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Posted 19 September 2007. Forage and Grazinglands. Late Summer Is Good Time to Control Sericea Lesepdeza Kansas State University. www.ag.ksu.edu Manhattan, Kansas (September 10, 2007)--Late summer and early fall can be a good time to treat sericea lespedeza with herbicides, according to Walt Fick, K- State Research and Extension range management specialist.
This noxious weed is a problem on grazing lands in Kansas since it is unpalatable to cattle and competes with desirable grasses and forbs, Fick said. Controlling sericea lespedeza has proven to be unusually difficult, but a combination of practices that include well-timed herbicide applications can be effective. "Sericea can be difficult to control with grazing, mowing, or burning alone. Most often, a herbicide application will be necessary as part of an integrated management approach. Managers should be aware, however, that drought stress can greatly reduce the effectiveness of herbicides applied for sericea lespedeza control," Fick explained. "A good indicator of drought stress is the amount of flowering. Sericea will produce very few flowers when under drought stress." If the sericea hasnīt flowered yet, Remedy (triclopyr) at 1.5 pints/acre can give good control, Fick said. Remedy can be applied anytime from four to six weeks after grazing termination up until the pre-flowering stage of growth. After sericea has flowered and up until the first freeze, metsulfuron (Escort, Ally, Cimarron, and other trade names) is the best herbicide to use, he said. "Metsulfuron can control sericea even through seed fill, unless the plants are under drought stress. Managers should control the plants before mid-seed fill, however. If the sericea has already formed viable seeds when it is treated with the herbicide, the seeds can germinate the following year and spread the problem," the agronomist said. Grasslands with sericea lespedeza infestations should not be grazed or hayed after the sericea has gone to seed. That could spread the seed to other areas, he said. Control measures taken this fall need to be followed up for control to be most effective. "Next spring, areas with a sericea infestation should be burned in the spring to encourage germination of sericea seed, to remove new sericea growth, and remove all dead growth. After the burn, these areas should be intensively grazed until no later than mid-July," Fick said. "Then, four to six weeks after grazing termination, any remaining sericea can be treated with Remedy (triclopyr) anytime up until flowering. An alternative to the burn-plus-graze-plus-herbicide approach is to spray sericea in June when the plants are in a vegetative growth stage with Remedy (1-1.5 pints/acre) or PastureGard (2 pints/acre)." More information about sericea lespedeza is available on the K-State Research and Extension Web site: www.oznet.ksu.edu. Brand names appearing in this article are for product identification purposes only. No endorsement is intended, nor is criticism implied of similar products not mentioned. K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan. Contact: |
