Weed Control Timing
Once alfalfa breaks dormancy and has appreciable new growth, most broadleaf herbicides can cause injury to alfalfa. When trying to determine whether to apply herbicides or not, remember in many cases the easiest and most economical solution for weed control is the first cutting.
May 20, 2010
“How late can I spray my corn?” or “How tall can my corn be when I spray?”. These are important questions to be considered, and the answer is not always obvious since delayed postemergence applications in corn have largely become a thing of the past.
June 24, 2010
Scouting will be key to stopping the spread of glyphosate-resistant Palmer amaranth in Michigan.
It has been almost three years (fall 2010) since Palmer amaranth resistant to glyphosate (Roundup) and ALS-inhibiting herbicides was first reported in Michigan. Initially, populations of this weed appeared to be localized to parts of St. Joseph and Kalamazoo counties. However, last summer more populations of Palmer amaranth were confirmed in nine Michigan counties: St. Joseph, Kalamazoo, Cass, Barry, Ionia, Clinton, Shiawassee, Gratiot, and Livingston. This weed is not native to Michigan and with resistance to glyphosate and other effective herbicides this weed is undoubtedly the toughest that Michigan growers have ever faced. In fact, in many Southern states where this weed is a problem it has been reported that the average increased cost to manage this weed ranges from $30 to $50 more per acre.
May 30, 2013
Studies conducted at Michigan State showed the highest yields and greatest weed control were observed where a residual herbicide was applied preemergence and followed by either glyphosate or glufosinate postemergence.
June 3, 2010
Wet conditions this spring have made it a challenge for growers to plant corn and soybean. Due to these planting delays, once fields are dry enough getting the crop into the ground will be the first priority. However, it is important to remember good weed control will be essential to get the most out of these crops...
May 20, 2014
Over the next 2 ½-months many Michigan dry bean fields will be treated with preharvest herbicides. Preharvest herbicides, also known as “Harvest Aids”, are used to desiccate or dry down “green” stem and leaf tissue that can hinder dry bean harvest. The main intention of preharvest herbicide applications is to desiccate weeds; however many growers use these herbicide applications to hurry along or even out the maturing process of dry beans. Currently in Michigan, there are four different herbicide options...
Posted August 20, 2015
Early season weed competition may be one of the biggest contributors to unseen yield losses in soybean. Appropriately timing postemergence herbicide applications is critical to preserving crop yields.
June 10, 2010
For most of us the use of glyphosate (Roundup) in Roundup Ready sugarbeets has made weed control simpler and more consistent. However, as with any changes in production practices there is still a learning curve to using this technology.
May 14, 2009
The colder than normal spring and recent wet weather has made it difficult to spray winter wheat this year for weeds. While we normally would have all of our wheat herbicides applied by now, there are still several fields that have not been sprayed...
May 15, 2014
When application timings are missed, common lambsquarters is often the number one weed escape. These escapes can reduce yield by competing for moisture and light, cause problems with topping and harvest, and produce seed that will lead to future problems.
June 12, 2008
Consider using a preharvest herbicide application in weedy soybean fields this year.
The lack of good row closure and challenges with weed control this season has left several soybean fields weedy as harvest approaches. Without a killing frost, the “green” stems and leaf tissue of these weeds can cause issues with harvest. Currently in Michigan there are four different herbicide options labeled as “Harvest Aids” to help desiccate or dry down the “green” stem and leaf tissue of weeds that can hinder soybean harvest. These herbicides are glyphosate (Roundup and several other formulations), Gramoxone 2SL (paraquat and other formulations), Clarity 4L (dicamba), and Aim 1.9EW (carfentrazone). Differences in these products include the speed of activity, preharvest intervals, recropping restrictions, and effectiveness.
September 20, 2012
Preharvest herbicide applications in dry edible beans have become more popular as growers switch to direct harvesting techniques. Herbicides used prior to harvest, also known as “Harvest Aids”, are used to desiccate or dry down “green” stem and leaf tissue that can hinder dry bean harvest. The main intention of preharvest herbicide applications is to desiccate weeds; however many growers are using these herbicide applications to hurry along or even out the maturing process of dry beans.
August 25, 2011
Not starting with a clean field will lead to soybean yield reductions.
May 5, 2011
There are several herbicide options available for weed control in winter wheat. However, weed control spectrums and the maximum stages of winter wheat growth when these herbicides can be applied can be very different.
April 29, 2010
As several no-till drills start planting fields, remember the importance of a timely burndown application.
April 29, 2010
The development of stacked trait technology and the increased interest in herbicide tolerant corn has led to an increase in postemergence herbicide applications for weed control. Postemergence programs without a residual herbicide applied at planting have their place, and can provide excellent season long weed control. However, important considerations that should be made include timing, herbicide resistance, and management strategies.
