Fixed copper sprays have a significant place in your apricot disease-fighting arsenal. Designed to avoid fungal and bacterial infections, they do not discolor foliage, they’re easier to mix and they’re more compatible with insecticides than some of the alternatives, such as Bordeux spray. One of the negatives of fixed copper sprays as that the protection they offer is not as long-lasting as the alternatives, so you may need to employ them more often, particularly during periods of rain.
The primary use for fixed copper sprays on apricot trees is in the control of shot hole disease, caused by Wilsonmyces carpophilus, a fungal pathogen. Also known as coryneum blight, the first signs of this disorder would be purplish brown splotches on fresh leaf. As the spots enlarge, the centres turn darker and brown specks may form in the middle. If the pathogen does not kill the buds in winter, the apricot tree’s fruit will develop similar ailments.
Timing of the fixed copper spray program depends on whether the apricot tree reveals symptoms of ear hole disease. If the tree revealed symptoms in fall, employ the fixed copper spray once the apricot tree’s leaf first looks. Reapply if new leaf reveals signs of infection and during periods of lengthy rain in spring. If the apricot tree’s leaf wasn’t infected in the previous season, you will just need to employ the fixed copper spray if symptoms appear on new spring leaf.
Use a conventional insecticide sprayer, such as a tank sprayer or, for a single tree, a hose-end sprayer. It’s important to follow the sprayer manufacturer’s instructions to ensure that it’s calibrated correctly. Typical stationary copper product labels instruct you to blend from 1/2 to 2 ounces of the item in 1 gallon of water, although instructions may vary according to manufacturer. Swirl the tank frequently during program to ensure the item remains mixed as you spray.
Fall is the time to confirm the apricot tree for disease and construct your spring spray program around the outcomes of the inspection. Pruning away infected parts of the tree as soon as symptoms arise helps keep the disease in check, as does ensuring that soil does not dash on to the leaf once you water. Copper spray is the best way, however, to protect your apricot tree and it must be implemented to ensure that all surfaces of the tree are covered.