FFF04-04 May 7, 2004

Crop Conditions.  Well just when the season was looking goodÉ   Early
warm temperatures were followed by a cool snap that hit around the time
of apple flowering (the last 2 weeks) across much of the state.
Obviously this didnÕt help bee activity or pollination.  Frost has
damaged some apple crops in northern areas of the state.  Warmer
temperatures are forecast for at least the next week or so providing
good chemical thinning opportunities.

Frost Affects Fruit Crops Ð frosts were recorded in some places across
the state on April 28 and at a few sites on May 3.  A brief scroll
through the weather station data (available online at
http://shadow.agry.purdue.edu/sc.index.html) shows the following
minimum temperatures at sites across the state:  Angola27, Bloomington
41, Columbus 35, Greenfield 35, Lafayette 38, LaPorte 28, Martinsville
37, New Castle 31, Plymouth 32, Tell City 46, Terre Haute 43, Vincennes
39, Wabash 29. These temperatures were recorded at weather stations and
the actual temperatures at your farm are likely to differ.  At the time
of the year a few degrees can make all the difference in the world.

A few orchards in the northwest part of the state sustained quite a lot
of damage to apple blooms as a result of frost.  Some orchard blocks
have little damage while in others the damage is extensive. Even with
frost damage, donÕt give up on the idea of chemical thinning yet.  Less
than 10% of live buds are needed for a full crop, so even with damage
you may still need to thin.  A couple of years ago I visited an orchard
with extensive frost damage and bet the grower a steak dinner that he
would still need to thin.  I won the bet, but he has yet to pay up (you
know who you are!).  Wait for fruit drop and see what sets before
deciding on your thinning strategy. (Hirst)

IHS Summer Meeting:  The summer meeting of the Indiana Horticultural
Society will be held at in the North Eastern part of the state on June
28-29.  Full details will be provided soon, but write these dates on
your calendar and plan to attend. (Hirst)

Apogee:  If you are going to apply Apogee this year, the time is now!
Apogee is a relatively new growth regulator for use on apples.  It can
reduce shoot growth dramatically, but it is expensive so itÕs probably
not a product you want to spray over your whole orchard each year.  Its
main application is likely to be in blocks where there is excessive
vigor due to crop loss, or inappropriate tree spacing / rootstock
combination.  Apogee can also reduce the incidence of fireblight Ð it
does this not by affecting the fireblight bacterium, but by reducing
the amount of susceptible new shoot growth on the tree.  Timing of
application is critical, and if this product is applied after shoots
are about 3Ó long, then it is likely to have little effect. Rates of
application and more detail are in the 2004 Commercial Tree Fruit Spray
Guide. (Hirst)

Apple Thinning:  The thinning decision you make with apples is one of
the most critical management decisions you will make all year, and one
that affects not only the crop this year, but next year also. Thinning
is all about tradeoffs and compromise.  The earlier you thin, the
better the response will be, both in terms of fruit size increase and
in return bloom for next yearÕs crop.  The problem is that early
thinning is risky, so what to do?  Use the nibble approach where you
donÕt try to get the job done in one shot.  Put on a mild thinner
application early (say around petal fall) and then follow up with
another application about 10-14 days later if you think it is needed.
This way you achieve some of the benefit of early thinning while at the
same time spreading some of your risk.  A few other pointers for
thinning: _ Thinners work best when temperatures are 70-80F at the time
of application and for a few days afterwards.  DonÕt apply thinners
when temperatures are below 65 F, as they will have little affect. _
Keep detail notes of what you applied, what rate, when, what the
conditions were at the time of application and for a few days
afterwards, and what the result was.  This will help you build up a
picture of what works best on your farm _ If you suffered some frost
damage, think long and hard before you decide not to thin this year.
The risk is that there may be more crop left than you think, and by not
thinning you may be compromising next years crop as well as the crop
this year.

