While no fruit tree owner wants to have to spray her fruit, if the trees come under siege from pests, it may be a choice she has to make. While there may be some increased risks with pesticides, both to the harvest and the consumer, these can often be mitigated with proper pesticide application and cleaning. Knowing what to buy and when to apply it are keys to getting the most out of a fruit tree spray.
Insect sprays for fruit trees should be effective enough to take care of the pest problem, but yet have a low toxicity for humans. One of the most common active ingredients is carbaryl, which is sold under a variety of brand names. Malathion is also common in fruit tree sprays. Permethrin, which also has a low toxicity, is less common, but also found in some products. Never use general purpose pesticide on fruit trees.
When possible, make sure you identify the pest causing the problem. If you are unsure, take a sample to a local extension office, which should be able to help. Some pests, for example, respond better to certain insecticides. For example, malathion is very effective against the strawberry bud weevil. Carbaryl, on the other hand, is a good choice for various types of aphids, apple maggots and the cherry fruit fly.
Almost as important as choosing the right product is knowing when to spray. Generally speaking, all spraying for insects should stop during the blooming season. This is because the insecticide could kill beneficial pollinators, such as bees. If you are using a spray that includes both a fungicide and pesticide, you may wish to switch to a straight fungicide spray at this point. This protects the bees, yet still provides protection against fungal diseases.
Always be aware that the fruit you are spraying is eventually going to be eaten. Take all precautions necessary first by purchasing a spray specifically for fruit trees. Spraying should generally end several weeks before harvest, which is usually around the end of August or beginning of September for apples and pears. This allows time for the pesticide to break down and be rendered harmless. Always wash the fruit, no matter when the last spraying was.
Some fruit tree insecticides may use endosulfan, a highly toxic pesticide dangerous around children and pets. If you use this product, make sure children and animals do not have access to the trees and keep the bottles out of reach. Generally, it is safe to allow children and pets around the trees 24 hours after application, but some commercial products may require 72 hours before being rendered harmless to humans and animals.