The 2016 Southeast Hay Convention is planned for March 8-9, 2016 at the Sunbelt Ag Expo grounds in Moultrie, GA. This event follows on the resounding success of our previous programs. This two-day workshop will focus on techniques for producing high yields of high quality hay and baleage, along with a more detailed look at specific topics. The agenda is provided in the Program Details at this link.
Category Archives: Pasture
UGA Extension Forage Scientist Dr. Dennis Hancock has new information on moldy hay issues:
Because of the wet fall, many producers have faced extremely difficult field curing conditions for their hay. Additionally, hay that was bone dry in the field has, in many cases, developed mold problems in the barn. This later issue has been problematic for us in 2015, resulting in a large number of square and round bales covered with black sooty mold. It is arguably more problematic because this is often a barn design issue (e.g., open sides, poor air drainage, lack of ventilation, inability to close off ventilation, etc.). Under the high levels of humidity that we’ve had (because of periods of nearly continuous rain and cool weather) the last 2 months, dry hay will draw moisture from the moist air. For example, hay that is 12-15% moisture (the appropriate moisture for hay storage) may have a 6-12” layer along any exposed surface that may equilibrate at about 30%+ moisture if the surrounding environment is cool (< 70 F) and moist (relative humidity stays > 60%). Any moisture level greater than 20% on the surface could result in significant mold growth/discoloration, and levels greater than 30% moisture can result in the entire stack’s exposed surface being covered in black sooty mold.
As a result, our County Extension Agents and I have had an extraordinary number of emails and calls about feeding moldy hay, especially to horses. First, let me clearly state: moldy or dusty hay should NOT be fed to horses. Moldy and dusty hay can lead to respiratory issues in the horse, and can also pose health risks to the men and women who feed the hay to the livestock (e.g., farmer’s lung, etc.). Here’s a link to an excellent Extension article on the subject. Soaking the hay in a water trough before feeding will reduce the “dust” (which is usually mostly mold), but it will also leach out soluble sugars and lower forage quality. This may not reduce the risk of mycotoxins (and yes, hay can have mycotoxins in it just like moldy grain, peanuts, or oilseeds can have in them). For a discussion of mycotoxins, see this article I wrote on the subject. Several companies now sell hay “steamers,” which is a chamber or box wherein hay bales are placed and steam is pumped into the chamber. In addition to the expense, the downside of these steamers is that they will lower the forage nutritive value of the hay and they are unlikely to change the mycotoxin levels appreciably.
Ruminant animals aren’t as sensitive to mold problems as horses, but they still can be negatively impacted if care is not taken to prevent health challenges. Feeding slightly to moderately moldy hay (mold spore counts up to 1 million cfu/gram) is relatively safe if feeding cattle or small ruminants, as long as the animals are fed outside or in a very well-ventilated feeding area. Keep in mind that palatability is likely to be a challenge. Hay that emits a substantial cloud of “dust” or continues to emit dust after the disturbance ceases should be assumed to be > 1 million cfu/gram. A test can confirm mold levels. Hay that is obviously moldy (moldy or “mousey” smell or sending off visible “dust” or mold spores when disturbed) should be tested for mycotoxins before being fed. UGA’s Feed and Environmental Water Laboratory is not equipped to conduct the mold spore count test or the mycotoxin screen. (I contacted Waters Agricultural Labs in Camilla, GA and they are set up for this test.) You can, however, work through the UGA lab to arrange for these tests to occur. Alternatively, you can submit samples directly to labs that do conduct these tests (e.g, Cumberland Valley Analytical Services, Dairy One).
Bales that are covered with black sooty mold on the exterior can be removed and discarded, and usually the interior bales are not affected. Bale stack design can help minimize the surface area exposed and, thereby, minimize the damage. Barn design issues can also be corrected to prevent this problem in the future. Barns that can be open to allow moisture to escape during the initial 2-4 weeks of storage and then shut during prolonged periods of high humidity and cool temperatures will offer flexibility in this regard.
For more information on forage management issues, visit our website at www.georgiaforages.com.
Here are some weeds we have seen in pastures the past few weeks. Some of the weeds have toxic properties, so we do need to be aware of these.
Tropical Bush Mint
This is also called bittermint (Hyptis mutabilis). Originally, we thought this was perilla mint, which does have toxic properties. We noticed a square stem with similar leaf shape. When we looked close, we could see the leaves appeared smaller than perilla, and the flower arrangement was different. It is in the same family as perilla mint – Lamiaceae. However, there are no known toxicities with this plant.
