Having your own fruit trees, whether it's just the one or a miniature orchard taking up your yard, can be a rewarding and low-labor experience. All you must do is make sure they stay watered and fertilized and you can expect a nice crop of fruit once a year; unfortunately that's around the same time all the insects show up. There are a few home remedies you can spray your fruit trees with that won't harm the coming crop.
Fruit Fly Remedy
Boil two quarts of water in a pot with two chopped cloves of garlic and five chopped jalapeno or habanero peppers. Once it's boiled, let it sit for a full day before straining out the solids and adding a cup of white vinegar. Spraying this over the fruit tree repels fruit flies in several ways. They are repelled by the oils in garlic. The capsaicin in peppers is the exact same chemical by which pain receptors in the body are activated. It does the same thing for fruit flies and causes extreme pain when introduced to the fly's mucous membranes.
Vinegar is acidic enough to cause irritation but not acidic enough to harm the tree. Not only that, but garlic can help protect against bacterial and fungal infections to the tree.
Aphids secrete oil, which protects them from pesticides and entrench themselves along the stems of fruit trees in order to consume the tree's moisture. Grate a cake of soap into a pot of boiling water. Add one teaspoon of hand dishwashing soap and three teaspoons of cooking oil. Include two teaspoons of caustic soda and then allow the mixture to cool before spraying it across the fruit trees.
It's not recommended that the spray come into direct contact with the fruit, as it has a strong surface tension that will keep the spray from dripping off the fruit, depriving it of air. This is essentially the same way the spray works on aphids. The soap cuts through the oil they secrete and the other materials are designed to cling to the aphid, obscuring its breathing pores until it suffocates to death.
Leaf Curl Disease Remedy
In a gallon jug of water dissolve 1/4 pound of slaked lime, also known as calcium hydroxide. Fit 1/4 pound of copper sulfate fertilizer into an old sock, stocking, or porous bag and soak in the jug overnight. Remove the bag and dilute the content of the jug with another gallon of water before spraying over the tree. This is what is known as a Bordeaux mixture, a traditional fungicide historically used to combat fungal infections in vineyards. The ions of the copper sulfate, having been freed by the lime in the solution, attach themselves to enzymes within the fungus. By doing so, the solution stops the fungus from propagating.