All but the thickest of grass pastures and hayfields are being invaded. Invaded by winter annual or biennial weeds like buttercup, chickweed, henbit (and its cousin deadnettle), musk or nodding thistle and poison hemlock. All are winter annuals except for musk thistle, which is a biennial – meaning it takes two years to complete its lifecycle. These plants can be very competitive with our perennial cool season grasses, especially in new seedings. Mowing these weeds is generally ineffective, but they can easily be controlled with common broadleaf herbicides in the coming weeks if we get temperatures approaching 60o F. These weeds can be recognized pretty easily (with a little coaching, which is just about to happen, so read on).
Every year, I personally struggle with identifying these weeds, especially early enough to have a meaningful chance at control. I am especially motivated this year as I am helping a producer nurse a few hundred acres of newly seeded orchardgrass and bluegrass through to spring.
This article will focus on five very common winter weeds of pasture: buttercup, common chickweed, henbit, purple deadnettle and poison hemlock. To determine the appropriate herbicides to use, see “Broadleaf Weeds of Kentucky Pastures (AGR-207)” by UK’s Dr. J.D.Green and Dr. Bill Witt. ~ Jimmy Henning, Farmers Pride
Poison hemlock grows in patches in fields and has a fern-like appearance with triangular, dark green leaves at a vegetative stage. At later stages, stems have a characteristic purple mottling.
Buttercup should be vegetative to get good herbicidal control. Leaves are shiny and about the size of a fingertip.
Vegetative henbit is easily confused with purple deadnettle which is a closely related species. Leaves are 1/2 to 3/4 inch across but are more ‘lobed’ than deadnettle. In the vegetative stage, leaves are at the end of a petiole, or stem. When flowering, leaves are directly attached to the elongating stem.
Common chickweed. Leaves are shiny and small, about a quarter inch across or less. This weed often grows in dense mats at the soil surface.
Vegetative purple deadnettle (above, right). Leaves are about ½ to ¾ inch across and are more heart shaped and less ‘lobed’ than henbit. Control for both is similar.
One of buzzwords around agriculture in recent years has been “sustainability” – what can farmers do to make their operations more sustainable for the future. Many are looking to incorporate cover crops, change up their continuous cropping rotations, or even add livestock where they previously were not used before. But one thing that is often overlooked is the benefit of adding a crop like alfalfa, and how it can improve your on-farm sustainability.
Alfalfa’s impact on soil health has been widely studied for many years. Because it is a perennial, fields will require less tillage throughout the stand lifetime, similar to perennial pastures. This decreased tillage often improves soil aggregation and organic matter content. Recent research has found that when alfalfa is included in a short-term rotation with corn and soybeans, the amount of carbon sequestered in the soil significantly increases over a continuous corn and soybean rotation. This increase in soil carbon means that soils can become more resilient to harsh environmental stresses.
Overall, alfalfa has a lot to offer agriculture. It is a great source of nutrition for livestock and provides many soil benefits that we are just beginning to fully understand. Its perennial growth habit helps provide protection to soils as well as benefical insects and wildlife, and makes fields more resilient to environmental stresses. Including alfalfa in your cropping rotations makes sense for many reasons. ~ Excerpt from: Emily Meccage, PhD, Forage Genetics International. NAFA News Release Nov. 2019. Read the full release here.
The new Hardin county Extension Office will be hosting the 39th Kentucky Alfalfa and Stored Forage Conference. Topics include:
- Managing Alfalfa Nutrient Uptake
- Don’t Let Insects Eat Your Alfalfa Profit
- Fertilizing Profitable High Yield Alfalfa
- Getting the Upper Hand on Alfalfa & Grass Diseases
- Updates on an Online Alfalfa Management Tool
- What’s New in Alfalfa Weed Control
- Advances in Hay Mechanization
- Making a Profit with a Cash Hay Operation
Early registration is just $30. Find the full agenda and register here. For paper registration, mail a check with your name and address to: Ray Smith, N-222E Ag. Science Center North, Univ. of Kentucky, Lexington, KY 40546-0091.
Tall fescue is the most important cool-season grass in Kentucky. In most unimproved pastures, tall fescue is infected with a fungal endophyte that imparts tolerance to grazing and environmental stresses. The endophyte improves persistence in low input grazing systems, but it also results in the production of alkaloids that cause tall fescue toxicosis. Worse case symptoms include: fescue foot, fat necrosis, and loss of ear tips and tall switches. However, the symptoms that are not readily observed are often the costliest. These include vasoconstriction, elevated body temperature, lower forage intake, lower milk production, lower growth rates and weaning weights, compromised immune system, and lower conception/calving rates. Strategically manage tall fescue by:
- Replacing of Toxic Stands
- Managing Existing Tall Fescue Stands
- Dilution with other forages
- Clipping seadheads
- Strategic avoidance
- Using local animal genetics
- Supplement tall fescue pastures
While management strategies can mitigate impacts, the only way to completely eliminate the harmful effects of endophyte on livestock is to replace infected stands with other forages or novel endophyte tall fescue. ~ Dr. Chris Teutsch, Cow Country News.
Toxic tall fescue reduces livestock weight gains and lowers reproductive performance. This one day workshop will give you the tools and information needed to improve your management of toxic tall fescue or to remove it and replace it with novel endophyte varieties. Speakers include local producers, company representatives and extension specialists from across the country. Topics include: Fescue toxicosis, Economics, Testing, Establishment, Management, Products, and Incentives. Registration includes all materials, refreshments, and lunch. Early registration ends March 11th. Space is limited. Register today here or email us at firstname.lastname@example.org.