• TABLE OF CONTENTS
HIDE
 Front Cover
 Title Page
 Table of Contents
 Introduction
 Diseases
 Nematodes
 Mites and insects
 Time of application of pestici...
 Precautions to be followed with...
 List of figures
 Back Cover














Group Title: Bulletin - University of Florida. Agricultural Experiment Stations ; no. 857
Title: Diseases, nematodes, mites, and insects affecting strawberries in Florida
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00027347/00001
 Material Information
Title: Diseases, nematodes, mites, and insects affecting strawberries in Florida
Series Title: Bulletin Agricultural Experiment Stations, University of Florida
Physical Description: iii, 41 p. : ill. (some col.) ; 23 cm.
Language: English
Creator: Howard, C. M
Publisher: Agricultural Experiment Stations, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville Fla.
Publication Date: 1985
 Subjects
Subject: Strawberries -- Diseases and pests -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: C.M. Howard ... et al..
General Note: "November 1985."
Funding: Bulletin (University of Florida. Agricultural Experiment Station)
 Record Information
Bibliographic ID: UF00027347
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000579572
oclc - 14221791
notis - ADA7418

Table of Contents
    Front Cover
        Front Cover
    Title Page
        Page i
    Table of Contents
        Page ii
        Page iii
    Introduction
        Page 1
    Diseases
        Page 1
        Crown and root diseases
            Page 1
            Page 2
            Page 3
            Page 4
            Page 5
        Leaf diseases
            Page 6
            Page 7
            Page 8
            Page 9
        Fruit and flower diseases
            Page 10
            Page 11
            Page 12
            Page 13
            Page 14
            Page 15
            Page 16
        Virus diseases
            Page 17
        Noninfectious diseases
            Page 18
            Page 19
            Page 20
            Page 21
            Page 22
            Page 23
    Nematodes
        Page 24
        Page 25
        Page 26
    Mites and insects
        Page 27
        Mites
            Page 28
            Page 29
        Insects primarily affecting foliage
            Page 30
            Page 31
            Page 32
        Insects primarily affecting fruits and flowers
            Page 33
            Page 34
            Page 35
            Page 36
        Insects primarily affecting roots and crowns
            Page 37
            Page 38
        Miscellaneous insects
            Page 39
    Time of application of pesticides
        Page 39
    Precautions to be followed with pesticides
        Page 40
    List of figures
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
        Page 46
        Page 47
        Page 48
        Page 49
        Page 50
        Page 51
    Back Cover
        Back Cover
Full Text



November 1985


DISEASES, NEMATODES,
MITES, AND INSECTS
AFFECTING STRAWBERRIES
IN- FLORIDA






C.M. Howard
A.J. Overman
J.F. Price
E.E. Albregts


Agricultural Experiment Stations O Institute of Food and
Agricultural Sciences O University of Florida, Gainesville


Bulletin 857













DISEASES, NEMATODES, MITES,
AND INSECTS AFFECTING
STRAWBERRIES IN FLORIDA

C. M. Howard, A. J. Overman,
J. F. Price, and E. E. Albregts





















Authors
C. M. Howard is a Professor of Plant Pathology, Agricultural Research
and Education Center, Dover. A. J. Overman is a Professor of Nematol-
ogy, and J. F. Price is an Associate Professor of Entomology, Gulf
Coast Research and Education Center, Bradenton. E. E. Albreghts is a
Professor of Soil Science, Agricultural Research and Education Center,
Dover.









TABLE OF CONTENTS

INTRODUCTION ........................................ 1
DISEASES .......................................... 1
Crown and Root Diseases .................. ............ 1
Anthracnose.. ......................... ............ 1
Bud Rot.......................... ...................... 2
Root Rot ................... ............. ............ 3
Southern Blight ..................... ............ 4
Verticillium W ilt .................. ... .. .............. 5
Black Root ....................................... 5
Leaf Diseases........................ ... ........... 6
Common Leaf Spot ................................. 6
Leaf Blight......................................... 6
Leaf Scorch .................. ..................... 7
Leaf Blotch....................... ............... 7
Powdery Mildew ................... .. ............. 7
Angular Leaf Spot ................................... 8
Black Leaf Spot ........... ...................... 9
W eb Blight ............... ..... ........ ............. 9
Vein Infection ................................... 9
Control of Leaf Diseases ............................... 10
Fruit and Flower Diseases ............... ............... 10
Gray Mold or Brown Rot .............................. 10
Colletotrichum Rot .................................. 11
Dendrophoma Rot...................... ........... 11
Leaks or Whiskers. ................................. 12
Hard Brown Rot ................... ................ 12
White Rot ...................... ........ ........... 13
Alternaria ....................................... 13
Stem-End Rot ....................................... 13
Pestalotia Rot ................ .................... 14
Leather Rot ........................................ 14
Light Tan Rot .................... ................... 14
Powdery Mildew ...................................... 15
Anther and Pistil Blight ............................. 15
Brown Cap ................... ... ................ 15
Control of Fruit Diseases ........................... 16
Virus Diseases
Mottle ................... ................ .. 17
Noninfectious Diseases ................. .............. 18
Albino Fruit ................ ..................... 18







Weather Burn ................................ .. 19
Sunscald ............... ......... .............. 19
Fasciation ............... .................. ... ...... 19
Tip Burn............................................. 20
Cat Face ............... ....................... 21
Proliferation ............ ..... ....................... 22
Yellow Leaf and White Streak ....................... 23
NEMATODES ............. ....................... 24
Sting Nematode ........................................ 25
Root-Knot Nematode .................................. 25
Bud Nematode ...................................... 26
MITES AND INSECTS ................. .............. 27
Mites ............................................. 28
Twospotted Spider Mite ............................ 28
Cyclamen Mite ..................... ............ 29
Insects Primarily Affecting Foliage ........................ 30
Fall Armyworm .................................... 30
Southern Armyworm ................................. 30
Cabbage Looper .................. ................... 31
Granulate Cutworm .................................. 31
Wooly Bear Caterpillar ............................. 32
Strawberry Root Aphid............................... 32
Insects Primarily Affecting Fruit and Flowers ............ 33
Field Cricket ......................................... 33
Flower Thrips ....................................... 34
Plant Bugs, Including the Tarnished Plant Bug ......... 34
Sap Beetle ......................................... 35
Tomato Fruitworm or Corn Earworm................. 36
Pamera ............................................. 36
Insects Primarily Affecting Roots and Crowns............. 37
Lesser Cornstalk Borer (Budworm) ................... 37
Mole Cricket .................... ..................... 38
Wireworm or Click Beetle ............... ............. 39
Miscellaneous Insects ................................... 39
TIME OF APPLICATION OF PESTICIDES ................ 39
Pesticide precautions .................................... 40
FIGURES ......................................... 41











INTRODUCTION
Strawberry plants are grown in all months of the year in Florida-
in plant nurseries during the winter, spring, summer, and early fall,
and in fruit production fields in the fall, winter, and spring. The
warm, humid climate of the state that permits year-round growth of
plants in the field is also ideal for the development of a large number
of diseases and pests on the crop as environmental conditions become
favorable for their activity. Growers must be concerned about grow-
ing disease-and pest-free plants that will be used for fruit production
or for establishing new nurseries.
This bulletin offers causes, symptoms, and control measures for
strawberry diseases and pests that are important in Florida. Since
control recommendations may change frequently, specific recom-
mendations are not listed. Consult extension or research personnel or
publications for current control recommendations.

