Group Title: Berry/vegetable times.
Title: Berry/vegetable times. February 2005.
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Title: Berry/vegetable times. February 2005.
Uniform Title: Berry/vegetable times.
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Creator: Gulf Coast Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida
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Gulf Coast Research and Education Center
Publication Date: February 2005
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Berry/Vegetable


Times

February 2005


In this issue...
Recognize These Beneficial Page 2
Insects in Your Crop
Tank Mixing Fungicides Page 3
Fertilization and Water Page 3
Management for February
2005 Spring Blueberry Field Page 4
Day Pre-registration
SPECIAL GCREC FACT Page 5
SHEET-Sap Beetle
(Coleoptera: Nitidulidae)
Management in Strawberries

SPECIAL GCREC FACT Page 7
SHEET- Anthracnose Fruit
Rot of Strawberry


















A monthly newsletter of the University of Florida IFAS,
Gulf Coast Research and Education Center, and Flonda
Cooperative Extension Service
Hillsborough County Cooperative Ext Service
5339 CR 579, Seffer, FL 33584
(813) 744-5519 SC 541-5772
Alicia Whidden, Edtor Mary Chemesky, Director
Gulf Coast Research and Education Center
13138 Lewis Gallagher Road, Dover, FL 33527
(813) 744-6630 SC 512-1160
Christine Cooley, Layout and Design
Jack Rechcigl, Director
http //gcrec ifas ufl edu


From Your Extension
Agent- Important
SWFWMD Rule
Change and Robin
Control


The Southwest Florida
Water Management District has
made a change to the rule (Rule 40D-
2.352) about transferring water use
permits when ownership of property
changes. This goes into effect Feb.
1, 2005. If you have acquired
ownership or legal control of a piece
of property that has a water use
permit you must apply to transfer the
permit into your name within 45 days
of acquiring the property. You must
make this request using a specific
form entitled "Notification and
Request for Transfer of a Water Use
Permit". If you do not make the
request within the 45 day time limit
the permit will become void.
To most people the song and
sight of the American Robin (Turdus
migratorius) means spring is here.
A strawberry farmer feels very
differently about this bird of spring.
If the robins are flying over on their
way up north it is a good sight. If it
is the sight of robins flying into the
grower's field to eat their fill of
luscious strawberries it is not happy
thoughts of spring that fill the
grower's mind. In some years as
they migrate back north the robins
stop in central Florida for an
extended time due to bad weather
farther north. The birds are hungry
and fields of red ripe fruit are a
favorite feeding ground. Due to the
vast numbers of robins invading a


field the cost of lost fruit especially at
a time when prices are good for the
grower can be quite substantial. Also
the cost of deterring the birds from
the field is another expense for the
grower. As every grower knows
robins quickly adjust to any type of
scare tactic you use and you have to
keep changing what you do. If the
birds are here for an extended time it
gets to a point where nothing scares
them out of the fields.
Thiram, a fungicide that is
labeled for use on strawberries, has
been shown to have some feeding
deterrent properties for vertebrates.
In some crops it has been shown to
deter birds. I think it is worth trying
on strawberries, since we don't have
many options for this problem, but
growers should not expect dramatic
results. As far as thiram's effect on
predatory mites, for Amblyseius
californicus it is considered harmless
on all stages and for Phyoseiulus
persimilis it is slightly harmful on the
eggs but not harmful on the nymph
and adult. Please don't confuse
thiram with Topsin-M. Topsin-M is
harmful to the predatory mites.
Thiram is used for anthracnose and
botrytis control so now is a good
time to be using it. If you have used
thiram on strawberries and have an
opinion on its effectiveness as a robin
deterrent, I would be interested in
hearing from you.

