FFF04-10 September 13, 2004

Crop Conditions:  Apple harvest is progressing well.  Gala is still
being harvested in more northern parts of the state but finished in the
south.  Size and quality are looking good, and the season is still
running 7-10 days early.  Grape harvest is winding down in the southern
part of the state with only the late ripening varieties remaining. In
central and northern areas harvest got underway this past week. Fall
bearing raspberry harvest continues. A late infestation of Japanese
beetles is causing some problems. Strawberries in the region look good
and the cooler temperatures and plentiful moisture should help assure a
good crop for next year.

Grape Harvest Continues: Grape harvest is underway in central and
northern areas. Despite the recent rains, fruit quality has been good.
Unusually high bird damage has been reported by a number of growers
this year.  One of the most worrisome pests is the multi-colored Asian
lady beetle. They were a serious problem in 2001 and 2003, but appear
to be in very low numbers so far this year, as they were in 2002
season. We are trying to monitor the problem and would like to hear
from any fruit grower that sees a significant build up of this insect
in their plantings. If you have any questions or want to report
sightings of this pest, please contact Bruce Bordelon or Rick Foster.
Our contact information is at the end of this newsletter. And ÒthanksÓ
in advance for your help.  (Bordelon)

Fall Small Fruit Care: Grapes- Grapes should be encouraged to harden
off for winter by avoiding nitrogen fertilizers at this time.  Apply
non-nitrogen fertilizers and lime, as needed based on soil and tissue
test results. It is especially important to maintain healthy leaves
through fall to promote proper hardening. Downy and powdery mildews
often build to epidemic levels on susceptible cultivars in fall. Both
can cause defoliation and reduce winter hardiness so itÕs important to
maintain protection against these diseases throughout the fall until
leaves drop naturally.

Blueberries-
	Blueberry plants should be encouraged to harden off for the winter.
However, growers should continue to irrigate if dry weather persists.
Fruit buds are developing now for next yearÕs crop so it is important
to avoid water stress on the plants during this time.  Apply
non-nitrogen fertilizers and materials for soil pH adjustment based on
foliar analysis and soil tests.  Apply these before fall rains begin
and also before adding any supplemental mulch to plantings.

Strawberries-
	Flower bud initiation occurs during late summer and fall, so
maintaining good plant health into the fall is important for high yield
potential next year. Dry conditions can significantly reduce
fruitfulness next year.  Irrigate to provide at least 1 inch of water
per week through October if rainfall is not adequate. We mentioned the
importance of an application of nitrogen fertilizer in the last issue
of this newsletter.  If it hasnÕt been done yet, itÕs not too late. If
tissue analysis shows deficiencies in magnesium or boron, early fall is
a good time for foliar applications of Epsom salts (15 lb./100
gal./acre) for magnesium and Solubor (3 lb./100 gal./acre) for boron.
Phytotoxicity can be a problem with these materials so read the labels.
 In addition to fertility, controlling leaf diseases improves the
ability of the plant to carry on photosynthesis and store starch in the
crowns.  Check fields for infestations of leafhopper or aphids.
Generally, plants can take a fair amount of feeding by these insects,
but heavy infestations can be a problem.

Brambles-
	Encourage hardening off of canes in summer bearing varieties of
brambles by avoiding nitrogen fertilizers and supplemental watering at
this time.  Spent floricanes can be removed now, or later during fall,
winter or early spring.  Fall bearing raspberries can still benefit
from irrigation in dry weather to help maintain fruit size.  Apply
non-nitrogen fertilizers and lime as needed based on soil and tissue
test results.  If Phytophthora root rot has been identified in a field,
treat the affected area with Ridomil Gold EC, Alliette or phosphorous
acid in September or early October.  This timing is important to get
the material in place in the root zone before the onset of cool wet
weather in the fall. (Bordelon)