DISEASES
Although several organisms attack more than one part of the
plant, the diseases are divided into the following groups: 1) Crown
and Root Diseases; 2) Leaf Diseases; 3) Fruit and Flower Diseases;
4) Virus Diseases; and 5) Noninfectious Diseases.

CROWN AND ROOT DISEASES
DISEASE.-Anthracnose
CAUSE.-Colletotrichum fragariae Brooks
Glomerella cingulata (Ston.) Spauld. & Schrenk
SYMPTOMS.-The first symptom of anthracnose usually is the
formation of very small, black, sunken lesions on the youngest run-
ners. (Occasionally black leaf spot, described under "Leaf Diseases,"
is the first symptom noticed.) Lesions on the runners enlarge and
coalesce to form long, black, dry, sunken areas up to an inch (2.54 cm)
or more long (Fig. 1). These often girdle the runner, resulting in
death of unrooted daughter plants beyond the lesion. The black,
sunken lesions also occur on leaf stems, especially on highly suscepti-
ble cultivars. Infected stems often bend downward sharply at the
point of the lesion, causing the leaves to hang downward (Fig. 2). The
fungus also can infect the crowns of plants. If this occurs early











INTRODUCTION
Strawberry plants are grown in all months of the year in Florida-
in plant nurseries during the winter, spring, summer, and early fall,
and in fruit production fields in the fall, winter, and spring. The
warm, humid climate of the state that permits year-round growth of
plants in the field is also ideal for the development of a large number
of diseases and pests on the crop as environmental conditions become
favorable for their activity. Growers must be concerned about grow-
ing disease-and pest-free plants that will be used for fruit production
or for establishing new nurseries.
This bulletin offers causes, symptoms, and control measures for
strawberry diseases and pests that are important in Florida. Since
control recommendations may change frequently, specific recom-
mendations are not listed. Consult extension or research personnel or
publications for current control recommendations.

DISEASES
Although several organisms attack more than one part of the
plant, the diseases are divided into the following groups: 1) Crown
and Root Diseases; 2) Leaf Diseases; 3) Fruit and Flower Diseases;
4) Virus Diseases; and 5) Noninfectious Diseases.

CROWN AND ROOT DISEASES
DISEASE.-Anthracnose
CAUSE.-Colletotrichum fragariae Brooks
Glomerella cingulata (Ston.) Spauld. & Schrenk
SYMPTOMS.-The first symptom of anthracnose usually is the
formation of very small, black, sunken lesions on the youngest run-
ners. (Occasionally black leaf spot, described under "Leaf Diseases,"
is the first symptom noticed.) Lesions on the runners enlarge and
coalesce to form long, black, dry, sunken areas up to an inch (2.54 cm)
or more long (Fig. 1). These often girdle the runner, resulting in
death of unrooted daughter plants beyond the lesion. The black,
sunken lesions also occur on leaf stems, especially on highly suscepti-
ble cultivars. Infected stems often bend downward sharply at the
point of the lesion, causing the leaves to hang downward (Fig. 2). The
fungus also can infect the crowns of plants. If this occurs early











INTRODUCTION
Strawberry plants are grown in all months of the year in Florida-
in plant nurseries during the winter, spring, summer, and early fall,
and in fruit production fields in the fall, winter, and spring. The
warm, humid climate of the state that permits year-round growth of
plants in the field is also ideal for the development of a large number
of diseases and pests on the crop as environmental conditions become
favorable for their activity. Growers must be concerned about grow-
ing disease-and pest-free plants that will be used for fruit production
or for establishing new nurseries.
This bulletin offers causes, symptoms, and control measures for
strawberry diseases and pests that are important in Florida. Since
control recommendations may change frequently, specific recom-
mendations are not listed. Consult extension or research personnel or
publications for current control recommendations.

DISEASES
Although several organisms attack more than one part of the
plant, the diseases are divided into the following groups: 1) Crown
and Root Diseases; 2) Leaf Diseases; 3) Fruit and Flower Diseases;
4) Virus Diseases; and 5) Noninfectious Diseases.

CROWN AND ROOT DISEASES
DISEASE.-Anthracnose
CAUSE.-Colletotrichum fragariae Brooks
Glomerella cingulata (Ston.) Spauld. & Schrenk
SYMPTOMS.-The first symptom of anthracnose usually is the
formation of very small, black, sunken lesions on the youngest run-
ners. (Occasionally black leaf spot, described under "Leaf Diseases,"
is the first symptom noticed.) Lesions on the runners enlarge and
coalesce to form long, black, dry, sunken areas up to an inch (2.54 cm)
or more long (Fig. 1). These often girdle the runner, resulting in
death of unrooted daughter plants beyond the lesion. The black,
sunken lesions also occur on leaf stems, especially on highly suscepti-
ble cultivars. Infected stems often bend downward sharply at the
point of the lesion, causing the leaves to hang downward (Fig. 2). The
fungus also can infect the crowns of plants. If this occurs early







enough, infected plants wilt and die suddenly in the nursery. These
plants later turn back and appear as if they had been burned by fire.
When infected plants are set into the fruit production field, indi-
vidual plants wilt and die at any time during the fruiting season. A
cut lengthwise through the crowns of freshly wilted plants reveals
streaks or large areas of reddish-brown, firm tissue.
DISEASE DEVELOPMENT.-Anthracnose is most important in
summer plant production beds. The disease is favored by high
temperatures, moisture and high fertility. After initial infection,
spores are formed abundantly on developing lesions. These spores
blow and splash to other plants and initiate new infections. Crown
infections occur when the fungus grows into the crown from lesions
on runners or leaf stems, or when spores that are washed into the bud
germinate and infect the crown directly.
In the fruit production field, C. fragariae usually causes a fast wilt,
with individual plants completely wilting within a few days after the
first sign of wilt. Wilting is most severe during periods of warm
weather. Slow wilting occasionally can be found during periods of
cool weather (below about 60F (150C). In these cases, the oldest
leaves begin to dry and turn nearly black. If temperatures remain
low, the symptoms occur on successively younger leaves until the
entire plant is affected within about two weeks. These symptoms
somewhat resemble fertilizer burn, but unlike plants affected by
fertilizer burn, those affected by C. fragariae do not recover regard-
less of how much overhead irrigation is applied.
CONTROL.-Apparently all, or nearly all, infection by C. fragar-
iae occurs in the summer nursery with little or no spread in the fruit
production field. Therefore, excellent control of anthracnose in the
summer nursery will also prevent wilt in the fruit production field.
Anthracnose can be controlled by the use of resistant cultivars. If
susceptible cultivars are used, they should be set in the summer
nursery no earlier than June, soil fertility should be kept at a low
level through July and August, foliar fertilizers should never be used,
and approved fungicides should be applied every two days from late
June at least through mid-September. If heavy or frequent rains
continue through mid-September, fungicide applications should con-
tinue at 2-day intervals through the end of September. Spray inter-
vals then may be extended to 3 or 4 days until the plants are dug.