UGA Extension Livestock Scientist Dr. Jacob Segers reminds us the plants in the mint family are known to cross. This makes ID more difficult, since they all look similar. This is about as far north as tropical bush mint grows.
This is one we need to watch for. This is the time of year when showy crotalaria is blooming and everyone knows this one. It’s a summer annual in the bean family and is a tall growing weed along pastures. It’s leaves are alternate and waxy. Its flower has bright yellow petals, spirally arranged on the stalk. It forms an inflated-looking pod with kidney-shaped seeds. Showy crotalaria is toxic to all livestock. The seeds contain the highest amount of toxins. The leaves also contain enough of the alkaloids to be toxic. The leaves of showy crotalaria are toxic even when dried. Here’s some more information on Showy Crotalaria.
We are also seeing some grass weeds in pastures. Vasseygrass is starting in spots in this Bermuda pasture. This is a perennial grass with a bunch-type growth habit that does not have a significant rhizome system, like Johnsongrass. Vaseygrass is more commonly seen in wetter fields or ditches. It has a seedhead with alternating spikelets forming silky hairs around the seeds. Seeds are produced along the entire length of the seedhead branch, which is not the case with johnsongrass. One thing you will notice are hairs where the leaf and stem meet and toward the base of the plant. It also has a pretty prominent midbrib. Controlling vaseygrass is not as easy, but here is a good source for information on control of grasses in pastures: Identification and Control of Johnsongrass, Vaseygrass, and Guinea Grass in Pastures.
Here is a Tift 85 pasture that has been cut twice so far and is showing symtpoms down on the leaves and lower down the stem. We are seeing both leaf blight (helminthosproium) and leaf rust. These issues we commonly see in late summer when weather is warm, usually between 75 degrees F and 90 degrees F, and with high relative humidity.
Bermudagrass leaf spot is caused by a fungus from the genus Helminthosporium, and the disease has been informally called Helminthosporium leaf spot, Helminthosporium leaf blotch, or Leaf Blight. Leaf lesions of helminthosporium are irregularly shaped and brownish green to black in color. We may see it in irregular patches. Leaf spots are more numerous near the collar of the leaf blade.
Leaf rust or Puccinia disease has similar impacts as Helminthosporium. We will also see red to orange lesions can on leaf and stem. Look for a raised area or blister which is the rust postules like we see in wheat and corn. Rubbing your finger over the leaf will leave a rusty color.
Management is strictly avoidance. Coastal, Tift 44, and Tift 85 have some level of resistance while Alicia is extremely susceptible. But even less susceptible varieties are infected with leaf spot when potassium is low. Most reported leaf spot cases are directly related to low soil potash. Nutrients are removed from bermuda hay fields in about a 4-1-3 ratio of N, P2O5, and K2O with harvest. We need 75 percent as much potash as nitrogen applied each season. Split applications of K are better in sandy soils. With helminthosporium, removing the inoculant is also recommended. In addition to tying up nutrients, thatch holds water and reduces air circulation. This is a conducive environment for inoculum. The only practical way to reduce thatch is burning in spring before green-up.
Visit Leafspot Diagnosis and Management in Bermudagrass Forages for more information.
Briars such as blackberry and dewberry are seen in pastures this time of year. UGA Forage Team Memeber and Miller County Agent Brock Ward has come up with some pointers on controlling these weeds:
There are many bramble type weeds that are called blackberries by area forage producers. These weeds often require significant growth before we can tell them apart. The good news is that they generally can be controlled using the same chemistry.
For areas where briars are a problem, control is a matter of herbicide timing. For instance, if spring was the first time a bramble weed was identified, you can wait until late September or mid-October to apply a herbicide. Waiting until fall is preferred because most of the herbicides are systemic and need adequate leaf surface to take in the chemical for translocation. During the Fall, the weeds prepare for overwintering.
Water is also needed for many of our herbicides to affect the plants. Timing application both after and ahead of a rain / irrigation will help ensure the plant is actively growing to maximize efficacy. Applying herbicides to drought stressed weeds can lead to a failure in control. Moisture stress can cause the cuticle on the leaf to harden off which reduces herbicide penetration. Delaying applications until brambles have recovered from drought stress will enhance herbicide absorption and improve efficacy for control. It will also take some time for the herbicides to fully control the weeds. Waiting six to eight weeks before mowing the weeds after application of a herbicide is recommended.
