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6/9/99
Hoary Cress (white top). Typical density of this weed throughout Crum Canyon. Sprayed 5/19/99 with Escort herbicide. |
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4/26/00 |
1. Treatment.
2. Results.
3. Conclusion.
| Crum Canyon | |||||
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1. Treatment. |
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| This demonstration was for control of Hoary Cress (Whitetop) by Escort and Rodeo herbicides. In 1999 about 3¼ miles along the bottom of Crum Canyon were sprayed. The following year another ¾ mile of the canyon was treated, and spot treatment was done to clean up the areas missed the previous year. Only one application was made on each area. The areas sprayed were heavily invaded by Hoary Cress. Crum Canyon supports a perennial stream, Rock Creek. The area along the stream was sprayed with a 1% solution of Rodeo herbicide. Escort herbicide was applied away from the stream at a rate of 1 oz. active ingredient per acre. Spraying each year was done during early June, before seed formation and during flowering. | |||||
2. Results. |
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| Both herbicides were highly effective against Hoary Cress. Nearly 100% kill was achieved with a single application. There was no apparent difference in control between the two herbicides. Some growth of perennial grasses was evident the second season after spraying. It must be noted that the treated area was grazed by sheep and cattle the first and second seasons following treatment. This grazing has complicated the evaluation, especially concerning the survival and growth after spraying of both perennial grasses and Hoary Cress. The treated area is being monitored to see what happens in this respect. | |||||
3. Conclusion. |
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| Hoary Cress is effectively controlled by a single treatment of either Escort of Rodeo herbicide. Treatment while the plant is actively growing is probably critical to a high kill rate. After seed has formed movement of herbicides within the plant and uptake by the leaves is significantly slowed. | |||||
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