Judging Apple Maturity:  If you want a long answer to a short question
sometime, ask a post- harvest physiologist about what is the best way
to assess apple maturity.  All kidding aside, as an apple becomes more
mature, a whole heap of complex chemical changes take place inside that
apple.  Generally speaking, the longer you intend to store fruit, the
more important it is to accurately determine maturity.  Luckily this
lets most of us in Indiana off the hook to some extent, since most
growers only store fruit for short periods.  There is no one single
test that will give you the whole apple maturity picture, but for
short-term storage perhaps this is not too important.  Many growers go
by calendar date to get in the right ballpark, then use the taste test
to determine when to harvest.  If you are going to perform just one
test, probably the most useful is the starch-iodine test.  Many of you
will have heard of this already.  As an apple ripens, starch stored in
the flesh of the apple is converted to soluble sugars Ð this is why
fruit are sweeter as they become more mature.  As any nurse will tell
you, iodine stains anything with starch in it black.  So cutting an
apple in half then dipping it in an iodine solution will give you a
visual picture of how far along the conversion of starch to sugar is,
since the iodine stains the starch black but not the sugar.  To make up
the iodine solution with easily available materials, David Bedford of
University of Minnesota suggests the following:  purchase a one-ounce
bottle of tincture of iodine at a drugstore.  Pour the entire contents
into a one-pint spray bottle.  Fill the bottle with water.  The iodine
solution is light sensitive, so wrap the bottle in aluminum foil.  The
solution and the fumes are poisonous.  Label it and store it away from
children and pets, and use it in a well-ventilated area.

Cut apples in half through the equator so that one half has the stem
and the other half has the calyx.  Spray the cut surface of one half
with the iodine solution and wait 30-60 seconds. Compare the pattern
with that on p.99 of the Tree Fruit Handbook or look under ÒBulletinsÓ
on the Purdue Tree Fruit Connection site
http://www.hort.purdue.edu/fruitveg/    Although apple varieties differ
slightly in their pattern of starch to sugar conversion, the 8 point
scale shown in the handbook should give a reasonable guide.  Fruit
harvested for immediate sale should have a rating of 6-7. If left until
they are an 8 where virtually all the starch has disappeared, fruit may
be too soft.  For storage of 1-2 months, a starch rating at harvest of
3-5 is more appropriate.  Bear in mind that starch will continue to be
converted to sugar following harvest, and this process still continues
slowly in cool storage.   (Hirst)

Pinpoint Scab:  Wet weather during the apple harvest period can lead to
the development of pinpoint scab and other fruit infecting diseases,
such as sooty blotch and fly speck.  Pinpoint scab can infect fruit up
to and during the harvest period if wet weather persists at this time,
however, the symptoms of pinpoint scab may not show up until the fruit
have been stored for several months.   Late season apple scab can also
build up on leaves after harvest, resulting in large quantities of
primary scab spores the following season, even though a good spray
program was followed early this year.  Help prevent such problems by
maintaining scab fungicides in late cover sprays; also do not stop
cover sprays too early. Check the label for days-to-harvest
restrictions before making the final application. (Pecknold)

Collar Rot:  Late summer is a good time to inspect trees for
aboveground symptoms of collar rot.  Look for weak trees with premature
leaf reddening (especially on Goldens); sparse, yellow foliage; and
many small, highly colored fruit.  Keep in mind that such symptoms are
general stress symptoms that may be caused by a number of factors, such
as wet feet, mouse injury, trunk decay, root rot, etc.  However, trees
that show the above-described symptoms AND ALSO have a canker at or
just below ground level are likely infected with collar rot.  If collar
rot is suspected we advise the use of Ridomil Gold EC in the fall after
harvest.  Apply Ridomil as soon as possible after harvest so it will be
in place before the fall rainy periods begin and possible new
infections occur.  Also be sure to concentrate your Ridomil treatment
on surrounding healthy appearing trees, not just trees already showing
symptoms of collar rot.  Ridomil is best used to prevent collar rot,
not cure it.  NOTE: The soil-borne fungus, Phytophthora, which causes
collar rot can be even more of a problem on stone fruits, such as
cherry and peach.  DonÕt forget to check out your stone fruits for
symptoms of collar rot as described above. (Pecknold)

HACCP Workshop:  As all cider makers should be aware, HACCP is now
mandatory unless you are selling all your cider directly to the
consumer and therefore qualify for the retail exemption.  For those
performing HACCP this year for the first time, you should have at least
one person from your operation attend a HACCP training course. Dr. Rich
Linton, in food science here at Purdue, along with colleagues from the
University of Arkansas, is organizing a Workshop ÒDevelopment and
Implementation of HACCP and Prerequisite ProgramsÓ from September
27-29, in West Lafayette.  This 2 1/2 day program will cover all
aspects of HACCP, with break out sessions focusing on fruit and
vegetable juice production.  Cost of the program is $350.  I have
brochures and registration forms, so please contact me if you require
further information.  (Hirst)

NAA For Control Of Preharvest Drop: Shortly after synthetic auxins
(NAA, 2,4-D, 2,4,5-TP) were discovered it was learned that these
materials had activity as stop drops. Auxins interfere directly with
the enzymes that create the abscission zone. Today the one remaining
auxin that is registered for this use is NAA (Fruitone N).