DISEASE.-Bud Rot
CAUSE.-Rhizoctonia spp.
SYMPTOMS.-When strawberry plants with a single-bud crown
are attacked in the fruit production field, the bud is killed by dry-rot
and may be pulled easily from the remainder of the plant. When the







bases of the older leaf stems are attacked, they become dry-rotted,
and the leaves lie flat on the plastic mulch. They may continue to
grow in this position and live out their normal life span. Death of the
main bud results in death of the plant unless lateral buds subse-
quently develop and are not themselves attacked by the fungus.
The fungus attacks flower buds in any stage of development. When
the early forms are attacked, the buds develop dry rot and die. When
an open or nearly open bud is attacked, a large purple or black lesion
forms on the calyx, and the center of the blossom becomes black
(similar in appearance to freeze damage).
In the nursery, Rhizoctonia may cause a wet, slimy rot of leaf buds
and stems or dry rot of the bases of the petioles (Fig. 3) and of the
buds.
DISEASE DEVELOPMENT.-Rhizotonia solani Kuhn is gener-
ally considered to be the cause of bud rot; however, other species of
Rhizoctonia also may be involved. Rhizoctonia species are widely
distributed in Florida soils and cause diseases of many species of
plants. The Rhizoctonia species that causes bud rot is favored by high
moisture conditions.
Bud rot becomes a problem in the nursery only where plants are
very crowded or in wet areas of the field where drainage is poor. One
of the major causes of vegetative bud rot is plants being set too deeply
in either the nursery or fruit production field. Any time a portion of
the central bud is covered by soil, bud rot is likely to occur.
In established fruit production plantings, bud rot is favored by high
humidity and wet soil caused by extended periods of rainy or foggy
weather and heavy dews which keep the plants wet for long periods.
Large plants or plants set too closely together on the bed tend to hold
a moist atmosphere around the buds and thus favor the disease.
CONTROL.-Every possible precaution should be taken to insure
that the plants are not set too deeply in the nursery or fruit produc-
tion field. Plants should be spaced widely enough on the beds in the
fruit production field to allow air circulation which will facilitate
drying of foilage and buds after the plants have grown. Within 3 to 4
weeks after the plants are established, approved fungicides should be
applied at 3 to 4-day intervals.
Only sites with excellent drainage should be chosen for nursery
areas. Ditching around the nursery should be done if necessary to
improve drainage, and plants should be set widely enough that over-
crowding will not occur as runners are produced.

DISEASE.-Root Rot
CAUSE.-Rhizoctonia fragariae Husain and McKeen
SYMPTOMS.-Dark brown lesions up to an inch (2.54 cm) long







form on infected roots and the entire root system may be attacked and
turn brown. Severely infected plants cease growing and remain
stunted in relation to surrounding healthy plants. They may die very
slowly, or if good drainage is supplied, they may recover.
DISEASE DEVELOPMENT.-Root rot occurs in both the nursery
and the fruit production field. The major cause of the disease is poor
soil drainage. It usually occurs only in wet areas where the soil
remains saturated for extended periods after rains or irrigation.
CONTROL.-Root rot can be controlled by ditching around poorly
drained fields to improve drainage. Very poorly drained areas should
be avoided for fruit or nursery production.

DISEASE.-Southern Blight
CAUSE.-Sclerotium rolfsii Sacc.
SYMPTOMS.-Sclerotium rolfsii causes a wet rot of crowns, leaf
stems, and buds in the nursery. Web-like, white mycelium of the
fungus usually can be found growing profusely over the infected
crowns and surrounding soil. Small, hard sclerotia (resting bodies of
the fungus) are usually found scattered through the mycelium. The
sclerotia are about the size of large strawberry seeds. They are white
at first, then tan, and eventually dark brown.
When S. rolfsii attacks plants in October or November soon after
they have become established in the fruit production field, it causes
dry rot of the young leaves, the central bud, and some or all of the
emerging flower buds. The affected leaves and buds die and become
light tan in color. The large outer leaves usually remain green for a
few weeks, but lie flat on the plastic because of infection of the bases
of their stems. Sclerotia (Fig. 4) usually can be found on the dead
central bud, or on the bases of the stems of the dead young leaves.
When S. rolfsii attacks plants in the fruit production field during
the spring, it causes dry rot of crowns, leaf stems, and buds of indi-
vidual plants. The plants then wilt and die slowly. Mycelium and
sclerotia may or may not be found on the crowns of these plants.
DISEASE DEVELOPMENT.-Southern blight is favored by hot,
wet weather. It seldom becomes a major problem in strawberries. In
the nursery, it is usually limited to individual plants or a few plants
in areas 1 to 2 feet (30.48 to 60.96 cm) in diameter.
Southern blight usually does not occur in fruit production fields
until mid-April or May near or after termination of commercial
harvest. Thus, losses are minimal even though many plants may be
killed at that time.
CONTROL.-Southern blight is widely distributed in Florida and
affects a wide range of plants. Specific control measures on strawber-
ries have not been determined.







DISEASE.-Verticillium Wilt
CAUSE.-Verticillium albo-atrum Reinke and Berth
SYMPTOMS.-Verticillium wilt is first noticed as older leaves on
individual plants begin to wilt. The margins of the leaflets on these
leaves then turn brown or nearly black along the edges. The younger
leaves remain light green, usually with yellow margins around the
edges of individual leaflets, and often become slightly wilted. As wilt
progresses, successively younger leaves turn brown to nearly black.
Plants wilt slowly, and infected plants may survive in a stunted,
partially wilted stage (Fig. 5) for three months or longer. Plants that
survive until spring often recover and appear to grow normally.
DISEASE DEVELOPMENT.-The Verticillium fungus is widely
distributed in the highly calcarious soils of south Florida and is a
serious problem there. It apparently does not occur naturally in soils
in the central and north Florida strawberry production areas. It
becomes a problem in these two areas only when infected plants from
other states are set in the fields.
CONTROL.-In infested soils, adequate control of Verticillium
wilt is obtained by preplant treatment with soil fumigants approved
for control of this disease. Growers in central and north Florida
should make every effort to avoid setting infected plants in order to
prevent introduction of the fungus into those areas.

DISEASE.-Black Root
CAUSE.-Varies
SYMPTOMS.-Roots of plants dug from the nursery are dark
brown or black and appear dead.
DISEASE DEVELOPMENT.-Black root in Florida usually ap-
pears to be caused by physiologic factors rather than by pathogenic
organisms. When plants from a winter nursery are allowed to grow
through the summer, or when summer nurseries are established
early and the beds become full of plants by mid-August, their roots
often will be black when they are dug in October.
Water standing for long periods around plants in the nursery will
also cause black root. In this case, blackening of the roots is probably
caused by a combination of microorganisms and lack of oxygen in the
soil.
CONTROL.-Black-rooted plants can usually be induced to form
new white roots by running a blade under them about six inches
(15.24 cm) deep two or three weeks before digging. This is seldom
needed, though, because even without this treatment they usually
grow normally after transplanting. When plants become black rooted
because of water standing in spots in the nursery, most of them will
form new white roots after natural drainage occurs. Recovery can be







hastened by ditching or cultivation to allow the soil to dry more
rapidly.

LEAF DISEASES
There are several important leaf diseases of the strawberry in
Florida. Some of them can be serious at any time of year. Others are
serious only in the winter or only in the summer nursery. Control
measures for leaf diseases are presented at the end of this section.

