Title: Florida plant disease management guide
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 Material Information
Title: Florida plant disease management guide
Alternate Title: Ornamentals and turf
Fruit and vegetables
General plant pathology, field crops and pasture grasses, fungicides, adjuvants and application techniques
Physical Description: v. : ; 28 cm.
Language: English
Creator: University of Florida -- Dept. of Plant Pathology
Florida Cooperative Extension Service
Publisher: The Extension
Place of Publication: Gainesville Fla
Frequency: annual
regular
 Subjects
Subject: Plant diseases -- Periodicals -- Florida   ( lcsh )
Pesticides -- Periodicals   ( lcsh )
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Statement of Responsibility: Plant Pathology Dept., University of Florida and Institute of Food and Agricultural Sciences, Florida Cooperative Extension, University of Florida.
Numbering Peculiarities: Issued in three volumes: v. 1, General plant pathology, field crops and pasture grasses, fungicides, adjuvants and application techniques; v. 2, Ornamentals and turf; v. 3, Fruit and vegetables.
General Note: Description based on: 1999-2000.
General Note: "SP-52"
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Bibliographic ID: UF00053871
Volume ID: VID00033
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 44549741
lccn - 00229071
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Preceded by: Florida plant disease control guide

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PDMG-V3-15
UF UNIVERSITY of

UFLORIDA
IFAS Extension



2007 Florida Plant Disease Management Guide: Grape

(Vitis spp.)1


Tim Momol, Laura Ritchie, and Hank Dankers2

ANTHRACNOSE

Introduction

Also called bird's-eye rot, anthracnose on grapes
reduces berry quality and may weaken the vine. The
disease can be particularly severe in the southeastern
United States due to the warm, humid weather.

Symptoms

Circular lesions on leaves are light to dark brown
and sunken, with dried grayish white centers which
often drop out leaving a "shot-hole" appearance.
Lesions may cover the leaf surface or develop along
the vein, preventing normal development. Tips of
shoots may appear burned as the highly susceptible
young leaves become malformed and dry. Lesions on
shoots are small and isolated with a violet brown to
violet black margin; lesions may eventually crack
causing the shoot to become brittle.

Symptoms on berries resemble birds eyes.
Lesions are surrounded by a narrow, dark margin and
have a violet center that gradually changes to a


whitish gray. Lesions may extend into the pulp and
induce cracking or shriveling of the berries (Figures 1
and 2).


Figure 1. Grape Anthracnose and Bird's eye rot, Elsino6
ampllina Shear, damage. Credits: Clemson University -
USDA Cooperative Externsion Slide Series.The Bugwood
Network, NSF Center for Integrated Pest Management and
the University of Georgia


1. This document is PDMG-V3-15, one of a series of the Plant Pathology Department, Florida Cooperative Extension Service, Institute of Food and
Agricultural Sciences, University of Florida. Revised December 2006. Visit the EDIS Web Site at http://edis.ifas.ufl.edu.
2. Tim Momol, associate professor, Plant Pathology Department, North Florida Research and Education Center--Quincy, FL; Laura Ritchie, biologist, North
Florida Research and Education Center--Quincy, FL; Hank Dankers, senior biologist, North Florida Research and Education Center--Quincy, FL; Florida
Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611.
The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the
products named, and references to them in this publication does not signify our approval to the exclusion of other products of suitable composition.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and
other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex,
sexual orientation, marital status, national origin, political opinions or affiliations. U.S. Department of Agriculture, Cooperative Extension Service,
University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry
Arrington, Dean







2007 Florida Plant Disease Management Guide: Grape (Vitis spp.) 2


Figure 2. Grape Anthracnose and Bird's eye rot, Elsinoe
ampllina Shear, damage. Credits: Clemson University -
USDA Cooperative Externsion Slide Series.

