Psa risk is high
01 June 2017
Winter is here, bringing cold conditions and plenty of rain - both of which increase the risk of Psa infection and spread. This Whangarei weather station image emphasises this change, predicting severe Psa risk for the area throughout the coming week. Heightened risk is also currently predicted for Northland, Gisborne and Hawke’s Bay. All growers should ensure full winter rate coppers are applied, as soon as possible after harvest, to protect fruit stalk wounds and leaf scars through this high-risk period. Include spreaders to improve coverage of these difficult targets and, where leaf condition remains strong, application of Actigard is also recommended. A second application of Actigard can be applied to blocks which harvested early if leaf condition is still strong. Take care to avoid drift to unharvested fruit and wash out spray tanks and spray lines thoroughly to avoid the risk of contamination. In frosted areas or where vines have begun to shut down, ensure further copper is applied as leaves continue to fall. Remember late season canopies are difficult targets and impossible to cover with a single spray. Change direction of sprayer travel in consecutive spray rounds to help improve coverage. Pay special attention to high-risk areas of the orchard, such as those with high levels of leaf spotting through spring, or areas where you have previously cut out infection. Areas with new plantings or newly-grafted blocks also need excellent protection through this period.