Johnsongrass:  Friend or Foe
Plus Master Cattleman Program in Dalton this Fall
By:  Eddie Ayers, County Extension Agent

A common sight right now is thick stands of what might be confused for corn growing on roadsides, pastures, and hayfields. What you’re seeing is most likely Johnsongrass (Sorghum halepense.)  Two important questions often asked are “what good is this plant” and “is it a beneficial forage plant or merely a persistent weed?”

Johnsongrass is a summer perennial grass that belongs to the sorghum family and can serve as a good forage crop in our pastures and hayfields. Livestock will graze young Johnsongrass plants if given the chance, as it is relatively high in crude protein and highly digestible. The issues with Johnsongrass arise from its persistent growth and potential toxicity issues for livestock.  When stressed by drought or frost damage, the plant produces hydrocyanic acid which is a derivative of cyanide, also known as prussic acid. This compound can be very toxic and even lethal to cattle.

Johnsongrass grows from a very thick set of fibrous roots and rhizomes (underground root nodules that form new plants) that make the plant more difficult to kill because it can “fall back” on energy stores in these rhizomes whenever the plant is stressed, whether by grazing, mowing, or herbicides. These rhizomes can also form new plants if disturbed or cut (by plowing or leaving part of the root in the ground). These rhizomes over‐winter and send out new shoots in the spring and early summer. Johnsongrass also reproduces by seed, with a single plant producing 80,000 seeds per year. Because of these tendencies, Johnsongrass can be very persistent in a field if not controlled early and often.

Even though the symptoms of poisoning from Johnsongrass look like nitrate poisoning, the prussic acid can dissipate over time within the forage. If a large field of Johnsongrass is cut for hay, the hay should be dried to a safe baling content (15 to 18%) to ensure the prussic acid content has dissipated. Young plants, plants killed after frost, or plants growing after a long drought are the most susceptible to high prussic acid levels.

Control of this plant is difficult if it’s allowed to take control of a field in large areas.  Tillage is not recommended as it will most likely make the problem worse by distributing more rhizomes. Pulling up of plants is possible, but making sure that all the root is dug up is important. Mowing or grazing to prevent seed head production will help keep the plant at bay, but it will not remove the plant from the field.

There are some herbicides available to control Johnsongrass, but most of them cannot be used in tall fescue, which is the major part of our hayfields and pastures in Gilmer County.  Treatment of plants with glyphosate (Roundup) will allow for translocation of the product into the root system. One good option to get the glysophate to the Johnsongrass and not harm the desirable forage is through a wick applicator.  Fortunately in our area the Limestone Valley Soil and Water Conservation District has one that can be rented. It is housed at Hinton Milling Company in Jasper. Contact them at 706-692-3626 to schedule a time to use it. You can also make or buy a wick applicator to try and control this (and other) pesky weeds.

I also want to mention that the UGA Extension office in Whitfield County is hosting a Master Cattleman Program this fall in Dalton from September 4th through October 23rd from 6:30 – 8:30 pm, which is every Tuesday for 8 weeks.  Paid registration before August 17th entitles participants to one free forage sample analysis; sample must be submitted no later than September 11th.  Registration is $85 per person and includes a dinner on the final night.  Pre-Registration deadline is August 24th and can be done on-line at: https://nwgeorgiacattle2018.eventbrite.com or for more information, contact me in the Gilmer County UGA Extension office.

An Equal Opportunity/Affirmative Action Organization

By:  Eddie Ayers, County Extension Agent

As I ride through the county I’ve noticed some webs are back in the wild cherry trees but before you start having nightmares about the webbing we had last fall, you can rest assured that this insect is different.  This culprit is the Eastern Tent Caterpillar. The webs serve as a home to the newly emerged larvae or as we like to call them, caterpillars. The eggs are timed to hatch when the cherry buds unfurl as they need to eat to grow and complete their life cycle.

Older larvae are generally black, with long brown hair and a white stripe down the middle of their backs. Along the midline is a row of blue spots with brown and yellow lines. At maturity, the caterpillars may reach a length of 2½ inches. The adults are reddish-brown moths which have two white oblique stripes on each forewing.  These are harder to notice, but they are the final step in the life cycle.