The best book I know of on thinning is the ÒApple Thinning GuideÓ by
Phil Schwallier at Michigan State University.  It costs about $10 and
is available from Great Lakes Publishing, Phone 1-616-887-9008. (Hirst)

IDFTA ÔHoneycrispÕ Summer Tour Ð The International Dwarf Fruit Tree
Association (IDFTA) is holding their summer tour for 2004 on June
21-22, and this year will be headquartered in La Crosse, Wisconsin.
The emphasis for the tour is ÔHoneycrispÕ, without doubt the hottest
apple in the country for the last few years.  Orchards included on the
tour are: _ Sunrise orchards, Gay Mills, WI.  A third generation family
owned operation growing, packing and marketing apples on 240 acres. _
ShefelbineÕs Orchard, near Holmen, WI.  Established in 1951 and now
growing strawberries, and various apple varieties including 30 acres of
Honeycrisp. _ Sacia orchard, one of the largest orchards in west
central Wisconsin, with 230 acres of apples and 32 acres of Honeycrisp
on M.7, G.16, G.30, B.9 and Supporter 4 rootstocks. _ Maiden Rock
Apples, near Stockholm, WI.  An 80-acre retail farm growing 25
varieties on dwarfing rootstocks. _ Bridal Rock Orchard, near Lake
City, MN. In operation since 1907, recent planting includes 3000
Honeycrisp on B.9 rootstock. _ Pepin Heights Orchard, Lake City, MN.  A
vertically integrated grower, packer, processor and broker of apples
and apple products.

The cost of the tour is $250 for members (membership is $85 which
includes their magazine, the Compact Fruit Tree). This includes motor
coach transportation, lunches and a group dinner.  More information is
available on their website: http://www.idfta.org  (Hirst)

European Red Mite Management Ð We are rapidly approaching the time when
we have some major decisions to make about managing European red mites.
Managing this important pest has five components.

1. Dormant oil sprays 2. Conservation of predator mites 3. Preventive
miticides 4. Curative miticides 5. Resistance management

Hopefully you all put on a timely dormant oil spray several weeks ago.
I have preached to you for many years about the importance of
conserving predator mites. The effectiveness of the miticides we have
available now gives us more flexibility than we had several years ago,
but conserving those predator mites is still the key to effective mite
management. Avoid the use of Ambush, Pounce, Asana, Vydate, Carzol, and
Lannate if at all possible. Now you have to decide whether to put on
one of our excellent preventive miticides, Apollo, Savey, or Agri-Mek.
With the revision in labels several years ago, we no longer have to
apply Apollo and Savey before petal fall, which allows us to prolong
their effective life. Those products should always be used after petal
fall. My data indicates that they will be effective if applied as late
as early June. Agri-Mek can be applied up to six weeks after petal
fall, but most of the entomologists in the Midwest agree that first
cover is about the right time for this product. We also have two
effective rescue miticides, Pyramite and Acramite. My observation is
that Pyramite may be slightly more effective at controlling European
red mites than Acramite, but it is also more toxic to the predator
mites. Also, Acramite is sensitive to hard water, so itÕs important to
resolve that problem is you use Acramite. We are in a very good
situation right now with the materials we have available. Avoiding the
development of resistance is important so that we continue to have this
selection of products. Remember that Apollo and Savey have similar
modes of action and should be considered as the same product in terms
of resistance management. The primary method for avoiding resistance is
to limit the exposure of the European red mites to a single compound or
mode of action. Based on the products we have available, I recommend
that growers follow a four-year program for mite management. Year 1 Ð
Apply either Apollo or Savey as a preventive miticide. If you are
already seeing a fair number of mites, you should probably start with
one of the preventive miticides this year. Also, if you had a serious
mite problem last year, you should definitely start the program with a
preventive miticide. Year 2 Ð DonÕt apply a preventive miticide. Wait
to see if a problem develops. Often, mite populations will remain below
the threshold and no applications will be necessary. However, if a mite
problem develops, apply either Pyramite or Acramite to clean up the
problem Year 3 Ð Apply Agri-Mek as a preventive miticide. Year 4 -
DonÕt apply a preventive miticide. Wait to see if a problem develops.
If a mite problem develops, apply either Pyramite or Acramite to clean
up the problem Whether you start the program with Apollo/Savey, or
Agri-Mek is not important. The important thing is that you try to limit
the exposure of these products to every fourth year. If we can do that,
we should be able to make these products last for a long time. There
are several new miticides that may be coming along soon. This will give
us even greater flexibility. I will keep you posted when those products
become available. (Foster)

