Group Title: Berry/vegetable times.
Title: Berry/vegetable times. March 2002.
Full Citation
Permanent Link:
 Material Information
Title: Berry/vegetable times. March 2002.
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: March 2002
 Record Information
Bibliographic ID: UF00087388
Volume ID: VID00003
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.


This item has the following downloads:

BVTMar02 ( PDF )

Full Text

M luic o I Foori ncd LcrlC Itural Sclenwx
A monthly newsletter of the University of Florida Institute of Food and Agricultural Sciences, Gulf Coast Research and Education Center, and Florida Cooperative Extension Service.
Gulf Coast Research and Education Center, 13138 Lewis Gallagher Road, Dover, FL 33527 (813) 744-6630 SC512-1160 Website: http//
Editors: Dan Legard (leard( & Craig Chandler I ....i! .i i Design & Layout: Christine Manley ( 11....1. .. .il 1.. Director: Jack Rechcigl
March 2002

Late Season Disease Control Dan Legard

As March begins we enter a month when it is often
challenging to make disease management decisions. What
fungicides should growers apply at the end of the season and
when should they apply them? Many factors influence these
decisions including weather, cultivar, fruit development stage,
and market conditions. Typically, Botrytis fruit rot becomes a
less important disease and anthracnose fruit rot becomes more
important in March due to seasonal changes in the weather. In
February, the weather is usually cooler and there are long
periods of fog and dew. These produce conditions ideal for
Botrytis fruit rot. Botrytis is also favored by long periods of
rainy weather. However, when we enter March, the weather
usually warms up, and long dew periods occur less frequently
and growers should be more concerned about controlling
anthracnose fruit rot.
First we will address late season control of Botrytis
fruit rot. In March, epidemics of Botrytis can still occur
although they usually happen early in the month. The key to
controlling Botrytis fruit rot is to protect the flowers (go to this
internet address for more information: Applications
made after flowering are less effective. There are two periods
that are important for the development of Botrytis fruit rot.
One is during the first few days the flower is open. This is
when most infections begin. The other is 7 to 10 days before
harvest when heavy rains can
damage fruit and cause infected
fruit to become diseased.
Fungicides applied after heavy
rains will not prevent previously
infected fruit from becoming
diseased but will protect new
flowers. Fungicide applications of captain, thiram, Elevate@
and Switch@ protect fruit that are harvested 20-30 days later
(depending on cultivar and weather conditions). Because of
this lag period between fungicide applications and control we
do not recommend that growers apply fungicides to control
Botrytis as the season progresses into mid March, and Botrytis
epidemics no longer develop.
However, we do recommend that growers continue to
apply fungicides in March to control anthracnose fruit rot
caused by Colletotrichum acutatum. Anthracnose infections
typically begin in the flowers like Botrytis although they may
also become infected 7 to 10 days before harvest (go to this
internet address for more information: So regular
fungicide applications are important from flowering through
harvest. Applications of Quadris can effectively control
anthracnose but it must be applied for several weeks before

results will be observed. We recommend that growers apply
Quadris in alternation with Captan on a 7 day schedule to
control anthracnose fruit rot on
susceptible cultivars. Ideally these
applications should begin during
January or February when
environmental conditions (warm and
wet) are favorable for the disease, and
continue through the end of the season
observing label restrictions on the
.number and rate of application. Links
to fungicides mentioned in this article:
Elevated - US.htm
Quadris -

Development of a Grow-Out Certification
Test to Detect Colletotrichum acutatum in
Nursery Plant Material Dan Legard

Severe epidemics of Colletotrichum root rot and fruit
rot caused by C. acutatum have occurred in Florida and
California this season. It appears that the disease was
introduced into fields on infected transplants. This is a
particularly serious problem since plants infested with the
pathogen are often symptomless in the nursery, and only
express the disease after transplanting into fruiting fields. To
help nurseries improve their detection and control of this
important disease, we are collaborating with several nurseries
from California and one from Colorado to evaluate foundation
plant material for the presence '.
of C. acutatum. In this study
we have planted ten different
sources of nursery material at
the research center in Dover
and will allow them to grow
for 3-4 weeks. We hope that
the environmental conditions
during March will be
conducive to the production of
disease symptoms if C. acutatum is present. Before the end of
March we will sample the material and look for either
symptoms of the disease (Colletotrichum root rot) or try to
detect the pathogen using a petiole test. This information
should help nurseries control C. acutatum. We appreciate the
willingness of nurseries to collaborate with us and hope by
working together to solve this problem we can prevent future
epidemics on strawberry.

