Radio advertisements, email blasts, and other media are warning of corn diseases and the need for fungicides. Two months of humid, wet weather has allowed for disease development. It’s important to know what diseases truly are in your field before spraying a fungicide, particularly with today’s economics. Here’s what we’re seeing in fields right now in the Clay, Nuckolls, Thayer, Adams county area. Based on the diseases we’re seeing, we would recommend you scout your fields to know whether you have mostly bacterial or fungal diseases present. Consider disease pressure, where on the plant the disease is occurring, growth stage, and economics. We have had southern rust show up in 10 of the last 11 years I’ve been serving in this area. If you spray a fungicide at tassel, you may not have enough residual to ward off southern rust when it appears later, potentially resulting in the need for a second application. In our area thus far, I’m not seeing enough disease pressure in many fields to warrant a fungicide at tassel; consider delaying an application till later for economic and resistance-management reasons. Ultimately this decision needs to be done on a field by field basis. Please also see this UNL CropWatch article regarding fungicide application and corn growth stage. Although I don’t have a photo of it, I’ve also seen common rust in the mid and lower portions of corn canopies thus far.
Determining Your Needs
In the Clay County Fair Open Class flyer printed in the Clay County News, you will find the middle page pulls out and is a survey. Nebraska Extension in Clay County and our Clay County Extension Board have launched a survey to determine programming/information needs you deem critical to you and your families. We know that we provide crop, 4-H, and some horticulture programming and information, but there is much more that Nebraska Extension as a whole provides that we haven’t necessarily offered as much as we could in Clay County.
The survey is meant for those of you in Clay County, if you’d be willing to take less than 5 minutes to fill it out, we’d greatly appreciate it! You can also fill it out online at: https://www.surveymonkey.com/r/clayext. The survey will remain open till the conclusion of the Clay County Fair on July 12 this year. Please pass this information along to Clay County constituents as we’re trying to reach as many people as possible. It really is important that we receive as much feedback as possible. It’s important as the goal is to better serve you-and we can’t do that without your input! Please do take a few minutes and complete this for us as we’ve only had a handful complete it thus far. Thank you and please encourage others to complete it as well!
Early in my Extension career, I inherited the job of injecting trees with a solution of iron sulfate. There would often be a waiting list of people to help, particularly in Sutton, when they’d see the jugs hanging from trees. As a plant pathologist, I was concerned about how much damage we were doing to the trees with repeated injections every five years or so…if secondary pathogens would affect these areas we were drilling in the trees. I was also concerned about providing a free service that took a great deal of time and if we were competing with industry by doing so. Eventually we stopped providing the service but we do rent out the equipment and can provide the recommendations on how much iron sulfate to add based on tree diameter if you are interested. But you may be interested in another less invasive method instead.
You most likely will not see any changes the first year, although the grass under the tree may appear greener. The goal is to change the soil pH to make the iron more available to the tree in the future. This may be a process that needs repeated for several years in a row and while it doesn’t show instantaneous results, it will most likely aid in the longevity of your trees by reducing the symptoms without additional harm to the tree through injections.
Corn is approaching or at V7-V8 growth stage. A few weeks ago, we published research results in our UNL CropWatch website. That information can be found in the links below the video. If you are interested in trying this in your field this year, please see the Nebraska On-Farm Research protocals also shown below.