Causal Organism

The causal organism of anthracnose is Elsinoe
ampelina (anamorph Sphaceloma ampelinum).
Acervuli are found on the exterior of lesions and
contain short, cylindrical conidiophores. Conidia are
small, hyaline and ovoid, with mucilaginous walls
and one or two refractive spots. Asci contain eight
brown to black, four-celled ascospores.

Disease Cycle and Epidemiology

Sclerotia overwinter in infected areas of the
grape vine or infected berries on the vineyard floor
and in the spring release conidia when wet for 24
hours or more at temperatures above 35.60F.
Conidia germinate in green tissue when free water is
present for 12 hours or more. Optimal temperatures
for disease development are 75.2-78.8 F. Disease
development can be severe during years of heavy
rainfall.

Management

Care must be taken in selection of grape
varieties, as some are more susceptible to anthracnose
than others. Fungicides should be applied at
label-recommended intervals and rates. See Table 1.


BITTER ROT

Introduction

Bitter rot is a common disease of grape in the
southeastern United States and can be particularly
severe on muscadine grapes. Yield for grapes grown
for direct consumption may be reduced as well as
yield for those grown for wine, as the bitter taste of
infected fruit is carried through the winemaking
process.

Symptoms

The fungus usually invades the cluster stem
causing initial berry discoloration at the attachment
point. Brownish, water-soaked lesions develop on
maturing berries and rapidly spreads, often in
concentric rings. Black, raised acervuli appear on the
decaying fruit (Figure 3) and can cause the epidermis
and cuticle to rupture. Some berries become soft and
are easily detached, others continue to dry and
shrivel, appearing similar to grapes affected by black
rot or rpe rot.



























Figure 3. Close-up of fungal fruiting bodies on grape berry
infected with bitter rot. Credits: Ohio State University
Extension






2007 Florida Plant Disease Management Guide: Grape (Vitis spp.) 3


Other symptoms may include flecking of young
leaves and shoots, greenish brown lesions on young
berries, and a blight of the pedicels which causes
young berries to shrivel and drop.

Causal Organism

Greenaria uvicola is the causal organism of
bitter rot. Acervuli are sub-epidermal, separate to
confluent, with irregular dehiscence. Conidiophores
are irregularly branched, septate, and hyaline.
Conidia are dark in color, thin-walled, non-septate,
fusiform to oval, with a truncate base and obtuse apex.

Disease Cycle and Epidemiology

G. uvicola overwinters on infected senescent and
fallen leaves and berries, damaged shoot tips, and
necrotic bark. The fungus invades the dead cells of
corky lenticular warts on the berry pedicels and
remains latent until the berries reach maturity. At
berry maturity the fungus invades the pedicel, moves
into the berry and produces conidia. At this stage any
injury to the berries, such as bird pecking, insect
damage or cracking of berries due to rain, can lead to
rapid spread of the disease. The optimal temperature
for infection is 82-860F.


Around the same time, small, dark lesions may
appear on the petioles, eventually turning black.
Lesions may girdle petioles, killing the leaf.
Throughout the season elongated black cankers
containing pycnidia may develop on young shoots.











Figure 4. Black Rot lesions on grape leaf. Credits: Paul
Pecknold, Perdue University

Berry symptoms differ between bunch grapes
and muscadine grapes. On bunch grapes a small
whitish dot bordered by a reddish brown ring is the
first symptom of infection. The berries will dry and
shrivel into hard, blue black mummies. Infected
muscadine grapes develop dry, black scabby lesions
which may enlarge and rupture, leading to
mummification of the berries (Figure 5). Pycnidia
may be found on mummified berries.


Management


Fungicide sprays are the most common form of
management of bitter rot. See Table 1.

BLACK ROT

Introduction

Black rot is an economically important disease
of grape, often affecting bunch grapes more severely
than muscadines. Disease severity is dependent upon
inoculum level, weather, and cultivar susceptibility.
Crop losses can range from 5-80%.

