metribuzin (Lexone, Sencor) NYSDEC Approval of 2(ee) for Sencor DF 5/96
New York State Department of Environmental Conservation
Division of Solid & Hazardous Materials
Bureau of Pesticides & Radiation
Pesticide Product Registration Section
50 Wolf Road, Albany, New York 12233-7257
Phone 518 457-7446 FAX 518 485-8990
May 21, 1996
Mr. William G. Smith
Senior Extension Associate
Pesticide Management Education Program
Cornell Cooperative Extension
5123 Comstock Hall
Ithaca, New York 14853-0901
Re: FIFRA 2(ee) Recommendation - Use of SENCOR DF Herbicide (EPA Reg No
3125-325) on Carrots at Less Than Labeled Rate for Application at an
Earlier Growth Stage
The New York State Department of Environmental Conservation has
approved your request for a FIFRA 2(ee) recommendation for use of SENCOR
DF Herbicide (EPA Reg No 3125-325) on Carrots at Less Than Labeled Rate
for Application at an Earlier Growth Stage. Copies of the accepted
recommendation are enclosed.
Anyone using SENCOR DF under this recommendation must have the
recommendation in their possession at the time of application.
If you have any questions on this matter, please contact Frank
Hegener of this office at (518) 457-7446.
Maureen P. Serafini
Pesticide Product Registration Section
cc: R. Mungari - NYS Dept. of Agriculture and Markets
Proposed FIFRA 2(ee) Recommendation
Researcher and Title: Robin R. Bellinder, Associate Professor,
Department of Fruit and Vegetable Science, Cornell University, Ithaca,
Pesticide Name and EPA Registration No.:
Metribuzin Sensor 75DF (3125-325)
Target Crop: Carrots (Daucus carrota)
Proposed Application Rate: 0.125 lb ai/A to be applied broadcast:
postemergence to carrots having at least 1 fully-developed true leaf.
Subsequent applications of 0.25 lb ai/A may be applied after the 3-leaf
Nature of 2(ee) variation from product label: The chemical is currently
labelled for application at 0.25 lb ai/A (113 lb product/A) but cannot
be applied until the crop has 5 to 6 leaves. This recommendation is for
the use of lower rates at earlier timings.
Complete Recommendation: Sencor effectively controls many broadleaf
weeds, including redroot pigweed, common lambsquarters, galinsoga, and
some annual grasses. Suppression of nutsedge and common ragweed have
been observed. For control of emerged broadleaf weeds early in the
development of the carrot crop, apply 0.125 lb ai/A (1/6 lb product/A)
to carrots having at least 1 fully-developed true leaf and 0 25 lb ai/A
(1/3 lb product/A) to carrots having 3 or more leaves. A single
application applied prior to the 5-leaf stage of carrots will not
provide adequate season-long control. Multiple applications at 1- and
3-, 2- and 4-, or 3- and 5-leaf stages will significantly improve weed
control. Crop injury shortly after application, has been seen in
research trials however the effect has been transitory, with no yield
losses attributable to crop injury. Sencor is currently to be applied
at 0.25 lb ai/A but not until carrots have at least 5 to 6 true leaves.
However, failure to control weeds before this stage of development
will result in significant yield losses due to weed competition.
The activity of metribuzin on both carrots and weeds is increased
if applied after 3 or more cloudy days and when applied on very hot
days. Do not apply when the temperature exceeds 85 F. Crop injury or
delayed maturity may result from applications of Sencor if applied to
carrots growing under stress conditions.
Metribuzin often reacts with other herbicides or insecticides and
damages carrots when the chemicals are tank-mixed or applied
sequentially at close intervals. Thus, several days, preferably 1 week,
should elapse between metribuzin applications and applications of
Metribuzin is not to be applied with surfactants and no more than
0.5 lb ai/A (2/3 lb product/A) may be applied in a growing season.
Applications may be made up to 60 days before harvest.
Accepted for registration May 21, 1996. New York State Department of
Environmental Conservation, Division of Solid and Hazardous Materials,
Pesticide Product Registration.