A41;icia W Idden
Hillsborough County Extension
Service
813-744-5519, ext. 134
AJWhidden(.ifas.ufl.edu


IFAS is an Equal Employment Opportumity Affirmative Action Employer authored 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 U S Department of Agnculture, Cooperative Extension Service, University of Flonda, IFAS, Florida A & M
Umnversity Cooperative Extension Program, and Bloards of the County Commissioners Cooperating


February 2005


Ben-y/Vegetable Times









Berry/Vegetable Times


Recognize These Beneficial Insects
in Your Crop
Silvia I. Rondon and James F. Price

Not all insects, mites and pathogens in a
strawberry crop are pests. Some (predators) eat pests or
(parasitoids) parasitize them; some others (pathogens) Fig 4 larva (Cret. Fig.
Fi.g 4 larva (Credzt. Fig. 5
transmit diseases to them. The organisms that control O.S.U.). Also known as
harmful pests are called natural enemies, beneficial, 11. Lar
biological control agents or simply, 'good guys'. They adults prey on
may be native or introduced from other areas. Some of worms (Credit
them are commercially available, but mostly they are
freely available in our strawberry crop environment.
Predators are those that violently attack, kill,
and feed directly on prey. Examples of predators of
insects in strawberries are lady beetles (Fig. 1, 2, 3),
syrphid flies (Fig. 4, 5), lacewings (Fig. 6, 7, 8); also
spiders, predatory mites, solitary wasps, midges and
ants. Parasitoids are insects that lay their eggs on or in
a pest host. The developing larva lives and feeds on the
host and eventually kills it. Common examples are the
tiny wasps that attack aphids (Fig. 9). Pests can also
acquire pathogens (viruses, bacteria, fungi) that cause
disease in strawberry pests. Bees are a different class of
beneficial insect since they benefit the producer not by Fig. 6 Green lacewing eggs. Fig. 7 Green lac
Eggs are tiny and oblong, laid larva. Larvae a
killing pests, but by aiding in strawberry pollination. singly connected to the leaf by six legs (Credt.
It is important that growers identify, conserve a long thread (Credt. O.S. U).
and sometimes augment beneficial in their strawberry
crops. Beneficials are conserved by using least toxic
pesticides, but only when and where needed, and at a
time that they are most effective and least damaging to
beneficial.

Fig. 8 Green lacewing adult. In general the adult is g
net-hke dehcate wings (Credit. O.S. U).








Fig. 1 Eggs of the pink spotted Fig. 2 Larva of the pink
lady beetle. They are small and spotted lady beetle (Credit.
cigar shaped (Credit. Ento- Entomos).
mos).



Fig. 9 Mummtfied parasitized aphid on the far right
Healthy aphids on center and left (Credit. S.I.Rond


Web links
Fig. 3 The pink spotted lady beetle adult. Medium size beetle with http://edis.ifas.ufl.edu/HS244
characteristic spots on the forewings. Larva and adult prey on
aphids and mites (Credit. M.E.Rice, K. S.). hil I. i. ,, ,, .hos.ufl.edu/protectedag/links.htm


adult.

vae and
aphids and
G.I.N.A.)


ewing
e flat with
O.S.U.).


reen, with


It.
'on, UF).


February 2005








Berry/Vegetable Times


Tank Mixing Fungicides
Natalia Peres and Tom Kucharek

Tank mixing is a common practice that allows
the grower to reduce the number of times spray
machinery is used, reducing costs, soil compaction,
damage to the crop, and spread of diseases. It is a
complex issue and although some tank mixes are
beneficial, others may be deleterious. As the number of
ingredients increase in a tank mix, chances for
incompatibility increase, particularly at lower spray
volumes.
Loading the spray materials into the spray tank
should be done with the tank at least half filled with
water. The agitation system should be operating to attain
thorough mixing. This minimizes the risk for physical
and chemical incompatibilities because of the dilution
effect of water. Dry formulations should be added to the
tank first followed by the liquid formulations. As a
general guide, the loading order for spray tanks should
be: Wettable powders, Prills (DF's, DG's, and WDG's),
Soluble powders, Flowables, Adjuvants, Emulsifiable
concentrates (EC's), and Oils.
The use of adjuvants in a tank mix is a
controversial topic. Adjuvants are chemicals, generally
classified as non-pesticidal, that when added to a spray
mix are supposed to enhance chemical effects or spray
delivery. The key to success with adjuvants is to use
them as little as possible because they can also cause
damage to plants. Some adjuvants reduce the waxy -like
coatings on the exterior of the plant. When these
coatings are reduced, plants are more susceptible to
chemical damage and are more likely to transpire water
resulting in increased sensitivity to dry weather. The
adjuvants most likely to damage plants when used with
fungicides are crop oils, petroleum-based oils, and those
with alcohols. Besides these adjuvants possessing
phyotoxicological properties themselves, the tank
mixing of them with some chemicals increases the
probability for additional phytotoxicity. Another group
of adjuvants that are of concern are silicon-based
adjuvants. While this type of adjuvant is likely to be
very beneficial in attaining entrance of herbicides into
weeds and insecticides into insects, it does increase
movement of bacteria into plants.
Success with tank mixing is based upon slowly
acquired experience. It is not possible to test the
numerous combinations that exist so if your cocktail

