Facts for Fancy Fruit 2000-05 May 3, 2000

Crop Conditions:  In southern parts of the state, petal fall on apples
has come and gone, and fruit are up to about the 12 mm stage of growth.
 Here in Lafayette we are approaching petal fall on most varieties and
full bloom in the north.  Pollinating conditions in most places have
been reasonable with some good bee activity observed.  Peaches are done
flowering across the state and crops are variable.  Some growers are
reporting total crop loss due to the early April freeze, whereas others
are looking at good crops.  Grapes in southern areas are at the 4-6
inch shoot stage and some minor damage occurred from recent frosts.
Strawberries are in full bloom in central and northern areas.
Strawberry and blueberry growers in northern Indiana have experienced
several late frosts and freezes, 3 last week.  Most are irrigating for
frost protection.  Now that May has finally arrived, the chances of
damaging frost are fairly low for most parts of the state.

Frost Damage and Thinning:  Now that the flowers are open, itÕs much
easier to see the state of the crop.  In many cases, severely damaged
flowers wonÕt open at all, and many are surprised to see so many
healthy open flowers.  Look carefully at the open flowers to check that
the pistils looks green and healthy.  The pistils (stigma, style and
ovary) are the thread-like structures in the center of the flower.
These are the female parts and the pollen is transferred to these by
the bee (or other pollinator) and the pollen grains grow down the style
to reach the ovary where it fertilizes the egg and forms seeds.  If any
part of the pistil is damaged, the bee can do its thing and transfer
the pollen, but the pollen canÕt grow down to fertilize the egg so the
job just doesnÕt get done.  Look carefully at open flowers to check
that the pistil is green and not brown. Around the state, damage on
most varieties is limited Ð remember even 10% of live buds can result
in a full crop.  Red Delicious seem to be the worst affected, with
significant damage in some places.  Many have lost their king blooms
but probably have enough surviving side blooms to carry a crop.  Mutsu
are also badly damaged OK, so you have some damage and need to make a
thinning decision Ð what do you do? Well assuming you have some frost
damage, this effectively achieved some early thinning.  Many across the
state have seen heavy fruit drop this year, so IÕd suggest holding off
on your thinners for a while yet to see what sticks, and then try a
late application of Sevin or NAA if needed. Although youÕll often hear
me talk about being more aggressive with your thinning, this is not the
year to do it Ð the freeze has been aggressive enough!

Powdery Mildew of Apple:  This fungus overwinters as mycelium in the
terminal buds.  Although the disease is present every year, it is more
prevalent during years when weather is dry and the previous winter has
been mild.  Keep a close watch for the first symptoms of powdery
mildew, especially on those inner, shaded, water sprouts.  Growers of
mildew susceptible varieties, eg. Jonathan, Rome Beauty, Ida Red (my
favorite disease apple), Cortland,etc. should be especially diligent in
their watch for mildew. Apple fruit can become infected with mildew at
pink.  Fruit infections become evident later in the season, as netlike
russet lines on the fruit surface.  The tight cluster, pink, bloom,
petal fall and first cover sprays are most critical for controlling
mildew, but fungicide protection is needed until terminal buds are set.
Your best mildewcides are the SI fungicides (Bayleton, Nova, Rubigan
and Procure) and the new strobilurins, Sovran and Flint.   Good old
captan, Vangard, Polyram and mancozeb products do not provide adequate
control of powdery mildew. -Pecknold

Nova, Procure & Rubigan Resistance: Speaking of Nova, Rubigan and
Procure. A number of commercial Indiana apple growers have been using
sterol inhibiting (SI) fungicides (Bayleton, Nova, Procure and Rubigan)
for 7 yearsÉ or more. As reported last year, research out of Geneva,
New York, indicates that in orchards where SI fungicides have been used
for 7 to 8 years there is a significant increase in the potential for
strains of the scab fungus resistant to SI fungicides to be present.
The researchers, Drs. Koller and Wilcox, ask the question:  ÒWhere do
we stand right now on SI resistance to registered SI fungicides in New
York apple orchards?Ó  Their answer is as follows:

_ SI resistance has increased in New York over the past 10 years, but
in most orchards, resistance remains at a low and manageable level.  In
the vast majority of commercial orchards, SIs will remain effective, if
they are used carefully according to the Òrules.Ó

_ The first rule.  Use full rates of the SI.  Do not ÒcheatÓ on the
rate, the coverage, or the spray intervals.  Alternate row-middle
spraying may spell disaster with the SIs.  Using full rates is even
more important with continued use and as the scab fungus becomes less
sensitive.

