Pest Management in the Mississippi Delta

In the Mississippi Delta, pest management is something Bubba Simmons is all too familiar with. The pest? Weeds. The chief offending weed? Palmer amaranth.

“The country thinks they have a bad herbicide-resistant weed problem, but in the Mississippi Delta, we’ve got a bad, bad problem,” said the soy checkoff farmer-leader from Leland, Mississippi.

Palmer amaranth is native to the southwestern U.S. and can grow up to 3 inches a day. It’s one of the most competitive and aggressive pigweed species. Season-long competition by Palmer amaranth at 2.5 plants per foot of row can reduce soybean yield by as much as 79%.

“We were faced with a real situation. If we didn’t adapt, we were gonna risk losing a crop,” said Simmons. “The weed pressure was so intense the last few years that if you didn’t have the application timed properly, or you didn’t have the right herbicide or use a pre-emergent herbicide, you just couldn’t stay ahead of the weeds.”

Staying on top means changing

Using multiple herbicide sites of action has been an effective tactic for Simmons. He’s also recognized the importance of application timing and proper weed species identification.

Non-chemical control measures, such as tillage, coupled with herbicides have worked for Simmons on his farm, but he knows he can’t use the same system forever.

“We’re always looking to change and are aware of the fact that we need to, so things like metolachlor or metribuzin work really well and continue to work really well. But we know we can’t ride that pony forever,” he added.

Although Simmons said he hasn’t changed his pest management strategy significantly in the last three to five years, he said there are several issues he keeps in mind. Ever in the front of his mind is flexibility based on each operation’s needs.

“You have to be flexible. You have to be able to adapt,” he said. “We get a lot of violent rainfall, a lot of rainfall in general, but you have to be able to adapt to your particular situation. The days of blanket application have come to a close.”

Simmons said herbicide tolerance traits built into seeds has been another tool he’s found valuable on his farm. University research and on-farm trials are what drew him to dicamba-tolerant soybeans and what continues to draw him toward new chemistries.

“Most of the soybeans in the Mississippi Delta, and all of the soybeans on my farm, are dicamba tolerant. That’s another tool we’ve been able to use, just like glyphosate or other pre-emergence herbicides,” he said. “But, we know that the life of those products is limited without proper stewardship.”

Looking all around

Stewardship isn’t just on the farm for Simmons. He said being conscious of what is going on around you is key to sustainable practices.

“Neighbors communicate a little more now than they did in the past. We’re all more aware of what technology is next door and what crops are next door,” he said.

Knowing what’s surrounding your farm needs to inform your practices. “You don’t want to apply anything that’s going to damage a neighbor’s crop. Back when you had just acres and acres of glyphosate genetics, it wasn’t as big of an issue. Now with 2,4-D, dicamba and other traits, you need to know what your neighbor is spraying. And they need to know what you’re spraying.”

Invest against the pest

Simmons works closely with a crop consultant to ensure things operate smoothly. Jason Fratesi, a consultant with Southern Ag Consulting, is also a Mississippi Delta native and well-versed with pest management in the area.

Fratesi said there haven’t been any new chemistries added to the market that have grown widely popular in recent years. As Simmons said, herbicide traits, such as dicamba- and glyphosate-tolerances, have regained popularity.

“It was old chemistry, but when varieties came out a few years ago that you could use dicamba over the top, it brought the chemistry back to life with a new purpose,” said Fratesi.

Revitalized technology has been a critical weapon in the arsenal for fighting Palmer amaranth.

“Palmer amaranth probably has more money spent on it than anything else,” said Fratesi. “The farmers here have done a really good job at controlling it, but there’s been a lot of money and effort put into fighting it.”

A single female Palmer amaranth can produce approximately 600,000 seeds, making the sheer volume tough to grapple with when trying to control it. The plant is also extremely adaptive, sometimes developing resistance to herbicide chemistries within a year.

“It builds up resistance to certain chemistries faster than any of us have ever seen,” Fratesi said.

Fratesi’s biggest piece of advice for farmers is to follow labeled application rates.

“There are a lot of areas a farmer could save money and cut costs, but pest management is not one of them,” he said. “The most expensive pest treatment is one that doesn’t work.”