Help Growers Fight Floral Pests
By Marcia Wood
October 2, 2001
Garden roses--the kind that you buy
as bare-root plants at the nursery for your home garden--cant
flourish if theyre harassed by soil-dwelling pests called nematodes.
Thats why U.S. growers of bare-root roses typically fumigate their fields
with methyl bromide, a chemical that kills nematodes and other pests, as well
as weed seeds.
Because of indications that methyl bromide depletes the Earths
protective ozone layer, methyl bromide is now being phased out.
Agricultural Research Service scientists
in Fresno, Calif., are helping garden-rose growers by testing other compounds
that might protect roses.
Plant pathologists Sally M. Schneider and James S. Gerik of the ARS
Water Management Research
Laboratory in Fresno, Calif., are scrutinizing about a half dozen different
compounds, such as propargyl bromide, or combinations of compounds, such as
iodomethane plus chloropicirin.
They are also experimenting with different ways of applying the chemicals,
such as injecting them into the soil or distributing them through
The researchers are using concrete pipes, turned on end and buried in the
ground, to form small, self-contained study sites called microplots
for the research. Each pipe is 4 feet long and 18 inches in diameter. Their key
target is root-knot nematodes that feed on roots and cause galls to form. Galls
interfere with the roots ability to take up water and nutrients from
The scientists are collaborating with
Jackson & Perkins, the
worlds largest grower of roses.
ARS is the U.S. Department of
Agricultures chief scientific research agency.
The garden roses research is part of an ARS
National Program on Methyl Bromide