DISEASE.-Common Leaf Spot
CAUSE.-Mycosphaerella fragariae (Tul.) Lindau
SYMPTOMS.-Spots are small at first, less than 1/s inch (3.2 mm)
in diameter, and are purplish red. They increase in diameter to about
3/16 inch (4.8 mm) on most cultivars and up to %/ inch (9.5 mm) on
some. The spots remain nearly circular with purple borders and
white or gray centers (Fig. 6). Spots number from one to many on each
leaflet and, if extremely numerous, cause death of the leaflet. If many
leaflets die, the plant itself may die or be stunted.
DISEASE DEVELOPMENT.-Common leaf spot is favored by
warm, wet weather but it can become serious at any time of year.
Under favorable conditions the fungus sporulates profusely on the
undersurfaces of the spots. The spores are blown or splashed to other
leaflets and initiate new infections.
In rare instances, when spores are plentiful from old infections and
weather conditions are extremely favorable, common leaf spot is
manifested in an unusual manner. In these cases many tan spots
lacking purple borders appear during a period of two or three days
and large portions of leaflets die and turn light tan. On the undersur-
face of the leaflets, the spots appear water-soaked when the leaves
are wet and closely resemble angular (bacterial) leaf spot. This seems
to occur only after periods of warm, rainy weather followed by two or
three days of foggy mornings and heavy dews. Symptoms differ from
those of angular leaf spot in that no whitish bacterial ooze is found on
the water-soaked spots, and as the leaves dry, the spots dry to a light
tan and are not covered by the slick, shiny bacterial deposit that
occurs with angular leaf spot. Purple borders form around the indi-
vidual spots after about a week.

DISEASE.-Leaf Blight
CAUSE.-Dendrophoma obscurans (Ell. & Ev.) Anderson
SYMPTOMS.-Young spots of this disease are often difficult to
distinguish from those caused by common leaf spot. They are round,
purple, and have gray centers. As the spots enlarge, the central zone







becomes dark brown, surrounded by a lighter brown zone which in
turn is bordered by a purple, red, or yellow zone which blends into the
normal green of the leaf. Mature spots are usually V-shaped with the
wide part of the V at the edge of the leaflet (Fig. 7). Small black dots,
the fruiting structures of the fungus, appear in the central, dark
brown zones of the spots.
DISEASE DEVELOPMENT.-Leaf blight is favored by warm,
wet weather but may become severe at any time of year.

DISEASE.-Leaf Scorch
CAUSE.-Diplocarpon earliana (Ell. & Ev.) Wolf
SYMPTOMS.-Spots first appear on the upper surfaces of leaflets
as small purplish discolorations which enlarge into irregular purple
or red blotches from V16 to /16 inch (1.6 to 4.8 mm) in diameter. In
these spots are very small, black, glistening bodies which are the
fruiting structures of the fungus. The spots on some leaflets may
become so numerous that they coalesce and give a dark reddish cast
to the entire leaflet (Fig. 8). In cases of severe infections, the edges of
the leaflets curl upward and the tissue dies and dries to a tan color,
progressively from edge to midrib, giving the plant a scorched
appearance.
DISEASE DEVELOPMENT.-Leaf scorch can appear at any time
of year.

DISEASE.-Leaf Blotch
CAUSE.-Gnomonia comari Harsten
SYMPTOMS.-Leaf blotch lesions begin as small, circular, tan
spots and rapidly enlarge to an inch (2.54 cm) or more in diameter.
The lesions usually remain round, but occasionally become V-shaped
and resemble leaf blight lesions. However, blotch lesions remain
lighter tan and are not surrounded by colored borders (Fig. 9). Small,
black fruiting bodies appear in concentric circles within the blotch
lesions. One or two lesions on a leaflet will often enlarge to encompass
the entire leaflet within four or five days. Killing of leaflets in this
manner sometimes causes rapid defoliation of entire plants.
DISEASE DEVELOPMENT.-This disease is usually found only
during late fall and early winter on plants shipped into Florida from
other states. It has been found occasionally in mid to late winter but
has not been detected in the summer nursery.

DISEASE.-Powdery Mildew
CAUSE.-Sphaerotheca macularis (Wallr. ex Fries) W. B. Cooke
SYMPTOMS.-A sparce, white, web-like growth covers small
areas of the undersurfaces of leaflets in the early stage of this disease







(Fig. 10). Tiny, nearly transparent spores produced on the growth
give a powdery appearance to these spots. As the disease becomes
more severe, more leaflets become infected, and the web-like growth
spreads until it covers nearly the entire undersurface of some leaflets.
Irregular-shaped yellow or black spots up to 3/% inch (8.5 mm) in
diameter often form on the upper surfaces of leaves that have been
infected for some time. The edges of the leaflets curl upward (Fig. 11)
as infection continues and the entire field (or sections of the field) may
have a silvery appearance because of the exposure of the fungus
growth on the undersides of the leaflets.
At times, specialized fruiting structures (the cleistothecia) of the
fungus can be found scattered through the weblike growth. These are
white at first and gradually turn black.
DISEASE DEVELOPMENT.-Powdery mildew is favored by cool,
moist conditions and may become a serious problem any time from
November through February.


DISEASE.-Angular Leaf Spot
CAUSE.-Xanthomonas fragariae Kennedy & King
SYMPTOMS.-Lesions begin as small, irregular, water-soaked
areas on the undersurfaces of leaflets (Fig. 12). When moisture is
plentiful on the leaflets, especially in the morning, whitish, sticky
droplets of bacterial ooze occur on the water-soaked spots on the
undersides of the leaflets. As the moisture dries, the droplets of
bacteria also dry and form a slick, shiny covering over the lesions. At
this stage, the undersides of infected leaflets appear as if clear lac-
quer had been dabbed on them. As the spots enlarge and become more
numerous, corresponding yellow, dark green, or red areas appear on
the upper surfaces of the leaflets. In severe cases entire leaflets are
killed and turn light brown. Plants may be defoliated except for a few
very young leaves in the centers of the crowns.
DISEASE DEVELOPMENT.-Angular leaf spot is the only straw-
berry disease in Florida caused by a bacterium. It is favored by cold
weather and becomes especially severe during and after periods of
frequent night-time freezes coupled with low day-time temperatures.
With the advent of continuing warm weather in the spring, even
severely defoliated plants produce new leaves which, at worst, may
become lightly infected. By mid-April it is often difficult to find any
signs of the disease. Angular leaf spot is never a problem in the
summer nursery, although a low incidence of the disease sometimes
occurs there.







DISEASE.-Black Leaf Spot
CAUSE.-Colletotrichum fragariae Brooks
Glomerella cingulata (Ston.) Spauld. & Schrenk
SYMPTOMS.-Spots first appear as tiny black dots less than
1/16 inch (1.6 mm) in diameter. They enlarge to Vi6 to 1/s inch (1.6 to
3.2 mm) in diameter and remain black (Fig. 13). Although many
spots may be present on individual leaflets, they do not cause death of
the leaflets.
DISEASE DEVELOPMENT.-Black leaf spot is caused by the
same fungus that causes anthracnose. It occurs any time from June
through mid-September in the summer nursery, and in late April and
May in the winter nursery. Black leaf spot usually appears only after
anthracnose has become moderate to severe on runners and leaf
stems. At times, however, black leaf spot appears first and is the first
indication that the anthracnose fungus is present. At the first sign of
black leaf spot, approved fungicides should be applied on a 2-day
schedule and after every rain and every irrigation to minimize
anthracnose.