The use of trade names in this publication is solely for the
purpose ofproviding specific information. It is not a guarantee
or warranty of the products names and does not signify that they
are approved to the exclusion of others ofsuitable composition.
Use pesticides safely. I. ,, directions on the
manufacturer's label.


works, don't change it until you have tested the new
idea on a small scale or have asked informed sources for
their opinions. While tank mixing is often essential, the
grower should tank mix only what is necessary. The
more chemicals that are used in the same mix, the more
likely that an adverse effect on the crop will occur, and
the less likely that a professional can determine what
caused a problem related to the tank mix.




Fertilization and Water Management
for February
John R. Duval

February is here and our plants are gearing up
for rapid growth. In the next two months we will
produce 60-70% of the berries for the season. In
addition, the temperatures are nudging up. This means
that our plants will need greater amounts of water and
fertilizer to meet their optimum output. Nitrogen and
potassium applications should be increased to 3/4
pounds of each per acre per day. If you are monitoring
your crop nutrition with petiole sap testing, nitrogen
levels should be 300-500 ppm and potassium levels
should be 2000-2500 ppm. Guidelines for supplemental
fertilizer applications can be found in the Vegetable
Production Guide for Florida (Pg. 11 in the 2004-2005
guide) or http://edis.ifas.ufl.edu/CV134 online.
Soil water monitoring becomes more important
as temperatures rise and strawberry bushes get larger.
Soil water tensions should be maintained between 8 and
15 cbars for those using tensiometers and granular
matrix sensors (watermark sensors). For those who are
using the evapotranspriation method of irrigation
scheduling 60% of the previous days ETo should be
applied to the soil. Furthermore, it may be wise to split
irrigation so that water is applied twice or more times a
day to minimize water loss due to deep percolation (see
http://edis.ifas.ufl.edu/HS145 ).



Bradenton GCREC Faculty and Staff
Relocate to the New Balm Center

As of February 7, faculty and staff from
Bradenton will be occupying the new GCREC Balm
Center. The center's address is 14765 CR 672,
Wimauma, FL 33598. The main phone number is (813)
634-0000. The Dover Center remains open until the
strawberry season is over. Visit our website at http://
gcrec.ifas.ufl.edu for all the details and a new directory.


February 2005









February 2005


Berry/Vegetable Times


- I


8:45 a.m.

9:15 a.m.



9:35 a.m.





10:00 a.m.


Late Registration Meal not included

FBGA Annual Business Meeting -
Mr. Joe Keel, FBGA president,
presiding.

Recent history and current status of
Florida's blueberry industry Dr.
Jeff Williamson, horticulturist,
Horticultural Sciences Dept., IFAS,
University of Florida, Gainesville, FL

Update on blueberry insect pest
management Dr. Oscar Liburd,
entomologist, Dept. of Entomology
and Nematology, IFAS, University of
Florida, Gainesville, FL


10:30 a.m. Spring and summer blueberry
disease management Dr. Phil
Harmon, Department of Plant
Pathology, IFAS, University of
Florida, Gainesville, FL

11:00 a.m. Will there be enough honey bees for
blueberry pollination in the future?
Mr. Jerry Hayes, chief of apiary
inspection, Dept. of Plant Industry,
FDACS, Gainesville, FL

11:25 a.m. Presentation by Florida Fruit and
Vegetable Association TBA.

11:45 a.m. Preview of the field tour Dr. Paul
Lyrene, blueberry breeder,
Horticultural Sciences Dept., IFAS,
University of Florida, Gainesville, FL

12:00 noon Lunch -

1:00 p.m. Field tour Dr. Paul Lyrene,
blueberry breeder, Horticultural
Sciences Dept., IFAS, University of
Florida, Gainesville, FL


2005 Spring Blueberry Field Day
Pre-registration
Where: Alto Straughn's Blueberry Farm
Windsor, Fla.
When: Thursday, March 3, 2005.

