Thursday, January 24, 2019

Inspect Your Trees Regularly for Symptoms of Disease

On the market today you can find products designed to treat fruit trees from multiple diseases like insects, mites, fungi, and bacteria. These products are called all-in-one products and are suggested to be used on a regular basis in order to ensure that your tree is healthy and free of all diseases. Although this sounds like a good idea, we strongly discourage the use of these products. This article will discuss the dangers of blindly spraying your fruit trees, and why regular inspections will improve your tree's health and save you money in the process.

Not All Fruit Tree Diseases are Treated the Same

Fruit tree diseases can be classified into several categories, each category is treated in a different way. Fungal diseases for example are treated with sulfur and/or copper, where as insects can often be controlled with barriers, traps, and biological controls. By visiting a garden center or big box store you can find hundreds of different control measures for pests. Some of which are a mixture of several chemicals that treat different types of pests. This can take the guess work out of what to spray.

Timing is Critical for Disease Control in Fruit Trees

Fruit trees change throughout the year from dormancy, blossom, leaf, fruit, abscission and then back to dormancy. Diseases also follow similar patters. For example, the Greater Peach Tree Borer hatches from an egg as a caterpillar, bores into the bark of a tree where it feeds on the cambial layer,  pupates, emerges, flies around seeking a mate, and then lays a new generation of eggs. It is important to interrupt this insect's life cycle before the disease becomes an infestation. When the larva is inside of a tree's bark, it is protected from pesticides making this pest a difficult one to control. When the adults emerge and before they lay their eggs is the best time to treat for this pest. The problem is, Greater Peach Tree Borers do not emerge at the exact same time each year. A treatment too early or too late will result in undesirable results. When using a pre-mixed solution designed to treat all fruit tree diseases, you will be instructed to treat your trees on a four to six week interval. You may or may not time your application according to the emergence of this pest making your application ineffective.

Fruit Trees Change Throughout the Year

Regular Inspections of you Fruit Trees Will Help you Identify Symptoms of Disease

Many Fruit Tree Diseases are difficult to identify. Bacterial diseases for example are microscopic and can only be viewed under powerful magnification. Finding symptoms of disease will give you hints as to what disease is causing the damage to your tree. When symptoms of disease first appear you can often treat those symptoms and prevent further damage to your tree. It is important that you identify these symptoms early, before your tree has become "infested". This can only be done by regular inspections.

Bacterial Diseases are Difficult to Identify

Using the right treatment for fruit tree diseases

Once you have identified symptoms of disease, it is important to research what disease is causing the symptoms. Some symptoms of disease look similar, but are caused by two very different diseases. For example, drying leaf margins could be a result of lack of water, too much water or improper water. Identifying the symptom may not be enough in this example. If the leaf margins are drying you may need to inspect your tree further to identify the disease. Checking the soil texture, past relative humidity, and past precipitation rate will help you know what your tree's watering needs are and comparing the tree's needs to what it has been receiving may give your the clues to identify the cause  of disease symptoms.

Once the symptoms have been identified and the disease has been discovered, it is important to treat your trees symptoms according to the disease causing the symptoms. Before reaching for a chemical treatment it is important to research the disease and to find the best treatment with the least impact. Some diseases are a result of environmental or cultural practices. For example, you can treat powdery mildew with a fungicide, but powdery mildew may be a result of water standing on the leaves of your tree. Changing you watering schedule might be enough to eliminate further spread of the disease. Also, as mentioned earlier, timing your treatment might be the difference of controlling the disease or not.

Why All-in-One Treatments are Not Recommended

All-in-one pesticides are a mixture of several products that will treat a large variety of disease. Although this sounds like a good thing, we recommend avoiding the use of these products for several reasons.

First, spraying a tree for disease when there are no symptoms or signs of disease will only interrupt natural process that keep diseases in check. For example, spraying insects when there is no damage to your fruit tree from insects will only increase the risk of killing beneficial organisms like lady bugs and praying mantises. Once beneficial insects have been removed from an ecosystem and an insecticide has worn off, your tree well become more susceptible to destructive insects like aphids, and caterpillars because there will be no natural processes to keep them under control.

Chemical Pesticides Could Increase Pest Activity
Avoiding all-in-one pesticides will also reduce your maintenance costs. Most pesticide labels recommend a preventative schedule that includes up to six treatments throughout the season. By inspecting your trees regularly, defining a threshold for disease control and only treating when symptoms of disease exceed the predetermined threshold, you will minimize the number of applications to your tree and save money in the process.

Finally, by avoiding all-in-one pesticides, you will avoid any long term affects to your health, the health of your pets and family, and the environment. For more information about the affects of pesticides to your health click here.

Thanks for reading. If you have any questions about fruit trees and/or fruit tree maintenance please visit, email me at, join our Backyard Fruit Growers Facebook Group or your can comment below.