Group Title: Berry/vegetable times.
Title: Berry/vegetable times. August 2003.
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Title: Berry/vegetable times. August 2003.
Uniform Title: Berry/vegetable times.
Physical Description: Newspaper
Creator: Gulf Coast Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida
Publisher: Gulf Coast Research and Education Center, University of Florida
Gulf Coast Research and Education Center
Publication Date: August 2003
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Bibliographic ID: UF00087388
Volume ID: VID00019
Source Institution: University of Florida
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9. FLORIDA Berry/Vegetable Times

EXTENSION P August 2003 4
imtlute ot Fwoid and Agracultural SceWnCs ... 0V 1

From your Extension

In this issue...
Sting Nematode Plagues
I 11 Growers
during 2002-2003 Season
Promoting Bee Pollination
for Blueberries
New Admire2F may be

Soil and Water Management
for the 2003 -2004 Season

Aug 26r an 2-Aii chE

Page 2

Thi Institute ot Fod arnd Agricultural Sciene6 (II in t ,lhil I-. pl'nment Opportunity A- Affirmative Action Employer anuthorizrd t provide re-rch, educational
infonnation and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap or national origin.

Crop Advisors, there are a total of
10 CCA credits being offered. This
is a great way to get a major portion
of the credits you need in a short
time. For information on
registration contact the Florida
Strawberry Growers Association at
In our last newsletter there
was a short article on heat stress and
illness. This is very important when
it feels like a sauna when you walk
outside even first thing in the
morning. Be sure and drink plenty
of fluids and watch for the signs
that you, your buddy or coworkers
are overdoing it. Early signs are:
exhaustion, headache, nausea,
chills, muscle weakness or cramps,
dizziness or fainting, loss of
coordination and severe thirst or dry
mouth. If you or someone else has
heat stress orillness do the
following quickly: move out of the
direct sun, loosen clothing and lie
down, fan to cool off, wet a cloth
and put on the person. Do as much
as possible to cool them off quickly
to get their body temperature down.
Then seek emergency health care.
Take care of yourselves
out there!
Alicia Whidden

Se ce

(813)744-5519 SC541-5772
Edtor AhaWli Wdden, Drector MayChemesky
Gulf CoS Res- d EducaDon C.nte r-Dove
13138 Les Gallaher Rad, Dove FL 33527
hp //strawbeny ifas uf ed
(813)744-6630 SC512-116

A reminder for blueberry
Page 3 growers who are growing in
containers to monitor the moisture
Page 4 level in your pots even though this
is the rainy season. Don't rely on
Page 4 Mother Nature alone if you turn off
your water system during the rainy
months. Pots can dry out very fast
in the hot temperatures we have
during the summer. What may be
T enough rainfall to take care of
Il watering plants in the ground may
5 not be sufficient to wet the well
draining media in containers. Be
sure to actually dig down several
S inches in the container and see if the
potting mix is damp; if not you will
need to water. Damage to the bush
this year will affect next year's
S harvest. Damage severe enough to
1 loose leaves and tender new growth
*lbl can occur in a short time under high
temperatures and intense sun if the
ut- -
S potting medium dries out. In severe
cases you can lose your bush. Keep
this in mind and don't forget to
keep a check on your plants through
S the rainy season.
The 2003 AgriTech
Educational Session and Trade
Show will be held August 26th
&27th at the Arthur Boring Building
r in Plant City and has a very good
program lined up. For the two days
there will be a total of 7 CEUs
offered for holders of restricted
S pesticide licenses, with 1 of the
credits being CORE. For Certified

Volume III Issue 8

Berry/Vegetable Times

Volume III Issue 8 Berry/Vegetable Times

Sting Nematode Plagues
Local Strawberry Grow-
ers during the 2002-2003
Growing Season
Jon Hamill, UF Graduate Student
and Don Dickson, Professor, UF
Entomology and Nematology De-

Sting nematode is an im-
portant disease pathogen of straw-
berry in the Plant City Dover
region of Florida. This nematode
is considered a highly aggressive,
virulent plant-pathogen that is ca-
pable of causing severe crop dam-
age even at low numbers of less
than 10 nematodes per half-pint of
soil. The purpose of this article is
to show how sting nematode num-
bers are distributed over the sea-
son and at different soil depths,
and perhaps most importantly to
show why crop destruction and
weed management at the end of
the strawberry season is critical
for sting nematode management.
Three different farmer fields were
chosen to determine sting nema-
tode numbers. They are listed as
Farms 1, 2, and 3. Fields at each
farm are being sampled monthly.
In September, before fumigants
were applied, we initiated sam-
pling at Farm 1. Sampling at
Farms 2 and 3 was begun January

