By Chris Hicks, County Director – UT Extension Smith County
It’s a common sight in May in Tennessee. You drive down the road and see a pasture that looks like a “sea of yellow” due to the hairy buttercup present. While some folks can appreciate the beauty of the countless yellow blooms in these fields, livestock producers feel the pain from these weeds which outcompete more desirable grass, use up valuable nutrients, and are even toxic to livestock.
What you may not know about these yellow weeds is that they are actually present right now. Oh sure, they aren’t blooming so you may not see them from the road, but get out of the truck and walk your pasture and you are sure to find these members of the genus Ranunculus if you know what to look for.
While many producers try to spray these weeds with herbicide in March or early April, the fact that they are actively growing right now makes the fall a good time to spray. There are at least 5 reasons why:
1) Buttercups emerge in the fall and they are small and actively growing then. One of the most important keys to getting good results is to spray buttercups before they bloom. This is an automatic with fall applications, given that buttercups generally do not bloom until spring.
2) Weather conditions may be more favorable in the fall. Oftentimes in the late-winter to spring it is very wet and windy, making it difficult to spray before they are in bloom. I advise producers to make plans to spray in the fall and use a spring application as a plan B. If you wait until April, there is no plan B.
3) Time availability may be higher in the fall compared to the spring. Time consuming activities such as calving, spreading fertilizer, and getting ground ready for row crop planting often make it difficult to get pastures and hay fields sprayed on a timely basis in March.
4) The lack of sensitive crops in the fall is another thing to consider. There are no greenhouses full of tobacco plants this time of year and fewer vegetable crops, gardens, and other plants that might be damaged by an herbicide drifting. This makes the risk of off-target damage to sensitive plants much lower.
5) The ability to reseed clover in the spring is a huge plus. In most cases, 2, 4-D ester at 1 qt/ provides excellent control of annual buttercups in the fall. Since there is no residual activity from this product, you can reseed clover in February and secure all the advantages those wonderful plants provide.
Favorable weather (3 days of daytime highs of 60 F); plenty of water (at least 20 gallons per acre spray volume); and the addition of a good, nonionic surfactant (1 qt/100 gallons of spray mix) are all important ingredients in success. Always remember to thoroughly read the herbicide label before application and follow all directions and precautions. For more information on weed control in pastures and hayfields, contact the local University of Tennessee Extension office at 615-735-2900.
