RSSHelp available for commercial orchardists, backyard growers
This fungal disease caused by Stigmina carpophilum, results in purple spots on the leaves, as well as spots on the shoots and sometimes on the fruit. The fungus causing this problem kills leaves reducing the amount of sugar available to size up the fruit. When shoots are infected their growth is inhibited and the following years’ production is reduced. (Photo courtesy of Curtis Swift)
Curtis Swift, Ph.D., is an expert in horticulture with the Colorado State University Extension office in Grand Junction. He writes a monthly column about lawns and gardens for Real Estate Weekly.
Peach growers throughout western Colorado are gearing up for this season’s harvest, resulting in thousands of bushels of tree-ripened peaches.
One of the reasons why western Colorado peaches are known as the best in the nation is our dry weather and warm, sunny summer days. These conditions create a peach that is luscious and blemish free, at least in most years. This year is slightly different due to the moist spring weather we have experienced.
One of the problems I’ve seen throughout our local orchards is Shot Hole Disease caused by Stigmina carpophilum, previously known as Coryneum beijerinckii.
This fungal disease causes purple spots on the leaves, as well as spots on the shoots and sometimes on the fruit. The fungus causing this problem kills leaves reducing the amount of sugar available to size up the fruit. When shoots are infected their growth is inhibited and the following years’ production is reduced.
Once an orchard or a few trees in an orchard are infected with Coryneum blight it is very difficult to eradicate.
While the hard and crusty spots that form on the fruit reduce the marketability of the fruit, it is still safe to eat. Either cut off the infected layer of skin or eat these crunchy spots along with the rest of the peach.
I recently looked at a new planting of 100 peach trees that had been severely infected with Coryneum blight in the nursery the previous year. The growth rate of these trees was severely limited due to the blistering of the young bark as a result of this disease.
I recommended these trees be pulled and either buried or burned immediately. These young trees had already released and were going to continue to release spores that would cause the disease to spread to other areas of the orchard. Even though Coryneum is not unusual in our area, there is certainly no reason to increase the amount of disease potential by planting infected trees or allowing them to produce spores.
Our locally grown peaches give all of us a reason to look forward to this time of year. When there is a disease (or insect pest) in an orchard that can negatively affect the continuation of this industry, we need to be proactive and take care of the problem. That may mean applying a synthetic or organic chemical to correct the problem or tearing out the tree or trees to eliminate the source of the problem.
Commercial orchardists having problems with insect or disease problems can give me a call at 244-1840 to set up a visit.
If commercial orchardists have a concern with a neighboring orchard that is abandoned or mismanaged and is causing trouble for their commercial orchard and they live in the Upper Grand Valley Pest Control District (this covers much of Clifton and Palisade) a call to Karen Eslinger, the Mesa County Pest Management Specialist at 255-1721, may result in a visit to scope out the problem.
If you are a backyard fruit grower, ( i.e. not making a living off fruit production) and need a visit, contact Susan Rose at 244-1841 to schedule a house call by a Master Gardener. There is a $25 charge for this service. You can also bring samples of your problems to our office at no charge; we are located on the Mesa County Fairgrounds.
Whether you are a commercial or backyard peach grower and need more information on this disease give us a call at 244-1836 and we can send you the most up-to-date info available on how to manage this disease.
COMMENTS
Commenting is not available in this channel entry.