If the weeds have been previously mowed or a mature stand is currently overgrown, the area needs to be evaluated and managed to get herbicide on the actively growing material. In the case where a large mass of weeds have grown for more than two seasons, mow the weeds to get a flush of younger, more susceptible leaf tissue. This can be timed by cutting about six months before applying the chemical. A potential method is to cut in the fall through late winter and treat in the fall of the next year. This allows the foliage to have adequate growth for the herbicide to interact with and get better control.
To help your county agent with the herbicide decision, be prepared to discuss your desired grass or forage and what you are looking to control. Oftentimes there are numerous weed species needing treatment. We may prioritize weeds of greatest concern. In most cases, control of multiple broadleaf species with a single application can occur, but timing is critical.
Jefferson County Agent Jed Dillard came across creeping indigo that he hasn’t seen in Monticello. Much has been discussed by Equine vets at UF since it is TOXIC to livestock. Below is some information from put together by Jed:
The plant is a low growing legume with pink blooms somewhat like clover and small bean like seed pods (attachment 2). Leaves contain seven to nine leaflets, and the prostrate stems creep along the soil surface. The plant can also form mats underneath a healthy pasture canopy as shown in this Creeping Indigo Fact Sheet. This will make it even more difficult to find if it migrates to Panhandle pastures.
Creeping indigo (Indigofera spicata) should not be confused with hairy indigo (Indigofera hirsuta). Hairy indigo can approach waist high, but creeping indigo will barely rise above the toe of your brogans.
Annual lespedeza (Lespedeza striata) (shown in attachment 3, mixed with centipede grass) is similar in appearance, but unrelated and non-toxic. Its prostrate growth habit is similar to creeping indigo, but its leaves are somewhat smaller and have only three leaflets. The stems of the common lespedeza plants I found across the sidewalk were also woodier than the stems of the creeping indigo.
Identification of any toxic plant is the first step in its control. Next, mechanical control may be a feasible option if the population is small when you find it. If you pull or hoe the plants, make sure you destroy any seeds as well as the plants. Seed can be viable surprisingly early and the stem and leaves remain toxic after they die and dry. The plant has a deep tap root, so mechanical control can be challenging.
Chemical control has not been established, but GrazonNext HL at 24 oz. per acre may be effective as it has good control of other legumes. Remember the dead plants in your pasture are still a threat. Manure from animals grazing treated pastures or hay from treated should not be used for compost.
This plant has been a problem in South and Central Florida and much good information on specifics of toxicity and symptoms.
Creeping Indigo Toxicity – Dr. Rob MacKay
Creeping Indigo: A Small, Yet Lethal Plant – Sellers, Carlisle and Wiggins. South Florida Beef Forage Program.
I’ve looked at a few pastures this week that show signs of fertility and cultural issues. These are horse pastures which were planted in bermudagrass but have been overtaken by centipedegrass. This is very common in pastures that have not been limed over the years. Centipedegrass can withstand a lower pH than bermudagrass. Bermuda likes a pH no lower than 6.0.
I observed another pasture today where bermuda was established but now taken over by bahia and broadleaf weeds. Bahiagrass can also tolerate low pH and fertility. Horses also graze this pasture which results in soil compaction. In this pasture many broadleaf weeds have taken over like serrated ground cherry and chamberbitter. When much of the pasture is struggling to produce, it is recocomended to do a pasture renovation.
The first step in renovation is killing out the current grass species. This is better accomplished in the late summer/early fall with glyphosate. It can then be followed up by another spray, followed by planting a winter grass, like ryegrass. The next spring, that site needs to be cut or grazed real close and then sprig/seed your desired grass. UGA Extension Forage Agronomist Dr. Dennis Hancock has information on the UGA Forages website on specific grass species. (Click on Establishment Guidelines on the left and scroll down.) Here is what Dr. Hancock recommends:
“Renovating an old common bermudagrass stand is very difficult. Even with repeated glyphosate sprays, there will be some survival of old rhizomes. Some tillage in combination with glyphosate sprays with help expose rhizomes and increase percent control. Common bermudagrass can be more completely controlled if the land can be rotated for one to three years to crops where intensive grass control measures can be employed, in addition to using the glyphosate sprays.”