Followingapplication best practices is vital for optimal control of black-grass inwinter wheat this spring, says Stuart Jackson, Dow AgroSciences cerealsherbicide specialist.
Mildtemperatures this winter have led to forward growth in both crops and weeds,with black-grass already romping through its growth stages. As the raincontinues to fall and sprayers sit in sheds unable to travel, farmers will faceincreasing pressure to spray rapidly to cover large areas, once they are ableto. However, fast forward speeds will dramatically reduce the efficiency ofgraminicides.
Optimisingblack-grass control this season will need every factor from weather conditionsto weed growth to be taken into account, says Stuart. Choosing the rightforward speed, boom height, nozzle type and spray quality for your target weedscould make the difference between good and poor control.
Operatorsshould ensure that appropriate forward speed is used to allow for even coverageof target weeds, without boom bounce and yaw. UNITE (pyroxsulam +flupyrsulfuron-methyl) should be applied in the spring with conventional flatfan, variable pressure flat fan or twin fluid nozzles, but not Bubble Jets.
UNITEremains effective on black-grass up to growth stage (GS) 24 and should beapplied in 130-150 l/ha using a fine to medium spray quality. Where black-grassplants are small and have not tillered, the lower rate of 130 l/ha using a finespray would be more appropriate to ensure optimal coverage.
Itsas important to have active growth after spraying as it is before, otherwisethe effectiveness of contact products will be reduced, says Stuart, Despitethe time pressure to get sprayed-up, UNITE should only be applied whereyou have two to three days active growth either side of the application.
Ten top tips for optimal spring black-grass controlwith UNITE:
- Apply to as small a target weed as possible up to GS24
- Apply during a period of active growth 2 to3 days active growth either side of the application
- Ensure correct application rate dontstretch a pack to fit a field
- Always apply with a recommended adjuvant
- Apply with a residual herbicide if appropriate
- Apply using conventional Flat Fan, VariablePressure Flat Fan or Twin Fluid nozzles
- Apply in 130 150 l/ha using a Fine to Mediumspray quality
- Apply to a dry leaf and at least 2 hours rainfree
- Ensure boom height is correct
- Ensure chosen forward speed allows for evencoverage of the target without boom bounce and yaw