Symptoms

The fungus can infect any new growth during the
growing season. On leaves, lesions begin as small,
tan to reddish-brown, circular spots on the leaf
surface, then expand and darken, bordered by a
narrow band of dark tissue (Figure 4). Within the
dark border small, raised, black pycnidia appear.


Causal Organism:

Guignardia bidwellii (anamorph Phyllostica
ampelicida) is the causal organism of black rot.
Produced in the stroma on overwintered mummies,
pseudothecia are black and spherical with a flat or
papillate ostioles at the apex. Asci are thick-walled,
fasciculate, cylindrical to clavate, and eight-spored.
Asci, often surrounded by a mucilaginous sheath, are
hyaline, non-septate, oval or oblong, and biseriate.
Pycnidia are solitary, black, spherical, erumpent, and
ostiolate at the apex. Conidia are hyaline, nonseptate,
ovoid or oblong, and rounded at the ends.

Disease Cycle and Epidemiology

G. bidwellii overwinters on infected vines,
tendrils, fallen leaves and mummified berries on vines
or in the soil. Ascospores are discharged by rainfall,
causing leaf lesions and infecting blossoms and
young fruit. The optimal temperature for leaf






2007 Florida Plant Disease Management Guide: Grape (Vitis spp.)

infection and germination is 80.60F. Longer wet
periods are required for lower temperatures. Pycnidia
develop in mummified and newly rotted berries,
develop leaf lesions, and release conidia during rain,
causing secondary infections of leaves, blossoms and
young fruit.

Management

Removal of overwintering mummified berries
from the vine and disking mummies into the soil can
reduce initial inoculum. Chemical control of black
rot has been based on the use of protective fungicides.
See Table 1.

BUNCH ROT Figure 5.
Credits: F
Introduction HortRese


Bunch rot can be locally damaging if cool, wet
weather prevails during the growing season. A
reduction in yield and fruit quality can be substantial.
Wine flavor may also be negatively impacted;
however, in certain cultivars a late-season infection
may contribute to exceptionally sweet wines.



Symptoms

In early spring infected buds and young shoots
may turn brown and dry out. Later large,
reddish-brown necrotic patches may appear on leaves.
Before bloom infected inflorescences may rot or dry
out and fall off

Rot can occur quickly in compact grape clusters.
Infected white grapes will turn brown, dark grapes
develop a reddish color. Infected berries may dry out
in drier weather, or become covered by a grayish
brown fungal growth (Figure 5).

Causal Organisms

Botrytis cinerea is the causal organism of bunch
rot. Mycelium are composed of brownish olive,
cylindrical, septate hyphae. Conidiophores are
slender, dark, and branched with apical cells bearing
clusters of conidia. Single-celled conidia are gray,
smooth, and ovoid or globose. Under adverse


w- wM
Bunch rot of grapes caused by Botrytis cinerea.
photographh coutesy of R. M. Beresford,
arch, New Zealand.


conditions black sclerotia may be present on infected
tissue.

Disease Cycle and Epidemiology

B. cinerea overwinters in mummified grapes,
canes, bark and dormant buds. Conidia are
disseminated by rain, overhead irrigation, and wind.
Germination can occur in the absence of water if the
humidity is above 90%. Optimal temperature for
germination is 64.40F. Penetration ofhyphae is
usually direct. However, injury from insects, birds,
hail, or powdery mildew can facilitate infection.

Management

To reduce disease incidence avoid excessive
vegetation, increase aeration and exposure of clusters
to the sun, and protect against diseases and pests
capable of injuring berries. Fungicides are best used
as preventative treatments. See Table 1.



DOWNY MILDEW

Introduction

Downy mildew is common in regions such as the
southeastern United States where it is warm and wet
during the vegetative growth of the vine. Severe
infections can cause losses to current season crops by
reducing the sugar accumulation in fruit and the fruit







2007 Florida Plant Disease Management Guide: Grape (Vitis spp.) 5


yield. Future crops can also be affected by reducing
the hardiness of overwintering buds.