Please pre-register now for the Annual FBGA
Spring Field Day. Pre-registrations must be post-
marked by February 19.2005 to guarantee a meal.

About the Field Day On-site registration (meal not
included) will begin at 8:45 a.m. The program will
begin with the annual business meeting at about 9:15
a.m. Presentations will be followed by lunch and an
afternoon tour of the farm, including a look at ad-
vanced selections from the University of Florida
breeding program. We are planning to offer Florida
CEU credits for this meeting.

Location of the Field Day Alto Straughn's Blue-
berry Farm is located in eastern Alachua County on
CR 234 just north of Windsor Fla. CR 234 runs be-
tween Hwy 20 and Hwy 26, east of Newmans Lake
which is just east of Gainesville. If coming from Hwy
26, turn south on CR 234, continue about 1 to 2 miles.
Look for the blueberry farm and field day sign on your
right. If coming from Hwy 20, turn north on CR 234,
proceed about 6 to 7 miles through Windsor. Look for
the blueberry farm and sign on your left at the farm
entrance. Please complete and return the bottom of this
form to the address provided.


Florida Blueberry Growers' Association
P.O. Box 163, Island Grove, FL 32654

Thankyou for your continued support of the Florida
Blueberry Growers 'Association!


Please cut here and return to above address.

Name(s) attending the Short Course













Ummmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm









Berry/Vegetable Times


SPECIAL GCREC FACT SHEET


Sap Beetle (Coleoptera: Nitidulidae)
Management in Strawberries
Silvia I. Rondon, James F. Price and Daniel J. Cantliffe

Sap beetles (Coleoptera: Nitidulidae) are
conspicuous arthropods that feed on flowers, fruits, sap,
fungi, stored products, decaying and fermenting plant
tissues from diverse trees and crops, including
strawberries. Sap beetles work in association with yeasts
and other fungi causing the fermentation of infested
plant parts (Fig. 1). They also are known to transport a
variety of microorganisms that cause plant diseases; a
few species can behave as predators of various
ornamental pests (Dowd, 1991; Dowd and Weber,
1991). Sap beetles are often considered minor pests;
however, their main impact is due to the contamination
of products caused by adults and larvae.











Figure 1 fruits infested with a sap beetle
adult. CREDITS: J.F. Price, UF/IFAS, GCREC-
Bradenton.

Description
Sap beetles, also known as Nitidulids or picnic
beetles, like most of the beetles, present complete
metamorphosis: eggs, larvae, pupae, and adults. Eggs
are white and small; larvae are about the same size as
the adults, white, with lateral projections on abdominal
segments, presenting a light brown head (Fig. 2); adult
strawberry sap beetles are less than 1/8 inch (3.2 mm)
long to 1/4 inch (6.4 mm) wide, oval shaped, usually
black, brown, or grayish (Fig. 3).


figure z. oap toe
State University.


Figure 3. Nitiduhds adults can be recognized by the unexposed
tip ofabdomen heavily sclerotized and antenna distinctly capt-
tate. (A) Carpophilus pallipennis (Say) (2.3 mm); (B) Carpophi-
lus hemipterus (L.) (2.8 mm). CREDITS: Arnett, Jr. et al., 1980


Sap Beetles in Florida
There are more than 2,500 species of Nitidulid
described with more than half of the genera
cosmopolite. Six genera are endemic of North America;
twenty-one genera have been reported in Florida
including the genera Carpophilus, Stelidota,
Glischrochilus, and Epuraea (Parsons, 1943). Potter
(1995) indicated that nine Nitidulid species can be found
on strawberry fruits in east Hillsborough County (Plant
City, FL). These species are: Carpophilusfreemani
Dobson, C. fumatus Boheman, C. humeralis (F.), C.
mutilatus Erichson, Colopterus insularis (Castelnau),
Stelidota geminate (Say), and S. ferruginea Reitter.
Approximately 94% of the Nitidulid population is
represented by H. luteolus, L. insularis, and C. fumatus,
however, consideration must be given to all. Correct
identification should be followed by preventive methods
to control damage by sap beetles.