DISEASE.-Web Blight
CAUSE.-Rhizoctonia solani Kuhn
SYMPTOMS.-Web blight is of minor importance in Florida. The
fungus grows over the lower surfaces of leaves and causes death of
some leaves. Close examination reveals the web-like growth of the
fungus on infected leaves.
DISEASE DEVELOPMENT.-Web blight is favored by high mois-
ture levels and crowding of plants. It occurs most frequently in the
summer nursery during periods of frequent irrigation or rainfall
after plants have become crowded. It is found occasionally in fruit
production fields when plants become very large and crowded.

DISEASE.-Vein Infection
CAUSE.-Rhizoctonia spp.
SYMPTOMS.-Vein infection is another disease of minor impor-
tance in Florida. In this case the Rhizoctonia fungus infects the lower
surfaces of main veins. This retards or stops growth of the vein in the
infected area and causes the leaflets to curl downward or to pucker.
DISEASE DEVELOPMENT.-Vein infection is favored by high
moisture levels and crowding of plants. It occurs most frequently in
the summer nursery during periods of frequent irrigation or rainfall
after plants have become crowded. It is found occasionally in fruit
production fields when plants become very large and crowded.







CONTROL OF LEAF DISEASES.-Excellent control of all the
strawberry leaf diseases except angular leaf spot and black leaf spot
can be obtained by applications of approved fungicides at 3- to 4-day
intervals in fruit production fields and nurseries.
Angular leaf spot is caused by a bacterium, and most fungicides are
ineffective for its control. At the present time, copper fungicides are
the only ones known to give some control of angular leaf spot. Copper
becomes toxic to strawberry plants, though, after a few applications
and should not be applied more than four or five times during any
2-month period. Since that number of applications will not give
noticeable control, especially during extended periods of cold weath-
er, it is questionable whether attempts to control angular leaf spot
are worthwhile.
To control black leaf spot, approved fungicides should be applied
every two days and after every rain or application of irrigation from
early July through early September. Soil fertility levels also should
be kept low through August because high fertility appears to increase
susceptibility to black leaf spot and anthracnose.


FRUIT AND FLOWER DISEASES
Fruit rots may occur in the field before harvest or at any time after
harvest until the fruit is consumed. When infection of fruit occurs
shortly before harvest, rot often will not develop until after harvest.
Thus it is essential to cool the fruit to 330 to 35F (0.5 to 1.6C) as
quickly as possible after harvest to retard growth of the fungi that
cause rots. Control measures for fruit diseases are presented at the
end of this section.

DISEASE.-Gray Mold or Brown Rot
CAUSE.-Botrytis cinerea Pers.
SYMPTOMS.-Infected areas on fruits are light brown at first,
then become dark brown. The flesh in the infected areas is slightly
soft at first, then becomes hard and dry. There is no distinct line of
demarcation between diseased and healthy tissue. Under moist con-
ditions, infected fruits are covered with gray, dusty spores of the
fungus (Figs. 14, 15).
DISEASE DEVELOPMENT.-Gray mold becomes most serious
during periods of prolonged wet weather. Under moist conditions the
fungus may attack strawberries in all stages of development from
blossom bud stage to fully ripe. The spores that are formed on buds,
flowers, and fruit blow around readily and initiate new infections.







DISEASE.-Colletotrichum Rot
CAUSE.-Colletotrichum fragariae Brooks
Glomerella cingulata (Ston.) Spauld. & Schrenk
SYMPTOMS.-Rotting spots on ripe fruit are round, sunken, firm,
light brown to black, and vary from 1/s to 1/2 inch (3.2 to 12.7 mm) or
more in diameter (Fig. 16). Salmon-colored masses of spores often can
be seen on the spots. Two or more spots sometimes coalesce.
Spots on green fruits are hard, dark brown or black, sunken, and
usually /16 to /V inch (1.6 to 3.2 mm) in diameter. As the infected
green fruits enlarge, the spots usually remain small and become
progressively more sunken. Red or purple borders often form around
the infected spots as the fruits mature to the white stage. As the
infected fruits ripen, the spots enlarge rapidly and form the typical
ripe fruit rot as described above. The spots sometimes enlarge on the
green fruits. It is then often impossible to distinguish this rot from
Rhizoctonia rot with the unaided eye. Inspection of such lesions with
a dissecting microscope usually reveals small, crusty spore masses in
cases of Colletotrichum rot.
Flower blight (Fig. 17) occurs when the flower, or the fruit stem
immediately below the flower, becomes infected. The center of the
flower turns black, and the calyx (the cap) and a portion of the stem
becomes tan or light brown and dry. Sticky, gelatinous masses often
form on infected flower stems. These masses are apparently sap
exuded from the plant, but Colletotrichum spores are sometimes
present in them. Stem lesions may extend 2 to 3 inches (5 to 7.6 cm)
below the flowers.
DISEASE DEVELOPMENT.-This rot is caused by the same fun-
gus that causes anthracnose. It becomes serious only during warm or
hot weather. Colletotrichum rot is extremely difficult to control once
it has reached moderate levels in a field. It is primarily a rot of ripe
fruit, but when disease incidence reaches a high level, it also affects
green fruit. A few fields have been seen in which one or more lesions
were present on nearly every green fruit.
To date flower blight has been seen only on the Pajaro variety. It
has been very severe in some fields ofPajaro, with nearly all blossoms
of a particular flush being affected. Flower blight is favored by warm,
rainy weather.

DISEASE.-Dendrophoma Rot
CAUSE.-Dendrophoma obscurans (Ell. & Ev.) Anderson
SYMPTOMS.-In early stages rot appears as round, light pink,
water soaked, nonsunken spots. Two or more lesions often coalesce.
Infected areas later turn light brown (Fig. 18), and the entire fruit is







invaded and becomes soft. Infected fruits eventually mummify and
sometimes appear black after numerous pycnidia (fruiting structures
of the fungus) develop.
DISEASE DEVELOPMENT.-Dendrophoma rot is caused by the
same fungus that causes leaf blight. It is favored by warm weather,
but occasionally becomes serious during cool weather. Dendrophoma
rot is primarily a disease of ripe fruit but is found on green fruit when
disease incidence reaches a high level. Dendrophoma rot, like col-
letotrichum rot, is one of the most difficult of diseases to control when
rot levels reach a moderate or severe degree.

DISEASE.-Leaks or Whiskers
CAUSE.-Rhizopus stolonifer Ehrenb. ex Fr.
SYMPTOMS.-In the field, fruits in the early stages of infection
often appear healthy from above, but when an attempt is made to
pick them, the part of the fruit in contact with the plastic mulch is
found to be very soft and mushy. Infected fruits lose juice rapidly and
collapse into a mushy mass. A blueish growth occurs on the collapsed
fruits as the fungus sporulates. Infected fruits often can be found
easily in the field by looking for juice trails on the plastic mulch down
the sides of the beds.
Rot that develops after harvest causes collapse of the fruit tissue
and rapid loss of juice, which drips out of the container, thus giving
rise to the common name "leaks." A loose cottony growth of the
fungus may appear over the surface of the fruit. This is the "whisk-
ers" stage. This growth takes on a blue color when the spore bearing
structures of the fungus form on the white mycelium, or "whiskers,"
of the fungus (Fig. 19).
DISEASE DEVELOPMENT.-This rot is favored by hot, moist
conditions. It is of most importance during transportation and
marketing. Generally it is found in the field only on overripe fruits. It
usually does not become serious in the field until after overripe fruit
has accumulated because of an interruption of the picking schedule.