Cicada Update Ð By the time you receive this newsletter, I suspect that
cicada emergence will have begun in southern Indiana. The warm spring
we have had has apparently moved up the time of emergence of the
cicadas.  See the April 9 edition of FFF for more details. (Foster)

Codling Moth Ð In West Lafayette, I have caught just a couple of random
codling moths in two different traps. The recent cool weather has
slowed down their development, but I suspect that the warm weather late
this week (IÕm writing this on May 6) will result in moths starting to
fly very soon. Generally we wait until we had a sustained flight,
arbitrarily set at five moths in a trap, before we establish our
biofix. At that point we start accumulating degree days (base 50) to
determine the optimal time to put on our first cover spray. For most of
the products available, the general consensus is that the first spray
should go on at 150 Ð 200 degree days after biofix. If you have had
good results with Imidan or Guthion in the past, those products will
most likely still give well to excellent control. If you want to switch
to an alternative product, I would recommend Danitol for first
generation control if you are in an area where cicadas are a problem.
The results throughout the lower Midwest from last year showed that
Assail and Calypso also provided control comparable to Guthion. These
products have similar modes of action and I would not recommend using
both in the same year, for fear of developing resistance. (Foster)

FIRE BLIGHT ALERT:  Bloom + Warm Weather + Rain = Fire blight!  A few
weeks ago I had a number of phone calls from nervous growers asking
about the potential for fire blight, especially with the early warm
weather we experienced.  At that time, the one ingredient that was
missing was RAIN; however two days later, at full bloom in many parts
of the state, we had an all-day rain.  Therefore, IÕm expecting a good
deal of fire blight to pop up throughout the state over the next few
months.  Expect fire blight symptoms to begin showing about May 15 in
southern Indiana, move on to central Indiana about June first and hit
northern Indiana by mid June.  Growers in southern Indiana should be
scouting their orchards NOW.  Be especially diligent in patrolling
young blocks of apples (<5-7 yrs old) for the first symptoms of fire
blight, wilted terminal tip ends.  Cut out blighted twigs 10 to 12
inches below any sign of infection, being sure to sterilize pruning
tools between each cut.  If the infected shoot is associated with the
main trunk or a major scaffolding limb you may want to try the Òugly
stubÓ cut, deliberately leaving a naked 4 inch branch stub above the
supporting limb.  Marking the ugly stubs with flags or a bright colored
paint when the cuts are made can help in relocating them during the
winter pruning operation.  And remember, when severe windstorms or
rainstorms with or without hail occur during peak fire blight season
(now), apply streptomycin within 24 hoursÉthe sooner it is applied the
better. (Pecknold)

Powdery Mildew of Apple:  While most fungal diseases do best with wet
conditions, the one exception is powdery mildew.  Powdery mildew 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 such as Jonathan, Rome Beauty, and Ida Red
(my favorite disease apple) should be especially watchful.  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 strobilurins,
Sovran and Flint.   Good old Captan, Vangard, Polyram and Mancozeb
products do not provide adequate control of powdery mildew.  I
especially like the use of Sovran or Flint at first cover, not only do
you get control of powdery mildew but you also get good control of
fruit scab and an early start on sooty blotch and flyspeck. (Pecknold)

EBDC Fungicides:  We strongly suggest that growers calculate the 77
days to harvest date for each of their major cultivars and make the
final application of EBDC fungicide (Dithane M-45, Manzate 200,
Penncozeb, Polyram) on that date to take full advantage of the
excellent control these fungicides provide for sooty blotch and
flyspeck.  In the Lafayette area this would make July 20th the final
spray date assuming harvest occurs October 4th (unless I counted my
days wrong).  This recommendation applies only to growers who used the
low rate of mancozeb - 3 lbs/acre.  Refer to page 13 of ID-168, Ò2004
Indiana Commercial Tree Fruit Spray GuideÓ, for further information.
(Pecknold)

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, Ò2004 Indiana Commercial Tree Fruit Spray
GuideÓ, for further information.  (Pecknold)

Indar Receives Section 18 Exemption for Use on Blueberries:  EPA has
granted a section 18 Specific Exemption for fenbuconazole (Indar)
fungicide for use on blueberries in Indiana for the 2004 growing
season.  Indar 75WSP (fenbuconazole) is used for the control of mummy
berry disease.  The supplemental label for the Section 18 exemption has
been issued by Dow AgroSciences.  This supplemental label must be in
the possession of the user at the time of application.  Contact Dow
Agrosciences, (http://www.dowagro.com/label/index.htm) for a copy of
the label.  If you have questions about section 18 exemptions for
pesticides, contact the Indiana State Chemist at 765-494-1587.
(Bordelon)

Getting the Most out of Early Season Weed Sprays:  Fruit growers often
apply a post-emergent herbicide beneath the tree or vine row in spring
to control winter annuals and other weeds.  A pre- emergent herbicide
may be included in this application.  Glyphosate (Roundup) is a post
emergent systemic herbicide that is widely used for this first weed
spray.  In order for glyphosate to be effective, it needs to be
absorbed into the plant.  In soft water glyphosate has no problems in
being absorbed.  However in hard water glyphosate will be Ôtied upÕ and
not absorbed as readily.  Hard water, common in many parts of Indiana,
contains high concentrations of soluble salts, calcium and magnesium.
When these cations are present they react with the negatively charged
glyphosate to form compounds that are not readily absorbed by plants.
This results in poor uptake and poor weed control. The solution to the
hard water problem is to add ammonium sulfate to the spray water before
mixing with glyphosate.  Ammonium sulfate ions tie up the calcium and
magnesium ions forming conjugate salts.  Additionally, some of the
glyphosate reacts with ammonium to form a compound that some weeds
preferentially absorb.  Follow the Roundup label recommendations on the
amount of ammonium sulfate to add. Another problem associated with
spray water quality is that many fungicides and insecticides break down
quickly in high pH water.  Captan, Imidan, Malathion, and Omite are
examples of compounds that are especially vulnerable to alkaline
hydrolysis.  Both the Commercial Tree Fruit and Small Fruit and Grape
Spray Guides have a discussion of spray tank pH.  Briefly, addition of
about 2 ounces of food grade citric acid per 100 gallons of water will
lower the pH from about 8.0 to about 5.5. (Bordelon)

Grape Phylloxera:  The foliar or aerial form of grape phylloxera is
starting to show up in vineyards across the southern and central parts
of the state. The pest is normally not damaging enough to warrant a
special insecticide application. However, this past season, phylloxera
damage was particularly severe across the region, so we expect it could
be damaging again this season. The best products for controlling the
foliar form of phylloxera are endosulfan (Thiodan) and fenpropathrin
(Danitol). The appropriate time to apply these materials is at or just
before bloom and then 10 days later. Growers should be aware that
Thiodan can cause phytotoxicity on certain varieties, and that Danitol
is a Restricted Use Product (RUP) requiring applicator license and
record keeping. Always read the label. Leaf phylloxera is normally more
severe on thin-leaved varieties such as the French hybrids rather than
American or labrusca types. And the insect seems to be particularly
attracted to certain varieties. We have noted that Leon Millot,
Chambourcin, Frontenac, LaCrescent, and a few others are particularly
attractive. (Bordelon)

Contact Us Toll Free!!! Growers, homeowners, and anyone else with
questions for state Extension Specialist can contact us using the
Purdue Extension toll free number: 1-888-EXT-INFO (398-4636). The
operator (a real live person!) will direct your call to the appropriate
specialist. We ask that you start by contacting your county Extension
Educator for help, and then if you need our assistance, feel free to
call us and save yourself a little money. You can use this same line to
order Extension Publications from the Media Distribution Center.


Upcoming Meetings:

June 21 Ð Indiana WinegrowersÕ Guild summer meeting & workshop. Chateau
Pomije Winery, New Alsace. Visit www.indianawines.org for details.

June 21-22 Ð IDFTA summer tour (see article in this FFF or
http://www.idfta.org for more details).

June 28-29.  Indiana Horticultural Society Summer Tour Ð more
information coming soon.