Dallas Morning News - June 5, 2019
Fruit Tree Diseases and Insect Problems
There is no "product" that will solve the insect and disease problems plaguing your fruit trees.
Don't get me wrong. There are several organic products that will kill or neutralize fungal diseases like brown rot and peach scab. Some of the choices include baking soda or potassium bicarbonate at a rounded tablespoon per gallon of water, garlic oil or essential oil products used at label directions, cornmeal tea made from soaking a cupful of whole ground cornmeal in 5 gallons of water and hydrogen peroxide mixed 50/50 with water. There are also commercial, properly labeled products.
However, all these products will do is temporarily shut down the disease pathogens or insect attacks. If the true cause of the pest attack is not addressed, the assault will re-establish and continue to be a problem. Toxic chemical disease control products work even less effectively because they kill the beneficial microbes more so than the targeted pathogens. The killing insecticides kill the pests but also hurt and kill the beneficials that can be part of the solution.
Fungal disease called "peach scab"
There are effective organic insect controls. For example, if borer beetle larvae are drilling holes and the trunk is bleeding, they can be shut down with orange oil. Mix 4 – 8 oz. of it in a gallon of water, paint it on the problem area and the borers will be killed. But once again, they will be back unless the real problem is addressed.
What works is to change the conditions that lead to the plant stress that weakened the tree enough to allow the pathogens or the insects to move in. The stress causing conditions can vary. Planting ill-adapted fruit tree varieties is a common cause. Use varieties recommended locally and plant several different varieties to give yourself the best odds as the weather changes unpredictability. Poor drainage, contaminated soil, compacted soil, wrong sun conditions can also be causes. Correcting these environmental problems is important.
Seeping is evidence of borers in a young tree
However, the most common cause of the stress is buried plants. Fruit trees being too deep in the soil is the most common problem I see. Gardeners and farmers that think that their trees are planted high enough with the proper amount of trunk fare exposed are usually wrong. The flares of all woody plants need to be dramatically exposed. Flares are part of the trunk and need to breathe. They can't breathe when buried in moist soil or mulch.
Although being the most important step of the Sick Tree Treatment, exposing the flares properly is only the first step. Here's where I provide the details of the rest of the procedure.