone to shattering are LCS Albany and Forefront. Harvest the crop sooner rather than later to reduce shattering losses and chose to dry down the crop in the bin rather than waiting for the crop to reach 13.5%.

The same conditions that may increase the problems with shattering this season will also cause pre-harvest sprouting. Pre-harvest sprouting, even without a visible sprout, will result in poor seed vigor and reduces bread making functionality as the enzyme alpha amylase will degrade over time once the post-harvest dormancy is broken. The recipe to void problems with pre-harvest sprouting is the same as for reducing shattering losses: harvest the crop sooner rather than later and chose to dry the crop in the bin rather than in the field. HRSW varieties known to be more susceptible to pre-harvest sprouting are Advance, Breaker, Jenna, LCS Albany, Jenna, Select, Samson, and WB-Digger. Elevators will use the Hagberg Falling Numbers test to determine the extent of pre-harvest sprouting damages.

Initial harvest reports and the findings of the scouts suggest that we will have to content with more Fusarium head blight and ergot this year as compared to recent years. Scab causes not only yield losses directly but also will yield the presence of deoxynivalenol (DON) - sometimes referred to as vomitoxin - in the infected grain. Simultaneously some producers have noted higher incidence of ergot. Ergot too is a fungal disease but rather than causing the grain to shrivel to a white chalky kernel in the case of Fusarium head blight or scab, the whole kernel is replaced by a hard dark purple to black hardened fungal mass called a sclerotium. Ergot sclerotia contain ergotamine, the toxin that causes St. Anthony's fire.

The first step to reduce the number of Fusarium damaged kernels (FDK) and DON concentration is to adjust the fan speed on the combine, thereby removing the lighter fraction of the kernels from the harvested grain. A second step to remove FDK is the gravity table separator. Removing ergot is more difficult and will require the use of a gravity table separator.

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