Facts for Fancy Fruit 99-03 April 7, 1999

Crop Conditions:  Above normal temperatures over the past
week have started the growing season. WeÕve received about
75-100 growing degree days (base 50) in the Southwest part
of the state.  Peaches in that part of the state are just
starting to bloom, and in many places the bloom looks good.
In most northern areas of Indiana, peach bloom is not a
happy situation and a good bloom probably wonÕt be seen for
about 12 months.  Apples are at green tip in most areas.
Grapes and brambles are at early bud swell in the south and
still mostly dormant elsewhere.  Strawberries are starting
to push new leaves so the straw should be off and the
irrigation equipment ready for frost protection.

Weather Update: (from the Purdue Crop and Weather Meeting
3/26/99) Fall and winter 1998-1999 has been a period with
dramatic swings. The last six months (October - March) have
been rather warm overall and predominantly dry.  November
and December were quite warm, both in the top 10 warmest in
the last 100 years, January was cooler then February warmed
back up to be in the top 5 warmest in the last 100 years.
Following the warm February, temperatures in March dropped
dramatically with March looking to be in the top 12 coldest
in the last 100 years.  During the same period Indiana was
predominantly dry.  January and February were quite wet,
with both ranking in the top 5 wettest in the last 100 years
then we moved into one of the driest MarchÕs on record. --
Ken Scheeringa These swings could be attributed to the La
Nina period. Typically during strong La Nina periods the
northern 1/3 of the United States experiences cold and wet
conditions. During weak La Nina periods, such as the one we
are experiencing, we are more likely to experience the
flip-flops we have had.  -- Ken Scheeringa & Tom Priddy
Several new products have been added to the Indiana Weather
and Climate by County page on the internet.  Included in
these are Palmer Drought, Lows, Past Rain, Past Temps
(Indiana and nation), Dewpoint, Regional Observations and
other items. Take a look at these at
http://wwwagwx.ca.uky.edu/innowwx.html.  Tom would be glad
for feedback on these products and others you would like to
see added. You can email Tom at tpriddy@ca.uky.edu The
medium and long range outlook for 6-10 days calls for much
above normal temperature and above normal precipitation. The
30 day outlook calls for below normal temperature and normal
precipitation while the 90 day outlook calls for normal
temperature and above normal precipitation.

Apple Diseases:  Tight cluster to pink is a time for maximum
disease control efforts.  During this period primary scab
spores often reach their peak; powdery mildew infection is
occurring on new growth; cedar apple rust is discharging
spores with each rain; and fire blight is building, ready to
be carried to opening apple and pear blossoms. ItÕs an ugly
picture! 1. Apple scab:   The potential for severe scab
infection is high.  The amount of scab is directly dependent
on the frequency of spring rainfall.  If we have a wet
April, scab pressure will be high, if it turns dry, scab
pressure will be low, spray accordingly. 2. Rust:   The pink
stage of apple growth generally coincides with the time rust
spores begin to infect apple foliage and fruit.  If rust is
a chronic problem consider the use of a sterol-inhibiting
fungicide such as Nova or Rubigan. 3. Powdery mildew:  If
mildew has been a chronic problem in certain blocks
(Jonathan, Rome, Ida Red) the above mentioned
sterol-inhibiting fungicides are excellent in helping to
control mildew. 4. Fire Blight:  Cool spring temperatures
help prevent a rapid increase in the fire blight population;
warm spring temperatures can cause very sudden, dramatic
increases in the fire blight population.  HereÕs hoping for
a cool spring. -Pecknold

Apple Scab:  Apple scab infection was above normal last
year, you should therefore expect an above normal amount of
primary scab spores this spring.  The most important time of
year for scab control is from green tip to petal fall.  If
you donÕt control scab during this period itÕs an uphill
struggle the remainder of the season.  Be sure sprayers are
properly calibrated; thoroughly read the label of all
pesticides you will be applying;  use sufficient water to
provide good coverage; choose calm, good drying conditions
for spraying (Good luck on this suggestion); prune trees so
they have an open canopy allowing for good spray
penetration; and maintain a tight schedule if wet weather
persists during the primary scab period. -Pecknold

