Tips for th eapproaching wheat harvest

Wheat is ahead of schedule and likely will see some area harvest in the next 10 days. Reports from other areas of the state are indicating an average to below average year and test weights ranging from 49 to 59 pounds per bushel and an average of 54. Head scab and associated vomitoxin levels rate from very low near zero to 9.1 regionally.

While the local survey showed some scab our number tended to be lower than other parts of the state. We also seemed to have a high incidence of glume blotch which reduces yield but does not produce toxins. (see previous article)

As we approach harvest I think we can maximize yield with some good harvest practices. I found an excellent reference from Kentucky. The highlights of the article are:

1. While we tend to harvest once wheat reaches 13-15% moisture we can capture more yield by beginning harvest at 20-24% moisture and doing some drying. The amount of drying depends upon the equipment available. If you have a high speed dryer moisture of 21-24% can be harvested, with a bin dryer with heat and stirring we can harvest15-20% and bin dryers without heat 15%. We also need to be aware of temperature. Heat above 140 degrees F affect milling quality and heat above 110 affects seed germination, so stay below these temperatures. Field trials have shown a 1.7 bushel yield loss per acre when wheat dries naturally from 23% to 13% moisture.
   
2. Adjust cylinder speed, concave clearance, screen opening and fan speed by manufacture's recommendations. If you have a field with high levels of head scab raise the cylinder or fan speed to blow out light weight kernels. If you have glume blotch you will not necessarily need to blow out the kernels but will have a lower test weight. Kernels on the ground equal to 20 seeds per square foot is equivalent to 1 bushel per acre yield losses.
3. Avoid over dry to below 13.5% which cost in excess energy usage and loss of weight of grain.

There are a number of potential adavtages to harvesting wheat and drying.

• Reduce potential for weather losses from sprouting and/or storm shatter or hail.
• Higher test weights. Test weights seem to go down when wheats goes through wetting drying after initial dry down.
• Potential for double cropped beans.

The full article from Kentucky on wheat harvest and drying is worth a quick read.