| Application
Timing |
Material and Rate |
| Dormant immediately
prior to bud swell |
Lime sulfur 10
gallons/A |
| 1-3 inch shoot |
Lime sulfur 2 qt/100
gal |
| Comments: Primarily for
control of
Phomopsis and powdery mildew. |
5-6 inch shoot
or 7-10 days after last spray |
Lime sulfur 2 qt/100
gal |
| Comments: Primarily for
control of
Phomopsis and powdery mildew. |
10-12 inch
shoot
or 7-10 days after last spray
|
Flowable sulfur 6F
(4 qt/A)
or
Wettable sulfur (8-10 lb/A)
or
Potassium Bicarbonate (2-5 lb/A)
or
JMS Stylet Oil (1%) |
| Comments: For control of
powdery mildew |
Immediate prebloom
|
Bordeaux mixture
or
Fixed Copper fungicide
|
| NOTE: This is the CRITICAL
period to control
fruit infection by black rot, powdery mildew, and downy mildew. |
| Comments: The period
from immediate
prebloom through 3 to 4 weeks after bloom is the most critical
for protecting the fruit from infection by Phomopsis, black rot,
powdery mildew and downy mildew. Although not highly effective against
black rot, copper fungicides appear to be the most effective organic
materials for black rot and are highly effective for control of powdery
and downy mildew. For this reason, a copper fungicide should be applied
during this period if conditions are wet and conducive to black rot and
downy mildew infection (Table 1). Black rot and downy mildew require
free water on the plant surface in order to infect. Powdery mildew does
not require free water, only high relative humidity. Therefore, when it
is very dry, sulfur, potassium bicarbonate, or JMS Stylet Oil can be
used in place of copper for powdery mildew control only.
In tests in New York and Ohio, three applications
of a
conventional fungicide such as Myclobutonil (Nova) on a 10 to 14 day
schedule during this critical period (immediate prebloom
through 3-4 weeks after bloom), provided excellent control of
black rot without any additional applications. By 3 to 4 weeks after
bloom, the fruit of most varieties become resistant to infection by
black rot, powdery mildew and downy mildew. Although fruit become
resistant, cluster stems (rachis) and leaves remain susceptible to
powdery and downy mildew infection throughout the growing season. Under
the proper environmental conditions, additional applications later in
the growing season may be required.
|
| Application
Timing |
Material and Rate |
First post bloom
spray
10-14 days after last spray
NOTE: Critical period application.
|
Bordeaux mixture
or
Fixed Copper fungicide |
Second post bloom
spray
NOTE: Critical period application.
|
Bordeaux mixture
or
Fixed Copper fungicide |
|
| Summer Sprays -
throughout summer until
harvest. |
| Remaining sprays should be determined by
weather. At
this point, the threat of black rot infection should be over. If it is
dry and powdery mildew is a concern or problem in vineyard, sulfur
would be the material of choice. Potassium bicarbonate or JMS Stylet
Oil could also be used. If powdery is a problem, sprays should not
exceed 10 to 14 days. If weather is wet, foliar infection by downy
mildew may need to be controlled. A copper fungicide is most effective
against downy mildew |
| Summer Spray Materials |
Disease
Controlled
|
Material and
Rate
|
Powdery mildew
|
Flowable sulfur 6F
(4 qt/A)
or
Wettable sulfur (8-10 lb/A)
or
Potassium bicarbonate
(Kaligreen) (2.5-5 lb/A)
or
JMS Stylet Oil (1%) |
| Downy mildew and
Powdery mildew
|
Bordeaux mixture
or
Fixed Copper fungicide |
| NOTE: Black rot should
not be a
problem during this period. |
| Comments: Do not apply
copper or sulfur
within 30 days of harvest or fermentation may be affected. |
|
Post
harvest
|
|
| Depending upon varieties, there may be
considerable
time between harvest and the first killing frost. Especially in wet
years, post harvest applications of copper may be required to control
downy mildew. If downy mildew develops to sufficient levels, it can
result in premature defoliation. Premature defoliation prevents vines
from hardening off properly and they are much more susceptible to
winter injury. |