Q: How do you control corn earworm in sweet corn?
A: A lot of the pioneers at Acres U.S.A. in decades past have spoken about the value of monitoring Brix readings and having high-Brix plants to provide insect resistance and disease resistance.
There are some challenges with Brix readings, though. One is that you can have one location on the plant that has a high Brix reading and others that have very low readings. The key is that it is the location on the plant with the lowest Brix reading that is the indicator of overall plant susceptibility.
Sweet corn has been propagated to have an artificially high level of sugar concentrated in the kernel. If you measure that, you can have Brix readings of 24, 26, sometimes as high as 28 — and yet you can still have corn earworm. Why is that? Because when you measure the Brix on the silk, which is where corn earworms begin feeding, you often have Brix readings in the single digits — two or three or four. Genetics and breeding have been used to influence how sugar moves around inside the planet.
From John Kempf’s Eco Ag U session at the 2023 Acres U.S.A. conference. Get access to all of our recent conference archives by becoming a member at members.acresusa.com.
