Across the South, rice farmers are beginning to strategize their weed killing game plan for the spring. Some farmers struggled with aquatic weeds early in the season last year, while others experienced resistant weeds later in the season.
Whether aquatic weeds or tough late spring weeds are the problem, researchers suggest starting the fight early will be the best defense in controlling weeds in 2010.
“We had an extremely delayed crop last spring due to wet weather, which also caused us to delay our herbicide applications,” says Charles Wood, manager at Crop Production Services in Cardwell, Mo. “Weeds were very hard to control after a certain point, and many of our farmers were left with an uphill battle the rest of the season.”
Eric Webster, weed scientist at LSU AgCenter, says getting out in rice fields early can greatly increase the success of your weed control programs.
“I suggest that farmers get in the rice field with a burndown residual application, like Valor, 30 days before planting or earlier,” Webster says. “This will help control weeds before they become a bigger problem.”
Weeds to look for this season
In many parts of the South, researchers forecast barnyardgrass to be prevalent in 2010, as well as other weeds, such as Pennsylvania smartweed and sprangletop.
“Sprangletop is the newest and hottest weed to hit rice farmers,” says Frank Carey, field market development specialist with Valent. “It’s critical to come in with a different mode of action and control this tough weed this season.”
With Clearfield acres at an all time high in 2009, using multiple modes of action is more important than ever.
“The absolute worst thing you can do for the development of herbicide resistance is apply a sub-lethal dose of a herbicide or not adequately kill a specific weed,” Carey says. “It’s kind of like an antibiotic; if you don’t take the full dose, your body builds up a tolerance to it.”
Carey suggests tankmixing Regiment with Newpath, along with UAN on Clearfield rice.
“Newpath is excellent on red rice, but it is not as effective on barnyardgrass. Even though Regiment is also an ALS product, it will effectively control barnyardgrass, as well as other aquatic weeds and broadleaves that Newpath won’t control – this process of fully and completely killing weeds can stop or delay resistant issues in rice.”
Aquatic weeds and broadleaves
In Louisiana, Webster says that many farmers also struggle with aquatic weeds, such as alligatorweed and pickleweed.
“One of our biggest issues is controlling aquatic weeds in our area. I recommend that farmers apply Roundup as a burndown and an application of Grasp or Regiment as early as possible following rice emergence,” Webster says. “Just like a burndown program, the earlier the better with postemergence herbicide applications – start controlling weeds as soon as possible.”
In Wood’s area, broadleaves, such as ducksalad, can cause major problems for rice farmers. “We have the most issues with the broadleaves, so finding a herbicide that can control these tough weeds is very important to farmers in my area,” he notes. “Regiment seems to be the best fit in our programs.”
Making the most of your herbicide
Think ahead for best results
With the broad spectrum of weeds that rice farmers can face across the South, researchers suggest finding a product that can control multiple weeds in a field.
“You need to make the most of the herbicide that you apply on your rice fields,” Carey says. “Finding a herbicide that has that ability to control both broadleaves and grasses will give farmers the most for their dollar.”
Wood agrees that broad spectrum weed control is essential to rice farmers.
“Weeds can really vary from field to field,” he says. “I stress the importance of finding a product that can tackle many different weeds to my customers.”
No matter if you have problems with aquatic weeds, broadleaves or even gly-phosate-resistant weeds, researchers stress starting early and finding a product with broad spectrum weed control will be the best strategy in fighting weeds this spring.
Archer Malmo, which represents Valent,
contributed information for this article.