Manhattan, Kansas
September 25, 2007
It may be tempting to squeeze out
one last cutting of alfalfa in mid-October, especially if a late
rain encourages late growth, but producers must consider the
long-term effects of such a decision, said Jim Shroyer,
Kansas State University
Research and Extension crop production specialist.
"The last cutting of alfalfa for the year should be timed
carefully since it could have a long-lasting impact on the
productivity of the stand," Shroyer said.
At this stage of the growing season, plants need to store enough
carbohydrates to survive the winter, the agronomist explained.
"To do that, the last cutting has to be timed properly," he
said. "If root reserves are not replenished adequately before
the first killing freeze (24 to 26 degrees F.) in the fall, the
stand is more susceptible to winter damage than it would be
normally. That could result in slower early growth next spring."
The last cutting, prior to fall dormancy, should be made so
there are
8 to 12 inches of foliage, or four to six weeks of growth time,
before the average killing freeze date, Shroyer said. This
should allow adequate time for replenishment of root reserves.
For northern areas of the state, particularly northwest, late
September should be the target date for the last cutting before
dormancy, he advised. The first week of October is the cutoff
for southeast Kansas.
Later cutting dates could reduce root reserves during a critical
time.
"About the worst thing that could happen to an alfalfa stand
that is cut in mid-October would be for the plants to regrow
about 3 to 6 inches and then get a killing frost. In that
scenario, the root carbohydrate reserves would be at a low point
going into winter,"
Shroyer said.
After a killing freeze, the remaining forage (if any) can be
hayed safely, he added. However, the producer should act quickly
because the leaves will soon drop off.
More information on alfalfa management is available at county
and district K-State Research and Extension offices or on the
Web in the K-State publication C-683 "Alfalfa Production
Handbook," at:
http://www.oznet.ksu.edu/library/crpsl2/c683.pdf .
K State Research and Extension is a short name for the Kansas
State University Agricultural Experiment Station and Cooperative
Extension Service, a program designed to generate and distribute
useful knowledge for the well being of Kansans. Supported by
county, state, federal and private funds, the program has county
Extension offices, experiment fields, area Extension offices and
regional research centers statewide. Its headquarters is on the
K State campus in Manhattan. |
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