Unlike ReTain, fruit maturity of apples treated with NAA is not
delayed, and in some cases may be accelerated. For this reason, the use
of NAA for control of preharvest drop has been overshadowed in recent
years by that of ReTain. However, ReTain use must be planned weeks
prior to harvest. Since the optimal application time for NAA is just
before the onset of drop, NAA offers a ÒrescueÓ treatment, should the
threat of preharvest drop be increased due to unforeseen circumstances.
Examples of such situations include unavoidable delays in harvest due
to bad weather or labor issues, slow red color development, and
overlapping harvest schedules of varieties with similar maturity
windows, such as that of Empire with Delicious.

A single spray of NAA can provide about seven days of drop control.
Since it is less expensive than ReTain, it may be more cost effective
to use NAA when only a few days of drop control are needed to conduct
an orderly harvest. For example, when using ethephon (Ethrel, Ethephon
II) to promote fruit coloring, growers should also use NAA to prevent
excessive fruit drop resulting from accelerated fruit maturation. When
NAA is used to control drop on ethephon-treated trees, the two may be
tank-mixed if the fruit is to be harvested within seven days. If the
fruit is to be left on the tree longer than seven days after the
ethephon, then NAA should be applied two to three days after the
ethephon.

Other than when applying NAA with ethephon, timing an NAA stop-drop
spray is a little like a game of chicken, requiring both steely nerves
and a good understanding of your opponent. The label says to apply NAA
when the first sound fruit begin to drop. Based on research with
McIntosh, a variety that is very prone to drop, a single spray of 10-20
ppm NAA can control drop for about seven days from the date of
application, but it takes two or three days to Òkick inÓ. If NAA is
applied too early, then effective drop control may wear off when it is
needed most. On the other hand, if NAA is applied just a few days too
late, a significant portion of the crop may be on the ground before it
takes effect. Predictive degree-day models and the pattern of starch
disappearance, as gauged by the starch index test can provide a general
indication of whether the potential for drop is earlier or later than
normal, but more direct monitoring is required for the actual timing of
the sprays.

Varieties that are susceptible to preharvest drop should be monitored
to determine when fruit drop is beginning. Limb tapping is one method
that can be used to determine the onset of drop as fruit near maturity.
Bump several scaffold limbs of three or four inches in diameter
throughout the block on a daily basis. Use the palm of your hand with a
short firm stroke, striking the limb at its mid-point (just like golf,
this skill improves with practice and experience). If zero to one
apples per limb drop on average, itÕs too soon to apply NAA. If the
average is about two, check again later the same day or the next
morning. When several apples drop in response to limb bumping, its time
to harvest within two days or apply NAA.

Rates of 10-20 ppm NAA are usually needed to be an effective stop-drop.
To obtain the maximum drop control, use a split application of 10 ppm
in the first spray, followed by a second spray of 10 ppm five days
after the first. Split applications can provide some drop control for
about 12 days from the date of the first application.

NAA must be taken up by the spur leaves in order to be effective and
does not translocate very far within the tree, so it must be applied
with good coverage and plenty of water. Concentrating beyond 4X (less
than 75 gallons of water per acre for 300 gallon TRV trees) may
diminish the effectiveness. The use of alternate row spraying is
discouraged. Use of a non-ionic or organosilicone surfactant is
recommended to enhance uptake.

Calcium in the spray water is detrimental to NAA efficacy. This
includes both tank mixed calcium for bitter pit control as well as
calcium present because of hard water. If your water source provides
hard water, use of a water conditioner is advisable.

Weather conditions following the application also impact efficacy.
Rewetting within two or three days of the spray application and
spraying under slow drying conditions (high humidity) both will
increase the uptake of NAA. Temperatures in the mid-70s produce a
better response than cooler temperatures, while excessively hot weather
immediately following an NAA spray may result in accelerated ripening.

