Waimea Nurseries

How to Guide

Pest & Disease Prevention

Very few of us want to spray our fruit trees, but especially young fruit trees can be susceptible to pest and disease infections. Preventing infections with a few well timed spray applications will help to ensure a bumper crop of fruit and a healthy tree. New generation products are usually organic-based and are very effective. For deciduous fruit trees the following programme is recommended as best practice to prevent pests and diseases:


Spring (August-October)
Timing is very important, as the spray coverage is essential to prevent rapidly multiplying disease spores infecting the tree during flowering and coming into leaf – a very vulnerable time. Apply a fungicide like Yates Liquid Copper pre-bud burst and 10-14 days later (or immediately after rain if raining more regularly than this). Use the rates and frequency as recommended on the label of your preferred fungicide as it will vary between brands and products.

For pipfruit trees (apples, pears, quinces, nashis), hang a codling moth pheromone trap about half way up the tree (one trap is sufficient for three to five trees). The trap releases a pheromone which attracts male moths and means fewer eggs and larvae. The traps should not be used as an entire prevention method though, and should be monitored during September and October to determine the levels of male moth activity. When there is a high level of activity, spray with Yates Success ULTRA.

Summer (November-March)
Apply Yates Fungus Fighter up to four times during Summer to stonefruit trees to prevent Brown Rot disease. Do not apply within 35 days of harvest.

Autumn (April/May)
When the leaves have fallen, apply a good coating of Yates Liquid Copper to smother disease spores that can over-winter and re-infect the tree in the following season.

Winter (June/July)
Timing is less critical for the Winter (or dormant) oil spray. Use Yates Conqueror Oil, to smother insects, eggs or larvae, when the tree has no leaves or bud development.



For citrus trees only a few spray applications are required. In late Spring/early Summer (November and December), after petal fall and when the fruitlets have formed, apply Yates Liquid Copper to prevent verrucosis, brown rot and thrips. Repeat this in May and June. In February, use Yates Success ULTRA to control scale insects.