Technical Update - Sept 2018
Pre-Flower Girdles (PFG) are a useful tool for those orchards that historically show bud rot, sepal stain or multiple Psa infections - it is even possible to target specific vines that have previously shown symptoms. Often these vines are located in colder, wind-exposed areas. Last spring we used PFG on approximately 39 Ha, of females and on some males.
Important things to remember if opting for PFG are:
Never perform PFG on a stressed vine (as could hinder more than it helps).
In Hayward, PFG is best performed 30-40 days pre-flower.
Tools to use are a chain or double knife (remember tool hygiene between vines is very important).
Estimate flowering date at full bloom (80-90%), use historical dates & winter chill data.
By now all winter bases and the first round of side dressing have been applied to both green and gold varieties. It is essential to have the side dressings applied when recommended, in order for the nutrient to be in the soil and ready for uptake by the plants during periods of high nutrient demand.
With spring arriving we are seeing the Psa starting to move, and our team is busy removing anything we can find on our ACL orchards to reduce the amount of inoculum floating around. So far we have seen a reduction in Psa infection compared to last season, and the 2 weeks of fine weather has certainly helped!
Here are a few guidelines if you intend managing your own Psa monitoring and removal.
Monitor your orchard as often as you can.
Pay extra attention to HW males as they express symptoms first and are more susceptible.
GA males and females express Psa at the same rate and so every vine needs thorough inspection.
Use either ribbon or spray paint to identify vines with infections.
On subsequent rounds pay extra attention to vines previously marked.
For cut out:
Remove infected plant material 20cm back from any visual symptoms.
Use methylated spirits to sanitise tools.
Seal wounds to stop further infection.
Remove infected material from the orchard.
Keep up regular copper applications and time them in to follow Psa cut-outs.
If you require further assistance with Psa Management, please contact Ethan England - Horticulture Technical Manager on 021 0215 7062.