The Psa Risk Model predicts low-risk weather for most regions into next week, providing growers with a great opportunity to apply all-important post-harvest coppers.
Where there is no risk of drift to unharvested blocks, Actigard should also be applied to strengthen protection into the leaf-fall period. Most canopies are still in good condition with ample green leaves to absorb Actigard (see image below) but the window of opportunity for this product will close as leaves deteriorate and more frosts occur.
Advice is to also monitor blocks for evidence of Psa and check young plants and girdled vines for evidence of Psa symptoms. Focus on more Psa prone areas of the orchard first, and mark affected vines to prompt the removal of infections through winter. Flag possible hot spot areas and use this information to create winter pruning strategies, and spring monitoring.
KVH has this week received calls from growers who are seeing red exudate on girdles indicating Psa risk is still out there. Good proactive management will minimise orchard risk going forward.