Going head-to-head with weeds Controlling marestail and other weeds
May 9, 2013
Farmer Claygatt Shulda in Cuba, Kan., is going head-to-head with weeds; spraying for marestail and all weeds now while the pesky plants are easier to control in the early stages. Having farmed for 30 years, Shulda, a third generation farmer in North Central Kansas, enthusiastically prefers prevention, rather than being behind the proverbial eight-ball; and having to do damage control later. As soon as the extended cold winter gave way to warmer temperatures as April ended, Shulda was outside; getting his sprayer ready, and heading out to his fields.
"I'm putting a pre-emergence herbicide down; Authority First. I do it once a year for soybeans. Although I haven't seen much marestail; it's probably a little too cool for it, but once this herbicide gets in the ground, it's supposed to kill whatever might be coming up," said Shulda, as he climbed up in the sprayer cab. In addition to Authority First, Shulda also simultaneously sprayed 2,4-D and Round-Up.
The full complement of spraying takes Shulda a week to tackle his eight fields because he plants corn at the same time.
Farmers are being advised to plan now to control any spread of marestail in their soybean fields. The horseweed is already rearing its telltale signs in some Kansas fields. Experts say it's currently more prevalent in central and Eastern Kan., but has also been increasing in numbers in northwest Kansas. The only area in Kansas that doesn't have a big problem is southwest Kansas.
"Yeah, we've seen it," said Farmer Wayne Pachta of Cuba, Kan. "It's out there," Pachta told the Fence Post, as his sons and an associate helped spray their Republic County fields. Pachta sprayed 2,4-D LV6 and an Authority product that has residual.
"Authority will kill the weeds that are out there, and any seedlings that could develop. We'll be spraying for much of the week," relayed Pachta. He shared that he's intent on getting a jump on weed control, since Marestail is harder to get rid of later when it gets too big.
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The weather is the driver of soil changes and weed development fluctuation. Because of last year's dry fall and spring, fewer marestail germinated and survived the winter.
"Last year at this time — it wasn't common. We were way early in the growing season, and everything was three weeks early last year. There wasn't very much marestail," said Dr. Doug Shoup, southeast-area agronomist for Kansas State University in Chanute, Kan. "When it rains, like any seed, marestail will germinate and establish itself. It sprouted this past fall, and now that temps are starting to warm up, it's growing actively," said Shoup.
In fact, this 2013 season is already dramatically different from 2012.
"Now, we're about two weeks behind normal, and it's been really cold this year. Because last year's season was so early, and this year — so late, we're about five weeks different this year," Shoup said.
Shulda agrees. "The cool weather has affected more things, than the wet weather. It kept it dormant, but now it's starting to come up," Shulda observed.
Shoup and his counterparts spotted the marestail while scouting fields this winter, during research studies.
"We already see a more significant population in eastern Kansas. We had more moisture in the fall and marestail is more of a winter annual, so it tends to germinate in fall, and survive in winter. Therefore, when temperatures warm up in the spring — that's when it causes a lot of growth, and problems result," said Shoup.
"While some fields don't have any marestail, I have seen a number of fields that are pretty dense, and thick," said Shoup. He urges no-till producers to get a handle on marestail sooner, rather than later; especially with the imminent onset of soybean planting.
"For most farmers, planting gets in full swing whenever the soil warms up above 60-degrees, in mid to late May. We're getting warmer planting temperatures. Soybean planting may not be delayed, but corn planting sure is in Kansas," said Shoup.
Since soybeans are planted later in the season, and marestail usually germinates in fall or early spring, it's important to consider weed size and application timing for successful control of marestail.
Marestail is more of a problem with soybeans, than with corn.
"That's because corn has a few more options for weed control," said Bruce Ball of Rural Gas Incorporated, Belleville, Kan., an herbicide retailer.
The latest and most effective products to eradicate marestail, are chemicals that have been available for about a year.
"Sharpen is a pre-emergence chemical that seems to work pretty well. You spray it on the marestail before your crop comes up," said Ball. "As far as a residual herbicide in the soil, we have some producers who are using Authority First, which has residual in the soil and seems to control later-germinating marestail," Ball said.
Ball also recommends that an early application of 2-4D or Dicamba with Round-Up is important too.
However, there is a waiting period after applying 2,4-D and Dicamba. Each product has specific label restrictions for safe planting back to soybeans, so producers need to carefully read and follow label directions on each product before use, Dr. Shoup advised.
If time has gotten away from a farmer and marestail is already up and growing, then Ball recommends using an ounce of Sharpen with your standard use of Glyphosate or Round-Up. Glyphosate, a generic brand, is the same as Round-Up.
"If you want to plant soybeans in a timely fashion and you don't want to have a waiting period if using 2,4-D or Dicamba, you have to use a different product; possibly Liberty, Classic, or Firstrate tank-mixed with Glyphosate," said Shoup.
It's a good idea to scout your fields ahead of time to make sure you know what's there, in order to use the right products for the needed application.
For future years, Dr. Shoup says the preferred method is to control marestail in the Fall.
"There are a lot of options to control it in the fall when it's young. However, even this spring, we're two weeks behind normal growth due to the extended cold weather in Kansas, so we can still use growth regulator herbicide like the 2,4-D and Glyphosate until the plant starts to bolt," said Shoup. Bolting is when it starts to shoot its main stem up out of the rosette. "We just have to watch for the plant back restrictions to soybean. Once the plant has bolted, products like Liberty, Classic or Firstrate tank-mixed with Glyphosate are some of the better options for large marestail," Shoup said.
Meanwhile, farmers like Shulda and Pachta are bolting out to their fields with great anticipation for this spring season. There's no time for burning daylight. ❖