Volume 2

Issue 3

You Can See Spider Mites Invading from
the Sky Jim Price

Twospotted spider mites become established in fruit
production fields by two important means. The first is by
accompanying transplants from the nursery and mites
introduced this way are most likely to pose chemical control
difficulties. These are the mites that have been exposed to
pesticidal selection pressures in the nursery, and may possess
an even longer history of pesticidal selection pressures from
pesticide use in the foundation nursery.
The second means of introduction for spider mites is
by arriving, after the crop is established, on strands of silk
carried in air currents. These mites
may be from non-cultivated plants
and not possess the history of
r C. intensive pesticide selection
pressure. Thus these mites should
not be as difficult to control with
modern miticides.
Growers can actually
observe the movement of spider mites within their fields or
from their fields to perhaps their neighbor's field, and the sight
is an interesting one. When spider mite colonies become over-
crowded and mite feeding has reduced the food quality of the
strawberry leaves, mites will disperse. That is nature's way of
preserving the species from extinction by starvation.
Dispersal begins with the immature mites attaching a
strand of silk to the strawberry leaf, and then dropping over
the edge. A breeze can lift the strand and allow more to be
extended. At some point the strand breaks and the mite and
remaining strand are released into the air currents.
Growers can observe this in heavily infested fields on
warm days in February, March, or April when air movement is
very light. As the sun begins to lower at about 3:00 p.m. or
4:00 p.m., one who looks across the infested field in the
direction of the sun can see the glistening strands of spider
mite silk just becoming airborne. It is exciting to watch this
process of nature and to gain a clearer understanding of the
ecology of spider mites in our community.

Pamera Bugs Run Amuck on Mulch in
Springtime Jim Price

Pamera bugs can
become plentiful on the plastic
mulch around strawberry
plants as the strawberry season
draws to an end. They
shouldn't cause economic
damage to the crop under most
conditions experienced in Florida, but their control may be
desirable if they accompany the harvested fruit to the market.
Adults are brown, about 1/8 to 1/4 inch long, and
longer than they are wide. Also they have an obviously
enlarged upper portion of their front legs. The easiest
diagnostic feature may be, however, that they run from the
base of plants as the leaves are disturbed.

These insects can fly, but rarely do so. Young are
usually mixed with the adults and possess a similar behavior,
but they are smaller. Pameras are very common in our
environment and often are the insect most caught in an
entomologist's sweep net along ditch banks and weedy fields.
Because of their abundance in areas surrounding fields, they
are more problematic along field margins than in interiors of
large fields.
Pamera bugs are true bugs (Hemiptera) in a family
that includes seed feeders (pameras) and natural beneficial
predators (big-eyed bugs). They have piercing and sucking
mouthparts and suck nourishment from seeds, including
strawberry seeds.
Good weed control within and around the farms is
useful to reduce pameras, but when populations require
control, several of the broad-spectrum pesticides used in
strawberry production can be effective. It is when these
products are not used that pameras become noticeable, a
consequence of reduced pesticide use associated with
biological control of spider mites. Usually a single application
of a broad spectrum insecticide is sufficient to control pameras
for the remainder of the season. No insecticide is registered
specifically for pameras on strawberry, but labeled
insecticides generally considered effective on bugs include
neem oil, organophosphates and pyrethroids.

Summary of Rule Changes to Pesticide
Certification and Licensing
Effective March 1, 2002 Erin Rayfield

Fee Increases
License fees will increase for pesticide applicators and dealers
licensed under the Florida Pesticide Law, Chapter 487, Florida
Statutes, effective March 1, 2002. The new fees are as follows
Private Applicator $60 for a 4-year license;
Public Applicator $60 for a 4-year license;
Commercial Applicator $160 for a 4-year license; and
Pesticide Dealer $175 for a 1-year license

Core CEUs
Effective January 1, 2005 all applicators licensed under
Chapter 487, F.S. who renew their licenses using Continuing
Education Units (CEUs) will be required to have 4 core CEUs
in addition to the number of category CEUs now required. At
that time, all category CEUs must be approved for the specific
category. There will no longer be a requirement for having 2
core CEUs per primary category, and core CEUs will no
longer apply to the required number of category CEUs.
Applicators will have the option of retaking the core and/or
category exams if they do not have enough CEUs for renewal.
For example, effective January 1, 2005, private applicators
will be required to have 4 core CEUs plus 8 CEUs approved
for the private applicator agriculture pest control category. A
private applicator that has 8 private applicator CEUs and only
2 core CEUs may choose to take the core exam instead of
earning 2 additional core CEUs.