Biology and Ecology
Sap beetles fly into strawberry fields from
wooded areas (overwintering sites) at about the time
when temperatures exceed 160C (67F) and berries
begin to ripen. Adult sap beetles attack fruits
throughout the growing season (2 generations). Adults
live approximately 2 to 22 months. A few hours after
mating oviposition occurs. After hatching of eggs,
larvae burrow inside the berries, feeding on the flesh for
approximately 1% weeks. Subsequent to that period,
larvae fall onto the ground, burrow inside the soil, and
pupate. Sap beetles have a wide range of feeding
habitats, saprophagous and mycetophagous, feeding on
fruits and other plant parts which are ripening or
decomposing (Myers, 2001; Peng and Williams, 1990).


February 2005









Berry/Vegetable Times


Damage
There are two types of damage inflicted by sap
beetles: direct (feeding cavities) and indirect
(dissemination of microorganisms). Cavities in berries
also serve as oviposition substrate. Larvae inside the
berries is usually unnoticed until berries begin to
decompose as a result of the damage. Because overripe
berries are attractive to sap beetles, damage is often
greatest during harvesting when pickers leave large
numbers of ripe and overripe berries in the field, row
middle, pathways, and ditches (Fig. 4).

















Figure 4. Overripe berries in the field. Sap beetles are attracted to
the fermenting fruit. CREDITS: S.I. Rondon, UF/IFAS, Horticul-
tural Sciences Department.



Control
Sap beetles are not usually economically
important in field fresh market strawberries; however,
when overripe fruits are harvested for processing, sap
beetles may infest the fruit and make the product
unmarketable (Price, personal communication). Taking
in consideration the ecology of the pest, the following
practices are recommended.

1. If possible, avoid planting strawberry next to woody
area.
2. Pick berries before they become overripe.
3.Remove all damaged or overripe fruit from the field,
especially in warm to hot weather.
4. Similar sanitation practices should be done with other
fruits and vegetables.
5.Picking and placing infested fruit into the row middle
is an alternative method for reducing numbers of adults
in the field (Potter, 1995). Fruits decompose faster in the
middles than they do on the plant or bed. This faster
decomposition usually doesn't allow the beetle enough
time to complete its life cycle. Keep in mind that
fermenting berries may attract beetles capable of
migrating from long distances (Potter, 1995).


6.For monitoring, place pitfall traps or "trap buckets" of
overripe fruit outside field borders to intercept
immigrating beetles and reduce numbers in the crop
(Price, personal communication).
7.Biological control by means of augmentative releases
of nematodes is currently under study (Dowd et al.,
1995). In addition, researchers at the Ohio State
University are studying the usefulness of Brachyserphus
abruptus, a parasitic wasp, to control strawberry sap
beetles (Williams et al., 1984).
8.Apply recommended insecticides when conditions
justify. Insecticides recommended to control sap beetles
include Brigade, Diazinon, and Pyrenone. Some
formulations of Malathion and c ..ii are registered
for control of sap beetles on other crops and are allowed
to be used on strawberry. Insecticide use is limited by
frequent harvests. Frequent and thorough applications
should be made during early period of activity. Follow
label instructions for best results.