DISEASE.-Hard Brown Rot
CAUSE.-Rhizoctonia solani Kuhn
SYMPTOMS.-Hard brown rot may occur on blossoms and fruit in
all stages of development, but it is most often noticed on green fruit.
The infected parts of green fruit are light brown at first. These areas
later turn dark brown to almost black and become hard and dry (Fig.
20). Often only the tip of the fruit is invaded, and affected fruit closely
resemble freeze-damaged fruit. In some cases the entire fruit or the
stem end of the fruit is attacked, and a large purplish lesion forms on







the green calyx. When developing flower buds are attacked, large
purplish lesions form on the calyces and may extend an inch (2.54 cm)
or more down the flower stems (Fig. 21).
DISEASE DEVELOPMENT.-Hard brown rot is caused by the
same fungus that causes bud rot. It is favored by warm, moist
weather conditions and becomes especially severe during periods of
foggy weather.

DISEASE.-White Rot
CAUSE.-Unidentified Fungus
SYMPTOMS.-Rot appears as a large, soft, white or very light
purplish area on the ripe fruit (Fig. 22). The entire fruit is invaded
and becomes soft within two or three days after infection is first
noticed.
DISEASE DEVELOPMENT.-White rot is caused by a fungus
which has not yet been identified but is probably a species ofRhizoc-
tonia. Only ripe fruits appear to be attacked. The disease is erratic in
occurrence, seeming to appear suddenly in a particular field, then
disappear almost as suddenly.

DISEASE.-Alternaria Rot
CAUSE.-Alternaria tenuissima (Fries) Wiltshire
SYMPTOMS.-In early stages of Alternaria rot, lesions are irregu-
lar in shape and slightly sunken. A light green color develops on the
lesions as the fungus begins to sporulate. Advanced lesions are circu-
lar, sunken, firm, and dark green to almost black because of abun-
dant sporulation by the fungus (Fig. 23).
DISEASE DEVELOPMENT.-This rot may occur at any time
during the fruiting season. Although it is not one of the more serious
strawberry diseases, it does become quite severe at times in some
fields.

DISEASE.-Stem-End Rot
CAUSE.-Gnomonia comari Karsten
SYMPTOMS.-Stem-end rot is characterized by light brown dis-
coloration of the fruit, usually at the stem end. When small green
fruits become infected, irregular brown areas appear on them, and
the fruits dry and fail to develop further. Large green fruits begin to
ripen prematurely, and turn pale red and brownish. Ripe fruits
develop areas of soft rot. Infection often appears to start under the
calyx (cap) and to spread outward from there (Fig. 24).
DISEASE DEVELOPMENT.-This rot is caused by the same fun-
gus that causes leaf blotch. It is usually seen only on ripe fruit in







Florida. Stem-end rot is noticed only occasionally in Florida but can
become severe in individual fields in which leaf blotch reaches moder-
ate to severe levels. Stem-end rot is favored by wet conditions.

DISEASE.-Pestalotia Rot
CAUSE.-Pestalotia longisetula Guba
SYMPTOMS.-In early stages, lesions are 1/16 to 1/s inch (1.6 to
3.2 mm) in diameter, dry, light tan, slightly sunken, and often irregu-
lar in shape. As rot progresses, the central area enlarges and becomes
nearly circular but remains dry, light tan, and only slightly sunken
below the original surface of the fruit. A circular band of tissue
around this central area usually becomes soft and definitely sunken
(Fig. 25). The entire fruit is eventually affected and mummifies. At
times the central area enlarges until most of the infected fruit is dry
and light tan. With this type lesion, no soft rot band develops. Occa-
sionally, white mycelium of the fungus develops on infected fruits,
and droplets of liquid containing spores are scattered over the myce-
lium. In a third variation of symptoms, numerous fruiting structures
of the fungus form in the lesion, and part or all of the infected fruit
appears black.
DISEASE DEVELOPMENT.-This rot occurs only rarely in Flor-
ida. Conditions that favor its development have not been determined.


DISEASE.-Leather Rot
CAUSE.-Phytophthora cactorum (Leb. & Cohn.) Schroet
SYMPTOMS.-Leather rot occurs on green or ripe fruits as dark
brown, dry, leathery areas. On partially colored fruit there may be a
purple border around the brown lesion. If a diseased fruit is cut
through the lesion, there is no clear line separating diseased and
healthy tissue, but the water conducting system leading to each seed
is dark in color. Leather rot seldom becomes a serious problem in
Florida.

DISEASE.-Light Tan Rot
CAUSE.-Dischohainesia oenotherae (Cke. & Ell.) Nannf.
SYMPTOMS.-Spots produced on the fruit are small, sunken, and
tan. They increase in size very slowly. The infected tissue forms a
corky, cone-shaped core which can be removed intact from the sur-
rounding healthy tissue.
DISEASE DEVELOPMENT.-This rot occurs only rarely in Flor-
ida. Conditions favorable for its development have not been deter-
mined.







DISEASE.-Powdery Mildew
CAUSE.-Sphaerotheca macularis (Wallr. ex Fries) Jacz.
SYMPTOMS.-Infected green fruits become bronze or brownish,
and a network of very fine, shallow cracks develop in the surfaces of
these fruits (Fig. 26). These symptoms often are mistaken for spray
burn. As the fruits ripen, the cracks widen, and the fruits become
reddish brown or rusty colored and have a dry appearance.
DISEASE DEVELOPMENT.-Powdery mildew is normally a leaf
disease, but it sometimes also affects the fruit. Powdery mildew is
favored by cool, moist conditions and should be controlled as quickly
as possible after it is found on the foilage in order to prevent fruit
damage.

DISEASE.-Anther and Pistil Blight
CAUSE.-Rhizoctonia fragariae Husain and McKeen
SYMPTOMS.-This disease exhibits a wide range of severity. In
some flowers, some or all of the anthers are destroyed and appear
dark brown when the flowers open. With more severe infection, some
of the pistils are also attacked. When these flowers first open, the
anthers are dark brown, and a portion of the center (or pistilate area)
of the particular flower appears smooth and devoid of pistils. In still
other flowers, all anthers and pistils are destroyed before the buds
open. The entire centers of these flowers are black (Fig. 27) and
resemble freeze damage.
DISEASE DEVELOPMENT.-Infection occurs before or shortly
after flower buds emerge from the crown and ceases soon after the
buds open. Destruction of the anthers results in destruction of pollen;
however, flowers in which only anther destruction occurs can produce
normal fruit after fertilization by pollen from healthy flowers. Flow-
ers with pistil damage produce fruit with varying degrees of deform-
ity depending on the number of pistils that are destroyed. The pres-
ence of deformed fruit is not diagnostic of this disease because many
other factors also cause fruit deformity.
Buds in which pistil damage has occurred can usually be detected a
few days before they open. As these buds swell and the petals become
visible, tan lesions can be found on the petals, or much of the visible
petal area has a pink color. The causal fungus can be isolated readily
from unopened buds, but only rarely from infected flowers after they
have opened.

