Fruit Spray Schedules for the Homeowner

• Bruce A. Barrett
  Department of Entomology
• Michele R. Warmund
  Department of Horticulture
• Patrick L. Byers
  Department of Fruit Science, Southwest Missouri State University

Fruit plantings can be a source of beauty as well as fresh produce. However, for the inexperienced grower, they also can be a source of frustration and expense. Nursery catalogs are full of brightly colored advertisements depicting bountiful harvests of unblemished fruit. Harvests like these are possible, but only with careful selection of the fruit cultivar (cultivated variety) and with diligent pest management. Weather conditions in Missouri, such as high humidity, abundant rainfall and warm temperatures, increase disease and insect populations. With few exceptions, home fruit plantings require treatment with pesticides to control a variety of serious diseases and insect pests. Pesticides needed and frequency of application depend on the cultivars planted, location of the planting, weather conditions and cultural practices.

How to use this guide

These Web pages are subdivided into:

• Pome fruits
  • Apples and pears
• Stone fruits
  • Peaches, nectarines, plums, apricots
• Small fruits
  • Blueberries
  • Cherries
  • Grapes
  • Gooseberries and currants
  • Raspberries and blackberries
  • Strawberries

Within each section are listed the major developmental stages of the plants and the associated pests (insects and diseases) frequently occurring during each plant stage. These developmental plant stages are also referred to as "spray periods" when an application of a given pesticide is recommended in order to control a specific pest(s). Effective control of fruit insects and diseases depends on the proper timing of pesticide applications, and these spray periods indicate to the homeowner when certain sprays may be applied.

We have tried to list only the pesticides readily available to the homeowner at most nursery and garden, hardware, and home improvement centers. The pesticides are not listed in any particular order of effectiveness, although some products may be more effective against some types of pests than another product. In many cases, one or two pesticides listed in a given spray period will be effective against all the pests listed for that time of the season.

Several commercial fungicide/insecticide combinations are available for the homeowner. These may be more desirable for fruit growers not wanting to make their own combinations of pesticides that are recommended in this publication. Commercial home fruit spray mixtures are convenient to use but may not control all of the insects and diseases found on all fruit crops because each product usually contains only one type of insecticide and fungicide.

Cultivar selection

Choose a cultivar with care. Consider adaptability to Missouri soils, climate and intended use. Remember, the cultivar planted may often determine the amounts of pesticides needed to produce a crop. For example, Jonathan apples are an eating favorite but must be sprayed to prevent mildew, scab, fire blight and rust diseases. On the other hand, several recently developed disease-resistant varieties have a flavor similar to Jonathan and have the advantage of requiring fewer fungicide sprays. Differences in cultivar susceptibility to diseases exist within each fruit crop. All cultivars must be treated for certain insect pests.

Application equipment

In most situations, apply a fine spray to all parts of the plant until some of the spray liquid runs off. For most brambles, grapes, strawberries and small fruit trees, the conventional pump garden sprayer is adequate. For larger plantings, you may prefer a motorized sprayer.

Whatever type of sprayer you decide to use, rinse it thoroughly and allow it to dry after each use. Many pesticides are corrosive. During a single season, corrosive action can ruin many types of equipment. In addition, pesticide residues remaining in the tank after one spraying may break down or interact with the materials used in the next spraying in ways that can damage plants.

How much pesticide?

Too often, home fruit growers think that if a small amount will control the pest for one week, then twice that amount will give twice as much control. This is a dangerous assumption and can put both the applicator and the plants in unnecessarily dangerous situations. Recommended rates are based on the amounts needed for control. Applications that exceed recommended rates contribute needlessly to environmental contamination without increasing control. Repeated applications at seven-, 10- or 14-day intervals (i.e., cover sprays) generally are required to protect growth developed since the last spray, or to replace spray residues that are no longer effective because of weathering and chemical breakdown.

Pesticide safety

Pesticides are poisonous to people and animals. Handle with care! Read the label! The label is the most important piece of information you will find on the proper use of the material and its hazards. Follow these precautions with all pesticides used:

• Read the label! Be aware of the toxicity of the material you are using and wear appropriate protective clothing.
• Observe any days to harvest or re-entry precautions.
• Store pesticides only in their original labeled containers. Keep all pesticides and utensils used to measure them in a locked storage area out of reach of children and pets.
• Wear rubber gloves and protective eye wear when measuring chemicals, preparing spray mixtures and during the application of pesticides.
• Accurately measure the amount to be used each time. Guessing can be hazardous and expensive.
• Do not prepare more spray mixture than is required for the job. Do not attempt to store unused mixtures for later use.
• Spray small amounts of excess spray mixture onto the fruit tree(s) being treated. Rinse water from the sprayer away from food plants, water supplies and children's play areas.
• Do not attempt to reuse any pesticide container. Rinse cans and bottles (add the rinse to the spray tank); then dispose of them by delivering containers to an approved disposal site.
• Do not purchase larger quantities of pesticide than you expect to use in a single season.
• If a pesticide concentrate from a bag, can or bottle is spilled on you or others, wash it off immediately. Change clothing if it becomes contaminated.
• Save the bees. Bees are often very sensitive to pesticides. Avoid applying insecticides or miticides during the bloom period when bees may be pollinating flowers.