Symptoms

The causal fungus attacks all green parts of the
vine as well as fruit. Leaf lesions begin as irregular
yellowish spots on the upper leaf surface. They
become reddish brown and angular, often limited by
the leaf veins, and exhibit a dense, white, downy
growth of fungal spores on the lower leaf surface
(Figure 6). Severely infected leaves may drop.
Infected shoots curl, develop water-soaked lesions,
and become covered with downy, white growth
before they turn brown and die. Symptoms similar to
those of infected shoots may be seen on infected
petioles, tendrils and young inflorescences.


Figure 6. Downy mildew symptoms on lower leaf surface.
The patches of downy growth are usually directly beneath
the yellowish green spots observed on the upper leaf
surface. Credits: Hank Dankers, University of Florida,
IFAS, NFREC Quincy

Infected young berries may develop brown
lesions or appear grayish (gray rot) before being
covered by downy fungal growth (Figure 7). Infected
older berries may change to gray-green (white
berries) or pinkish red (dark berries), develop
brown-to-purple spots and drop easily, leaving a dry
stem scar.

Causal Organism

Plasmopara viticola, an obligate parasite, is the
causal organism of downy mildew on grape.
Sporangia are ellipsoid, hyaline, 14 xl pm and are
borne on treelike sporangiophores. Biflagellate,
uninucleate zoospores emerge from the side of the
sporangia. Oospores form in parasitized tissue, are


Figure 7. Downy mildew on grape fruit. Credits: Ohio State
University Extension

enveloped by two membranes and covered by the
wrinkled wall of the oogonium.

Disease Cycle and Epidemiology:

P. viticola overwinters in fallen and persistent
leaves, and in moist soil. Oospores germinate in
water when temperatures are above 51.80F and
produce sporangium from which zoospores are
released via rain-splash. P. viticola penetrates the
host via the stomata. Downy mildew is favored by
factors that increase the moisture content of soil, air
and host plant.

Management

Removal of sources of overwintering inoculum,
improved soil drainage, and pruning the ends of
infected shoots may help reduce incidence of
powdery mildew. This may be impractical or
insufficient in susceptible vineyards; therefore, use of
fungicides is often necessary. See Table 1.







2007 Florida Plant Disease Management Guide: Grape (Vitis spp.) 6


MUSHROOM ROOT ROT

Introduction

Mushroom root rot is also known as Armillaria
root rot, oak root fungus disease, and shoestring root
rot.

Symptoms

Infected vines may exhibit wilting, stunting,
small dark green foliage and will eventually die.
Foliar chlorosis and necrosis may develop depending
on the speed of plant decline. A creamy white layer
of fungus can be observed at the soil line beneath the
bark on trunks of infected vines (Figure 8). In late
fall or early winter honey-colored clumps of
mushrooms may arise at the soil line around the
trunk, adjacent to the stem, or within the root zone of
a declining plant.


Figure 8. Armillaria root rot on grape roots. Credits: OSU
Extension On-Line Guide, Everett Hansen, OSU

Causal Organism

Armillaria tabescens (anamorph Armillaria
mellea) is the causal organism of mushroom root rot.
Mushroom fruiting bodies vary in size, color and
number. Distinguishing characteristics are the
production of true rhizomorphs and large white
plaques ofhyphae found beneath the bark at the soil
line.

Disease Cycle and Epidemiology

A. tabescens moves between plants by root
contact; susceptible roots are penetrated by
rhizomorphs. In grapes the fungus tends to move
down rows, but can move across rows in older
vineyards.


Management

Avoid setting vines where vines have previously
died from this disease unless the root system has been
removed and several years of fallow have passed, or
in recently cleared land that had oak cover.
Fumigation of soil can assist in the control of
mushroom root rot.

