permaculture

[Victor Guest <vic@daena.eepo.com.au>]

Sender: ag-impact@freedom.mtn.org
Precedence: bulk
From: Earle Cummings <earlec@water.ca.gov>

When you gotta spray, you gotta spray, but here's a way to know when that
is.  Earle

To keep grapes healthy growers must contend with a persistent fungal
disease - powdery mildew. Now growers can control the powdery mildew in
their orchards through the increase of technology and decrease of
chemicals. "We identified, through our research, the environmental
parameters that result in severe disease," says Douglas Gubler, plant
pathologist at the University of California and a member of the American
Phytopathological Society. "By using the temperature, moisture and time
parameters we developed the UC Davis Powdery Mildew Risk Index, a computer
program forecasting model, which provides daily disease tracking
information to growers."

Growers can now predict how severe the disease will be in a week or two and
can determine which fungicides will be most effective as well as the rates
and intervals between application. "Compared with standard spray programs,
this forecasting model lets growers apply two to three fewer fungicide
applications during the growing season with equal or better disease
control," says Gubler. "That means better grapes for wine production and
potentially fewer fungicide applications which is easier on the environment." 

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