The adult moths emerge in May and early June and lay egg masses that resemble chocolate-colored collars that encircle the smaller limbs of their host. Each egg mass is about 1 inch long. Eggs overwinter and hatch in mid-March of the following year to start the cycle again. From each egg mass, several hundred tiny feeding machines emerge, and for four to six weeks they hungrily strip the trees of their leaves. The larvae are gregarious and upon hatching they gather in the forks of the limbs and develop the web that can be seen in the trees.  This serves as their home for the larvae. From this mass of silk, the developing larvae move outward to feed on developing leaves, but they return at night and during rainy weather. The nest gradually becomes larger and larger as silk accumulates. Although the nests are most commonly seen in the forks of wild cherries, this pest can be found in other ornamental, shade and fruit trees, especially apples. While not a serious pest in the natural forest, the unsightly web insect can reduce the beauty and esthetic value of shade trees and other hardwoods in the landscape.

About four to six weeks after hatching, full-grown larvae will crawl away from their nests and accumulate on the sides of homes, on driveways and sidewalks and on various woody ornamentals in search of sites to complete the next phase of life, the pupae phase.  This phase is a shell or cocoon in which the caterpillar matures into a moth. There is concern that they may be attacking other plants, but when they do leave their web, the larvae are finished with their feeding and will do no damage to plants on which they are found. The caterpillars are primarily a nuisance and do not usually pose a danger to the overall health of a larger, well-established tree as the tree can produce another flush of foliage.  However, young fruit and ornamental trees may be damaged, so it is a good idea to remove the web from these trees.

Usually, no chemical controls are necessary or very effective.  One reason is that the web is water proof and insecticides that are applied usually do not reach the larvae but you can break open the web and apply an insecticide such as carbaryl (Sevin), BT or a pyrethroid if you would like. If you decide to use an insecticide, please read the label and follow the instructions.  In addition, the egg masses can be clipped from the limbs in late June to prevent nests from developing the following spring.

For more information about the webs in trees right now, contact me in the Gilmer County UGA Extension office.

By:  Eddie Ayers, County Extension Agent

Whether you’re a new, beginner or veteran homeowner, landscaper (perhaps your own company) or golf course superintendent, you’ll find the latest research-based information on growing and maintaining Turfgrass at this year’s Turfgrass Research Field Day on the UGA campus in Griffin, GA on Thursday, August 9th.

The University of Georgia College of Agricultural and Environmental Sciences (CAES) researchers and UGA Extension specialists will present the latest information on how to care for residential lawns, commercial golf courses, athletic fields and any other space covered with Turfgrass.

Field day topics will include how to control weeds, insects and diseases, managing seed heads, heat and drought tolerance and an update on the UGA Turfgrass breeding programs.

A catered BBQ ribs and chicken lunch will be followed by product exhibits and demonstrations of the latest Turfgrass industry equipment. A self-guided research tour begins at 1:15 pm with at least half dozen programs to choose from. Guided tours will be offered in Spanish for Spanish-speaking attendees.

Registration is from 8:00 to 8:45 am followed by the welcome and presentations plus information regarding the available tours.  To view the Turfgrass research plots, the event is held outdoors, rain or shine, so dress appropriately and bring sunblock. The day concludes at 2:30 pm.

Pre-registration is required for the $65 individual fee ($25 for students) before July 17th. After that deadline, fees increase to $80 and $30. Receive a 10% discount for four or more registrants. The registration fee includes instruction, research tours, demonstrations and exhibits, Turfgrass research field day guide and lunch. You can register online at www.georgiaturf.com or via the Griffin location in person, by phone or fax, or snail mail.  Their telephone number is 770-229-3477. For more information, view or download the brochure at: http://caes2.caes.uga.edu/commodities/turfgrass/georgiaturf/FieldDay/index.html.  We also have a few brochures here in the office if you’d like to pick one up.

The event is sponsored by the UGA CAES, the UGA Center for Urban Agriculture, the Georgia Urban Ag Council, the Georgia Turfgrass Foundation Trust, the Georgia Golf Course Superintendents Association, the Georgia Golf Environment Foundation, the Georgia Sports Turf Managers Association and the Georgia Recreation and Park Association.

