 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
BAM News
Some Common Leaf Disease In Our Gardens
If disease has been a problem in seasons past, spring is the time to consider prevention. Common diseases found in Central Indiana trees are Apple Scab in Crabapples (and of course Apples) and various types of Rust found in many varieties of Hawthorns and Crabapples.
Scab is caused by a fungus (Venturia inaequalis) and is usually brought on by cool, wet springs(sounds like springtime in Indiana). Symptoms usually start to develop on more susceptible varieties in June, following a cool, wet spring. The more obvious symptoms are spots on the leaves, yellowing of the leaves and eventually leaf drop. The best way to prevent scab is to select resistant cultivars. But should you have one that is growing in your yard that has scab, you must act in a preventative manner. To treat effectively you must apply a fungicide at the pink bud stage, just before the tree fl owers. Then again approximately 10 to 14 days after, and if feasible again in another 10 to 14. Finally, one more thing to help control scab is good sanitation. When infected leaves fall, cleaning them up before they dry up and turn to dust will help control scab.
Rust is a common problem in many varieties of Hawthorns and Crabapples in our area. There are several types of rust that will occur on Hawthorns including Cedar-Apple, Quince and Hawthorn Rusts(Gymnosporangium juniperivirginianae, G. clavipes and G. globosum). Rust is a fungus that requires two parties, a host and an alternate host. Junipers and Cedars are the alternate host for rust, and due to their abundance, it makes it likely you may have Rust fungi in your Hawthorn or Crabapple. Symptoms are spots the leaves, the development of aecia on the fruit( kind of a hairy looking fungus) and cankers on the twigs. Treatment for rust is similar to that of scab, it must be done in a preventative manner based on the stages of the trees leafi ng out and fl owering, for hawthorns that is right as the leaves are coming out, at fl owering, and again about 10-14 days later. Again as in all leaf diseases, good sanitation is key, keep those fallen leaves cleaned up.
One final thought on trees that have been diseased for several years, would be to do a fall root fertilization every few years to help them recover.
Copyright © 2007. BAM Outdoor Inc.