By Jon Cooner
Imperial perennial forages are designed to perform for years with proper planting, Mother Nature’s cooperation and a little maintenance. Arrest and Slay are herbicide products offered by the Whitetail Institute to help you control weed competition in perennial forage stands. In this article, we’ll look at your entire weed-control arsenal and how Arrest and Slay fit into it.
Imperial perennial forages are designed to perform for years with proper planting, Mother Nature’s cooperation and a little maintenance. Arrest and Slay are herbicide products offered by the Whitetail Institute to help you control weed competition in perennial forage stands. In this article, we’ll look at your entire weed-control arsenal and how Arrest and Slay fit into it.
WEED CONTROL IN IMPERIAL PERENNIALS— GENERALLY
When we talk about “weeds” we’re referring to any plant that’s growing where we don’t want it. And again, that’s any plant — grass, broadleaf weeds, briars, ferns —anything that’s growing in our food plot that we need to control to keep it from competing with our forage plants.
A great way to get a good jump on weed control later is to do a good job of preparing the seedbed before planting so that the seedbed is as “stale” (free of growing weeds and dormant weed seed) as possible. No matter how good a job we do of preparing our seedbeds, though, odds are high that after we plant, weeds will return at some point. Weeds can appear from dormant seeds in the soil. Some weeds can produce millions of seeds, and many weed seeds have very thick seed coats, allowing them to remain dormant on or in the soil for years. Weed seed is also commonly introduced into our food plots by wind, animals, and even farming equipment.
In short, weeds almost always return, and we need to control them if we want our perennials to last as long as they should.
The good news is that most weeds can be effectively suppressed or controlled — if the right measures are taken, and timed correctly. Specifically, weed control efforts must be matched to (1) the forage we’re trying to maintain, (2) the specific weeds we’re trying to control and (3) performed at the optimum time in the weed’s life cycle.
PRELIMINARIES ABOUT SELECTIVE HERBICIDES
Following, we’ll be looking at some common types of weeds and methods that work best for controlling them. In many cases, the Institute’s two herbicide products, Arrest (a selective grass-control herbicide) and Slay (a selective broadleaf-weed herbicide) may be the best option. But that’s not true in all cases. Before using either, you absolutely must check the herbicide labels to be sure of three things: (1) that the herbicide will control the specific weeds you’re facing, (2) that it will do so without harming your forage plants if mixed and applied correctly, and (3) how to mix and apply them correctly.
This is an extremely important understanding. If you don’t read and follow the label directions, the herbicide may not control the weeds, or you can even damage or kill your forage plants. And that would be a shame, especially since the labels are so easy to access. They’re right on the back of the product packages, and the Whitetail Institute has even put them on its website along with an FAQ: www.whitetailinstitute.com/products/herbicides.
In the rest of this article, we’ll look at the best ways to control general weed types. Again, what follows will be general information. For control of specific weeds in your specific perennial forage stand, you should use a step-by-step approach. Herbicide labels clearly list the weeds the product will control, so your first step is to specifically identify the weeds you’re facing. Then, check the herbicide label to make sure the herbicide will control those weeds without harming your forage plants. If both are true, then follow the label instructions for mixing and applying the spray solution.
GRASS CONTROL
“When it comes to perennial maintenance, your first priority is to get any grass in the plot under control. If you don’t, grass can overtake the forage in a hurry!” — Dr. Wiley Johnson I can’t recall exactly how many times I heard Dr. Wiley Johnson, the Institute’s first Director of Forage Research, say that, but I know it was often. Dr. Wayne Hanna, who took over the reins as Director of Forage Research when Dr. Wiley passed away, has been just as firm in giving us this same warning. It’s also a caution we regularly hear from Dr. Carroll Johnson, the Institute’s Weed and Herbicide Scientist.
Arrest and Slay. Most grasses tend to reproduce through their root systems, so they are best controlled with a selective herbicide. The Whitetail Institute’s Arrest herbicide can be sprayed on any Imperial perennial forage stand, and it will control most kinds of grass. Some of the few types of grass Arrest won’t control can be controlled with the Institute’s Slay broadleaf weed herbicide, as long as the forage being maintained is clover (including Imperial Whitetail Clover) or alfalfa. (Do not spray Slay on any Imperial forage product other than Imperial Whitetail Clover, and don’t spray Slay on newly planted clover until the forage plants have grown to a height of about three inches and have unfolded all their leaves.)