Please note: the field day is certified for private and commercial pesticide recertification credits in Georgia and neighboring states. A license number is required to receive the field day pesticide credits.

Also this summer, if you or someone you know enjoys the amusement parks in the area, buy the tickets on-line at a discount and support the Gilmer County 4-H Club.  Selling tickets to Six Flags and White Water has been a local 4-H fundraiser for nearly 10 years. Day passes and combo vouchers for season tickets including parking are available. For every ticket purchased through our partnership log in, the Gilmer County 4-H Club gets $1.00 so be sure to write down the following information; it is needed to access the site. A word of caution: the name, password and promo code are case sensitive. Our partnership link is https://sixflags.com/partnerlogin?m=32824 and the name is:  GilmerOG and the password is:  SixFlags10 and the promo code is:  gilmer4h and if you need more information, call the Gilmer County UGA Extension office at 706-635-4426.

By:  Eddie Ayers, County Extension Agent

Driving around the area, I have been seeing a plant that has become a problem in both Gilmer and Fannin Counties.  The weed I’m talking about is Japanese knotweed, commonly known as crimson beauty, Mexican bamboo, or Japanese fleece flower.  It was probably introduced to the U.S. as an ornamental and a plant that has flowers that bees love. It’s fairly easy to spot as it has been growing in large patches all over the area.  The leaves are alternate, 6 in. (15.2 cm) long, 3-4 in. (7.6-10 cm) wide, and are broadly-ovate or heart shaped. Flowering occurs in late summer when small, greenish-white flowers develop in long panicles in the axils of the leaves.

This native of Japan was initially useful for erosion control, as an ornamental, and for landscape screening.  It spreads quickly to form dense thickets that can alter natural ecosystems or interfere with landscaping. It is a semi-woody, bushy perennial and a member of the Polygonaceae (Knotweed) family.  Another fact about the plant is that the stem is hollow. Knotweed spreads rapidly from stout long rhizomes. Seeds are distributed by water in floodplains, transported with fill dirt, and to a lesser extent are wind-blown. Populations escaped from neglected gardens, and discarded cuttings are common methods of distribution. Once established, populations are quite persistent and can out-compete existing vegetation.

Japanese knotweed can tolerate a variety of adverse conditions including full shade, high temperatures, high salinity, and drought. It is found near water sources, in low-lying areas, waste places, utility rights of way, and around old home sites. It can quickly become an invasive pest in natural areas after escaping from cultivated gardens. It poses a significant threat to riparian areas, where it can survive severe floods. It is rapidly colonizing scoured shores and islands.

Controlling this invasive fast growing plant is very difficult.  One method that is used is grubbing. This method is appropriate for small initial populations or environmentally sensitive areas where herbicides cannot be used. Using a digging tool, remove the entire plant including all roots and runners. Juvenile plants can be hand-pulled.  Any portions of the root system not removed will potentially resprout. All plant parts, including mature fruit, should be bagged and disposed of in a trash dumpster to prevent re-establishment.

There are several herbicides that can be used, but it takes some work for them to be effective.  One treatment method is the cut stump treatment. Use this method in areas where plants are established within or around non-target plants. Cut the stem 2 inches above ground level.  Immediately apply a 20% solution of glyphosate or a 10% solution of Arsenal AC, Polaris AC or Imazapyr 4SL and water to the cross-section of the stem. A subsequent foliar application may be required to control new seedlings and resprouts.

The other spray method is foliar spraying the plants.  Use this method to control large populations. It may be necessary to precede foliar applications with stump treatments to reduce the risk of damaging non-target species.  Apply a 1% solution of glyphosate or 20%Garlon4 and water to thoroughly wet all foliage. Do not apply so heavily that herbicides will drip off leaves. The ideal time to spray is after surrounding vegetation has become dormant (October-November) to avoid affecting non-target species.  A 0.5% non-ionic surfactant is recommended in order to penetrate the leaf cuticle.

For more information, contact me in the Gilmer County UGA Extension office.