Evaluation of herbicides and application timing for control of Japanese knotweed : final report, June 2003.

Details

• Creators:
  Kay, Stratford H.
• Corporate Creators:
  North Carolina State University. Dept. of Crop Science
• Corporate Contributors:
  North Carolina State University. Center for Transportation and the Environment ; United States. Department of Transportation. Research and Special Programs Administration
• Subject/TRT Terms:
  • Herbicides
  • Agricultural chemicals
  • Plants
  • Weeds
  • Weed control
  • Vegetation control
  • Herbicides
  • Plants--Effect of herbicides on
  • Japanese knotweed--Control--North Carolina
• Publication/ Report Number:
  FHWA/NC/2003-03
• Resource Type:
  Tech Report
• Geographical Coverage:
  North Carolina
• Edition:
  Final report; Oct. 2001-March 2003.
• Corporate Publisher:
  North Carolina. Department of Transportation. Research and Analysis Group
• Abstract:
  Testing was conducted from fall 2001 through spring 2003 to evaluate the efficacy of several herbicides, timing of ; application (foliar vs. dormant), and an alternative application method (Burch Wet Blade) for control of Japanese knotweed along ; highway rights-of-way. ; Foliar treatments with glyphosate (Rodeo) in late spring, fall, or in the fall following a single spring mowing did not produce ; apparent kill in the season in which it was applied but essentially no greenup of treated plants occurred in the following spring. ; Triclopyr amine (Garlon 3A) gave rapid top kill of leaves and stems within a week or two, which persisted until the end of the ; growing season. When evaluated during the following spring, there was no evidence in the triclopyr plots that any treatment had ; occurred; triclopyr-treated plots all were green and healthy. Clopyralid (Transline) and dicamba DGA (Vanquish) caused minor, ; but temporary leaf curling and slight discoloration; metsulfuron methyl (Escort) produced essentially no visible symptoms. All ; plots treated with clopyralid, dicamba DGA, or metsulfuron-methyl were green and healthy the following spring. Combinations ; (tank mixing) of herbicides did not improve knotweed control. When glyphosate was combined with triclopyr amine, control ; was poorer than with glyphosate alone. This suggested possible interference of triclopyr amine with glyphosate. ; Glyphosate (Rodeo) was applied at 0.5 to 2 gal/acre, with a retreatment of half of each plot in the summer. At the end of the ; growing season, only minor yellowing of leaves was apparent, in spite of the treatment rate or whether or not re-treatment ; occurred. In the spring, there was essentially complete kill in all but the 0.5 gal/acre treatments, and there were no obvious ; differences between areas receiving a single treatment vs. two treatments. ; Preliminary evaluation of triclopyr ester (Garlon 4) and imazapyr (Arsenal) were conducted at two sites at the fall treatment ; dates. Garlon 4 did not produce any obvious kill that carried over into the following growing season. There was slight, but not ; acceptable reduction in the following spring of shoot heights of knotweed that had received fall treatment with imazapyr. ; The use of the Burch Wet Blade to apply glyphosate (Rodeo), triclopyr amine (Garlon 3A), or imazapyr (Arsenal) in the ; summer did not produce any lasting effects on the knotweed. Substantial regrowth occurred throughout all of the treated plots by ; the following spring.
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/17171/dot_17171_DS1.pdf
• File Type:
  [PDF - 1.07 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:69c4df368d1db0fe9cfee38bc2f5d6859df8c74b29adf30e2216d2e0f203df9f