BROADLEAF WEEDS
(Mowing, Slay) The term “broadleaf weed” seems to be somewhat of a catch-all for weeds that don’t look like grass, don’t have woody stems like briars, and aren’t vining plants. Unlike most grasses, which reproduce through their roots, many broadleaf weeds reproduce by flowering and reseeding the next generation of weeds. The two best ways to control most annual, upright weeds that rely on flowering are mowing and, in some but not all cases, spraying the Institute’s Slay herbicide.
Mowing. The Whitetail Institute’s published maintenance guidelines for all its perennial forage products include mowing. Specifically, mow your Imperial perennials a few times in the spring, and if possible one more time as fall arrives. Try to time mowing so that you take just a couple of inches off the top of the plot when you see the forage plants, or any annual upright weeds, getting ready to flower.
Periodic mowing helps your forage plants in two ways. First, it can break the reseeding cycle of many annual upright weeds that rely on reseeding to stay in our plots. Second, as lush, nutritious and attractive as Imperial perennial forages are, periodic mowing can help them be even more so, if mowing is timed to prevent the forage plants from flowering. The Whitetail Institute’s perennial forage products are designed to last for years without having to reseed themselves by flowering. Flowering robs plants of nutrients and energy, and if you time your mowings to prevent the forage plants from flowering you’ll keep even more nutrients and energy in the plants.
In most cases, mowing a couple of inches off the top of the plot a few times in the spring, and if possible one more time as fall approaches, is sufficient to control many annual weeds and keep your Imperial perennial as attractive and nutrient-rich as possible. Don’t mow more than a couple of inches off the top of the forage plants at any one time; doing so can remove too much foliage and may also accelerate evaporation of soil moisture. And of course, don’t mow at all when conditions are excessively hot or droughty.
Slay: The Institute’s Slay broadleaf-weed herbicide controls a wide range of broadleaf weeds, and it can be sprayed on Imperial Whitetail Clover, and on any other clover or alfalfa once the forage plants have reached a height of about three inches and unfolded all their leaves. Applied to clover or alfalfa in the early spring, Slay can provide excellent control of emerged weeds. Slay also provides sustained weed control of weeds that appear after the plot is sprayed.
OTHER WEED TYPES
Although the most common weed types we face in our food plots are grassy weeds and broadleaf weeds, there are others that routinely appear. Again, this article could not, and is not intended to, be an exhaustive discussion of how to control every type of weed. The Institute’s consultants are regularly asked about two other types often enough, though, to at least mention them. These fall into the broad categories of vining weeds (weeds that grow a vine and run along the ground) and woody weeds (weeds that grow upright on woody stems).
Slay can control or suppress many vining weeds in clover or alfalfa. If you’re facing vining weeds, follow the standard path toward control: identify the weed first, and then check the Slay label to be sure the herbicide will offer control. Selective herbicides generally won’t tackle most woody weeds. However, periodic mowing can provide control of some, briars for instance. Once you identify the weeds you’re facing in your perennial forage stand and check the Arrest and Slay labels and decide that either or both is appropriate for your intended use, you still have two more steps to take: you still need to (A) mix the herbicide solution correctly and (B) spray at the optimum time.
MIXING THE ARREST AND SLAY SPRAY SOLUTIONS
The components and mix rates for each herbicide are not the same for all weeds they’ll control. That’s yet another reason to read and follow the label directions for your particular situation. For example, consider the following information on adjuvants and fertilizers, which the labels say should be included in the spray tank with some herbicides, but not with others. An adjuvant is basically something that’s added to a spray tank when spraying some herbicides to increase the herbicide’s effect. The Slay label says that the addition of an adjuvant to the Slay spray tank is “required.” Without it, Slay can’t do its job. The Arrest label, though, does not require the use of an adjuvant, although the Whitetail Institute recommends the addition of an adjuvant to the Arrest spray solution, especially when the grasses to be controlled are mature annual grasses or perennial grasses.
The two main types of adjuvants are oils and surfactants. Although oils and surfactants both increase a herbicide’s effectiveness, they work in different ways chemically. Oils tend to make the herbicide solution much more active than surfactants do and also help the herbicide penetrate the plant’s leaf. Oils are either vegetable seed based or petroleum based.
Surefire Seed Oil: The adjuvant recommended by the Whitetail Institute for use with both Arrest and Slay is Surefire Seed Oil. Surefire Seed Oil is a vegetable-seed-based oil that contains an anti-foaming agent to help the user properly mix the herbicide spray solution.
