Managing Psa risk this long weekend

31 May 2018

The KVH Psa Risk Model is predicting high-risk weather through Queen’s Birthday weekend and continuing into next week. Risk will be moderate for most regions from Saturday, while Monday through Wednesday risk builds to severe, reducing again from Thursday onwards. The higher risk reflects predicted rainfall, coupled with lower temperatures as we move towards winter.

Growers are urged to be proactive in applying winter rate copper sprays immediately after harvest, and again as needed to ensure fruit stalks, leaf scars and any wounds created by frost or wind damage are protected prior to high-risk weather periods such as these.

For more sheltered blocks where leaves are still in good condition a second Actigard may also be considered to provide additional protection as leaf-fall continues. Actigard may be tank mixed with copper but avoid spray drift onto unharvested fruit and wash sprayers out thoroughly afterwards.

Dropping strung canopies at risk of storm damage is also best practice as canes up strings are not adequately protected by sprays. Experience has shown canes damaged through autumn often suffer more Psa symptoms the following spring.