Today, we received an e-mail from Dr. Don Huber, Professor Emeritus of Purdue University with expertise in crop diseases and plant nutrition. He linked to a University of Nebraska field report commenting about stalk rot diseases, specifically naming:
Anthracnose stalk rot
Fusarium stalk rot
Diplodia stalk rot
Physoderma brown spot
Dr. Huber’s comment, a bit tongue in cheek: “I don’t see any mention of Goss’ wilt top die back/stalk rot — or shank rot. Does it stop at the Nebraska border?”
We’ve tested corn for Goss’ wilt in northeast Iowa, and concur with crop consultants that it’s present in most fields in this region. Here’s a photo of the AgDia test strip results, demonstrating its presence in corn in our neighborhood.
As of Sept. 16, 2016, most fields of corn across Iowa have turned brown in the past three weeks.
What’s surprising is that Goss’ wilt hardly has gotten a mention among observers the past couple of seasons, although our consultant friends say it’s virtually everywhere in the Midwest.
Here are the stalks which we sampled for the AgDia test — taking pith from the root crown. This is GMO traited corn, probably a triple stack hybrid. Looks like the Bt wasn’t 100% effective.
Dr. Huber often points out that “Corn used to be one of our healthiest crops.” But in recent years, farmers have been resorting to more fungicides to extend corn’s life a week or two.
Below is an overview of the field where we pulled the random samples of stalks and roots. In most stalks, only the top few leaves are still green. Iowa crop consultant Dr. Michael McNeill has often asked seminar audiences in the past few years: “Why does corn die-down occur a few days earlier each year? What’s the real reason corn is so vulnerable?” This photo was taken Sept. 16, 2016.
Report published Sept. 16, 2016