SaskWheat is cautioning farmers to be careful when applying pre-harvest chemicals for weed management.

Vice chair Scott Hepworth of Assiniboia says farmers must ensure registered products are used at the right stage of crop maturity.

He says offshore markets are sensitive to any traces of chemical in the grain.

Hepworth says farmers must allow for the right interval between spraying and harvest.

SaskWheat says similar to applying pre-harvest glyphosate, farmers must always wait until seed moisture content is less than 30 percent in the least mature areas of the crop before applying other herbicides.

Traces of the product can be absorbed by the plant, leaving residues behind if applied when the moisture content is above 30 percent.

SaskWheat also cautions farmers to check with their local grain buyer to see what is acceptable for later delivery.

SaskWheat says products containing saflufenacil are acceptable for pre-harvest application but harvest should not occur until at least 3 days following application.

SaskWheat says products containing glufosinate are not registered on wheat and cannot be applied to wheat under any circumstances.

For more information, farmers are advised to consult the Keep It Clean campaign.