| MSU Land Resources and Environmental Sciences
BOZEMAN This seems like it could be an X-Files story: Night
farming! What would you think if you saw your neighbor one night plowing
his fields in the dark, wearing a pair of night-vision goggles?
Crazy? Well maybe, or he might just be pretty smart according to some
weed specialists. We first heard of this from Pete Fay, former Montana
State University Extension weed specialist, who is now blissfully night
farming his Rocky Creek produce farm near Bozeman.
According to an USDA website, weed control costs U.S. farmers $15
billion each year. Tons of time and money have been spent trying to
develop methods to rid good farmland of these pesky weeds. Recent
attention has been given to the practice of night cultivation as a way to
deter the growth of weeds.
The idea is based on the fact that the germination of many weed species
will not be stimulated if cultivations are completed in the dark, because
of the absence of red light, known as the phytochrome system.
Ordinary daylight cultivation briefly exposes weed seeds to light
before they are reburied. Often this brief exposure, which could be as
short as a millisecond, can be enough to stimulate the seed to germinate.
Most species that germinate in light are not deliberately cultivated,
meaning theyre weeds. Most crop seeds on the other hand will germinate
in complete darkness. It makes for tough competition, since daylight
represents a good part of the year.
Various studies have shown significant decreases in weed densities with
nighttime tillage. Work done by USDA-ARS scientist Doug Buhler indicated
that tilling soil in darkness can reduce the presence of small-seeded
broadleaf weeds by 50 to 80 percent. Reductions ranged from 70 percent for
common lambsquarters to less than 30 percent for Pennsylvania smartweed.
Hartmann and Nezadal (1990) reported that weed cover in intensively
cultivated land in Germany was reduced from 80 percent to 2 percent if
cultivation was carried out during darkness.
This type of photo control is not without its problems. For one,
there are several weedy species which produce seeds which do not require
red light in order to germinate. There is also the issue of the logistics
of working in total darkness.
While understanding the dormancy requirements of weed seed provides a
new approach to managing weeds and offers potential, there seems to be a
consensus that it should not be viewed as a complete solution to ones
weed problems. |