Another tank additive you need to take into account is a high-nitrogen fertilizer solution or ammonium sulfate. The Slay label says this must be added to the Slay tank in some states, but that it must not be included in others. And the Arrest label does not require it at all.
By now, you should have the idea that the only way to know exactly whether or not you should use Arrest or Slay in a particular application and how to mix the spray solutions is to read the herbicide labels. With that clear, here’s some general information that may help you understand specific label information more easily.
Arrest Spray Solutions. Generally speaking, the Arrest label gives two main mix rates: one for seedling annual grasses, and a second, stronger rate for mature annual grasses and perennial grasses. Especially when dealing with the latter, the Institute recommends the addition of Surefire Seed Oil in the spray tank at a rate of one-half pint per acre of spray solution.
Slay Spray Solutions. The maximum amount of Slay that should be applied in any one calendar year is six ounces per acre. In some cases, a full six ounces is needed, but in most cases four ounces per acre is sufficient. Slay does require the addition of an adjuvant to the Slay spray solution, and again the Institute recommends Surefire Seed Oil at a rate of one half pint per acre of spray solution. Also include a high-nitrogen fertilizer or ammonium sulfate if the solution is to be sprayed in a state where a high nitrogen fertilizer component is required by the Slay label.
Small Sprayers. The Arrest spray solution can be easily prepared in quantities as small as one gallon at a time. With Slay, that’s a bit more difficult due to the comparatively tiny amount of Slay that will treat one acre (4-6 ounces, depending on weed type). When using Slay in small sprayers, the easiest way to correctly mix the herbicide solution is five gallons at a time, either directly in a 5-gallon backpack sprayer, or if a smaller sprayer is used then by mixing five gallons of spray solution in a new, clean five-gallon gasoline can and transferring the prepared solution to the sprayer as needed. If you have any Arrest or Slay spray solution left over after you’re through spraying, don’t try to store it. Instead, dispose of it according to the directions on the herbicide label.
TIMING ARREST AND SLAY SPRAY APPLICATIONS
While writing this article, I remembered something Dr. Wiley Johnson taught us years ago about timing Arrest and Slay applications “The optimum time to spray Arrest depends on the age of the grass you’re controlling. The optimum time to spray Slay, though, depends on the age of the forage you’re maintaining.” Here’s what he meant by that.
Timing the Arrest Application (by the Age of the Grass). The optimum time to spray Arrest is as soon as the grass emerges and begins to “actively grow.” Arrest enters grass through its leaves, so the grass must be actively growing to take the herbicide in. Also, if possible, Arrest should be applied before the newly emerged grass has a chance to mature its roots, which most grasses do once they reach a height of 6-12 inches. Arrest will still control most grasses once they mature, but you may have to use a stronger mix rate, multiple applications spaced a month apart, or both. As you can see, the optimum window for spraying Arrest isn’t very long. Accordingly, it pays to be diligent in determining when any grass in your perennial plot starts to actively grow. For folks who are able to monitor their plots every few days, the start of “active growth” will be apparent. Some of us, though, may not live close enough to our hunting property to regularly check our plots for grass growth. In such cases, our home lawns can be a good gauge. If your lawn is actively growing, it’s a reasonable assumption that any grass and weeds in your food plots are doing the same. But be sure exactly what I mean by “actively growing.” I’m not talking about the greenish tint most of our lawns take on as warmer weather approaches. Instead, I’m talking about seeing the grass actually growing, and in an active way. If you’re like me, that’s the point when you’ll see that your grass is growing and wonder if your lawn mower is going to start after winter storage. Again, the optimum window for spraying Arrest begins when the grass starts actively growing.
Timing the Slay Application (by the Age of the Forage). It’s a good idea to spray Slay when weeds you’re trying to control are still young. The more important consideration, though, is that Slay must not be sprayed on very young clover or alfalfa plants. Again, the Slay label provides specific guidance as to how to tell when newly planted clover and alfalfa are old enough to handle a Slay application.
Other Timing Considerations. As with any herbicide, don’t spray Arrest or Slay when the weeds you’re trying to control are dormant. Also, don’t spray either when the forage plants you’re maintaining are stressed due to excessive heat, drought or recent mowing.
For additional information on Arrest and Slay, check the product labels, which are on the back of the product packages and also posted on the Institute’s website at www.whitetailinstitute.com/products/herbicides. The Institute’s in-house consultants are ready to assist you with any questions you have about Arrest, Slay or weed control in general. If a fter reading the Arrest and Slay labels you still have questions about Arrest or Slay, call the Institute’s in-house consultants at (800) 688-3030 before you spray!