June 4, 2010
Managing weeds using stale seedbeds can reduce weed populations by stimulating the germination of seeds close to the surface so they can be managed prior to planting.
April 30, 2009
While the timing of glyphosate (Roundup, etc.) may not be as critical for weed control as some of the strategies that we currently use i.e., micro-rates and standard splits, there is still 50% of the acres that are planted with conventional sugar beets. Timely herbicide applications over these acres are critical for adequate weed control.
May 15, 2008
The drastic swings in temperature over the last several weeks have growers questioning what effect temperature has on weed control from burndown herbicide applications. Several years ago we conducted trials...
April 12, 2012
Frost usually helps desiccate these weeds, however if soybeans are ready to be harvested before weeds have dried down, there are a few herbicide options that growers can use as harvest aids to help desiccate or dry down “green” stem and leaf tissue.
September 17, 2009
In fields with emerged corn and no herbicide applied, growers have two primary options: to use an herbicide program typically applied before emergence; or switch to a total postemergence strategy.
May 7, 2009
Knowing what stage your wheat is at is critical when it comes to making decisions on what herbicide to use for weed control.
April 30, 2009
Making one more glyphosate application in Roundup Ready soybean is tempting when weeds are poking through the soybean canopy. However, it is important to remember that there is a maximum soybean growth stage for which glyphosate can be applied to Roundup Ready (glyphosate-resistant) soybeans.
August 6, 2009
Of all the crops grown in Michigan, winter wheat has typically been the crop that has not been intensively managed. However with higher wheat prices, growers are looking at more intensive management to maximize yield.
April 17, 2008
Glyphosate-/multiple-resistant horseweed (marestail) is fairly common in many of Michigan’s no-till soybean fields (Figure 1). In fact, of the 18 horseweed samples that were tested for resistance this winter by MSU Diagnostic Services 100% of them were resistant to glyphosate (Group 9) and 78% of them were resistant to both glyphosate (Group 9) and the Group 2 (ALS) herbicides. Because of resistance problems and weather conditions that favored horseweed emergence last year, horseweed control failures were common in soybean.
April 14, 2016
There are several things that should be considered to maximize postemergence weed control with glyphosate from these applications in Roundup Ready soybean.
May 28, 2009
With the wet conditions keeping many growers out of the field, soybean planting is occurring at a slower pace and once conditions are favorable many growers may opt to plant first and apply a burndown later. However, it is extremely important that weeds that are currently in fields be controlled prior to soybean emergence.
May 14, 2009
Over the next month, many of Michigan’s winter wheat acres will be treated with herbicides for weed control. While there are several herbicide options available for use in wheat, there are many factors that growers should consider prior to deciding when to spray and what products to use.
April 14, 2016
While glyphosate continues to provide excellent control of most weeds, timely applications before planting and after soybean emergence are necessary to ensure the best growing conditions for your soybean crop. The following recommendations are based on MSU research funded by the Michigan Soybean Promotion Committee (MSPC).
May 7, 2009
Preemergence herbicides should be applied as soon after planting as possible because delayed application increases the risk of poor herbicide performance, especially for grass control. However, there can be challenges for herbicide application following planting, such as high winds and rainfall.
May 1, 2008
Several studies have shown that delaying postemergence weed control strategies can substantially reduce crop yield. This has become more of a concern with the large number of glyphosate-resistant crop acres that rely on postemergence applications of glyphosate for weed control.
June 5, 2008
There are several things that should be considered to maximize weed control with glyphosate from these applications in Roundup Ready soybean. Following these guidelines can help reduce the risk of glyphosate failures, as well as reduce the chances of lower soybean yields due to weed competition.
May 29, 2008
Driving around the state I have noticed several no-till fields that still have carpets of winter annual and some newly emerged early summer annual weeds, like common lambsquarters and giant ragweed. With soybean planting is in full swing, it is extremely important that these weeds be controlled prior to soybean emergence.
May 15, 2008
The flexibility in application timing that glyphosate offers may make it easier to control larger weeds, however the benefits of early-season weed control to protect crop yield can be lost if applications are not made in a timely manner. Additionally, untimely applications can lead to a reduction in weed control.
May 1, 2008
No-till soybean production in Michigan relies almost exclusively on glyphosate for preplant and postemergence weed control. While glyphosate continues to provide excellent control of most weeds, timely applications before planting and after soybean emergence are necessary to ensure the best growing conditions for your soybean crop.
April 2, 2008
Early season weed competition may be one of the biggest contributors to unseen yield losses in corn and soybean. Appropriately timing postemergence herbicide applications is critical to preserving crop yields.
June 1, 2006