Keeping girdles safe from Psa

Previous Plant and Food Research (P&FR) trials showed that Psa can enter kiwifruit plants via girdles, remain within the girdle for at least five weeks, and move from the girdle point through the plant.

Cleaning and sterilising girdling tools between plants is therefore strongly recommended as best practice to reduce risk of introducing and transferring Psa between plants.

A recent P&FR report monitoring the effectiveness of wound protectants against Psa has also shown that the current grower practice of spraying girdling wounds with a solution of label rate copper was sufficient to prevent infection of girdles. This practice also allowed wound healing, with callus formation not obviously inhibited by application of the Nordox solution. Previously, science had shown that unprotected girdles can be infected for at least 15 days after girdling. This new result supports recommended best practice.

The report also notes that neither copper paste nor Inocbloc paste should be applied to girdling wounds. Copper paste did not provide protection and application of Inocbloc interfered with wound healing. These products were however the most effective wound protectant on pruning cuts.

A copy of this report will be available shortly on the KVH website.