Results obtained over the
2002-2003 season are as follows:
1) During the month of September
at Farm 1 sting nematode was de-
tected at depths greater than 30
inches (Fig. 1). At this time, a
greater number of nematodes
were detected below 18 inches

than in the top 0-18 inches of soil
(Fig. 1). 2) The numbers of sting
nematode were highest in the upper
soil profile throughout the months
of November February. They be-
gan decreasing gradually in March;
at which point the numbers of sting
nematode began to increase at soil
depths greater than 18 inches (Figs.
2 4). 3) The numbers of sting
nematode at all three farms were not
very different until the month of
June. At this time, Farms 1 and 2
(Figs. 2 and 3) removed the plastic
mulch from their beds but did not
destroy the strawberry plants nor
eliminate weeds after the growing
season. Favorable weather and an
acceptable food source allowed the
nematode numbers to increase.
Whereas at Farm 3 (Fig. 4), the
plastic mulch was removed
promptly after double cropping,
plants were destroyed, and the field
was disked and planted to a cover
In summary, sting nema-
tode appears to be fairly deep in the

soil at the time of soil fumigation. It
is unclear what percentage of these
nematodes living deep in the soil
profile are killed by soil fumigation
or whether they are capable of mo v-
ing back into the fumigated zone
(generally considered to be approxi-
mately 12-inches deep when chisels
release the fumigant 8-inches deep
in the soil). To determine informa-
tion about the nematode's resur-
gence in December February will
require additional studies. The
numbers of sting nematode that we
recovered from all three farms in
December February are considered
to be enormously high. This was
reflected in the number of severely
stunted plants observed at that time.
Lastly, it is of great importance to
keep the strawberry fields free of
suitable hosts for sting nematode
after the growing seasons. Crop
destruction in a timely manner can
prevent a resurgence of nematode
numbers late in the season.

Fig. 1. Numbers of sting nematode occurring at six soil
depths before fumigation at Farm 1 in Plant City, FL
S6 0-6"
E 18-24"
2 5 24-30"

September 2002
Fig. 2. Numbers of sting nematode in soil samples taken at six
soil depths at monthly intervals, Farm 1 in Plant City, FL

600 6-12"
SUI I 12-18"
500 18-24"
S400 4 30+"
) 300
2 200
S 10
So -___--- i L-_ T. --Ia-.
0 Sep-02 Oct-02 Nov-02 Dec-02 Jan-03 Feb-03 Mar-03 Apr-03 May-03 Jun-03

Volume III Issue 8

Berry/Vegetable Times

Volume III Issue 8 Berry/Vegetable Times

Promoting Bee Pollination
for Blueberries
Paul Lyrene, Professor, UF Horti-
cultural Sciences

The Florida highbush
blueberry crop, which was har-
vested in April and May this year,

Fig. 3. Numbers of sting nematode in soil samples taken
at six soil depths at monthly intervals, Farm #2.

Jan-03 Feb-03 Mar-03

Apr-03 May-03 Jun-03

was abut average in size when the
state is considered as a whole, al-
though the amount of fruit har-
vested each year is on an upward
trend due to increased acreage.
The cold winter and the lack of
hard, late freezes favored an
above-average crop, but persistent
rains and high humidity during the
4^^,,,,;,', ,,^^' ;^*, *,, ..+, T71, *,-

Fig. 4. Numbers of sting nematode in soil samples taken
= at six soil depths at monthly intervals, Farm 3.
E -n---

Jan-03 Feb-03 Mar-03 Apr-03 May-03

interfered with bee pollination and
reduced fruit set on many farms.
Most highbush blueberry varieties
require cross pollination by bees.
Individual flowers are only recep-
tive to pollen for about 7 days, and
flowers that are not visited by bees
during their receptive period either
set no fruit, or set fruit that is
smaller and ripens later than nor-
mal. It was apparent from observ-
ing farms in Alachua County just
prior to harvest that the smaller
plantings had better pollination
than the larger ones. The likely
reason is that wild bees, including

bumblebees and southeastern
blueberry bees, were able to polli-
nate the smaller number of flowers
on the small farms during the few
hours when the weather permitted,
whereas the enormous numb er of
flowers on the larger farms over-
whelmed the native bees. Honey-
bees, which are brought into the
fields by growers to pollinate
blueberries, were much less effec-
tive than usual in north Florida
this year because they were kept
in their hives by so many rainy
days and because the blueberry
pollen did not shed well when the

flowers were wet. Few years are
so rainy during blueberry pollina-
tion season as this year in north
Florida, but as farms get larger,
growers will be ahead if they do
all they can to promote bee polli-

