Role of Applying Pre-Harvest Glyphosate
Applying pre-harvest glyphosate to a crop will give the most effective long-term control of scutch, thistles, etc. The best results are achieved when the weeds are actively growing in moist soils.
Leaving glyphosate application until mid-September will miss some of the shoots that did not emerge after the harvest.
It should be noted that applying pre-harvest glyphosate has implications regarding cross-compliance, as these fields should have a green cover established within six weeks of application.
Crops intended for seed and certain premium markets should not be treated.
Assessing when the crop is ready for glyphosate
From 14 days before normal harvest date, collect 20 grains from the centre of several ears. Press your thumbnail firmly into the grain and if the indentation holds on all the grains, the crop is ready for spraying.
Target weeds must be green, actively growing and accessible to the spray. A minimum of five-to-six hours drying after application is essential for satisfactory results with all glyphosate products containing tallow amine surfactant formulation.
A number of adjuvants are available which will improve the spreading and deposition of the glyphosate, reduce the effects of hard water and also generally improve rain fastness, where not
already included in the formulation. Assess your water quality and select an additive carefully,
Options include: X-Change (good for hard water areas); Validate; Frigate; etc. The rate of adjuvant isrelated to water volume and pH of the water. Check your water pH and add a product like X-Change at a rate of between 0.1%- 0.25% depending on the water pH.