Options for controlling volunteer potatoes in corn fields
Volunteer potatoes are emerging in Michigan corn fields. Control is crucial for preserving corn yield and managing potato pests.
As reported in the Michigan State University Extension article on potential risk of survival of potato volunteers from last season’s crops, it can now be confirmed that volunteer potatoes are emerging, especially in early-planted corn fields. Over the past three years of monitoring, it has been recorded that over-winter soil thermal conditions have been conducive for the survival of volunteer potatoes. In some years during the emergence phase of corn, the population of potato volunteers can be as high as 150,000 tubers per acre (see photo). It is not only important to control volunteer potatoes to preserve corn yield, but controlling volunteer potatoes is critical for the management of potato pests, such as late blight and other potato diseases and pests.
Currently, there are no herbicides available that will completely control volunteer potato. However, there are a few different options that will provide good suppression of volunteer potato and significantly reduce the number of daughter tubers per plant. MSU researchers Karen Renner, Chad Lee, Chris Long and Gary Powell had evaluated the effectiveness of several different post-emergence options for control of volunteer potato in corn. Herbicide treatments were applied when volunteer potatoes were between 4 and 6 inches tall.
From this research, Callisto (3 fluid ounces) + crop oil concentrate (1.0 percent v/v) + ammonium sulfate (17 pounds per 100 gallons); Callisto (3 fluid ounces) + atrazine (0.5 pounds active ingredient = 1 pt) + crop oil concentrate (1.0 percent v/v) + ammonium sulfate (8.5 pounds per 100 gallons); Status (10 fluid ounces) + non-ionic surfactant (0.125 percent v/v) + ammonium sulfate (17 pounds per 100 gallons); and Status (10 fluid ounces) + atrazine (0.5 pounds active ingredient) + non-ionic surfactant (0.125 percent v/v) + ammonium sulfate (17 pounds per 100 gallons) were the best options available for controlling volunteer potato, 28 days after treatment (Fig. 1). Additionally, these treatments stopped daughter tuber production, reducing the risk of transmitting disease to the next year’s potato crop.
Figure 1. Volunteer potato control with post-emergence herbicide treatments in corn
* Use glyphosate only on Roundup Ready corn.
Something to consider: of the treatments that provided good suppression of volunteer potatoes, Callisto and Callisto + atrazine are the only treatments that can be applied to seed corn. Corn inbreds vary in their sensitivity to herbicides including Callisto, so it is important to consult the seed company on their inbred tolerances to Callisto.
Drs. Sprague and Kirk’s work is funded in part by MSU’s AgBioResearch.