Planting to Avoid Fireblight:   When establishing new
orchard blocks, consider varietal susceptibility to fire
blight.  Blight control is easier if plantings of
susceptible trees can be isolated.  Avoid interplanting
susceptible apple varieties ( Gala, Braeburn, Fuji,  Ida
red, Jonathan, Lodi, Rome, etc.) with pears or in fields
adjacent to pear plantings.  In mixed variety plantings, set
varieties susceptible to blight in solid rows for ease of
spraying with blight control chemicals.  Also, most of the
more severe fire blight problems have occurred in orchards
planted on poor sites.  These sites can be characterized as
having heavy, poorly drained, and/or highly acid soils.
Planting trees on poor soil invites fire blight damage and
poor fruit production.  -Pecknold

Brown Rot Of Stone Fruits:   Management of brown rot began
last year after harvestÉwith the removal of all fruit,
mummies and blighted twigs.  It continues this year at pink
with early season fungicide sprays.  We fortunately have an
abundance of fungicides for use in control of brown rot. See
 ID-168, Ò1999 Indiana Commercial Tree Fruit Spray GuideÓ,
for a complete listing of suggested fungicides. -Pecknold

Grape Sprays:  Bud swell to bud break is the perfect time to
apply liquid lime sulfur for control of anthracnose.  Lime
sulfur has also been shown to reduce overwintering inoculum
of black rot and powdery mildew.  It is likely that it helps
reduce inoculum of Phomopsis, but I know of no research
proof.  It is important to get thorough coverage of all
plant parts, especially the trunks and cordons where bark
crevices harbor fungal spores.  Other important pests to
control this time of year are flea beetles and climbing
cutworms.  These pests feed on swollen buds, destroying the
primary shoot.  The main damage is done when buds are in
full swell.  Once the shoots reach 1/2 inch long the damage
caused by these pests is minor.  Flea beetles seem to be the
more common of the two pests in Indiana.  Scout vineyards
for these insects or signs of feeding beginning at early
swell and continuing until shoots are about 1/2 inch long.
 The adult beetles are dark metallic greenish-blue or steel
blue and about 1/8 inch long.  They damage buds by eating a
hole in the side or tip, and hollowing out the center.
Scout perimeter rows, especially those adjacent to woods or
brushy areas where adult beetles overwinter.  If bud damage
averages 4% or more, an insecticide application may be
warranted.  Refer to the Commercial Small Fruit and Grape
Spray Guide (http://www.hort.purdue.edu/hort/ext/sfg) and
the Midwest Small Fruit Pest Management Handbook
(http://www.ag.ohio-state.edu/~sfgnet/) for complete
discussions of grape IPM. -Bordelon

Oil Sprays:  One of the first and most important parts of a
good insect and mite management program is the application
of an early season oil spray to control European red mites,
San Jose scale, and several species of aphids. Scales
overwinter on the tree as nymphs and European red mites and
aphids overwinter as eggs. Because two-spotted spider mites
do not overwinter on the tree, oil sprays are not an
effective control measure for that species. Although scales,
European red mite eggs, and aphid eggs may appear to be
inactive, they are living organisms and, therefore, must
respire, or breathe. The application of the oil creates an
impervious layer over the pests that will not allow the
exchange of gases, causing the pest to die of suffocation.
	Oil sprays should be applied between 1/2 inch green and
tight cluster. Apply a 2% rate at the 1/2 inch green stage
or a 1% rate at tight cluster. Oil sprays should not be
applied during, immediately before, or immediately after
freezing weather. For best results, apply when temperatures
are 45oF or above, and not just before rain showers.
Remember that the oils are not directly toxic to the pests.
They only work by suffocation. Therefore, the better the
coverage, the better control you will receive. Our data have
shown that mite control is improved if oil is applied at
tight cluster rather than at 1/2 inch green.
	One question that has arisen as a result of our research on
predator mites that showed that the predators overwinter on
the tree is: what affect will early season oil sprays have
on predator populations? In other words, will the oil sprays
kill the predators and create more serious European red mite
populations? Our research showed that oil sprays, whether
applied at green tip or tight cluster, had absolutely no
detrimental effect on mite predators. Therefore, we
recommend the use of early season oil sprays as a good
management practice.
	If you plan to use Apollo, Savey, Agrimek, Pyramite or some
other material for mite management, a reasonable question to
ask is, Is it still necessary to apply an early season oil
spray? I believe that the oil application is still a good
idea, for two reasons. First, it will provide control of
aphids and scales, as well as European red mites. Secondly,
I believe that the use of oil will reduce the likelihood of
developing resistance to these miticides. Therefore, I still
recommend oil sprays even if other miticides are going to be
used.

