One of the most common questions I receive during this time of the year is: “When and what do I need to spray on my peach trees?” Before I get into the answer of that question let me mention that growing peaches and other fruit trees in Georgia and the southeastern United States in general is very challenging. One must understand that in order to grow healthy disease free peaches in our area, it is essential to follow a spray program. So today I want to give you an effective, easy to follow spray program so you can have fresh peaches this summer.
Spray programs are implemented in order to protect the developing fruit from fungal and bacterial diseases as well as insect pests. Some of the more prevalent disease issues in peach include: brown rot, scab, and bacterial spot and leaf curl. Out of these four disease issues brown rot is most damaging in terms of fruit loss. It is very difficult to manage in Georgia without fungicides. In most years, 100% of the ripening fruit can be lost to this disease in unsprayed trees. The severity of the disease can vary from year to year depending on the amount of moisture.
Insects also can cause a lot of issues in peaches. The most common include: plum curculio, peachtree borer, oriental fruit moth, scale insects, and mites. Plum curculio is the key fruit insect pest that attacks peaches in Georgia. These small, native weevils can cause injury all season long and it is difficult to scout well enough to spray only as needed. In most of Georgia, plum curculio damage is typically most pronounced from petal drop at the end of bloom through the end of April. Damage typically picks up again as peaches ripen. The peaches often produce gum at the sites of curculio wounds. Preventative sprays are the only means of effectively preventing plum curculio damage. These applications can be made with a tank or backpack pump sprayer you can find at your local feed and seed or garden center.
Now let’s get to the spray schedule. I am going to start at bloom because that is the stage most peach trees are in here in our area. Despite their being other potential applications prior to bloom; applications from bloom on through harvest I would consider essential for healthy trees and fruit. At bloom it is important to understand that you should not be applying an insecticide. This is due to the activity of pollinating species such as bees. However it is important that you apply a fungicide containing captan or myclobutinil during bloom. This should consist of one to two sprays, 7-10 days apart, depending on length of bloom and weather. This application is considered one of the most important preventative sprays for pre-harvest suppression of brown rot. The next applications will be triggered at three growth stages: petal fall, shuck split, and shuck off. At each of these stages of growth I recommend applying a fungicide containing chlorothalonil or captan mixed with an insecticide containing malathion, carbaryl, permethrin, or esfenvalerate. These applications should be reapplied every 7-10 days if wet weather occurs. Once shuck off is passed it is on to the summer cover applications which should occur every 14-21 days. During dry summers, summer cover sprays may not be necessary. These applications should consist of captan or sulfur mixed with an insecticide mentioned previously. Finally there are the pre harvest applications which consist of one 14 days and the second 7 days pre-harvest. These should consist of any of the same fungicides and insecticides mentioned in the previous growth stages. It is important to understand that these pre harvest sprays are extremely important for protection against brown rot on mature fruit.
Peaches can be difficult to grow here in Georgia due to heavy fungal and insect pest pressure. However following the spray guide I outlined above will give you a great chance at harvesting fresh peaches this summer.