Preharvest management of small grains

University of Minnesota Extension
Farm Forum

There are two methods of pre-harvest management that can speed up the small grain harvest: Swathing or applying glyphosate. Because modern varieties allow for it, most wheat and barley is now straight-cut instead of swathed. Oats are still commonly swathed. A pre-harvest application of glyphosate is only labeled in wheat.

The advantages and disadvantages of the different preharvest management tactics can be found at https://extension.umn.edu/small-grains-harvest-and-storage/managing-wheat-harvest.

If you suspect you have a moderate to high infestation of wheat stem sawfly, swathing may be a good choice to avoid harvest losses. Because wheat stem sawfly migrated into this year wheat crop from adjacent wheat stubble, there is generally a very strong edge effect. To determine if you need to swath edges of fields, sample the wheat crop and determine the percent of plants infested by wheat stem sawflies before harvest. Simply split the stems longitudinally and look for the S-shaped larvae inside the stems.

If more than 15 percent of stems are infested by sawflies, you should consider swathing. Swath the sawfly-infested wheat as soon as the crop has reached physiological maturity to prevent infested stems from lodging.