Moderate Psa infection risk predicted

04 April 2019

The Psa Risk Model currently predicts moderate Psa infection risk for next week in most regions. This reflects increased Psa risk with autumn weather and provides a reminder to growers to again consider Psa management plans, particularly for recently harvested blocks and younger plantings.

For harvested blocks, best practice is to apply a copper product to protect all fruit scars. Winter rates of copper can be applied and Actigard may be added to the tank if there is no risk of spray drift to neighbouring unharvested blocks.

Apply copper alone if there is any risk of drift and then plan to follow up with an Actigard spray when neighbouring blocks have been harvested. Good spray coverage is essential and remember that for Actigard uptake leaves need to be active, so a good cover of green leaves in the canopy is needed. If blocks have suffered extreme drought stress apply copper on its own.

Also a reminder to trim out thick, hairy, late season male growth as this can be highly susceptible to Psa infection in autumn, particularly if frosted. Apply copper after male trimming rounds to protect wounds.