Wednesday, July 25, 2012

an apple tree with no apples



Before we know it, apple season will be here.  Apple trees can be finicky.  While they really are beautiful trees to look at, many apple trees won't produce apples every year.  For some trees it may even be a few years that it hasn't produced apples.  I often see apple trees in the middle of summer that the leaves die and fall off.  This defoliation will also result in lack of fruit.  If your trees are defoliating and are not producing apples, this is most likely due to apple scab.  Apple scab is a fungal disease most common in areas of relatively high rainfall and relative humidity. Because the scab fungus overwinters in fallen leaves, the disease can be partially controlled by raking and burning. However, fungicide sprays usually provide the only practical means of scab control in commercial orchards.
Correct spray timing during the primary scab cycle lessens the need for extensive fungicide applications during the later stages of disease development. The critical period for scab control is from the beginning of bud growth until the apples are 1/2 inch (1.27 cm) in diameter.
In order to properly control secondary scab, apple trees should be closely monitored for primary scab. Fungicides should be applied if one or two scab lesions per tree are present. Irrigation sets 12 hours or longer should be avoided.
There are two approaches to control of apple scab using fungicides. Protective, post-infective (kickback or eradicant), or a combination of both types of programs can be followed. The protective schedule is the least complicated, but usually requires more applications.
Sprays are applied as soon as susceptible tissue is exposed in the spring and every 7-10 days throughout the season if scab is present on the leaves, or until all of the spores are gone. The interval between sprays is dependent on the rate of growth of the host, weather conditions, and stability of the fungicide. Fungicides such as captan and dodine (dodine can also be used in a post-infective program) are examples of Protective materials.



Trees "R" Us, Inc. offers plant health care as well as a highly knowledgeable staff that includes 4 certified arborists.  When you choose Trees "R" Us, Inc. you can rest assured that you've made the right choice for your tree care, tree maintenance, and plant health care needs.  Trees "R" Us, Inc. services the North Shore and the Northwest suburbs of Chicago.  You can contact Trees "R" Us, Inc. via the web at www.treesrusinc.com or by phone at 847-913-9069.

Thanks for reading, 
Nick

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