DISEASE.-Brown Cap
CAUSE.-Varies
SYMPTOMS.-When the green calyx (or cap) of a fruit is killed by
any agent, it becomes dry, shriveled, and unattractive (Fig. 28).







DISEASE DEVELOPMENT.-Brown cap is not a fruit rot, but it is
listed here because it affects the marketability of the fruit. All the
organisms which cause leaf spot and many of those which cause fruit
rots can cause brown cap. In addition to these, undetermined environ-
mental conditions can cause death of the caps and subsequent de-
velopment of brown cap.
CONTROL OF FRUIT DISEASES.-Every effort should be made
to prevent fruit diseases rather than to try to control them after they
occur. Applications of approved fungicides at 3- or 4-day intervals
beginning at the time flower buds are first seen and continuing
throughout the season will usually prevent most fruit diseases from
becoming serious. It is especially important to adhere as nearly as
possible to the spray schedule during rainy or foggy weather.
Colletotrichum and Dendrophoma fruit rots are primarily diseases
of ripe fruit, although they will affect green fruit in severe cases.
Thus, a schedule of short harvest intervals (3 or 4 days) to prevent a
build up of overripe fruit in the field is a valuable aid in controlling
these rots. These rots are extremely difficult to control if they reach
moderate or severe levels. At times in severe cases, it may be more
practical to pick off and discard all ripe and pink fruit and then apply
fungicides at 2-day intervals for 8 to 10 days rather than to try to
control these two diseases by fungicides alone.
Since powdery mildew is erratic in occurrence, regular applica-
tions of fungicides effective for its control are not needed. However,
fields must be inspected frequently for the disease during the fall and
winter to prevent it from becoming severe before it is noticed. Fungi-
cides that are specifically approved for control of powdery mildew
should be applied as soon as the disease is noticed.
Anther and Pistil blight is favored by wet conditions. Precautions
should be taken to insure that plants are not set too deeply. Plants
should be spaced widely enough on the beds to allow air circulation.
This will facilitate drying of foliage and buds after the plants have
grown. Fungicides applied on a 3- to 4-day schedule are especially
important.
Fungicides will control brown cap if it is caused by any of the fungal
pathogens. If it is caused by the bacterium that causes angular leaf
spot, or by weather conditions, there are no presently known means
of control.







VIRUS DISEASES
There are several known virus diseases of strawberry plants, but
most of them do not cause definite leaf symptoms in commercial
cultivars. Viruses generally cause reduced plant vigor, reduced run-
ner production, and reduced fruit yield, although in some cases in
which plants are infected by a single virus, there is little measurable
effect. Combinations of two or more viruses in the same plant cause
much greater effects. Strawberry mottle virus is one of the few
viruses that cause recognizable symptoms in commercial strawberry
cultivars. Since-strawberry mottle is the only virus disease that has
definitely been found in Florida, only the mottle disease will be
described in this bulletin.

DISEASE.-Mottle
CAUSE.-Strawberry Mottle Virus
SYMPTOMS.-Severely affected plants produce several to many
small crown-buds. Leaves produced by these buds are small and have
very short stems. Individual leaflets are slightly deformed and have
yellow margins (Fig. 29). Less severely affected plants produce a
single central bud. The first 2 to 5 leaves that are produced are nearly
normal in size and appearance. All subsequently produced leaves are
small, and the leaflets are slightly deformed and have yellow margins
(Fig. 30). The root systems of plants affected by mottle virus are much
smaller than are those of healthy plants.
DISEASE DEVELOPMENT.-Mottle disease is noticed only in
the fruit production field in Florida. To date it has not been found in
any plants that have been grown in Florida nurseries. It has been
found only in plants that have been grown in other states and which
were then transplanted into fruit production fields in Florida. The
disease is first noticed 2 to 4 weeks after the plants have become
established in the fruit production field and have begun to produce
new foliage. Severely affected plants (those that produce many
crown-buds) do not produce fruit at any time during the season. Less
severely affected plants produce only a few very small fruits. Mottle
virus apparently does not spread in fruit production fields in Florida.
Strawberry plants become infected by viruses when certain species
of aphids or leaf hoppers feed on them after feeding on strawberry or
other plant hosts that are infected. When a strawberry plant becomes
infected by a virus, all daughter plants produced by that particular
plant are also infected.
CONTROL.-The only means of controlling strawberry virus dis-
eases is the use of plants certified virus-free. Cultivars are freed of







viruses by meristem culturing. Leaflets of each meristem-cultured
plant are grafted to indicator plants which show symptoms of particu-
lar viruses that may be present. The meristem-cultured plants that
index free of all known viruses are used for further propagation.
During the first generations after meristeming, insecticides are ap-
plied frequently in the nursery to control the insect vectors of viruses.
Whenever possible, the first generations of virus-free stocks are
grown in screenhouses or in areas where the vectors do not occur.

NONINFECTIOUS DISEASES
Noninfectious diseases are those that are caused by agents other
than living organisms. The causes of many of these diseases have not
been determined. Although nutrient deficiencies are often considered
as noninfectious diseases, they will not be covered in this bulletin.

DISEASE.-Albino Fruit
CAUSE.-Unknown
SYMPTOMS.-Fruits that are mildly affected have a slightly
lighter than normal color on the shoulders near the caps (Fig. 31).
These fruits are slightly softer than normal and are more easily
damaged by handling during harvesting, shipping, and marketing.
Moderately affected fruits are a light orange color, soft, and have poor
flavor. Severely affected fruits are a very light orange color, are very
soft, and taste very sour, as if they were fermented. Usually when
albinism is moderate to severe, many of the fruits are catfaced (the
tip fails to develop and turns black, resulting in small, knotty fruits).
When a hand lens is used to inspect the light-colored area of a fruit
affected by albinism, tiny, glistening, transparent structures that
appear much like grains of sugar are seen under the epidermis.
DISEASE DEVELOPMENT.-The albino fruit problem can occur
at any time during the harvest season, but is most likely to occur
when the heavy spring flush of fruit begins to ripen in March. It is
usually more prevalent and more severe in fields that have a very
heavy fruit set. Albinism may occur throughout a particular field, or
only in certain areas of the field. Albinism often seems to be associ-
ated with the use of excessively high rates of fertilizer.
CONTROL.-There are no definite control measures for this dis-
ease. In several cases in which albinism had been a problem for
particular growers for several years, it was no longer a problem after
nitrogen and potassium rates were reduced to about 200 pounds of
each per acre. However, an association between albinism and exces-
sive fertility has not been proven experimentally.







DISEASE.-Weather Burn
CAUSE.-Climatic Conditions
SYMPTOMS.-Bronze or light tan areas occur on part or all of the
upper sides of ripe fruits (Fig. 32).
DISEASE DEVELOPMENT.-Weather burn generally occurs
when there is a sudden change to hot weather after a prolonged
period of relatively cool weather. These weather changes generally
occur in March or early April. Weather burn is often mistaken for
spray burn, but when it occurs, it is found in fields scattered through-
out the area regardless of what pesticides are being used in any
particular field. It is generally a problem for only a short time and
disappears from all fields in the area at the same time.
CONTROL.-There is no known control for this disease.

