Author
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Koger Iii, Clifford |
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STRITZKE, J - OKLAHOMA STATE UNIV |
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Submitted to: Proceedings of Southern Weed Science Society
Publication Type: Abstract Only Publication Acceptance Date: 12/1/2003 Publication Date: 2/26/2004 Citation: Koger III, C.H., Stritzke, J.F. 2004. Sericea lespedeza (lespedeza cunetata. Proceedings of Southern Weed Science Society. Interpretive Summary: Technical Abstract: Sericea lespedeza (Lespedeza cuneata [Dum.Cours] G. Don) is a long-lived, warm-season, herbaceous, perennial legume. Mature plants form a crown of numerous erect stems that reach lengths of up to 75 cm, and that often persist into the next growing season. It was introduced into the southeastern United States in the late 1800's from Asia as a potential forage species. In the early 1900's, and continuing for most of the century, sericea was planted on many sites in southeastern U.S. for forage production and soil conservation. Sericea will tolerate and grow on acidic and low fertility soils. However, it thrives on clay and loam soils that are deep and fertile. In the early 1980's, some severe infestations of sericea were reported in pastures of Oklahoma and Kansas. This lead to our involvement in numerous studies and research efforts on controlling sericea lespedeza. Solid canopy cover of sericea have been documented in unfertilized bermudagrass, grazed tallgrass prairie, woodland, and ungrazed sites. No infestations of sericea have been documented in fertilized bermudagrass grazed pastures or hay fields. Sericea competes strongly with native vegetation in tallgrass prairies. Stems of sericea grow upright quickly as single stems upon emergence and then profusely branch in early summer. In addition, there is limited grazing of sericea in this ecosystem because the young stems are protected by "woody-like" stems from previous seasons growth, and high tannin levels. Within several years of introduction into a tallgrass prairie or unfertilized, heavily grazed bermudagrass pasture, sericea can become the dominant species. Sericea is a prolific seed producer, producing in excess of 6 million seed per hectare. Seeds often germinate in March, April, or early May, and survival of seedlings is often dependant upon summer environmental conditions, with 0% survival in dry hot summers to over 90% in cool wet summers. Sericea is not killed by herbicides commonly used to control undesirable species in pastures (2,4-D, dicamba + 2,4-D, picloram + 2,4-D). Triclopyr and fluroxypyr resulted in the best long-term control of established sericea. Triclopyr (0.56 to 0.84 kg/ha) applied to nongrazed, actively growing mature plants in late June to mid-July resulted in 95 to 99% stem reduction of established plants 2 years after treatment (YAT). Triclopyr or fluroxypry applied in May or September were not as effective. Spring burning before June/July applications of triclopyr or fluroxypyr had no negative effects on control of established plants. However, a combination of spring burning plus early double stocking of livestock before spraying resulted in only 65% control 2 YAT. Deferring grazing before spraying resulted in 85% control 2 YAT. Late summer applications of metsulfuron resulted in good control (95 to 99%) of sericea 1 YAT, however stem densities by 3 YAT were similar to untreated areas. An integrated strategy using triclopyr followed by spring burning and grazing can be utilized to manage sericea lespedeza in tallgrass prairies. We have documented that some sericea lespedeza can be tolerated in tallgrass ecosystems before yields of desirable grasses are reduced and that sericea will be utilized by cattle if the site is spring-burned and double stocked at initiation of sericea growth in April. |
