Strawberries, Apple Tree Sprays
Spring-bearing strawberry plants that were set out this spring should have blossoms pinched off. New plants have a limited amount of energy.
If blossoms remain on the plants, energy that should go to runner development is used to mature fruit instead. Plants that are allowed to fruit will eventually produce runners, but those runners will not be strong enough to produce a good crop of berries the following year. For an adequate strawberry plant population and a good crop next year, early runner development is necessary. Early runners will produce far more strawberries than runners that form later in the season.
Newly planted everbearing plants also should have fruits removed for the first four to six weeks after planting so they develop a strong root system.
Apple tree sprays
Two common diseases on apple trees are cedar apple rust and apple scab. Though some apple varieties are resistant to these diseases — including Liberty, Jonafree, Redfree, Freedom, Williams Pride and Enterprise — most varieties are susceptible. For a description of disease-resistant varieties, go to http://ohioline.osu.edu/hyg-fact/1000/1401.html.
Fungicide sprays during April and May are critical to preventing disease on susceptible varieties. A fungicide that is available to homeowners and very effective for control of apple scab and cedar apple rust is myclobutanil (Immunox). There are several formulations of Immunox but only one is labeled for fruit. Check the label.
Sprays should be done on a seven- to 10-day schedule to keep the protective chemical cover on the rapidly developing leaves and fruit. An insecticide will need to be added to this mixture after petal drop to prevent damage from codling moths that cause wormy apples. Methoxychlor or malathion can be used as an insecticide. In order to protect bees, do not use any insecticide during bloom.
Although gardeners may continue to use myclobutanil throughout the season (but not more than 10 times), certain other fungicides are more effective on summer diseases such as sooty blotch and fly speck. Consider switching to Captan or to a fruit spray mixture about June 1.
A spreader-sticker can be added to the fungicide-insecticide chemical mixture to improve the distribution and retention of the pest control chemicals over the leaves and fruit.
A hard, driving rain of about one inch or more will likely wash chemicals from the leaves and fruit. In such cases, another application should be made.
You can find information on controlling insects and diseases on fruit trees in our publication titled, “Fruit Pest Control for Home Gardens” at http://www.ksre.ksu.edu/bookstore/pubs/c592.pdf.
Matt Young50 Posts
Matt Young is the Brown County Extension District director, as well as an agent in the area of agriculture and natural resources.