07/11/12

LITTLE ROCK -- The extremely dry weather and hot temperatures have reduced pasture growth statewide. When forage is in short supply, cattle and other animals may eat plants that they normally would avoid.

“We are seeing very low availability of good forage right now, so producers should use caution when grazing,” said John Jennings, Extension Forage Specialist. Plants such as perilla mint and poison hemlock are more prominent this year and are toxic to grazing livestock. (See “Cattle deaths point up dangers of drought-stressed forage,” www.uaex.edu/news/june2012/0629ArkDeadlyForage.html)

Last week, there were two confirmed cattle deaths due to drought-damaged forage in Arkansas.

“Perilla mint is especially troublesome this year,” he said. “It normally is found in shady spots along pasture borders, but has become established out in open pasture areas over the past couple of years.”

“As the only green plant in some pastures, it’s poisoning hungry livestock,“ Jennings said. “Perilla mint can be easily killed with herbicide, but make sure the plants are completely dead before allowing livestock access to sprayed areas.”

Hemp dogbane is another very toxic weed that is becoming more prominent, especially in hay fields.

“Many producers have cut back on herbicide and fertilizer applications, allowing this weed to become established,” he said. “Plants such as perilla mint and hemp dogbane remain poisonous even in dry hay and can cause livestock poisoning when the hay is fed later in winter.”

Other plants that can be toxic include coffee senna, sesbania, and sicklepod.

“While these plants typically grow in cropland areas that are not grazed, poisonings can show up if drought affected crops infested with these weeds are salvaged by baling them for hay,” Jennings said. “That was a concern last year and will be again this year.”

Some producers are looking at any source of alternative forage, including the stalks from their sweet corn patch.

“In Clay County, stalks from sweet corn were tested and found to contain high levels of nitrate which is also toxic to livestock,” Jennings said. “Crop residues should be tested for nitrate before considering them as livestock feed.

“Confirming the crop chemicals used to grow those crops is important because many chemical labels prohibit use of treated crops for livestock feed,” he said.

Johnsongrass is tricky, not only because it contains prussic acid when drought-stressed, but

“the grass may appear normal in the morning, but can wilt during afternoon heat which increases toxic potential,” Jennings said. “Many producers believe the white powdery substance commonly seen on johnsongrass stems in late summer is prussic acid residue, but it is only common powdery mildew fungus and is not considered toxic to livestock.”

For more information on forages, visit www.uaex.edu or contact your County Extension office.

The Cooperative Extension Service is part of the University of Arkansas Division of Agriculture and offers its programs to all eligible persons regardless of race, color, national origin, religion, gender, age, disability, marital or veteran status, or any other legally protected status, and is an Affirmative Action/Equal Opportunity Employer.

04/23/12

Frost, dry weather, and armyworms hamper growth of pastures

Scattered frost has been reported across north Arkansas from late last week and many areas narrowly escaped frost Monday morning this week. Damage to forage in pastures and hayfields appears to be minimal. The consequences from frost vary, but the main problem is that grass growth has slowed sharply over the past week due to a combination of dry weather and very cool temperatures. Cooler temperatures favor continued growth of cool season forages such as ryegrass, fescue, orchardgrass, and clovers, but not warm-season grasses like bermudagrass. Fescue growth is far ahead of normal and many producers are cutting hay. Bermudagrass responds poorly to cool night temperatures and when nights cool to near frost conditions, growth stops. What looked like a very early bermudagrass hay crop appears to have been stalled by the cool weather and may be delayed to a near normal cutting date. The general recommendation for fertilizing bermudagrass is to wait for several consecutive nights above 60°F. Fertilizer applied earlier will result in forage greenup, but growth will be slow until both day and night temperatures warm up.

The slow grass growth has been compounded by dry weather and an onslaught of armyworms in many areas of the state. Areas hardest hit appear to be southwest, north-central, and northeast Arkansas. True armyworms prefer to eat grass more than clover. Fescue, wheat, and bermudagrass fields have been stripped in many cases. Most farmers are treating fields with recommended insecticides to protect remaining forage.

Farmers should use caution when grazing fields having johnsongrass. The johnsongrass is growing very early this spring and frosted forage could be hazardous due to potential for prussic acid poisoning. This is usually only a consideration in fall, but the early warm-up this spring prompted johnsongrass to break dormancy earlier than normal. Producers should scout fields closely and remove livestock from fields with frost-injured johnsongrass until the forage resumes normal growth.

The Arkansas Cooperative Extension Service offers its programs to all eligible persons regardless of race, color, national origin, religion, gender, age, disability, marital or veteran status, or any other legally protected status, and is an Affirmative Action/Equal Opportunity Employer.

EVENTS FOR FEBRUARY                       02/02/12

 PURPLE HULL PEAS         06/27/11

FAYETTEVILLE, Ark. – Colorful and hardscrabble, the humble pink-eye purple hull pea has been elevated to a multicultural symbol of good luck and is even celebrated with its own Arkansas festival. 

The peas have been cultivated for thousands of years and today are perhaps best known in the south for being served in Hoppin’ John, a traditional New Year’s Day dish, and at Rosh Hashanah, the Jewish New Year, for good luck. Each June, the pea is honored at the Purple Hull Pea Festival and World Championship Rotary Tiller Race in Emerson, Ark. This year’s festival is June 24-25.   