New Admire2F Insecti-
cide may be useful in

suitable composition Use pesticides safely Read and follow directions on the
man~ufacturerX s abel

-h-_ L -r JL ITL


Volume III Issue 8

Berry/Vegetable Times

Volume III Issue 8 Berry/Vegetable Times

James Price, Associate Professor,
GCREC Bradenton

Bayer Crop Science has re-
ceived a federal registration for Ad-
mire 2F9 to control aphids and
whiteflies on strawberry. The regis-
tration provides significant restric-
tions that limit the product's useful-
ness in Florida, but it still may be
valuable to manage some important
problems. Aamire1 is well Known
among vegetable growers for its
properties to control silverleaf white -
The product may be applied
as a foliar spray but a soil application
is recommended for best control.
Relative to strawberry culture in
Florida, the label provides for appli-
cation via the irrigation system, al-
though strict procedures are estab-
A 14-day preharvest inter-
val seriously limits the product's use
under Florida's conditions. In most
cases this means that farmers may
not apply AdmireR after late No-
vember. Those that do apply the in-
secticide then may expect aphid and
whitefly control for a month to 7
weeks, or through early to mid-
January. Admire@ applied in this
manner is fully systemic. Although
little data are available relative to the
matter under our conditions, it is
unlikely that soil applications of Ad-
mire@ would seriously interfere with
control of twospotted spider mites by
Phytoseiulus persimilis predators;
foliar sprays are harmful to the
nymphs and adults.
Since whiteflies presently
are not problematic on Florida straw-
berry, the best use here may be to
growers who apply it to the soil 14
days before the first harvest to con-
trol aphids that accompanied trans-
plants from the nursery. Doing so
will delay, reduce, and possibly
eliminate economically important
aphid problems. Several other insec-
ticides are available as foliar sprays
to control aphids on strawberry, but

most can reduce the efficiency of
biological control of twospotted spi-
der mites by P. persimilis.

Soil and Water Management
for the 2003 2004 Season.
John Duval, Assistant Professor,

With plants for the 2003 -
2004 season just two months away
from being planted it is time to start
thinking about soil fertility. Soil
testing should be conducted now to
allow for analytical results to be re-
turned and fertilizer and lime orders
to be placed. pH is the measure of
suil acidity. The ouil ptH affut'cl
chemical, physical and biological
properties of the soil. The availabil-
ity of nutrients in the soil is usually
the main concern for growers.
While pH affects the availability all
nutrients, micro elements
(manganese, boron, copper, and zinc)
are more severely affected than
macro nutrients. The pH range for
the production of strawberry is be-
tween 6.0 and 6.5 with 6.2 being op-
timum. Soil test results should give
a recommendation for the amount of
lime to apply to raise the pH into this
range. Liming materials are also
beneficial in adding calcium and
magnesium to fruiting fields. Lime
should be broadcast applied and thor-
oughly incorporated prior to bed for-
This is also a good time to
begin thinking of your means of soil
moisture monitoring for the coming
season. Tensiometers, gravimetric
sensors (watermark, gypsum blocks),
TDRs, and a host of other means are
available. Optimal soil moisture for
producing strawberries in this area is
between 8 and 15 cbars. Using
proper water management will pro-
duce the highest possible yields from
your plants and reduce pumping
costs and wasted water. Purchasing
this equipment now will give you

enough time to familiarize yourself
with their operations. Not only is
this a good idea for water manage-
ment it is also part of a Best Manage-
ment Strategy from which you can
benefit in the future with cost sharing
and presumption of compliance with
current regulations.

Disease Resistance and Fun-
gicides to be Discussed at
Jim Mertely, Plant Pathologist and
Craig Chandler, Professor, GCREC

Two experiments were car-
ried out last season to evaluate straw-
berry cultivars and advanced breed-
ing lines for resistance to anthrac-
nose fruit rot (Colletotrichum acu-
tatum) and Botrytis gray mold
(Botrytis cinerea). In each experi-
ment, fungicide applications were
manipulated to allow the target dis-
ease to develop while suppressing
the other disease. A severe epidemic
of anthracnose fruit rot developed
during the mid-February to mid-May
evaluation period. Cultivars in the
anthracnose experiment showed dis-
tinct differences in disease incidence.
Over 90% of the 'Treasure' and
'Aromas' fruit were infected, while
losses in 'Sweet Charlie' and
'Carmine' were less than 10%.
Results like these bring to
mind the question, "Shouldn't we
take advantage of disease resistance
when planning a disease manage-
ment programs?" While the answer
is obviously 'yes', much information
would be needed to develop fungi-
cide programs for specific cultivars.
Look for further information on these
topics, and an update on strawberry
fungicide label at the AgriTech
meeting. See you there!