_ The second rule: Mix the SIs with a protectant.

Proper use of SI fungicides is becoming even more important the longer
we continue to use them.

Peach Scab:   Early shuck-split and shuck-fall sprays are critical for
peach scab control.   The first spray should be applied about one week
after petal fall.  Do not wait until the shucks have slipped to begin
this program. Continue to spray on a 10-day interval until 40 days
before harvest. See ID-168, Ò2000 Indiana Commercial Tree Fruit Spray
GuideÓ, for further information.  -Pecknold

Codling Moths: In Lafayette, I reached biofix in my codling moth
pheromone traps on April 24. This is 9 days earlier than last year.
Remember that biofix is defined as the first sustained catch of moths,
which we have established as when 5 moths have been caught in a
pheromone trap. I have now started to accumulate heat units to estimate
when the first eggs should begin to hatch and, therefore, when I should
apply my first insecticide spray for codling moth control. See the
April 5 issue of Facts for Fancy Fruit for instructions on calculation
of heat units for codling moths. - Foster

European Red Mites: Shortly after petal fall, growers should begin
looking for European red mites in those block of trees that were not
treated with Apollo or Savey. Initially, sampling does not need to be
very intensive. Just look at the underside of leaves in areas where you
would normally expect to see your worst mite problems, such as in Red
Delicious blocks. Using a 10X hand lens will make the mites a lot
easier to see. Until you start to see a fair number of mites, there is
no point in counting mites on a large number of leaves. However, there
is a lot of tree to tree variation, so look at leaves from several
trees. After mite populations start to build up, I recommend counting
mites on 4 leaves from each of 5 trees per block. This will take you
about 10- 15 minutes and should be repeated every week or two. I know
that you are all busy, but this can be a valuable use of your time. The
generally accepted thresholds for European red mites is 2.5 mites per
leaf in early season, 5 mites per leaf in mid season, and 7.5 mites per
leaf in late season.. - Foster

Eastern Flower Thrips: Strawberry growers should be scouting for
Eastern Flower Thrips in blossoms and on developing fruit. Scout
closely for this pest. As you may recall, Eastern flower thrips have
been a serious problem across the Midwest off and on since 1994. It is
the consensus of the fruit entomologists in the Midwest, after
discussions with entomologists from around the country, that 10 thrips
per flower is a reasonable threshold. We must admit, however, that this
threshold is not based on hard data, but is our best guess. We all
agree that it is important that growers not treat during bloom unless
they have some evidence that an insecticide spray is needed. Our bee
colonies are in serious trouble, so we need to protect them as much as
possible. We strongly recommend that growers scout for thrips in their
strawberry flowers and confirm that thrips are present before applying
insecticides. Thiodan or Lorsban appear to be the best insecticides for
thrips control. See ID-169 Indiana Commercial Small Fruit & Grape Spray
Guide for complete information regarding this pest. -Foster

Grape Spray Recommendations:  The following is a small part of an
article written by Wayne Wilcox, Cornell University plant pathologists,
for the Finger Lakes Vineyard Notes Newsletter. It is applicable to
Indiana and other areas of the Midwest. The differences are that the
Midwest probably has less powdery mildew pressure, and more black rot
and downy mildew pressure than New York, and the use of sulfur for
powdery mildew control. Many French hybrid and American varieties are
sensitive to sulfur (phytotoxicity) especially if the temperature is
above 85ûF. I suggest trying sulfur on a few vines before spraying the
whole vineyard. If in doubt, leave it out.  - Bordelon

From Finger Lakes Vineyard Notes, April 5, 2000: We all know that there
are many good programs for controlling these diseases.  Here are a few
considerations.  As always, just because it isnÕt listed here doesnÕt
mean itÕs a bad idea.  Only products currently labeled in NY State are
listed.  Readers in other states (such as Indiana) have the option of
substituting Elevate into the mix for Botrytis control.

1-INCH SHOOT GROWTH.  A Phomopsis (Ph) cane and leaf spot spray may be
warranted if wet weather is forecast and the training system or recent
block history suggests high risk.  Option A:  Nothing.  Option B:
Captan or mancozeb.