Literature Cited
Arnett, R.H. Jr, N.M. Downie, and H.E. Jaques. 1980. How to know
the beetles. 2nd edition. McGraw Hill. 414 pp.
Dowd, P.F. 1991. Nitidulidae as vectors of mycotoxin-producing fungi
aflatoxin in corn, pp. 335-342. In new perspectives. O.L. Shotwell and
C.R. Hurburgh, (eds.) North Central Region. 329 pp.
Dowd, P.F. and C.M. Weber. 1991. A labor serving method for rearing
a corn sap beetle, Carpophilus freeman Dobson (Coleoptera:
Nitidulidae), on pinto bean-based diet. J. Agroc. Entomol. 8:149-153.
Dowd, P.F., D.E. Moore, F.E. Vega, M.R. Mcguire, R.J. Barlet, T.C.
Nelson, and D.A. Miller. 1995. Occurrence of a Mermithid nematode
parasite of Carpophilus lugubris (Coleoptera: Nitidulidae) in Central
Illinois. Environ. Entomol. 24:1245-1251.
Myers, L. 2001. Sap beetles in Florida. University of Florida,
Department of Entomology and Nematology. Featured Creatures.
EENY-256.
Parsons, C.T. 1943. A revision ofneartic Nitidulidae (Coleoptera).
Bulletin of comparative zoology, 92:121-248.
Peng, C. and R.N. Williams. 1990. Pre-oviposition period, egg
production and mortality of six species of hibernating sap beetles
(Coleoptera: Nitidulidae). J. Econ. Entomol. 23:453-457.
Potter, M.A. 1995. The Nitidulidae (Coleoptera) associated with
strawberry in eastern Hillsborough country, Florida. Thesis. University
of Florida, Department of Entomology and Nematology. 98 pp.
Williams, R.N., M.J. Weiss, K.V. Miller, and J.J. Werner. 1984. A
summary of experiments for control of sap beetles which attack fruit
crops. Research circular-Ohio Agricultural Research and Development
Center 283:66-68.

Additional Information
Related Web sites:
http://creatures.ifas.ufl.edu/field/corn/sap beetles.htm
http://strawberry.ifas.ufl.edu/

Footnotes
This document is HS993, one of a series of the Horticultural
Sciences Department, Florida Cooperative Extension Service,
Institute of Food and Agricultural Sciences, University of Florida.
Publication date: October 2004. Please visit the EDIS Web site
at http://edis.ifas.ufl.edu.


February 2005








Berry/Vegetable Times


SPECIAL GCREC FACT SHEET
Anthracnose Fruit Rot of Strawberry
J.C. Mertely and N.A. Peres

Anthracnose fruit rot, caused by the fungus
Colletotrichum acutatum, is an important disease for
strawberry production worldwide. Other species of
Colletotrichum, such as C. fragarie and C.
gloeosporioides, are less frequently involved in fruit
rot. Although fruit rot is the most important
symptom caused by C. acutatum, the fungus can also
attack other parts of the plant including the crown,
leaves, petioles, and roots.

Pathogens and Symptoms
Symptoms of anthracnose fruit rot appear as
dark and sunken lesions on infected fruit (Fig. 1). The
appearance of crusty masses of spores on and under
strawberry seeds is more diagnostic of this disease
(Fig. 2). On green fruit, anthracnose lesions are
small (1/16 to 1/8 inch across) hard, sunken, dark
brown or black. Lesions on ripening fruit are larger
(1/8 to 1/2 inch) hard, sunken, and tan to dark brown.
During wet weather, the lesions become covered by
sticky, light orange ooze composed of millions of
spores conidiaa) in a mucilaginous matrix (Fig. 3).
When conditions are favorable for infection, multiple
lesions nearly cover the fruit and lesions may appear
on petioles (Fig. 4). Strawberry flowers are highly
susceptible and blighted flowers turn brown and
remain attached to the plant (Fig. 5), a symptom also
produced by the fungus Botrytis cinerea. Small black
spots on young button-sized fruit may also develop
from flower infections (Fig. 6).

Disease Development and Spread
When conditions are favorable, anthracnose
fruit rot is the most important disease of strawberry in
Florida. Crop losses occur mostly in the field, since
forced air pre-cooling and refrigeration suppress
disease development after harvest. Because C.
acutatum is a strong invader of runner plants in the
nursery, infected transplants are a common source of
inoculum for the production field. Weeds and other
plants around production fields may also be
colonized by inoculum from a diseased strawberry
crop. In theory, these non-strawberry hosts could
provide disease inoculum for the next crop, although
this has not been demonstrated. C. acutatum appears
to spread first on the foliage, often without causing
visible symptoms. Some conidia are formed on green
leaves and petioles, and more are produced as the
tissue ages and dies. Molecular analysis of C.
acutatum revealed that the population on strawberry
reproduces asexually and has limited diversity.


Conidia (asexual spores) are moved from the foliage
to flowers and fruit by splashing water and harvesting
operations. There they germinate and infect. As
anthracnose lesions develop, abundant spores are
formed which may be moved to other plants and new
fields on equipment and harvesters. Warm wet
weather favors infection and disease spread.

