With drought concerns from last year, farmers have made decisions to best navigate what Mother Nature has given them while trying to find ways to increase their bottom line. Whether it is reducing tillage, cutting back plant populations and fertilizer, or switching the cash crop grown altogether, some farmers have made adjustments to their management plans. This growing season, we have been blessed with a cool wet spring in many areas throughout the Midwest, but it also delayed emergence in some earlier planted fields. This can open the door for some potential plant health issues which can cause problems later in the growing season such as lodging, stalk rot, etc.
Strobilurin fungicides do a great job controlling disease, but manufacturer’s supplemental labels list that their product will also have improved plant health benefits like improved plant tolerance to hail, drought, cold temps, and frost. Some labels also state that their use can increase tolerance to bacterial and viral infections and also improve plant use of nitrogen. These plant health factors are relevant, but fungicides do what fungicides do best - and that is treat foliar diseases such as gray leaf spot and southern rust.
That all being said, many farmers yield potential has increased dramatically from two months ago with the rainfall and may warrant increased management. To preserve yield potential this season it may be beneficial to use strobilurin fungicides to prevent disease and promote plant health. This spring some corn sat underground for nearly a month before it emerged, diminishing overall plant health which can make these plants more susceptible to diseases. With corn around $6/bushel, it makes more sense to fork out $28/A cost of spraying with only a minimum 5 bushel yield increase to justify an application.
When identifying what fields to treat, look for fields with hybrids that are susceptible to disease. These fields are more easily justified for fungicide application. Other contributing factors in addition to hybrid susceptibility are heavy residue (no-till) which can be an inoculum source for disease. Also, pay attention to these fields during extended cool wet periods which can vector disease. Finally, consider the management level of the field (i.e., irrigation, high plant populations, and high input rates) which can increase susceptibility of disease. The best two times to apply strobilurin fungicides are V4 to V6 when yield potential is determined or during pollination VT to R1.
If you have questions, contact your local Hoegemeyer District Sales Manager or Agronomist.