Develop a year-round protective spray plan using KVH recommended products with different modes of action to maximise disease control. Always use label rates to avoid the risk of product resistance or tolerance developing. The success of any spray programme is reliant on good spray coverage.
KVH recommended product list
The list below includes protective spray products that can be used from bud break. Only products with ACVM registration for Psa-V efficacy are listed.
For a year-round list of spray products and rates click here.
For advice about managing resistance to Psa control products click here.
For rules around the use of bactericides click here.
Psa protectant products
Products can be grouped into one of five categories, which are each listed below.
Copper sprays are used in many horticultural industries to protect foliage and fruit from a range of diseases. Successful disease control depends on both an even distribution, and good retention of the copper across all plant surfaces. Copper is most effective on those diseases that need water present to develop - such as Psa-V. Click on the links below for more information.
Bactericides have very strict use conditions. Misuse of bactericides can result in fruit residue and/or resistance developing. Always refer to the User Guides. Bactericides should always be used in a spray programme with other recommended products with different modes of action. Alternate between bactericides to minimise risk of resistance. Bactericides should only be used in high-risk situations and where Psa-V is present.
Elicitors are products that induce the plants defence mechanisms allowing them to fight infection. Generally, there is a time delay between the spray application and the elicitor effect being activated. The effect is relatively short term requiring additional applications. Knowing beforehand when an infection will happen and applying the elicitor appropriately is likely to be the key to success. Use Elicitors carefully as overuse can induce the plants to shut down resulting in decreased plant growth.
Biological control agents are more suited to use where disease risk is lower. Their mode of action is the same as copper sprays; acting as a protectant. They can provide this in a number of ways including:
- occupying the sites the pathogen would normally reside in;
- competing against the pathogen for food; and
- producing anti-bacterial compounds that kill the pathogen.
The specific mode of action of CPPU products is unknown. There is a time delay between the spray application and the CPPU effect being activated. Apply before leaf spot symptoms are seen. No efficacy in reducing flower bud loss.
Additional spray resources
Kiwifruit Spraying Factsheet 1: spraying issues and terminology
Kiwifruit Spraying Factsheet 2: interpreting chemical labels
Additional spray resources for assessing spray coverage
Sprayer prescriptions for protectant sprays on spring canopies
Reminder to comply with Regional Council rules when spraying
Growers are reminded to comply with Regional Council rules when spraying. More information can be found on the NZKGI website.