PIERCE'S DISEASE

Introduction

Pierce's disease is a principal limiting factor in
bunch grape production in the southeastern United
States. The pathogen can be transmitted by grafting,
but is spread primarily by insect vectors.

Symptoms

Symptoms vary with species and cultivar but
involve a general loss of plant vigor followed by death
of part or all of the affected vine. Leaves may display
marginal scalding or interveinal chlorosis and
necrosis, or appear mottled (Figure 9). Severely
infected leaves often drop from the vine, leaving the
petiole attached. Bud break may be delayed resulting
in stunted shoots and smaller leaves. Berries that set
may color prematurely, wilt, or dry up. Canes may
mature unevenly, leaving green tissue surrounded by
brown mature wood.















Figure 9. Concord grape leaf infected with Pierce's
disease. Credits: Photo courtesy of Breno Leite, IFAS,
University of Florida.






2007 Florida Plant Disease Management Guide: Grape (Vitis spp.) 7


Causal Organism

The causal organism of Pierce's disease is
Xylellafastidiosa. X fastidiosa resides in the plant
xylem tissue. It is a small, gram-negative bacterium
with a convoluted cell wall of several layers and
fibrous strands. It is difficult to culture, or fastidious,
hence its name.

Disease Cycle and Epidemiology

X fastidiosa can survive and reproduce in the
xylem tissue of many native plants, both
monocotyledonous and dicotyledonous. Varying
genera of sharpshooter leafhoppers (Cicadellidae)
and spittlebugs (Cercopidae) serve as vectors,
transmitting the bacterium between plants during
feeding. Bacteria form dense aggregates in xylem
vessels and restrict water conduction to tissue. In
Florida the disease is most commonly transmitted by
sharpshooters from vine to vine.

Management

The use of resistant cultivars is the only effective
control for Pierce's disease is the southeastern United
States.

POWDERY MILDEW


Introduction


Figure 10. Powdery mildew of grape. Credits: Photo by
Ken Johnson, Oregon State University

Cluster infections may result in poor fruit set.
Berries infected before they reach full size do not
attain proper epidermis growth and split from the
internal pressure of pulp growth. Split berries dry up
or rot, often becoming susceptible to bunch rot or
dropping. Berries may develop a blotchy appearance
or a netlike pattern of scar tissue.


Causal Organism


Powdery mildew is usually a minor disease in the
southeastern United States. Left uncontrolled,
however, it can reduce vine growth, yield, quality and
winter hardiness. Infected berries may be
unmarketable as fresh fruit and produce off-flavors in
wine.

Symptoms

Like downy mildew, powdery mildew can infect
all green parts of the grapevine as well as the fruit.
The presence of mycelia on the surface of host tissue
gives it a white to gray, powdery appearance (Figure
10). Both upper and lower leaf surfaces are
susceptible to infection; upper leaf surfaces may also
develop chlorotic spots similar to those of downy
mildew. Infected petioles and cluster stems may
become brittle and break. The tissue of infected
shoots may appear dark brown to black in feathery
patches.


Uncinula necator (anamorph Oidium tucker) is
the causal organism of powdery mildew. Hyphae are
septate and hyaline, and develop multilobed
appressoria with penetration pegs. Multiseptate
conidiophores form along the hyphae at regular
intervals. Conidia accumulate in chains and are
hyaline and cylindro-ovoid. Cleistothecia are globose
with long, flexuous, multispetate appendages and
four to six asci. As cleistothecia mature they change
from white to yellow to brown and appendages
develop a crook. Asci are ovate to subglobose with
four to seven ascospores. Ascospores are ovate to
ellipsoid and hyaline, with one or more short germ
tubes.

Disease Cycle and Epidemiology

U. necator overwinters inside dormant buds
(infected during the previous growing season), or on
the surface of the vine. After bud break, white






2007 Florida Plant Disease Management Guide: Grape (Vitis spp.) 8


mycelium covers emergent shoots and produce
conidia which are dispersed by wind to nearby vines.
Alternately, ascospores, released from cleistothecia
during rain, may germinate and infect green tissue,
producing conidia for secondary spread.
Temperatures of 68-80.60F are optimal for disease
development, as is low, diffuse light.

