Title Image
Image
Caption
peas turning following dessication
Portal
Categories

Harvest time is just around the corner with some producers already started and there are many things to keep in mind before harvest to ensure your grain can be sold into any market. Before applying pesticides as a pre harvest application, always understand the label and be aware of any restrictions that may affect the marketability of your grain.

When spraying harvest aids near the end of the growing season, be mindful of pre-harvest intervals (PHI) for the products you are using. The PHI is the minimum amount of time that must be left from when the herbicide is applied to when the crop is cut by swathing or straight-cut. If the proper time has not passed between application and cutting, residues may be left on the seed and may not be accepted by your grain buyer. PHIs are variable between specific products, ranging from several days to over 60 days. This time frame allows for the active ingredients of the pesticide to break down in the plant. The more time that has passed, the less residue is left on the plant.

Marketability of the crop can be at risk when not following the PHI of a product. Maximum Residue Limits (MRLs) are determined for pesticides based on the rates registered and staging of the crop. By applying a pesticide product at the incorrect maturity stage, the grain may have pesticide residues above the MRL set by regulatory agencies. Staging is an important factor for applying pre-harvest pesticides. Application should occur when the crop is physiologically mature. If a pre-harvest aid is applied to a crop that is too green, the seed can then take up the product, thus having high pesticide residues left on the grain and may not be accepted by the grain buyer. Pre-harvest products need to be applied at less than 30% seed moisture content throughout the whole field.

The Keep it Clean website has information and several tools such as the Pre-harvest interval calculator and product advisory webpage. Their five tips for producers for keeping your crops ready for the market are Use acceptable pesticides only, always read and follow the label, manage disease pressures, store crops properly, and deliver what you declare. For more information on PHIs, marketability and tools and resources, visit the Keep it Clean website.

More information can be found hereĀ 

Rebecca Hort, is a Crops Extension Specialist with the Saskatchewan Ministry of Agriculture.