“Pink-eye purple hull peas are the survivor in the garden,” said Craig Andersen, horticulture extension specialist-vegetables with the University of Arkansas Division of Agriculture. “They grow in poor, low-fertility soils, withstand heat and drought stress, and still produce a crop.” 

Andersen said the “pink eye” part refers to where the seed attached to the pod, and the purple hull comes from a pigment called anthocyananin, the same chemical that puts the purple in pansies and the blush in the cheeks of apples. 

“The truth is that the hull can be any color from a tan, to red or purple, and it does not determine the color of the peas,” he said, adding that the peas can be every color from white to black.  

“We call them Southern peas and others may call them cowpeas, but the botanical group they belong to is the species ‘Vigna’,” Andersen said. “This includes everything from crowder peas, lady peas, and black-eyed peas to long bean, asparagus bean to red ripper beans.”   

Peas have an advantage that helps them survive tough conditions. 

“Because the genus has a symbiotic relationship with the bacteria Rhizobium that fix nitrogen from the atmosphere for the plants to use, Vigna needs little nitrogen fertilizer, and is one of the most important sources of vegetable protein for humans around the world,” he said. “We rarely inoculate the peas with the Rhizobium bacteria, because they have been grown in the South for so long that most soils already have a population of the bacteria.” 

Black-eyed peas should be planted in a well-drained sandy loam soil. They do best if the soil pH is near 6.0 or above, with not much nitrogen fertilizer. Rhizobium bacteria in the soil will colonize the roots and provide nitrogen to the plant in exchange for carbohydrates from the plant.   

It is a warm-season plant that does best when soil temperatures are above 62 degrees.

Current dry spell pushing some landscape trees ‘over the edge’  

            A prolonged hot, dry spell may be pushing some landscape trees closer to their demise, said Jon Barry, extension forester for the University of Arkansas Division of Agriculture.

            Some trees have suffered through a string of dry summers even last year’s wet summer hadn’t done much to relieve the stress of the dry summers, Barry said. 

            “Many trees have already been damaged beyond repair,” he said. “A return to normal rainfall might prolong a stressed tree’s life a little, but many trees have already started dying and nothing will reverse that process.” 

            “For the last several years we have been getting calls about quite a few yard trees dying,” he said. “Most of these trees are large old trees that probably were under stress already, so a string of stressful years has given them that last shove over the edge.”

            Barry said yard trees face handicaps their wild cousins don’t.  

            “One of the reasons yard trees are so vulnerable to drought stress, is that they often do not have enough room to develop a good root system,” he said. “Houses, driveways, and sidewalks create dry zones in the soil.  

            “The few tree roots that might be in these dry zones cannot provide any water to the tree,” Barry said, adding that yard trees often have an abnormally large crown that creates a larger demand for water. 

            “The restricted volume of soil available for rooting reduces the water available to a tree that already has a king-size thirst, he said.

            The first of the 100-degree days started in June in some parts of Arkansas, according to the National Weather Service.  

            The drought stress is showing as some trees are turning their fall colors and shedding leaves. 

            “If leaf colors are changing as they would in the fall, and the leaves are dropping, that means the tree is going dormant,” Barry said.  “Normally they would do that in the fall in response to longer nights, but they will also go dormant due to drought stress.  Dropping leaves dramatically reduces water consumption.”

            Barry said that response also shuts down photosynthesis.

            “That means the tree may not make any more food this summer, unless it begins to rain and the tree puts out new leaves,” he said. “During the summer, food is normally made in the leaves and stored in the roots so the tree can produce new leaves and flowers next spring. 

            “Trees can usually survive one or two summers of going dormant early, but too many will kill the tree,” he said.

            According to The Arkansas Forestry Commission, the wildfire risk as of Wednesday was high in seven counties: Columbia, Hempstead, Lafayette, Miller, Nevada, Ouachita and Union; and moderate in 42 counties: Ashley, Chicot, Clark, Cleburne, Cleveland, Conway, Crawford, Dallas, Desha, Faulkner, Franklin, Fulton, Garland, Grant, Hot Spring, Howard, Independence, Izard, Jefferson, Johnson, Lawrence, Lincoln, Little River, Logan, Montgomery, Perry, Pike, Polk, Pope, Pulaski Sharp, Randolph, Saline, Scott, Sebastian, Sevier, Van Buren, White and Yell counties.             The wildfire risk is low in the remaining counties.

            Burn bans have been declared in 20 counties: Ashley, Chicot, Columbia, Conway, Falkner, Fulton, Garland, Jefferson, Johnson, Lafayette, Monroe, Ouachita, Phillips, Polk, Pope, Prairie, Sharp, Searcy, Van Buren and White counties as prolonged hot weather continues to dry out trees and increase dry leaf litter.

            For information on efficiently watering your landscape, visit http://www.uaex.edu/pulaski/water_conservation/default.htm.  For information on forestry, visit www.uaex.edu, or contact your county extension office. Current burn ban and fire risk information is available from the Arkansas Forestry Commission at http://www.arkfireinfo.org/index.php?do:showWildFires.

arMY WORMS SPOTTED IN SEVIER COUNTY    07/21/10

A few reports of army worms have been reported in Northern Sevier County. 

If you find them in your field, County Extension Agent, Rex Herring, recommends using either 80% Seven Dust or liquid Seven or Mustang Max.