Management

Orienting rows to provide good air circulation
and sun exposure, as well as using training systems
that allow good air movement through the canopy can
reduce disease incidence. An open canopy can also
allow for better penetration of fungicides. See Table 1.

PSEUDOCERCOSPORA LEAF
SPOT

Introduction

Pseudocercospora leaf spot, also called leaf
blight or Isariopsis leaf spot, occurs primarily in the
southeastern United States. This disease often
appears after harvest, when spraying is discontinued.

Symptoms

Symptoms first appear on the lower, more
shaded leaves as brown angular spots that eventually
darken and become brittle. The spots are often
surrounded by a clearly defined border on upper leaf
surfaces and a more diffuse margin on lower leaf
surfaces. Dark bristle-like fruiting bodies can be seen
on the leaf undersides when using a hand lens.
Premature defoliation may occur in wet seasons.

Causal Organism

Pseudocercospora vitis (perfect stage
Mycosphaerella personata) is the causal organism of
pseudocercospora leaf spot. Fruiting structures are
slender and black, bearing olive brown elongate
conidia. Found on dead leaves in late season,
perithecia are black, round, embedded and warty
above. Asci are club-shaped.

Management

See Table 1 for fungicide control.


RIPE ROT

Introduction

Ripe rot affects bunch grapes, but can be
particularly severe on muscadine grapes, especially in
the southeastern United States where the weather is
warm and humid. Losses vary between seasons,
regions and cultivars.

Symptoms

Ripe rot occurs on grapes as they ripen and has
symptoms similar to those of bitter rot. Infected
berries develop circular reddish-brown lesions on
their skins, which eventually enlarge to cover the
entire berry. Within the lesions are concentric zones
of salmon-colored conidia (Figure 11). Berries
shrivel as they decay and remain attached to the vine
or drop as the rot is complete.


Figure 11. Ripe rot of Muscadine grape. Credits: Photo
courtesy of Bill Cline, Plant Pathology Department, NCSU

Causal Organism

Glomerella cingulata (anamorph Colletotrichum
gloeosporioides) is the causal organism of ripe rot.
Acervuli are produced subepidermally in rings.
Conidia are hyaline, salmon-colored, guttalate,
rounded at the ends and slightly curved. Perithecia
usually grouped and subspherical. Asci are
subclavate.

Disease Cycle and Epidemiology

C. gloeosporioides survives between seasons in
mummified berries and infected pedicels. Production
of conidia is greatest in the early spring and decreases
in the summer months; conidia are spread to other
parts of the vine by rain. Disease development is






2007 Florida Plant Disease Management Guide: Grape (Vitis spp.) 9


favored by warm, wet weather. Conidia germinate,
produce appressoria and penetrate the cuticle of green
or ripening fruit. The fungus will delay further
growth until the grapes mature. Sporulation on ripe
fruit near harvest can provide a secondary inoculum,
which can be exacerbated by frequent rains and result
in severe crop loss.

Management

Removal of overwintered mummies before new
growth can reduce initial inoculum and disease
incidence. Fungicides sprayed on green berries
during the fruit-ripening period can reduce losses.
See Table 1.

INFORMATION SOURCES

Simone, Gary W., Mullin, R.S. 1999-2000
Florida Plant Disease Management Guide. Vol.
3: Fruit and Vegetables

Compendium of Grape Diseases. 1990.
American Phytopathological Society.

CDMS Chem Search.
http://premier.cdms.net/webapls







2007 Florida Plant Disease Management Guide: Grape (Vitis spp.) 10


Table 1. Fungicides approved for disease management of Grape in Florida.


