Weekly Vineyard IPM Scouting Summary
Report for the week of May 17 2007
Southwest Michigan
Grape Berry Moth:
Average Number of GBM in Traps
Percent Clusters Infested With
GBM (25 Clusters Scouted at 4 Locations at Each
(Average of 4 Traps Per Site)
Site)
5/11 5/17 5/24 5/31 4/26 5/3 5/11 5/17 5/24 5/31
0
0
0
0
0
0
Allegan
Berrien 1
12.8 6
0
0
0
0
Berrien 2
8.8
5
0
0
0
0
Van Buren
11 8.3
0
0
0
0
2007 Average
8.1 4.8
0
0
0
0
Grape berry moth adult
2006 Average
2
2
0.2
6
0
0
0
0
0
0
male caught in pheromone
2005 Average
4
3
3
13
0
0
0
0
0
0
trap. Note the distinctive
2004 Average
NA
8
4
7
0
0
0
0
0
0
dark grey/purple "saddle"
** Trap catches of male grape berry moth adults were down slightly this week
that identifies the adult
because of the colder weather. If the warm weather predicted for next week does
moths.
take place, look for moth catches to increase again. Egg-laying should begin in a
couple of weeks with the first larvae hatching a week or two after that.
Site
4/26
Chardonnay
0
Vignoles
0
Concord
0
Concord
0
0
0
0
NA
Variety
5/3
0
0.3
0
0.3
0.1
0
1
NA
Grape Flea Beetle (Steely Beetle):
Flea beetle leaf feeding
damage on Concord leaf
at the Van Buren site.
1 inch
** Flea beetles are no longer any danger to the developing clusters.
The only feeding you may see is some minor damage to leaves, but this
is of no importance. Some of this minor damage was found at the Van
Buren site (see picture to the right).
Leafhoppers:
** Grape leafhoppers have been found on yellow sticky traps at
the Berrien 2 site. No potato leafhoppers have been found yet,
but they should be showing up sometime in the next couple of
weeks. See the Northwest Report below for more information on
potato leafhoppers.
Adult grape leafhopper
with distinctive yellow
stripes and dark spots on
their wings.
** A grape plume moth larva was found at the Van Buren site. Plume moth larvae
Plume moth larva
are most often noticed early in the season when they web young grape shoots and
on Concord leaf
clusters together. The larvae themselves are yellow/light green with white hairs.
at Van Buren site.
You don't need to worry about them as they almost never reach economically
damaging levels.
Other Notes:
1 inch
Other Insects:
Upcoming Grape IPM Meetings:
This week Thursday! May 24- MSU-National Grape IPM Update
10:00am-12:00pm: Cronenwett Farms, Lawton
2:00pm-4:00pm: Berrien County Office at SWMREC
Thursday, June 14 - Grape IPM Scouting Workshop Twilight Meeting
6:00pm at Tim Seppala Farm, Lawton
Thursday, July 12 - Grape IPM Scouting Workshop Twilight Meeting
6:00pm at the Dongvillo Farm, Scottdale
Wednesday, July 25 - Viticulture Day
At SWMREC
Thursday, August 9 - Grape IPM Scouting Workshop Twilight Meeting
6:00pm at Jeff Lemon's Lemon Creek Farm, Berrien Springs
Disease Notes:
Early phomopsis spots on Vignoles leaf at Berrien 1 site.
** Small phomopsis spots are showing up on leaves at the
Berrien 1 site. Looking for these early spots may give you some
indication of how bad infections may be later on in the season.
** Now that young clusters are visible protectant fungicides may
be necessary. Pay close attention to wetting events that can
result in disease infections.
** Since 2006 was a year with a lot of powdery mildew
infections make sure to pay close attention to infection periods
this spring, especially in vineyards that had heavy infections last
year. Protecting clusters from powdery mildew during spring
time infection periods is a critical component to preventing
infections later in the season.
