Spray advice with harvest underway
Growers with early harvest blocks should apply copper as soon as fruit has been picked to protect fruit stalks and soft tissue within the canopy from Psa infection.
If there is no risk of drift to unharvested blocks Actigard can also be added to the tank-mix, to provide additional control though activation of the vine’s natural defence system. If there is any risk of drift, then plan to follow up with an Actigard spray when neighbouring blocks have been harvested. Actigard is taken up through the leaves and applications will be effective as long as there are 50% green leaves left in the canopy.
Be cautious in applying Actigard to vines that have been severely stressed by drought – it is not recommended for vines showing signs of stress such as wilting, premature leaf yellowing or leaf drop. For growers applying Movento for scale control, good practice is to maintain a five-day window between this product and Actigard. Be sure sprayers are well rinsed to avoid contamination of following tank mixes.
Young plants also benefit from protective coppers to avoid infection risk to late grown tissue, and especially for blocks with significant leaf spot as Psa can reactivate from the edges of these spots once conditions become cooler and wetter.