Sorghum growers in the middle part of the country know this ancient grain is where untapped potential can be in their crop rotation. And now with new technologies to help control the ever-present weeds or grasses, sorghum is able to get an even bigger foothold.
In 2021, sorghum acres reached 7 million, with farmers harvesting 448 million bushels with the most acres in Kansas, Texas, Oklahoma, Colorado and South Dakota, according to the National Sorghum Producers. As a dual-purpose grain, sorghum fits into animal feeds, industrial or food uses. Most recently the ethanol market has seen “tremendous growth” with approximately 30% of domestic sorghum going to ethanol production, according to NSP.
Most often producers have trouble controlling grasses in sorghum simply because it is a grass species itself. Controlling grasses within grain sorghum crop has been difficult because of this. Often killing the grasses meant harm to the sorghum. Producers now have a couple more tools in the toolbox to help with these issues.
Currently there are three herbicide technologies now on the market, which often pair a seed hybrid with a herbicide. Those include iGrowth from Advanta, Double Team sorghum from S&W and ADAMA, and Inzen sorghum from Corteva. Both iGrowth and Double Team were planted on a significant number of acres in 2022, according to United Sorghum Checkoff Program Agronomist Brent Bean.
“These two companies (Advanta and S&W) have seed available with a range of maturities to fit different environments,” he said. “Inzen sorghum from Corteva is also available, but seed supply has been limited.”
Sarah Lancaster, Kansas State University Research and Extension weed specialist, said the labeled herbicide in the iGrowth system is IMIFLEX. The active ingredient in IMIFLEX is imazamox, which is the same as Beyond herbicide that is used in Clearfield crops. The only labeled herbicide in the Double Team system is First Act (quizalofop) from ADAMA.
“Inzen herbicide varieties, which can be treated with Zest herbicide (nicosulfuron or Accent in corn) have also been developed, but it is my understanding that they are not widely available,” Lancaster said.
Underwood, South Dakota, producer Travis Madsen has found these new technologies to be a problem solver.
“Last year was really dry and my (pre-emergents) didn’t work well,” he said. “I sprayed First Act herbicide on my Double Team sorghum and it worked really well. It was as good or better than any other sorghum field on my farm.”
Mike Cline, an Augusta, Virginia, producer, has had similar success.
“The Double Team sorghum has provided a viable and potentially superior option from traditional forage and grain crops, at a most efficient cost of production,” he said.
Lancaster elaborated and said, “historically, herbicides for post-emergence control of grasses have been very limited and not very effective.”
“That meant that if rainfall patterns limited the incorporation of pre-emergence herbicides, grass control was difficult to impossible,” she said. “In fact, crop rotation is one of the best ways to manage grassy weeds in grain sorghum, where there are effective options for post-emergence grass control in corn.”
Even though sorghum is well adapted to drought conditions, Bean warns it’s not a fix-all.
“This does not mean sorghum can grow without any rainfall, but it is able to withstand periods of drought longer than many other crops,” he said. “This ability to wait longer for water also makes it a good fit as a companion crop with other crops under irrigation.”
Typically sorghum needs a little help with those annual grasses that often plague fields during pre-emergence.
“These pre-emergence herbicides typically require a timely rain or irrigation to move them into the soil to be effective. Under drought conditions this may not occur,” he said. “These new technologies give the grower the ability to control grass post emergence if their pre-emergence herbicides fail.”
Bean said USCP, along with seed and crop protection companies, is stressing the importance of good stewardship with these technologies to prevent the development and spread of resistant weeds.
“We want these technologies to last for many years,” he said. “Growers should be careful to follow all guidelines set forth by the companies and can expect to see much more on this subject in the coming months.”
Kylene Scott can be reached at 620-227-1804 or [email protected].