Early Season Miticides:  The decision to use or not use our
best miticides must be made early in the season before you
know if mites are even going to be a problem this year. So,
how do you know whether to go to the expense and trouble of
making that application? Below are a couple of suggestions
that may help you to make that decision. 1.  If you used
either Apollo or Savey last year, you should not use either
of them this year. I make this recommendation for several
reasons. First, if you did a good job conserving your
predator mites, there probably will not be enough European
red mites to cause a problem. Second, if you do run into a
problem later in the season, you can clean up the
infestation with Pyramite or oil sprays. Finally, leaving a
year between applications will delay the development of
resistance to Apollo and Savey, which is a definite cause
for concern. 2. If you did not use Apollo or Savey last
year, you should probably use one of them, especially on
those blocks of apples where you traditionally have mite
problems, such as Red Delicious. Some growers have tried to
skip two years and have run into problems. However, if you
did not use Apollo or Savey last year and monitored your
mite populations and know that there were very few mites
late last summer, you could consider waiting to see what
develops. Then, if mite problems arise, you can still use
Pyramite or oil sprays to get them under control.
	You may notice that I have not mentioned AgriMek in this
article. AgriMek has not performed particularly well in my
research trials and the reports I have received from growers
have not been very encouraging either. Although AgriMek is
an available alternative, at this point I believe there are
better options out there. I will continue to look at AgriMek
in my trials to attempt to find the best way to use this
product.

FQPA:  According to the US Apple Association, the EPA will
soon be launching public discussion of risk assessments and
risk mitigation options for a number of pesticides important
to apple production.  They report that the risk assessment
of OPÕs, starting with Guthion, will be released shortly for
public comment on both the risk assessment and the risk
mitigation strategies.  US Apple are lobbying for a slower
approach and would like to see the process delayed until
more scientific data are available.  Look right here in
Facts for Fancy Fruit for updates as the process proceeds.
-Hirst

Getting the Most Out of Roundup and Other Sprays:  Adapted
from an article by Gary Thornton in the Michigan State
University Fruit Crop Advisory Team Alert (Vol. 14 No. 1).
Glyphosate (Roundup) is a systemic herbicide that is widely
used by fruit growers.  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, Cygon, Imidan,
Kelthane, 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. Refer to those
publications for specifics on adjusting pH. -Bordelon

Hard Cider Conference:  A one day conference on hard cider
is being held on April 20 for cider makers and others
interested in hard cider.  The conference will be held at
Silver Lake Wineries, Woodinville, WA (a suburb of Seattle).
 Registration is $25 including lunch and cider tasting.  For
further information contact: Western Washington Tree Fruit
Research Foundation, 7220 88th Street Court SW, Tacoma, WA
98498  Email: gamoulton@wsu.edu  -Hirst

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Coming Meetings:

April 10 - Grape pruning demonstration at Fantasy Vineyards
near Rockville, Parke County. Contact Bruce Bordelon at
765-494-8212

April 13 - Twilight meeting, 6:30 pm.  LaPorte County.
Location to be announced.  Contact: Walt Sell at
219-326-6808 extension 271

April 20 - Twilight meeting, Elkart County. Contact Jeff
Burbrink at 219-533-0554.

May 5 - East Indiana Fruitgrowers twilight meeting 6:00 pm.
Minnetrista Cultural Center, Muncie.  Contact Harold Brown
at 765-747-7732.

June 8 - East Indiana Fruitgrowers twilight meeting 6:00 pm.
Minnetrista Cultural Center, Muncie.  Contact Harold Brown
at 765-747-7732.


---------- 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


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not an endorsement to the exclusion of others which may be
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accordance with current label directions of the
manufacturer.