Protect kiwifruit vines early with ACTIGARD
With NIWA forecasting a strong El Nino weather pattern this spring, growers can expect south-westerly winds and cool spring conditions. On the back of a cold, wet winter, Psa infection pressure in kiwifruit orchards is likely to be high.
”Psa bacteria can be present on the outside and inside of kiwifruit buds, with spring rainfall encouraging the multiplication and spread of the infection”, explains Andrew McIntosh, Territory Sales Manager for Syngenta based in Bay of Plenty.
“Newly expanding leaf tissue is particularly vulnerable to Psa,” says Andrew. “The highest risk period is one to three weeks after bud-burst."
“Best practice is to implement a robust early season disease protection programme to protect new leaf tissue and reduce the risk of leaf spot and bud rot developing. ACTIGARD® plant activator fits well in the Psa programme from 25 mm leaf diameter onwards as it stimulates the plant’s natural self-defence against Psa.”
“This early application of ACTIGARD® will take advantage of the systemic nature of the product, as it moves into and within the vine to protect rapidly expanding growth.”
The following is recommended when using ACTIGARD®:
- Make two applications in spring to give the best protection from Psa.
- Tank-mix a suitable copper product to give immediate protection from Psa infection.
- Make the first application from when leaves reach an average of 25 mm diameter.
- Make the second application 1- 7 days prior to flowering.
- Apply at 200 g per hectare, with 21 days intervals between applications.
Use of the Weather and Psa Risk Model, available on the Zespri canopy website is recommended to support applications for Psa protection. This online decision tool identifies the daily risk of Psa infection, based on forecasted weather variables and growers can then ensure adequate protection is in place prior to a risk event.
Andrew also urges growers to observe vines for stress around bud-break. “Common symptoms of water-logging stress – which many vines have suffered – include poor or delayed bud-break, small yellow cupped leaves and wilting. Exercise caution and apply an alternative Psa protectant while delaying ACTIGARD® application until vines show clear signs of recovery.”