When used as a stop-drop, NAA may advance ripening, especially at the
maximum label rate of 20 ppm. The primary impact of this advance in
maturity is reduced storage potential of the fruit, particularly in the
loss of firmness. This effect is not consistent from year to year, and
may be attributed to high temperatures, as mentioned previously.
Research by Rich Marini and Ross Byers in Virginia showed that the
deleterious effects of NAA sprays on fruit maturity and fruit softening
were minimized in Red Delicious by making repeated applications of 5
ppm NAA at four weekly intervals prior to harvest. This Òpre-loadingÓ
technique has recently been included as an application option in the
Fruitone N label. I have not repeated this research on Delicious, but
using NAA pre-loading on McIntosh resulted in more advanced ripening,
accelerated drop, and fruit softening, not less! I do not recommend NAA
pre-loading for McIntosh and other early season, high-ethylene
varieties. I suggest that growers use caution when trying pre-loading
on high ethylene varieties other than Delicious until more is known
about how different varieties will respond.

The question then arises whether NAA-treated fruit has potential for CA
storage or treatment with SmartFresh (1-MCP). Perhaps the simplest way
to answer the question with regard to CA is to remember the adage
Ògarbage in, garbage outÓ. If the fruit was left on the tree to the
bitter end of the drop control, is measurably softer than previously
harvested fruit, and has elevated starch index values, then it should
be marketed in the short term. On the other hand, if the fruit was
harvested within a week after treatment and has appropriate firmness
and starch values for CA storage for the variety, there is little
reason to expect it to perform differently than similar fruit that
received no NAA.

The question of whether NAA stop-drop sprays have advanced fruit
maturity may be most critical when using SmartFresh on McIntosh, where
the maturity of the fruit is an overwhelming influence on whether the
fruit will respond to 1-MCP. Quoting Dr. Chris Watkins in the
Proceedings of the 2003 Cornell Apple Storage Workshop: ÒWe do not have
any data yet, but we assume that induced ethylene production that
results from use of NAA will deleteriously affect fruit responses to
1-MCP. If you use stickers [NAA stop-drop], your storage operator
should be informed.Ó

Finally, a comment about use of NAA on trees previously treated with
ReTain. The use of both stop-drops at the respective correct times
results in drop control that is superior to that obtained by using
either one alone. Fruit treated in this manner, then left for an
extended time on the tree, often have limited storage potential (see
above); however, this combination can be an effective way of getting
the ultimate in drop control. This drop control comes at a high price
and should therefore only be used on high value fruit with little or no
storage period, such as for a few rows of trees held for late picking
in PYO blocks.  (Dr. Jim Schupp, Penn. State University)

Midwest Apple Improvement Association Annual Meeting:  Discussions of
apple breeding and a tour of the Kazah seedling orchard will take place
at the 2004 annual meeting of the MAIA, on Saturday November 13 at the
Dawes Arboretum in Ohio.  MAIA is a group made up primarily of growers,
whose mission is Òto develop economically and culturally viable apple
cultivars for the MidwestÓ.   Speakers will address topics related to
fruit breeding, with an update and discussion of the MAIA program.
More information and directions to the Dawes Arboretum are available at
the MAIA website at http://www.hort.purdue.edu/newcrop/maia/
(Hirst)

Upcoming Meetings:

Sept. 16	Commercial fruit and vegetable twilight meeting.  Meigs Farm,
Throckmorton Purdue Ag Center, Lafayette. Tours will highlight pumpkin,
apple and grape research. Meet at 5.00 pm, tour plots, then have
dinner. There will be informal presentations by Purdue Specialists.
Directions:  from Lafayette take US 231 S to CR 800S and turn left
(east).  Go for one mile and turn right (south) on CR 100 E.  The Farm
is approx 0.5 mile on the left.  For more information contact Liz
Maynard (219-785-5673), Peter Hirst, (765-494-1323), or Bruce Bordelon
(765- 494-8212).

Sept. 18	Throckmorton Purdue Ag Center Field Day at the Meigs farm.  To
showcase research activities to the local farmers, the public, and
anyone else interested. Tours start at 10.00 am and the last tour
leaves at 11.30 am.   For more information contact Jay Young,
765-538-3422.

Sept. 27-29	HACCP training course.  West Lafayette, IN.  Cost $350.
Contact Peter Hirst (765-494-1323) or Richard Linton (765-494-6481),
for brochures and registration forms.

Nov. 13	MAIA annual meeting-see article on this page.

Jan. 24-26, 2005  Indiana Horticultural Congress, Adams Mark Hotel,
airport, Indianapolis.