Drought unveils atypical crop issues

HOOPESTON, Ill. — The droughty growing season revealed some “oopsies” and unusual disease occurrences in fields.

Stephanie Porter, Illinois Soybean Association outreach agronomist, reviewed the 2023 growing season during an ISA Field Talk event.

“This year started out with a droughty-type situation, and I always like to say sometimes farmers find oopsies that would maybe be camouflaged in a normal year rain. There were a lot of those that were brought to our attention that we looked at,” Porter said.

“For example, we found some high pH situations. Also, weed control has been out of control. Normally, we do see some escapes towards the end of the season. This year has just been unbelievable as you drive across the state.”

Porter is often contacted to visit a field and determine the cause of a soybean problem.

“I’ve been called out to find things that may have been misdiagnosed or things that maybe people like to blame the chemical for a lot of times,” she said.

“One of the things in this part of the state that we have been seeing with the dry weather last year and now more dry weather is earlier in the season there could have been some herbicide carryover situations.

“We ran into some other weirder things in some parts of the state, and I think it had a lot to do with the drought, where there was some salt accumulation. That’s going to be more south of where I’m from (in Montgomery County). That was being blamed on chemical.”

Disease Pressure

There were also a lot disease issues reported across Illinois. The first issue of note was in late June after a derecho rolled across central Illinois.

About a week after the storm struck, Porter started getting calls and texts from farmers that they’re soybeans appeared to be dying.

“A lot of that was phytophthora root rot and stem rot. One project that ISA is funding with (Southern Illinois University plant pathologist) Jason Bond as well as (University of Illinois crops entomologist) Nick Seiter is on stem pests and stem diseases,” Porter said.

“At that time we were collecting samples of the diseases to get a better idea of what’s going on in the state. As an agronomist I think there were a lot of stem canker issues that were misdiagnosed. I’ve been seeing a lot of stem canker.”

Rain finally arrived after the drought, resulting in some “weirder things going on.”

“There was a lack of oxygen going on with the plants and then also a lot of nutrient issues. We were seeing a lot of phosphorous deficiencies. Not that there wasn’t phosphorous there available for the plant, but it was just due to the drought situation,” Porter said.

“We had a lot of stressed plants out there in certain areas and we found that was also with high pH. Then all of a sudden we get all of this rain and so a lot of pathogens like fusarium came in which is normally something that’s not a primary issue.”

Red Crown Rot

After the rainfall, red crown rot also started to pop up.

“Red crown rot is here and it’s here to stay. One of the questions I get asked is it real, and it is real. I think there’s a lot of misdiagnosis going on. So, we’re trying to get an idea and send plant samples into the plant clinic. Those are going to USDA Agricultural Research Service who’s trying to match where the disease is being found,” Porter said.

“I think a lot of people think it’s not that bad. In early September, I visited what I would call ground zero where they first found red crown rot in 2017 in Pittsfield area in Pike County.

“Disease cycles depend on Mother Nature. One year it might be bad, another year it might not be. Soybeans are every two years in a corn/soybean rotation. Two years ago, we talked to a farmer who has a field that made 10 bushels an acre because of red crown rot, but the field across the road made 70 bushels an acre. So, we’re seeing weird things with the disease.”

Red crown rot is similar to sudden death syndrome, but the difference is red crown rot has fungal structures on the exterior base of the stem.

“The even scarier part is red crown rot can have a very wide host range. SDS just affects soybeans. Red crown rot was originally found on peanuts. So, then we think it’s just on legumes or clover. No, it’s also been found on blueberries, as well as possible other woody hosts. It could be coming in our trees and other types of hosts. That’s what makes it scarier,” Porter said.

“At one time we were told we weren’t supposed to worry a lot about it, but it keeps popping up everywhere. It’s popped up throughout central Illinois. (ISA agronomy director) Abigail Peterson found it on one of her plots about a half hour south of Decatur.

“It is a disease that can be easily confused with SDS, stem canker, brown stem rot. If you ever had an issue and need help or you just want to send in a sample, I would encourage you to do that to give us an idea of where it’s at.”