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Invasive grasses and the hay industry
Rezilon Herbicide as a grass management solution to support warm season perennials
Grasses such as Bermudagrass, Bahiagrass and other warm season perennials are the cornerstone of the hay market, planted firmly on our soils and acclimated to our temperate climate. With their deep roots in the south/southeast, they display a bright green color, strong yield potential and drought tolerance.
Herbicides have a wide spectrum of control but have been limited in some ways. While they can take on broadleaf weeds, it’s much harder for a herbicide to control a grass within a grass. And it is these grasses, crabgrasses and ryegrasses among others, that steal nutrients and water and have become a nuisance to the industry.
Rezilon® herbicide from Envu protects desirable grasses and controls unwanted grasses that grow in hayfields and other hay production sites. Essentially, it manages grasses within grass, a quality that few pre- or post- herbicides can maintain.
“We're targeting those annual grass species that are problems in the production of hay,” said Jason Belcher, Envu Vegetation Management Eastern Stewardship Manager. “We think we have a great tool that benefits hay producers, because they have limited options right now.”
According to Belcher, Rezilon not only provides a wide array of control for the annual grass species but is also more consistent in its level of control. “Rezilon herbicide, in our testing, has been very consistent from year to year, and from area to area that we’ve tested it in,” he said. “It’s been very consistent in the level of control it has given us on many of these annual grasses, including crabgrass and goosegrass.”
Managing Grasses Improves Hay Quality
Bermudagrass hay producers strive for high-quality, high-value hay and maximize production, cutting hay between 4-6 times per season. For a market invested in the equine industry, Rezilon boosts the nature and condition of hay into a greener product, while also restricting the types and amounts of weeds. In turn, Bermudagrass greens up as much as 45 days faster, resulting in a higher-quality cut at first harvest and increased fertilizer utilization. With additional control of resistant ryegrass, Rezilon reduces the drying time for cut hay and minimizes labor, cleaning and storage.
Weeds like crabgrass and ryegrass reduce the amount of desirable and useable grass within hay production. Particular attention is paid in the southern hay market, because crabgrass lowers the amount of Bermudagrass that is available and decreases the quality of the hay. However, Rezilon is a product helps increase yield and enhances hay quality.
That quality enhancement is due to an exceptional mode of action, which controls annual grasses that other products have not been able to. With a long residual, Rezilon offers a wide application window. It doesn’t require an exact timing, however it should be applied well before weed emergence for best performance. It can sit on the surface for weeks, with no degradation, while waiting on rainfall for activation.
Perhaps what is most revolutionary about Rezilon goes back to the beginning. It’s different from other herbicides in that it fills that void that other herbicides haven’t been able to. Rezilon works to control annual grasses while partnering to promote the health of the desired perennial grass species.
Belcher sums it up, “There's a wide array of broadleaf control products that are available, but customers don't really have a lot of options for controlling grass in their hay fields. And so, Rezilon really brings a new tool for their toolbox that they're able to use.
Intended Use/Activity
Will Rezilon® control perennial species?
Rezilon is a pre-emergence herbicide and will not control existing plants or those returning from perennial structures such as rhizomes or stolons. For plants that have already emerged or are perennial in nature, a POST application of Cimmaron® Plus or Pastora® may be needed.
Does Rezilon control perennial species germinating from seeds, such as dallisgrass, vaseygrass, or KR bluestem?
Rezilon has excellent pre-emergence activity on seed germination of many broadleaf and grass weed species. Weeds not listed on the label, including perennial species, may or may not be controlled. However, species are continuing to be evaluated for control and additional species will be added once enough supporting data is obtained.
What grasses can I treat with Rezilon?
Rezilon is labeled for bermudagrass and Bahiagrass pastures and hayfields. Other warm-season grasses may be treated provided the user treats a small test area to verify safety. Rezilon may not be used on cool-season grasses as injury may result.
What varieties of bermudagrass can safely be treated with Rezilon?
While Rezilon has been tested on several species of bermudagrass and Bahiagrass, not all varieties have been evaluated for injury. However, we do not anticipate injury to occur on any variety of either of these species.
If I burn my pasture off, will that impact Rezilon activity?
Studies from the western U.S. have shown the burning does not negatively impact Rezilon activity.
Application
What rate of Rezilon can I spray?
Rezilon should be applied at 3-5 fl oz/A in a single application, and no more than 6 fl oz/A in a 12-month period. For best control, Envu recommends a program approach with a February application of 3 fl oz/A followed by an additional 3 fl oz/A sprayed in mid-to-late-summer.
How should I apply Rezilon?
We recommend that Rezilon go out in a broadcast application of at least 15 GPA with flat fan or similar nozzles that apply a medium-to-medium/coarse droplet size to get the best coverage possible. A surfactant is not needed unless combining with a product that requires it.
Can Rezilon be applied to newly sprigged fields?
No. Rezilon applications should only be made to fields that have been established for at least one growing season. Rezilon will inhibit stolon rooting, which can delay establishment.
How long can Rezilon stay on the ground before getting rain or irrigation?
Rezilon can remain on the surface for several weeks without rainfall with no degradation from sunlight or loss in efficacy.
Can Rezilon be impregnated on fertilizer or applied with liquid fertilizer?
We do not recommend making applications impregnated on fertilizer as soil coverage may not be adequate and poor weed control could result. We do not recommend applying Rezilon with liquid fertilizers currently but are testing this further for future recommendations.
Can Rezilon be mixed with other pesticides?
We do not anticipate any mixing issues when combining Rezilon with insecticides and other herbicides. However, a jar test should be done to evaluate compatibility. Always follow the label for mixing instructions and follow the W.A.L.E.S method for tank-mixing. The individual products are added in this order:
W – wettable powders, water dispersible granules, etc.
A – Agitate the tank
L – Liquids, flowables, and other suspensions
E – Emulsifiable concentrate (EC) formulations
S – Surfactants or other adjuvants
Timing
When should I apply Rezilon?
Rezilon is a pre-emergence herbicide and should be applied well-before target weeds are expected to germinate. It is better to be several weeks ahead of germination rather than several days. With Rezilon, “Early is on time”. When an application is made during the growing season, it should be applied soon after a cutting, to prevent the grass canopy from intercepting the spray.
If I use Rezilon in the spring, can I come back in the fall and plant a forage for winter grazing such as ryegrass or clover?
No. Rezilon is a residual herbicide and will inhibit seed germination of many species planted for forage the season following an application.
What should I do if I am making my application later than is recommended?
If Rezilon is not applied well before expected weed germination, a tank mix partner should be added to control weeds that may present or already germinated. Examples would be mixing in Roundup® or Pastora® to control ryegrass or Cimarron® Plus to control broadleaves.
How long do I have to wait to cut hay or graze my field after I apply Rezilon?
There are no grazing restrictions for Rezilon, and no haying restrictions provided no more than 3 fl oz/A have been applied. When applied at rates higher than 3 fl oz/A, hay may not be cut for a period of 40 days.
Miscellaneous
What size containers are available for Rezilon?
Rezilon is currently offered in quart sizes. However, larger sizes may be offered in the future.
How should I store Rezilon?
Rezilon should be stored in a cool, dry place. If Rezilon sits for a period of time, the container should be shaken well before using.
