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Small Grains Disease Update & Pest 07/26/2019

This will likely be the last small grains disease & pest update for the 2019 cropping season.  If you have not already done so, I encourage you to really evaluate the extent of the FHB infections in your fields (Photo 1)
Photo 1 - Wheat spikelet infected by Fusarium Head Blight
or scab. Note the slight salmon pink to orange color along
the edge of the glume and at the bottom near the rachis
of the right outside floret.
This is an important first step to not just become aware of the extent of the damages but also to start developing a plan of attack to minimize the impact of these FHB infections on the grain and possibly the straw you will market.

Photo 2 -  Close-up of a spring wheat rachis that is infected
by Fusarium Head Blight thereby arresting the development
of grain above the point of infection.
Your first step is to maintain quality and avoid the potential discounts due to low test weight, fusarium damaged kernels and the presence of DON is to segregate the worst affected fields or areas of fields and not co-mingle the grain.  Your second step is to increase the fan speed during harvest to reduce the number of fusarium damaged kernels in the grain tank. Unfortunately, you will also increase your harvest losses as you increase your fan speed as smaller but otherwise sound kernels will also be left in the field.  Often these smaller kernels come from the spikelets above the initial point of infection and where the FHB has grown into to rachis, thereby halting the grain fill of the kernels higher on the rachis (Photo 2).

If needed, the next step is to use a grain cleaner to further reduce the number of fusarium damaged kernels. A Kwik-Kleen grain cleaner or equivalent allows you to clean the grain prior to putting the grain in storage.

Meanwhile, the Wheat Stem Sawfly is completing the summer portion of its life cycle as the larvae are reaching the bottom of the infected stems and are now starting to girdle the lower portion of the stem to build the hatch in their home for the winter in the small piece of stem just above the crown but below the soil surface. Stems infected with WSS will start falling over anytime after the crop has reached physiological maturity and is drying down. 

Once more I ask you to let me know the extent of WSS damage you're encountering in individual fields as that will help us determine whether the pest problem remains a local problem in the Crookston area or whether it is becoming noticeable and possibly problematic in a wider region

Good luck and stay safe with harvest!
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