Summer has finally arrived. Hopefully yours is going well. The afternoon showers have helped to maintain soil moisture, where vegetables can become rooted in. This is also a good time to keep an eye out for foliar plant diseases, particularly on vegetables, since most plant diseases are tied to foliar moisture. We have also seen quite a bit of leaf spot on ornamental trees like maple trees, but for the most part this is strictly cosmetic.
When it comes to a plant disease, keep in mind that controls are always preventative measures. Once you see an active disease problem you have several options, but spraying to fix it, usually isn’t one of them. I tend to try my best to prune out any infected tissue, before the spores have a chance to spread. If there is plenty of air circulation and spacing, often times this will solve the problem. If rainfall persists, or if the plants are crowded, you might consider a fungicide application. Keep in mind these fungicides are meant to protect new growth, not to fix the infected tissue. Also keep in mind the fallen leaves or infected tissue is a vector for the disease to spread. Removing them from the garden is another key control measure to employ.
What happens if the plant completely wilts or collapses? In most cases this can be attributed to things like Southern Wilt, Bacterial Wilt or Tomato Spotted Wilt. In these cases it’s best to remove the plant completely from the garden and make a note as to the location. Most of these diseases can manifest themselves in the soil, so over the next few years you’ll need to employ proper crop rotation. When you do choose to plant back, try a variety that’s resistant to those particular diseases. It might not be your favorite variety in terms of flavor, but right now your focus in on success, not perfection.
We’ve also seen quite a bit of herbicide damage this season. It seems to be on the rise, and is an issue that is difficult to manage. Most often, the herbicides are coming in from mulch hay, or possibly manure. There are several herbicides that remain soil active for several years, so knowing the history of your hay or manure source is critical. Most common, problems come from producers who utilized Grazon or Milestone type products. The active ingredients of concern are aminopyralid and/or picloram. Once their applied to the area, they can remain active for up to 5-7 years. Tomato plants seem to be hit the worst since they are heavy feeders. It won’t always kill the plant, but often it limits production and is somewhat unsightly. If you have a severe case on your hands, it might be best to try sweet corn on the plot, or shift to another location. Rarely do we see “herbicide drift” these days. It’s all more tied to mulch or compost applications.
As your vegetables come into production you might want to consider canning some vegetables. There are several programs coming over the next few weeks that might be of interest. On June 20th at Freedom Park in Cleveland, GA Katie Hiers from Athens-Clarke County Extension will be offering a free Canner Testing Clinic from 9-11 at the White County Farmers Market. Also, on June 29th from 9-11 UGA Extension and Habersham Hardware will be teaming up for a Home Canning Class at the Cornelia store. Another option is to check our local Habersham County Cannery which should be poised for another active summer canning season.
For more information, contact your Extension Office at (706) 754-2318 or www.ugaextension.com/habersham.
About the Author: Steven Patrick is the UGA Extension Agent for the Northeast District. His office is based in Habersham County.