3-5 INCH SHOOT GROWTH.  A traditional time to control Ph shoot
infections; early rachis infections also can be important under rainy
conditions, once clusters emerge.  Time to start control of powdery
mildew (PM) on vinifera varieties if temps consistently remain above
50¡F; also in highly susceptible hybrid blocks if crop value justifies
it.  A possible time to experiment with ÒalternativeÓ PM materials
(salts, oils) if youÕre so inclined.  Black Rot (BR) control is seldom
justified unless youÕre trying to clean up a problem block AND weather
is wet.  Option A: Nothing.  Option B:  Mancozeb (BR, Ph).  Will also
control angular leaf scorch (ALS) on susceptible varieties if very wet.
(Note: ALS has not been observed in Indiana.)  Option C:  Captan (Ph).
Easier on predator mites than mancozeb (or ziram), but not as effective
against BR (not usually an issue this early).  Option D:  Nova or Elite
(PM, BR).  Use 3 oz/A for economy with so little foliage now.  Option
E:  Rubigan (PM).  At 2 fl oz/A, cost is only about $4.  Cheaper than
Nova and Elite, especially if BR control isnÕt an issue.  Option F:
Sulfur (PM).  Not very active at temps below 60¡F, but neither is the
PM fungus.  DoesnÕt control other diseases.  Option G:  JMS Stylet Oil
(PM).  Should eradicate young infections IF thorough coverage is
provided.  Can use with mancozeb (or ziram), but not with captan
(phytotoxicity).  Option H:  eKsPunge (PM). Should eradicate young
infections IF thorough coverage is provided.  Option I:  One of the PM
products plus mancozeb or captan for Ph.

10-INCH SHOOT GROWTH.  Traditionally, weÕve recommended not to wait any
longer to control BR.  Continued experience tells us that this
recommendation is conservative (the spray generally isnÕt needed)
unless BR was a problem last year and/or weather is unusually wet.
DonÕt wait any longer to control PM on susceptible varieties (but wait
until immediate prebloom on Concords).  One of the best times to use an
SI, but these arenÕt the only options.  DM control will be needed on
highly susceptible varieties if disease was prevalent last year and
rains of at least 0.1 inches at temps >50¡F occur.  Rachis infections
by Ph are a possibility, particularly if weather is wet and inoculum is
present.  Option A:  Abound, Sovran, or Flint (PM, BR, some Ph; also,
variable DM [Abound, excellent; Sovran, fair to good; Flint, poor to
fair].  Not the most efficient time to apply these expensive and
limited-use materials unless disease pressure is high.  Option B:
Mancozeb (BR, Ph, DM, ALS).  A broad spectrum, economical choice if PM
isnÕt a serious concern.  Or tank mix a PM material.  Option C:  Nova
or Elite (PM, BR).  Option D:  Rubigan (PM).  No BR but cheaper than
Nova and Elite.  Option E:  JMS Styl;et Oil (PM).  If (and only if)
coverage is thorough, this spray should eradicate early PM colonies
that may be starting because previous PM sprays were omitted.  At a
retail cost of $11/gal, a use rate of 1% (1 gal oil / 100 gal water),
and 50 gal/A spray volume, cost is about $5.50/A.  But donÕt waste your
money if you canÕt cover thoroughly.  Also may help with mites.  Option
F:  sulfur (PM).  Reduced activity at low temperatures is still an
issue at this time of year.  Option G:  eKsPunge (PM).  Short residual
activity, but has eradicative activity against recent infections.  Same
need for thorough coverage as JMS Stylet Oil.  Option H:  Mancozeb (BR,
Ph, DM, ALS) + a PM material (SI fungicide, sulfur, JMS Stylet Oil,
eKsPunge).  Choose PM material based on previously-discussed
characteristics and cost.

IMMEDIATE PREBLOOM (OR VERY EARLY BLOOM).  A critical time for PM, BR,
DM, and Ph (rachis and fruit infections).  Also important for ALS on
susceptible varieties. A good time to use a strobilurin on PM
susceptible varieties.  This and the first postbloom spray are the most
critical sprays of the season--DONÕT CHEAT ON MATERIALS, RATE, OR
COVERAGE!  Option A:  Abound, Sovran, or Flint (PM, BR, some Ph; also,
variable DM [Abound, excellent; Sovran, fair to good; Flint, poor to
fair].  The best choice if SIs have been used for a number of years
against PM, particularly if multiple disease control is needed.  May
provide some Botrytis control if a wet bloom period.  Option B:  Nova,
Elite, or Rubigan + mancozeb (PM, BR, Ph, DM).  Nova and Elite are the
biggest guns against BR, so might be the best choice if pressure is
high and BR control is more important than PM. (Note: This is the
situation in Indiana)  Nova and Elite provide postinfection activity
against BR if significant unprotected infection periods occurred within
the previous 4 days.  Rubigan is (was?) cheaper than Nova or Elite, but
doesnÕt provide the same BR control; however, mancozeb should be
adequate if postinfection control isnÕt required.  Option C:  Mancozeb
+ sulfur (PM, BR, Ph, DM).  Cheap and reasonably effective but not the
strongest choice at a time when the strongest choice is most justified.

