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2002 Index |
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Volume |
40 |
Page |
51 |
Title |
Evaluation of a New Formulation of Reward Landscape and Aquatic Herbicide for Control of Duckweed, Waterhyacinth, Waterlettuce, and Hydrilla |
Author(s) |
Ken A. Langelend, O.N. Hill, T.J. Koschnick and W.T. Haller |
| Keywords | diquat dibromide, chemical control, Reward, formulation, Hydrilla verticillata, Lemna minor, Eichhornia crassipes, Pistia stratiotes |
| Abstract | A new formulation of Reward Landscape and Aquatic Herbicide (Reward QIT) was recently developed by Syngenta to alleviate problems associated with particulates in the former formulation (Reward). Reward QIT was tested in outdoor tanks to compare its herbicidal activity to the older Reward formulation. No differences in herbicidal activity were observed between the two formulations when applied to hydrilla (Hydrilla verticillata L.f. Royle) at 0.25 ppm diquat dibromide cation or 0.25 ppm diquat dibromide cation plus 1.0 ppm copper. Also, no differences in herbicidal activity were observed between the two formulations when applied to, duckweed (Lemna minor L.), waterhyacinth (Eichhornia crassipes Mart Solms), or waterlettuce (Pistia stratiotes L.). Greater than 95% control was observed against all floating species tested when either formulation was applied at 4.7 or 7.0 l/ha. Reward QIT applied at 2.3 l/ha resulted in 92% control of duckweed and waterhyacinth and 96% control of waterlettuce. Additional waterlettuce plants were treated with 0.09, 0.18, 0.28, 0.56, or 0.84 l/ha of either formulation to determine if subtle differences in herbicidal activity could be observed at the lower rates. No differences were observed between equal rates of the two formulations at these lower rates, and all rates resulted in lower dry weights of waterlettuce after 24 days as compared to untreated plants. |