Control
Anthracnose fruit rot is best controlled by
exclusion, i.e., by not introducing the pathogen into
the field in the first place. Transplants should be
obtained from pathogen-free nurseries. In addition,
moving personnel and equipment from diseased
fields into healthy fields should be avoided without
proper cleaning and disinfection. Planting resistant
cultivars such as Carmine and Sweet Charlie has
consistently controlled anthracnose, possibly because
C. acutatum lacks the genetic diversity to overcome
this resistance. When moderately susceptible
cultivars (e.g., Strawberry Festival) or highly
susceptible cultivars (e.g., Camarosa and Treasure)
are grown, regular applications of fungicides are
often needed to suppress the disease.
In central Florida, strawberry disease
management is based on the use of captain or thiram.
Regular weekly applications of these broad-spectrum
protectant fungicides prevent extensive colonization
of the plant and suppress flower and fruit infections.
Because weather conditions are less favorable early
in the season, those applications can be made at lower
label rates. Often a few anthracnose-infected flowers
and fruit in late January or early February lead to
epidemics during warm, rainy weather in February
and March. During the critical January to March
period, protectant fungicides should be applied at
higher label rates and additional fungicides may be
needed for anthracnose control. Additional
fungicides can be applied when the disease appears,
or proactively throughout the critical period. If the
decision made is to wait, fields should be scouted
regularly to detect anthracnose early. Plants should
be examined for blighted flowers (Fig. 5) or black
spots on small green fruit (Fig. 6) approximately one
week after rain events. When the disease is found, a
strobilurin fungicide such as Abound or Cabrio
should be tank mixed with the standard protectant.
Switch is a good alternative to the strobilurins when
double cropping is not planned. Captevate,
Pristine, and Switch are particularly useful during
the main bloom period in late January and early
February. Each product contains two active
ingredients that either suppress anthracnose and/or
protect flowers from Botrytis cinerea. One active
ingredient in Captevate is captain. Tank mixes or


February 2005










Berry/Vegetable Times


higher rates of protectant fungicides should be
continued until the end of the season, or until dry
weather completely suppresses the disease.
Strobilurin fungicides such as Abound@, Cabrio,
and Pristine should not be applied more than four or
five times per season to avoid the development of
resistance. If a blocking program is followed, no
more than two sequential applications of Abound,
Cabrio Pristine, Captevate, or Switch should be
made. More information about these products is
given in the Table 1.


Fig. 4. Anthracnose lesions on petioles
Photo: UF, GCREC


Fig. 1. Anthracnose
lesions on a ripening
fruit. Credits:UF,
GCREC -


Fig. 2. Spores ofC. acu-
tatum on seed. Credits: UF,
GCREC


Fig. 5. Recently
Photo: UF, GCREC


Fig. 6. Anthracnose lesion on small fruit
Fig. 3. Spore mass ofC. acutatum on an- g. 6 Anthranose lesson on small
thracnose lesion. Credits: UF, GCREC Photo U, GC



Table 1. Products labeled in Florida for control of Anthracnose fruit rot.


Trade Active Type PHI or Comments
Name ingredient REI (hours)
Captan captain multi-site protectant 24 Suppresses anthracnose and Botrytis. Should not be mixed with
bicarbonate or sulfur fungicides
Thiram thiram multi-site protectant 72 Suppresses anthracnose less effectively, and Botrytis more
effectively than captain.
Abound azoxystrobin strobilurin 4 Do not add silicone surfactants or mix with EC formulations.

Captevate captain + protectant + anilide 24 Captan suppresses anthracnose and fenhexamid control
fenhexamid Botrytis.
Cabrio pyraclostrobin strobilurin 24 Controls anthracnose and suppresses powdery mildew.

Pristine boscalid + carboxamide + 24 Pyraclostrobin controls anthracnose and boscalid control
pyraclostrobin strobilurin Botrytis.
Switch cyprodinil + pyrimidine + pyrrole 12 For anthracnose and Botrytis. One year plant-back restriction.
fludioxonil
*PHI Postharvestinterval REI Restnctedentryinterval
Recommendations given in this fact sheet are based on experimentation and statements from the manufacturer Consult your product label for specific use requirements and restnctions
8


February 2005




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