Vignoles-Berrien 1
Current Growth Stages:
Concord-Van Buren
As of
May
17
As of May 17
As of May 17
Concord-Berrien 2
Wild grapes adjacent
to Berrien 1 site
Chardonnay-Allegan
As of May 17
As of
May 17
Starting April 1:
Starting March 1:
Growing
Degree
Days
(Base 50)
As of
May 17
As of May 17
As of May 17
SITE
4/29
5/6
5/13 5/17
5/13 5/17
Fennville
154
210
285 320
211 246
Lawton
218
284
382 425
277 320
Scottdale
203
270
358 400
260 301
SWMREC
188
253
338 384
245 290
Click here for more Information on GDDs
2006 2005
Previous
Year GDDs 241 258
on May 17
NA NA
(March 1
300 NA
Start):
280 305
2004 2003 2002 5 Year Avg.
310 225 202
247
NA
NA
NA
NA
NA
NA
NA
NA
304
384 303 248
This report is a summary of weekly scouting from winegrape and juicegrape vineyards in southwest Michigan. It should
be used only as a general guide, because pests vary greatly in their abundance from site to site. Scouting your own
vineyards is the best way to know whether pest problems are developing in your farm.
For more information on this project, contact Steve at (517) 242 1282
More information on Vineyard IPM is available online at: www.grapes.msu.edu
All photos: Steven Van Timmeren
Weekly Vineyard IPM Scouting Summary
Report for the week of May 17, 2007
Northwest Michigan
Grape Berry Moth:
Site
Leelanau
Old Mission
2007 Average
Average Number of GBM in Traps
Percent Clusters Infested With
GBM (25 Clusters Scouted at 4 Locations at Each
(Average of 4 Traps Per Site)
Site)
4/26
0
Chardonnay
Riesling
0
0
Variety
5/3
0
0
0
5/10 5/17 5/24 5/31 4/26 5/3 5/10 5/17 5/24 5/31
0 0.38
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
** We found 3 GBM in our Leelanau traps, all caught in border traps.
Grape Insects:
In vinifera varieties of grapes, we have many species of leafhoppers
that feed on the foliage of the plants. The primary leafhopper of concern in our region is
potato leafhopper (PLH). This pest typically does not show up in the northwest vineyards
until late May and early June. However, these pests do not overwinter in our area--they
actually ‘migrate’ northward on southern winds and are dropped down into vineyards
during spring rains. Because spring thunderstorms are unpredictable, we have no good
method for predicting when PLH will turn up in the vineyard, but typical timing for PLH in
vineyards is when shoots are at 8-12” in length. The Mother’s Day (13 May) thunderstorm
could have been a likely candidate for bringing PLH north, but no PLH were detected in our
weekly scouting. Click here for more information on leafhoppers.
If growers/vineyard managers are interested in monitoring for PLH, we
recommend the standard yellow sticky traps. Traps should be placed into vineyards
at or prior to 8-12” shoots, which may come quickly with warm temperatures. Yellow
sticky traps should be placed on the highest wire and secured in such a way that they
do not move on the wire. When we have foliage in the canopy, leaves should be
removed from the trap area. PLH are attracted to these traps and the ‘stuck’ PLH will
provide an early indication if the leafhoppers have arrived into the vineyard.
On a random note, we have spotted a few lecanium scale in the vineyard.
These insects are ‘curiosities’ and there is no need for control.
Adult potato leafhopper on leaf.
Yellow sticky trap in Pinot Noir vineyard.
Powdery Mildew:
Powdery mildew is the disease of concern at this time. In the spring powdery mildew is in the cleistothecia stage, which are
the fungal fruiting bodies that overwinter in bark crevices of the grapevine. When spring conditions are right, ascospores are
released from the cleistothecia to cause the primary inoculum for powdery mildew infections. Ascospore discharge from
cleistothecia is initiated if 0.1 inch of rain occurs with an average temperature of 50 degrees F. Mature ascospores are discharged
within 4-8 hours and are carried by wind. The spores land on green surface on the developing vine, where they germinate and
enter the plant. In the past week, we have had rain and optimum temperatures to cause a powdery mildew infection.
Growers/vineyard mangers should be covered up at this time. We should also remember that this disease was particularly
problematic last season, so there is lots of inoculum in the vineyard.
There are three suggested chemicals for this time of the season: sulfur, fixed copper, and lime sulfur. Sulfur 6L is
recommended at the 10lb equivalent (based on a standard 200 gal/acre dilute spray). Liquid sulfurs tend to have better efficacy
than powdered formulations. Copper compounds at labeled rates are also a good choice for this time of year, and Cuprofix is the
recommended copper of choice. Lime sulfur at 10-20 gallons is another choice; Sulforix, a newer and cleaner formulation of lime
sulfur, can be applied at 1 gallon/acre. Lime sulfur should not be applied to green tissue.
Powdery mildew on the clusters is best controlled by maintaining an open canopy and
applying effective fungicides during the critical period (immediate pre-bloom until three to
four weeks after bloom). For infection prevention, good fungicide options include sulfur,
sterol inhibitors (Nova, Elite, Procure, Rubigan, Bayleton), strobilurins (Pristine, Sovran,
Abound, Flint), Endura and Quintec. Remember that some grape varieties are sensitive
to sulfur, Pristine or Flint, and that fungicides differ in their pre-harvest intervals. Also,
sulfur applied late in the season may interfere with wine-making so is not advised beyond
Powdery mildew on Chardonnay cluster
veraison.
later in the season.
Climbing Cutworm:
** We are continuing to see minor cutworm damage in the northwest, mainly in areas that
are still in the bud burst to 1" shoot stage. Cutworms can still be a pest now, but there is
less risk now than at bud swell. The good news is that we have seen very few cutworms so
far this season, but if a vineyard has had climbing cutworm in the past, monitoring is still a
good idea at this time.
Other Notes:
Cutworm
damaged bud.
Upcoming Grape IPM Meetings:
Friday, June 1 - Northwest Grape IPM Scouting Workshop
3:00pm-5:00pm: Shady Lane Vineyard, Leelanau Peninsula
Friday, August 3 - Northwest Grape IPM Scouting Workshop
3:00pm-5:00pm: Leorie Vineyard, Old Mission Peninsula
Current Growth Stages:
Chardonnay-Leelanau Peninsula
Riesling-Old Mission
Peninsula:
No photos available this
week
Horticulture Topics:
Many varieties of vinifera are at 2” in shoot length. Reisling is not that
far advanced.
As of May 18
There is a lot of wine grape planting going on at this time. Crews are
also trying to finish up tying the vines. We have also noticed some
‘glass bead’ looking stuff on the leaves of the vines. These secretions,
called pearl bodies, are normal and no control is needed. Click here for
more details.
Frost damage has been observed in vineyards or sections of vineyards
in low lying areas. If a vineyard has had a history of frost,
growers/vineyard managers should investigate problem areas.
As of May 18
Starting March 1:
Growing
Degree
Days (Base
50)
Starting April 1:
Click here for more Information on GDDs
SITE
4/29
5/6
5/13 5/17
5/13 5/17
Benzonia
104
148
205 232
169 195
East Leland
81
110
159 182
137 160
Elk Rapids
96
129
185 210
155 181
Northport
63
88
126 145
108 128
NW Station
94
126
190 215
162 188
Old Mission
79
107
155 177
133 155
187 139 146 139 128
Previous
Year GDDs
on May 17
(March 1
Start):
2006 2005 2004 2003 2002 5 Year Avg.
217 185 177 169 145
193
173 135 141
NA
NA
150
226 164 130
NA
NA
173
131 103 117
NA
NA
117
210 160 167 158 141
167
148
This report is a summary of weekly scouting from winegrape and juicegrape vineyards in southwest Michigan. It should
be used only as a general guide, because pests vary greatly in their abundance from site to site. Scouting your own
vineyards is the best way to know whether pest problems are developing in your farm.
For more information on this project, contact Steve at (517) 242 1282
More information on Vineyard IPM is available online at: www.grapes.msu.edu
All photos: Karen Powers and Steven Van Timmeren