PCC MarchApril Final Draft

Life After Methyl Bromide in
California Berries
Growers lean on newer fumigant alternatives to control
key weed and disease pests.
BY WARREN E. CLARK, Contributing Writer
When methyl bromide was
banned in 2005, California
strawberry growers lost an
effective tool in their crop care toolbox
to control weeds, soilborne diseases,
nematodes and symphylans. Special-use
permits allowed them to continue using
the fumigant through 2016, but growers
feared final loss of the powerful soil
fumigant might be the end of profitable
production.
The California Strawberry Commission
agreed, noting that elimination of
methyl bromide fumigation brought
forth several soilborne diseases for
which there is no post-plant control. Of
particular concern were Fusarium wilt
(Fusarium oxysporum f.sp. fragariae),
Verticillium wilt (Verticillium dahlia)
and charcoal rot (Macrophomina
phaseolina), according to the California
Strawberry Commission.
But once again, necessity proved to
be the “mother of invention,” said
independent agronomist and PCA Lee
Stoeckle, owner of Stoeckle Agricultural
Consulting in Ventura, Calif.
Stoeckle has advised strawberry and
caneberry growers for more than
30 years, and he noted that effective
alternative fumigants have taken up
the methyl bromide void and are now
widely and successfully used. While
California strawberry acreage has
fallen, total production has actually
increased thanks to innovation and
application of new technology.
Stoeckle’s family-owned business
provides recommendations on 3,000
acres of strawberries and 100 acres of
blackberries in Santa Barbara County
and San Luis Obispo County and
2,000 acres of strawberries in Ventura
County. In addition, he consults on
production of 800 acres of strawberry
and 250 acres of raspberries in Baja
Mexico. While he is primarily responsible
for above-ground insect and disease
control, he doesn’t write fumigation
recommendations but instead advises
based on what he learns about weeds
and soil pathogens.
A One-Two Punch
Top problem soilborne diseases,
according to Stoeckle, are Fusarium,
Macrophomina, Phytophthora, Anthracnose
and Verticillium wilt. Top
Continued on Page 44
42 Progressive Crop Consultant March / April 2021