Psa protection and flowering

10 November 2022

This spring fewer orchards have reported high levels of Psa, but there are also pockets where symptoms have increased over the past two weeks.

Leaf spotting and tip dieback on RubyRed sites has been noted, as well as leaf spotting on young Gold3. Hayward blocks still need protection leading up to flowering to avoid flower bud loss on sites with Psa presence. Actigard and copper are pre-flower options for Hayward as well as Aureo Gold which can also be safely applied through flowering if needed on conventional and organic orchards.

A reminder to avoid applying Actigard to crops that have experienced a heavy frost and are still recovering.

Aside from the obvious frost damage symptoms, growers should look for yellowed leaves. If these symptoms are widespread, other Psa products prior to flowering are better options. If the crop has experienced only a light frost and has visibly recovered (green leaves and signs of vigour) Actigard and copper as a tank mix remains an excellent choice at preflower to protect the canopy through flowering.

Even with high crop losses Psa protection remains an important consideration. Failure to properly protect against Psa this season can result in disease carry over, meaning disease pressure is elevated both for both this season and the one following.

Growers holding stocks of nursery plants still awaiting planting are also prompted to ensure these are sufficiently protected. Younger plants are vulnerable and if left unmanaged, infection can pass readily between plants closely stacked or crowded together in bins.

View a photoset of recent Psa images here.