Volume 2

Issue 3

Direct Supervision
Licensed applicators who supervise unlicensed individuals
who mix, load, or apply restricted use pesticides will now be
required to be immediately available by voice communication
to the unlicensed individuals to provide direction and
instruction during all times restricted use pesticides are being

On-going Trials at GCREC-Dover
Concerning the Use of Plant Growth
Regulators -John R. Duval

On going trials at the GCREC-Dover concerning the
use of plant growth regulators to increase early yield and
reduce water use during establishment are showing great
promise. Apogee, classified as a reduced risk agri-chemical
by the EPA, is being tested at various rates and timings during
transplant production in Nova Scotia. Treated plants have
shorter petioles and larger crowns than untreated plants.
Treated plants grown out at Dover have shown increased early
and total yields. In addition, Apogee treated plants have
shown reduced runnering during the early parts of the season.
The manufacturer BASF has shown interest in the use of
Apogee in strawberry production, not only as a means to
increase the quality of transplants but also as a method to
prevent runner production in the fruiting field. BASF has
conducted trials on these aspects in California and Quebec.
However, formal investigations of this compound in Florida
have only been conducted on 'Sweet Charlie'. Informal work
indicates that different cultivars react differently to Apogee,
and more work is needed to determine optimum rates and
timing for these cultivars. Therefore it may be several years
before Apogee can be commercially used in strawberry.

Yields of Apogee treated 'Sweet
Charlie' transplants compared to a

Total Yield
up to 2/15/02


5000 10000 15000 20000

*Apogee treated plants

* Untreated plants

Spotlight on Diagnosis Jim Mertely, Ph.D.

The Strawberry diagnostic lab has been much quieter
over the last two months than earlier this season. Since
4 January 1, approximately 50
samples have been received.
Colletotrichum root rot and slow
decline was often diagnosed in
January (perhaps due to the
unusually warm weather), while
Botrytis fruit rot became prominent
in February. Several cases of Verticillium wilt have also been
diagnosed. This fungus causes a vascular disease on
strawberry. Infected plants die slowly, with the older leaves
turning uniformly yellow, then brown. While soil fumigation
this fall should eliminate the threat to the next strawberry crop,
spring-planted crops such as cantaloupe, peppers, and squash
may experience losses. Verticillium dahliae is a persistent
soil-borne pathogen that infects many vegetable and field

Center Update Christine Manley

Our center is a popular stop for educational tours during
strawberry season and this year has been no exception. In the past
few weeks, our faculty and staff have hosted several groups: home-
schooled students and their parents, a group of Junior Master
Gardeners, and a group of Hillsborough County Career Specialists
who assist students in determining their career paths. Many of these
career specialists work with
students in Tampa and the
immediate downtown area, and
this tour gave them some
information that many inner-
city students may not have
access to regarding agriculture
and the opportunities available
in this field.
As always, we
welcome any group to our center in order to educate the public as
well as allow our faculty and staff to illustrate the research that is
conducted at our center. If you are interested in having a tour at our
center, please call (813) 744-6630 #60 or e-mail to
schedule one.
Recently a small group of musical senior citizens known as
the Silver Strings toured our
center. However, they had to
work for their tour. They
performed several songs for the ,
enjoyment of our faculty and
staff. The group travels
throughout the immediate Plant
City/Brandon area during the
winter months performing at
various venues. These
snowbirds include my mother, Charla Pfeffinger, who directs the
band as well as several other musical groups involved at the SunBurst
Mobile Home Park in Dover. Many of the residents there have had
the pleasure of receiving our strawberries over the last few seasons
and this was their way of thanking us. It was an enjoyable
performance of about one hour, but we had the feeling that if given
the chance, they would have played all afternoon.

Volume 2

Late Breaking News Jim Price
The new miticide, Acramite (by Cromptom
Uniroval) received final approval on 3/7 for use on
strawberries in Florida.