BLOOM.  Rovral or Vangard (or Elevate in Indiana) for Botrytis control
may be beneficial in certain years, particularly in problem blocks if
weather is persistently wet.  Abound, Sovran, or Flint applied recently
may be adequate.

FIRST POSTBLOOM (10-14 days after immediate prebloom spray).  Still in
the most critical period for PM, BR, DM, and Ph (rachis and fruit).
Same considerations and options as detailed under IMMEDIATE PREBLOOM.
Juice grape growers (and Indiana growers under our Sec. 24 Special
Local Needs label) can substitute Ziram (very good BR and Ph, only fair
DM) for mancozeb if necessary.

SECOND POSTBLOOM.  BR control still may be needed if disease was
present last year and a spray is strongly recommended if berry
infections are evident this year, particularly if weather is wet.
Fruit are less susceptible to PM now, but vinifera varieties (and
susceptible hybrids?) still need PM protection, particularly on
varieties susceptible to PM.  Avoid SI fungicides if more than a little
PM is easily visible.  Ph danger is mostly over unless very wet.
Primary DM should be over, but continued protection may be needed on
susceptible varieties if weather is wet, especially if disease already
is established.  Option A:  Abound, Sovran, or Flint (PM, BR, some Ph;
also, variable DM [Abound, excellent; Sovran, fair to good; Flint, poor
to fair].  Provides good residual control of the listed diseases if
used now.  May provide some Botrytis control as bunch closure
approaches.  Option B:  Nova or Elite (BR, PM) + captan or mancozeb
(66-day preharvest restriction) if DM and Ph control are needed.
Option C:  Rubigan (PM) + either (a) mancozeb (if more than 66 days
before harvest) for BR, DM, and Ph; or (b) captan (DM, Ph, some BR); or
(c) ziram (BR, Ph, some DM).  Option D:  Sulfur (PM) + either (a)
mancozeb (if still allowed) or (b) captan.  In most years, lessening
disease pressure makes this economical option increasingly practical as
the season progresses.  Option E:  Copper + lime (PM, DM).  Adequate
for Concords, not enough PM control for vinifera and susceptible hybrid
varieties.

ADDITIONAL SUMMER SPRAYS.  Check the vineyard regularly to see whatÕs
needed, the main issues will be PM and DM.  On vinifera and other
cultivars requiring continued PM control, use sulfur as an economical
choice to maintain control; SIs and strobilurins are options if they
havenÕt been overused earlier AND little disease is evident.  Both
provide the advantage of longer residual activity than sulfur,
especially in wet weather.  Copper + lime will work for Concords.  For
DM, copper + lime or captan are economical standards; Abound is a
viable option if general disease pressure or other conveniences justify
its cost; Ridomil can be used in case of emergency.  BR should not be
an issue after the second post-bloom spray, except in unusual
circumstances (disease is established in the clusters, wet weather is
forecast, and itÕs possible to direct sprays onto the clusters).  Ph
should not be an issue.

Note: The following is a short synopsis of WayneÕs comments on Botrytis
control. BOTRYTIS SPRAYS: Botrytis bunch rot is most commonly a problem
on tight-clustered French hybrid and Vitis vinifera cultivars. Proper
timing and thorough spray coverage are essential for good control.
Removal of leaves around clusters on mid- or low-wire cordon-trained
vines before bunch closing has been shown to reduce losses caused by
Botrytis.  Direct the spray toward the fruit zone, and use a minimum of
100 gal/A of water.

There are several new fungicides for Botrytis on the market. This is
great news because resistance to Rovral has been showing up.  DonÕt
forget, however, that even the best fungicides is only a complement to
the various cultural control practices that promote air movement around
the clusters and help expose the fruit to sun and air.

Timing: There are four application times: 1. early to midbloom;  2.
prior to bunch closing;  3. veraison (beginning of fruit ripening);  4.
prior to harvest if needed. Do not make more than 4 applications of
these materials per season.

Traditionally New York recommendations for timing Botrytis sprays have
emphasized the importance of veraison and preharvest periods. Whereas
these recommendations were based on sound field data, they tended to
ignore the potential importance of infections occurring during the
bloom and or bunch closing periods, which are considered to be
important in other parts of the world.

We have found benefit from applying sprays during bloom and bunch
closing in 4 of the last 6 years of field trials in the Finger Lakes;
when directly compared in 1998 and 1999, these two sprays were as
effective as the veraison plus preharvest combination.  In a Long
Island trial, Alice Wise had only 6% infection  of Chardonnay clusters
when Vangard was applied at bloom plus bunch closing, versus 46%
infection in unsprayed plots. (This is even though there were only
three rain events totaling 1.0 inch from the bloom spray through 2
weeks after bunch closure spray, versus eight rain events totaling 9.7
inches between veraison and harvest). Furthermore, when we inoculated
Pinot noir clusters in Geneva at 90% bloom, the pea-sied berry stage,
or at bunch closing last year, virtually all berries developed latent
9dormant infections, and 14-20% of them activated into visible gray
mold at harvest.

Collectively these data suggest that we probably have under emphasized
the importance of early season Botrytis infections, although there is
still a lot of mystery as to when and why such latent infections turn
into rotten berries at harvest.  Nobody wants to spray four times per
year to control Botrytis for obvious reasons.  Nevertheless, it appears
that the fungicidal protection during the bloom through bunch closure
period may be appropriate under Òcertain conditionsÓ (yet to be
determined)

Return Bloom Fund: Peter or Rick are supposed to have something for
this sectionÉÉ

June 5-7 - Heartland Wine School, Ohio State University, Columbus, OH.
The Heartland Wine School is a joint project of Purdue University,
Michigan State University, and the Ohio State University and was
created in response to requests for a regional opportunity to train
winery personnel in classic wine making principles. Extensive tasting
sessions will complement the presentations. Register early to be sure
your place is guaranteed - space is limited and will be allocated on a
first-comeÐfirst -serve basis. To obtain a registration packet contact
Roland Riesen, OARDC, Department of Horticulture and Crop Science, 1680
Madison Ave., Wooster, OH 44691. Phone 330/263-3685.
E-mail:riesen.1@osu.edu

Coming Meetings:



May 3 Ð Eastern Indiana Horticultural Society meeting, Muncie.  Contact
Harold Brown (765- 747-7732).

May 9 Ð Twilight meeting. LaPorte Co. Ken Williams orchard, 6.30 pm.
Contact Walt Sell (219- 326-6808 ext. 271).

May 16 Ð Twilight meeting, North east fruitgrowers, 6.00 pm.  Contact
Ricky Kemery (219- 481-6826).

June 5-7 Ð Heartland Wine School, Ohio State University, Columbus, OH.
Contact Roland Riesen, OARDC/OSU Phone 330/263-3685.
E-mail:riesen.1@osu.edu

June 6 Ð Eastern Indiana Horticultural Society meeting, Muncie.
Contact Harold Brown (765- 747-7732).

June 27-28 Ð Indiana Horticultural Society Summer Meeting.  Write these
dates on your calendar Ð more details to follow.


--------------------------------------------------------------------------------------------
Bruce Bordelon, 1165 Dept. of Horticulture, Purdue University, West
Lafayette, IN 47907-1165, 317/494-1301, e-mail:
bordelon@hort.purdue.edu

Peter Hirst, 1165 Dept. of Horticulture, Purdue University, West
Lafayette, IN 47907-1165, 317/494-1323, e-mail: hirst@hort.purdue.edu

Paul Pecknold, 1155 Dept. of Botany & Plant Path., Purdue University,
West Lafayette, IN 47907-1155, 317/494-4628, e-mail:
Pecknold@btny.purdue.edu

Rick Foster, 1158 Dept. of Entomology, Purdue University, West
Lafayette, IN 47907-1158, 317/494-9572, e-mail:
Rick_Foster@entm.purdue.edu


Disclaimer:  Reference to products in this publication is not an
endorsement to the exclusion of others which may be similar.  Any
person using products listed in this newsletter assumes full
responsibility for their use in accordance with current label
directions of the manufacturer.