In order to avoid losses from shattering, oats are often swathed and threshed by a combine with a pickup attachment. This will also result in an evening of maturity in fields where ripening is uneven.
Swathing of oats should start when the kernel moisture content is about 35%. At moisture levels above 35% yield, groat yield and test weight can be negatively affected. Oats are usually ready to swath when the panicle has turned yellow or brown, even as some stems still may show some green color and the least mature kernels have changed from green to cream.
The application of glyphosate before harvest will provide excellent weed control on many perennial weeds. The application of glyphosate should not be made prior to the crop reaching 30% moisture. At this moisture level, the seeds will have reached the hard dough stage. When pressed with a thumb-nail, an indent should remain on the seed. Applying glyphosate off-label may have detrimental effects on oat quality and could lead to higher glyphosate levels in the grain than are acceptable, limiting marketability of the oats.
Seed from fields that have been treated with a pre-harvest application of glyphosate should not be saved for seed. Some customers may not want product that has had a pre-harvest application made to it. Producers should contact their customers to ensure that this practice is acceptable to them. Some formulations of glyphosate may not be registered for application on oats. Labels should be checked before applications are made.
The swathed oats should be threshed as soon as they reach an appropriate moisture. Straight cutting should not commence until all the oats have ripened as discounts will be made to seeds with green hulls. An alternative is to cut around the less ripe areas in a field and harvest these areas at a later date. Oats that are left too long in the field can weather and result in lower quality. If oats have been left to straight cut, weather may cause the stems to break down resulting in yield loss. As well, ripe oats are highly susceptible to shattering in heavy rain storms or wind.
Combine cylinder or rotor speed and concave clearances should be adjusted to produce a sample that does not contain de-hulled oats as a these may result in the sample being down-graded. Hull-less oats are highly vulnerable to cracking and damage. Care must be taken to properly set the combine to avoid damage. This may require a further reduction in cylinder or rotor speed.
Oats can be stored at or below 14% moisture. For long term storage, the moisture should be below 12% or the temperature must be below 20 degrees C at 14% moisture. If oats is harvested above 14%, measures must be taken to market it within 30 days or to reduce the moisture level. This will prevent heating, moulding or spoilage of the grain.
This can be done through aeration or artificial drying. Aeration should be done as soon as temperatures fall in order to cool the grain as well as dry it. An air flow of 1-2 L/s-m3 (0.08 - 0.16 cfm/bu) is recommended for adequate drying and cooling. Care must be taken to not over-heat the oats when drying. The maximum temperature for drying oats that are to be used for seed is 50 degrees C, for milling use is 60 degrees C and for feed use 80-100 degrees C.