Issue 3

Early Season Performance of Selections in
the 2001-02 Row Trial Craig Chandler
Each year, in the front section of the field at GCREC-
Dover, we plant 1-3 beds each of several standard cultivars
and promising selections. This "row" trial is planted primarily
so there will be an area where growers and other center
visitors can observe various strawberry clones growing side-
by-side. The rows are 150 feet long and are currently
harvested twice weekly into quart containers by a volunteer
group of senior citizens. The number of quarts harvested from
each row is recorded before these volunteers consolidate the
fruit and take it home.
This season nine entries were planted in the trial.
Plants of four entries (Sweet
Charlie, Strawberry Festival,
Aromas, and Treasure) came
from Canadian nurseries, plants
of three entries (Camarosa,
Gaviota, and FL 95-256) came
from a North Carolina nursery,
plants of one entry (Earlibrite)
came from a Michigan nursery,
and plants of one entry (FL 97-39) came from a Hillsborough
County, FL nursery. All plants were planted on October 12th
except those of Treasure, which were planted on October 19th.
Each row contains 246 plants (which is equivalent to 17,860
plants per acre).
FL 95 -256 produced the highest December yield
(Table 1), followed by Earlibrite and Gaviota. FL 95-256,
Earlibrite, and Gaviota's December yields were 60, 37, and
8% higher, respectively, than Camarosa. (Camarosa is
currently the major cultivar in Florida.)
For January, FL 95-256 again was the highest
yielding entry, producing over 500 flats on a per acre basis.
Treasure came in second with 490 flats per acre, while FL 97-
39 was third at 366 flats per acre.
FL 97-39 was clearly the most productive entry
during February with a yield of over 1300 flats per acre. This
is a 58% higher yield than was produced by its nearest
competitor, Earlibrite (839 flats per acre), and a 400% higher
yield than was produced by Camarosa (263 flats per acre).
FL 97-39 had the highest total yield (Dec.-Feb.),
followed by FL 95-256 and Earlibrite. These three entries are
products of the UF/IFAS strawberry breeding program.
Yields for Strawberry Festival, another UF/IFAS cultivar,
were very low in this trial, probably because many of the
Strawberry Festival plants suffered from Colletotrichum root
rot, a fungal disease caused by Colletotrichum acutatum.
Despite the large differences in yields between
cultivars, growers should be cautious when using these data to
make decisions on which cultivars to plant. Data from only
The use of trade names in this publication is solely for the purpose of providing specific
information It is not a guarantee or warranty of the products named, and does not signify that
they are approved to the exclusion of others of suitable composition Use pesticides safely Read
andfollow directions on the manufacturer s label
The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action
employer authorized to provide research, educational information and other services only to
individuals and institutions that function without regard to race, color, sex, age, handicap,
or national origin.

one season is presented here, and, there are factors in addition
to yield that make for a great cultivar (e.g., harvest efficiency,
shipping ability, and buyer acceptance). The data presented in
Table 1 does, however, provide further evidence that the
University of Florida strawberry breeding program is
accomplishing one of its main goals, which is to create
cultivars that have high early season yield potential. This is
important because fresh strawberries produced in December,
January, and February generally command high prices. The
average price per flat (4.65 kg) during the five seasons
between 1995 and 2000 was $17.38, $11.57, and $10.51 for
December, January, and February respectively, whereas the
average price per flat for March during the same five-season
period was $7.27 (Florida Agricultural Statistics,

Table 1. Fruit yield* from seven strawberry cultivars and two
UF/IFAS selections grown at GCREC-Dover during the 2001-
2002 season.
December January February Total
Aromas 449 204 227 880
Camarosa 458 254 263 975
Earlibrite 626 318 839 1,783
FL 95-256 733 556 647 1,936
FL 97-39 462 366 1,325 2,153
Gaviota 495 240 585 1,320
S. Festival 163 145 227 535
S. Charlie 345 222 690 1,257
Treasure 318 490 517 1,325

* Flats per acre. These yields were calculated using the following
equivalency: 8 quarts = 1 flat (instead of the more standard 6 quarts =
1 flat). This was done to take into account the small and misshapen
fruit that were likely placed into the quart containers by the volunteer

Volume 2

i -, ,, ,.
I F-. *4 *A*l S... o
Dover, FL 33527 oad
Dover, FL 33527

Issue 3

University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs