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| Cooperators: Tony Frerich |
| Robert Elledge, Kinney County |
| Bob Lyons, Extension Range Specialist |
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| SUMMARY |
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| Individual plant treatments for brush management are typically more effective than broadcast methods. Individual plant treatments using leaf-spray methods with various herbicide combinations were tested for coyotillo control. These treatments included 1% Tordon 22K, 1 and 2% Grazon P+D, and 1% 2,4-D. Although some of the treatments tested had shown promise in an earlier demonstration, essentially no kill was achieved in this demonstration. |
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| PROBLEM |
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| Coyotillo is a poisonous shrub occurring on many ranches alson the southwestern escarpment of the Edwards Plateau and the Rolling Plains. Seeds and leaves produce different symptoms. Ingestion of seeds results in weakness and incoordination of hind legs, exaggerated high stepping, jumping or moving backward and prostration. Symptoms from eating foliage include loss of condition, wasting, nausea, and progressive weakness. Many sheep and goat deaths are associated with consumption of this plant, particularly during droughts or when replacement animals have not ben raised in areas where the plant grows, allowing them to learn from their mothers to avoid eating coyotillo. Acceptable control methods have not been identified. |
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| OBJECTIVES |
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| This demonstration was established to evaluate the effectiveness of four herbicide leaf-sprays for control of coyotillo. |
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| MATERIALS AND METHODS |
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| Four plots were established on July 15, 1998. Herbicide treatments were applied as leaf-sprays of 1% Tordon 22K, 1% Grazon P+D, 2% Grazon P+D, or 1% 2,4-D. All treatments included 0.25% surfactant and 0.25% HiLite Blue Dye mixed in water. Sprays were applied using a backpack sprayer equipped with an X-8 Adjustable Conejet Nozzle. Plants were sprayed until all leaves were covered. |
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| RESULTS AND DISCUSSION |
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| Although the Tordon 22K and 2,4-D treatments had shown promise in previous work, essentially no plant kill was observed in any of the treatments in this demonstration. |
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| CONCLUSIONS |
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| Additional work will be conducted in this area to test alternative approaches. |
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| ACKNOWLEDGMENTS |
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| We wish to thank DowElanco for their support in these demonstrations efforts. |
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