Chemical (a.i.) Fungicide Max rate/acre Min. days Disease Remarks 2
Group Application Season to harvest


Pristine 7 8-12.5 oz 69 oz 14 Anthracnose,
(boscalid + Black Rot, Bunch
pyraclostrobin) Rot, Downy
Mildew, Powdery
Mildew,
Pseudocospora
Leaf Spot, Ripe
Rot

Basic Copper 53, M1 2.5-6 Ib Anthracnose, Some vinifera may
Cuprofix Disperss Black Rot, Downy be copper
(basic copper Mildew, Powdery sensitive
sulfate) Mildew
Kocide 101, M1 2-4 Ib Black Rot, Downy Use hydrated lime
Champion WP, Nu Mildew, Powdery for copper
Cop 50WP Mildew sensitivity
(copper hydroxide)
Kocide 2000, Kocide M1 1.5-4 Ib Black Rot, Downy Use hydrated lime
DF, Nu Cop 50DF Mildew, Powdery for copper
(copper hydroxide) Mildew sensitivity


Kocide 4.5LF, Champ M1 11/3-22/3 pt Black Rot, Downy Use hydrated lime
Formula 2F, Nu Cop Mildew, Powdery for copper
3L Mildew sensitivity
(copper hydroxide)
Dithane DF M2 1.5-4 Ib 24-25.6 Ib 66 Black Rot, Bunch
Rainshield, Manzate Rot, Downy
75DF, Penncozeb Mildew
75DF
(mancozeb)
Dithane F45 M2 1.2-3.2 qt 19.2 qt 66 Black Rot, Bunch
Rainshield, Manzate Rot, Downy
Flowable Mildew
(mancozeb)
Dithane M45, Manzate M2 1.5-4 Ib 24 Ib 66 Black Rot, Bunch
Pro-Stick, Penncozeb Rot, Downy
80WP Mildew
(mancozeb)

Manex M3 1.2-3.2 qt 19.2 qt 66 Black Rot, Bunch
(maneb) Rot, Downy
Mildew

Dusting Sulfur, M1 rate varies Powdery Mildew
Kumulus DF, see labels
Micronized Gold,
Micrthiol Disperss,
Sulfur 90W
(sulfur)







2007 Florida Plant Disease Management Guide: Grape (Vitis spp.) 11


Table 1. Fungicides approved for disease management of Grape in Florida.


Chemical (a.i.) Fungicide Max rate/acre Min. days Disease Remarks 2
Group Application Season to harvest


Thiophanate Methyl 1 0.6-1.2 Ib 3.2 Ib 14 Bitter Rot, Black
85WDG Rot, Powdery
(thiophanate methyl) Mildew

Topsin M 70WP, 1 0.75-1.5 Ib 4 Ib 14 Bitter Rot, Black
Topsin M WSB Rot, Bunch Rot,
(thiophanate methyl) Powdery Mildew

Ziram 76DF, Ziram M2 3-4 Ib 28 Ib 21 Black Rot, Bunch
Granuflo Rot, Downy
(ziram) Mildew, Ripe
Rot
Nova 40W, Rally 40 3 3-5 oz 1.5 Ib 14 Anthracnose,
WSP Black rot, Powery
(myclobutanil) mildew
1 Fungicide group (FRAC code): Numbers (1-37) and letters (M, U, P) are used to distinguish the fungicide mode of action
groups. All fungicides within the same group (with same number or letter) indicate same active ingredient or similar mode of
action. This information must be considered for the fungicide resistance management decisions. M = Multi site inhibitors,
fungicide resistance risk is low; U = Recent molecules with unknown mode of action; P = host plant defense inducers. Source:
http://www.frac.info/ (FRAC = Fungicide Resistance Action Committee).

2 Information provided in this table applies only to Florida. Be sure to read a current product label before applying any
chemical. The use of brand names and any mention or listing of commercial products or services in the publication does not
imply endorsement by the University of Florida Cooperative Extension Service nor discrimination against similar products or
services not mentioned.




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