Strawberries are among the
most valuable crops for which ARS researchers seek alternatives to methyl
bromide, an effective but environmentally unfriendly soil fumigant. Click
the image for more information about it.
Technology Complements Methyl Bromide
Alternative By Jim
Core January 21, 2005
A new type of plastic cover that helps stop chemical soil fumigants
from escaping into the atmosphere could provide a timely alternative for
farmers facing a ban on methyl bromide, according to
Agricultural Research Service
ARS scientists in Gainesville, Fla., are studying plastic covers
placed over raised beds where vegetables and strawberries are grown. Fumigants
applied to the soil are trapped underground by the plastic, controlling pests
under the soil surface.
One type of plastic cover, called virtually impermeable film (VIF),
contains a central, gas-impermeable layer designed to curb soil fumigant from
escaping into the atmosphere.
ARS is studying environmentally safe alternatives to methyl bromide as
a soil fumigant for crop protection. VIF alone isn't intended to serve as a
replacement for methyl bromide, according to researchers, but would allow
growers to use lower levels of fumigants that are more environmentally friendly
than methyl bromide.
Allen, a soil scientist at the ARS
for Medical, Agricultural and Veterinary Entomology's
Genetics and Environmental Research Unit in Gainesville, and collaborators
at the University of Florida showed that VIF
can retain alternative soil fumigants at higher concentrations for longer
periods in soil than standard high-density polyethylene film now used in
vegetable and strawberry production.
One alternative fumigant the researchers tested was
1,3-dichloropropene (1,3-D). Allen and
Vu, an ARS plant physiologist, and university researchers John Thomas,
Li-Tse Ou and Donald Dickson conducted several field trials in sandy soils at
Gainesville to compare VIF polyethylene film on raised beds.
They found that VIF retained more active compounds in the fumigants
for a longer period of time, provided more uniform distribution of 1,3-D, and
slowed surface emissions of the fumigant more effectively. Further development
of VIF technology is needed, however, to improve the speed and reliability of
Use of methyl bromide is due to be phased out in developed nations
because it was found to deplete the Earth's ozone layer.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.