Pre-flower trunk girdling - act now

Growers with green blocks at high risk of bud-rot infection should be applying a pre-flower girdle now to manage flower bud infection risk.

Sepal staining and leafspot are beginning to show on some Hayward and G14 blocks (see image) particularly in colder locations or where higher levels of Psa infection have occurred in previous years. These sites saw low levels of Psa symptoms through early spring but weather conditions have been conducive to an increase in risk of infection. Pre-flower trunk girdling can reduce Psa bud-rot and increasing fruit-set for both Hayward and G14 varieties. Best results are achieved when applied around 30 days before flowering. Many orchards are now within, or are fast approaching, this timing window. For best results apply full girdles to both male and female vines and avoid girdling stressed plants. Choose a low-risk weather period, apply girdles to stumps in preference to young scions, girdle to the correct depth and ensure tools are sterilised between plants. Even if sepal staining is already being seen, trial results suggest there is benefit in applying a pre-flower girdle. This tool is strongly recommended for at-risk organic sites. Leave some vines un-girdled to gauge the effectiveness of this technique on your site.