Harvest Award Nominations

Volume III Issue 8

Berry/Vegetable Times

Volume III Issue 8 Berry/Vegetable Times

Celebrating its 10th year as
the county's premier agricultural
awards program, the 2003 Harvest
Awards Luncheon has been sched-
uled for Wednesday, November 5th at
the Hillsborough County Fair.
Nominations are now being taken for
this year's event. Awards are pre-
sented to the outstanding farm fam-
ily, outstanding agribusiness, out-
standing woman in agriculture, and
outstanding young farmer, rancher or
nurseryman. In addition, two special
lifetime achievement awards are also
given during the luncheon. Nomina-
tion forms are now available at the
following locations: Cooperative
Extension Service in Seffner, Farm
Credit Office in Plant City, Farm Bu-
reau Office in Valrico and the
Ruskin Chamber of Commerce.
Deadline for submission is October
The 2003 Awards Luncheon
will pay special tribute to all former
Harvest winners in recognition of the
10th Anniversary. The annual lunch-
eon is the kickoff activity for the
Hillsborough County Fair which runs
from November 5 through 9 on the
grounds of the Raymond James Sta-
dium in Tampa. The Harvest
Awards were established in 1993 to
recognize and celebrate the out-
standing achievements in agriculture.
The Lifetime Achievement category
was added recently to honor the
county's agricultural pioneers.
Each nomination must be
accompanied by a brief statement
and resume of accomplishments.
Those wishing more information
may call Mike McKinney at the Co-
operative Extension Service at 744-
5519 ext. 107 or 128.

okra at 2.0 ppm, southern/blackeye
pea at 4.0 ppm; and turnip greens at
30 ppm. The regulation became ef-
fective May 30, 2003.
In addition, a tolerance has
been established for residues of the
insecticide imidacloprid in or on
popcorn gram (u.u3 ppm), popcorn
stover (0.2 ppm), strawberry (0.5
ppm), acerola, avocado, canistel, fe i-
joa, guava, jaboticaba, mango, okra,
passionfruit, papaya, sapodilla, ma-
mey/black sapote, star apple, starfruit
(1.0 ppm), longan, lychee, persim-
mon, pulasan, rambutan (3.0 ppm),
salal (3.5 ppm), and leaves of root
and tuber vegetables (Group 2) and
legume vegetables except soybean
(Group 6), both at 4 ppm. These tol-
erances replace existing or time lim-
ited tolerances already in place for
some of these crops. (Federal Regis-
ter, 5/30/03 and 6/13/03).

Pesticide Registrations and

On May 2, the FDACS reg-
istered the fungicide Acrobat 50
WP (dimethomorph) to control dis-
eases in Florida bulb vegetables, cu-
curbit vegetables, and lettuce. The
EPA registration number for the
BASF produce is 241-410.
On June 18, the FDACS
registered AgroFresh's postharvest
tool Smartfresh (1- methylcyclo-
propene) for mitigating undesirable
ethylene effects on harvested fruit.
The FP A registration number for the
product is 71297-2. (FDACS PREC
June and July Agendas).

conditions, and conditions, and con-
sumers were asked to judge the pro-
duce based on taste, looks and smell.
The judges were able to differentiate
between varieties (The Grower, May

0 0 0

CropLife America and the European
Crop Protection Association released
results of a study which shows that
the average discovery, development,
and registration costs to bring a crop
protections product to market have
increased from $152 million in 1995
to $184 million in 2000, a cost eight
times higher than 20 years ago. The
consulting firm conducting the study
attributed the increase primarily to
the adoption of new technology,
stricter regulatory standards insti-
tuted to ensure environmental and
consumer protection, and a rise in the
amount of data required by regula-
tory authorities. Also, the develop-
ment period for a new product (from
first synthesis to commercialization)
has increased from 8.3 years in 1885
to 9.1 years in 2000 and the average
number of molecules screened lead-
ing to the introduction of each new
product increased from 52,500 to >
139,000 for these same respective
years. (CropLife America, Spotlight,

Pesticide Potpourri

IR-4 Updates

Based on work by IR-4, a
tolerance has been established for
residues of the insecticide methox-
fenozide (Intrepid ) in or on cucur-
bit vegetables (Group 9) at 0.3 ppm;

According to researchers at Ohio
State University, consumers could
not tell the difference between or-
ganically grown and conventionally
grown strawberries. Researchers
grew the berries under matted row

Volume III Issue 8

Berry/Vegetable Times

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