Dr. Grow: Spray plan to help reduce orchard diseases

Each summer and fall several home orchardists give me samples of pears, peaches and apples that are full of disease and insects. They want to know what they can do about their problem

Unfortunately, when I get the samples, it is too late in the year to do anything about the problem. Therefore, before this season begins, I thought I would discuss a general spray and fertilization schedule to help most home orchardists reduce insect and disease problems in their fruit trees.

If you are starting a new orchard in your back yard, cultivar selection becomes very important. Some varieties of fruit trees are less susceptible to disease and insect problems when grown in this area. Other varieties have more problems. Check with your local garden center to select varieties that do well in this area.

If you already have trees growing on your property, then cultivar selection is not an issue. You must deal with the existing varieties.

Fertilizers should be applied each spring and fall for best results. Be sure you use a fertilizer, such as 19-10-5, that is formulated for fruit trees. Make sure the fertilizer also contains micronutrients. These elements, needed by fruit trees in small quantities, may be lacking in your soil.

Before I give you a spray schedule to use, I want you to understand the importance of proper spraying technique.

First, you must adequately cover the tree with spray to the point of run off.

Most fungicides control by contact. Therefore it is important to cover every square inch of the tree.

Second, consistency in spraying is as important as the selection of the right chemical and the adequacy of application.

If you put off a spray, or just forget about one application, all of your efforts for the season may be for nothing. Don't forget to make all of the applications at the right time.

I have put together a general spray schedule that can be used for most fruit trees. This will provide you with a general program that you can begin with. Depending upon results from year to year, you may want to make minor changes in the schedule to suit your own particular needs. Always follow the manufacturer's directions when mixing and spraying pesticides.

The first spray that you want to make is an application of dormant oil. This one-time application, made during the winter on a day when the nighttime temperature will not get below freezing, will help clean up scale and aphid problems.

During the winter you will also want to apply lime-sulfur to your trees. This product is a good clean up for fungal problems. Be sure that you do not spray this within 2 to 3 weeks of spraying dormant oils. Application of both products at the same time can cause some burning on your fruit trees.

Make an application of fruit tree spray when the flower buds have swollen, but before they are open. Fruit tree spray is a combination of a fungicide, miticide, and insecticide. This all-around pesticide should give you good control of most of the insect and disease problems that are found in orchards in this area.

The next application of fruit tree spray should be made at petal fall. Petal fall is that period when flowers are done blooming, and the petals begin to fall from the trees.

From then on, make applications of fruit tree spray every 7 to 10 days until early August. These cover sprays should be made consistently. Remember, don't forget to make an application and do not allow more than 10 days to go without making an application.

This general schedule, if used properly, should provide your fruit trees with adequate protection from insect and disease problems that affect the quality of the harvested fruit. Good picking to you.

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SPRAY SCHEDULE FOR FRUIT TREES

1 Apply dormant oil one time during winter.

2 Apply lime-sulfur in winter. Wait a minimum of two to three weeks after spraying dormant oil.

3 Apply fruit tree spray when flower buds are swollen but have not opened.

4 Apply fruit tree spray when flowers are done blooming and petals begin to fall from trees.

5 Apply fruit tree spray every 7 to 10 days until early August.