DISEASE.-Sunscald
CAUSE.-Climatic Conditions
SYMPTOMS.-Large, opaque, puffy blisters that appear to be
filled with fluid develop on the upper sides of fruits that are exposed to
the sun. These blisters look much like burn blisters on human skin.
The blisters subside within 1 or 2 days. The affected areas are then
slightly sunken and water-soaked, as if they had been scalded with
hot water (Fig. 33).
DISEASE DEVELOPMENT.-Sunscald occurs when the days be-
come hot in the spring. It is usually more severe and more widespread
after a sudden change from cool to hot weather. It is also more severe
if the soil becomes dry enough to cause wilting of the plants. When
rows are oriented east and west, sunscald is much more severe on
fruits that hang over the south side of the row.
CONTROL.-Sunscald can be prevented or, at least, greatly de-
creased by maintaining adequate moisture levels in the beds and by
using overhead irrigation during the hotter part of the afternoon. It
has been thought for years that overhead irrigation during the hotter
part of the day increases sunscald. However, observations at the
Agricultural Research Center at Dover, Florida indicate that this
decreases or prevents sunscald.

DISEASE.-Fasciation (Cockscomb)
CAUSE.-Unknown
SYMPTOMS.-In the most typical type of fasciation, large, flat
fruits shaped like fans or cockscombs are formed (Fig. 34). In a less
typical fasciation, fruits may have two or more points protruding
outward in different directions.
DISEASE DEVELOPMENT.-Fasciation is initiated as the flower







buds begin to form within the crown of the plant when two or more
flowers and stems become fused. When the flowers open, they appear
to be very large single flowers on single stems, but close inspection
reveals the fused stems. There is much variation in susceptibility to
fasciation among cultivars. Fasciation is severe in some cultivars
during some years but practically never present in other cultivars.
CONTROL.-The only known means of controlling this disease is
the use of cultivars that are not prone to fasciation.

DISEASE.-Tip Burn
CAUSE.-Unknown (sometimes excess fertilizer)
SYMPTOMS.-The tips of young unfolding leaves die and turn
brown to nearly black. As these leaves continue to expand, they are
irregularly shaped and puckered (Fig. 35). Fruit calyces (caps) are
sometimes affected (Fig. 36). This can vary from nearly unnoticable
browning of the extreme tips of the sepals to browning of entire
calyces. Sepals are the narrow, pointed green structures that make
up the calyx (fruit cap).
DISEASE DEVELOPMENT.-Tip burn is usually seen only dur-
ing the fall in Florida, although occasionally it occurs during the
winter or spring. It often occurs on the first one or two leaves that
emerge after transplanting. Leaf tip burn is most noticable when it
occurs on plants that have made considerable growth. The tip-burned
leaves in the centers of the plants then contrast sharply with healthy
older leaves. Although affected leaves are permanently disfigured,
the plants always recover. Usually only one or two leaves per plant
are affected.
Tip burn can be caused by a deficiency of boron or calcium. Since
other symptoms of boron deficiency, such as yellowing of leaf mar-
gins, mottling of leaves, and leaf distortion are not present when tip
burn occurs in Florida, boron deficiency probably is not the cause of
the disease here. Calcium deficiency would not seem to be the cause,
because calcium levels are quite high in most fields in Florida in
which strawberries have been grown for a few years. Boron or cal-
cium can become unavailable to plants under certain conditions. It is
also possible that under certain conditions the plants may be unable
to absorb one of these elements. In either case, if these conditions
existed for a sufficiently short time, then tip burn could occur on only
one or two leaves, and other deficiency symptoms would not occur or
would not be noticed.
Although the cause of tip burn usually is not definitely known, it is
sometimes caused by high fertilizer salt concentrations in the soil.
This usually occurs after the plants are well established when less







water is being applied through irrigation. The soil then begins to dry
slightly, and the soil solution (water plus fertilizer salts) becomes
more concentrated. If the solution becomes sufficiently concentrated,
it causes tissue damage after it is absorbed by the plants. This
damage often occurs first as tip burn of unfolding leaves and of sepals
if flower buds have emerged from the crown (Fig. 36). If the soil
continues drying, burn of leaf margins (typical fertilizer burn) usu-
ally occurs one to two weeks after the onset of tip burn. All cases of
calyx tip burn that we have seen have been associated with exces-
sively high fertilizer salt levels in the soil.
CONTROL.-No controls are known for tip burn that is caused by
factors other than excessive fertility. These plants recover without
treatment. Tip burn caused by excessive fertility is controlled by
applying sufficient irrigation to lower the concentration of fertilizer
salts around the roots of the plants.

DISEASE.-Catface
CAUSE.-Varies (often unknown)
SYMPTOMS.-Catface denotes fruits that are furrowed and
gnarled. Dark brown to nearly black areas where the seeds are
crowded closely together often occur on the tips (Fig. 37) and some-
times on the sides of catfaced fruits.
DISEASE DEVELOPMENT.-The normal development of a
strawberry fruit is dependent upon development of many viable seeds
which must be spaced uniformly around the fruit. To produce viable
seeds, pollination (transfer of pollen from the stamens to the stigmas)
and fertilization (the union of male and female sex cells in the ovule)
must take place. Any factors which contribute to incomplete pollina-
tion or fertilization may cause catfacing. Some of the known causes of
catfacing in Florida are lygus bug injury, anther and pistil blight,
albinism, and freeze injury.
Some factors which may contribute to incomplete pollination are
lack of viable pollen at certain seasons, insufficient distribution of
pollen by wind or insects, and undetermined environmental factors.
Catfacing often becomes most severe in Florida after prolonged
periods of cold weather, during which time large amounts of water
have been applied by sprinkler irrigation for freeze protection.
However, it generally does not occur in the fruits that mature from
the flowers or buds that are present during the periods of cold
weather. It usually occurs in the fruits that begin to mature 6 to 8
weeks after the cold period. Also, catfacing usually is severe only in
those fields which produce a very large crop of fruit in response to the
prolonged cold weather. Thus, catfacing which occurs after prolonged







periods of cold weather is usually caused by the effect of the low
temperatures on the plants as the flowers are being initiated or
during the early stages of flower development, rather than by in-
terference with pollination by the irrigation for freeze protection. The
nature of the effect of the prolonged periods of low temperature which
cause the catfacing in these cases is not known.
When plants are flowering profusely, and periods of several con-
secutive days of rainy weather occur, or the plants are irrigated for
freeze protection for long periods during several consecutive nights,
some catfacing may occur. However, severe catfacing seldom can be
correlated with either of these conditions.
CONTROL.-Catfacing caused by lygus bugs can be prevented by
inspecting for the insects during flowering periods and controlling
the insects if they are found. Catfacing caused by anther and pistil
blight probably can be controlled by applying fungicides at 3- to 4-day
intervals beginning about the time the first flower buds begin to
emerge from the crowns in a particular field. There are no known
measures for control of catfacing caused by factors other than lygus
bugs and anther and pistil blight.

DISEASE.-Proliferation
CAUSE.-Environmental
SYMPTOMS.-Proliferation is the development of leaves and
small plants on flowers or fruit (Fig. 38).
DISEASE DEVELOPMENT.-When proliferation occurs in a
flower before the fruit has begun to form, usually the entire center (or
pistillate) portion of the flower is obscured by the many tiny leaves
that develop. When proliferation occurs after the fruit begins to
develop, it may vary from one or a few tiny plantlets to almost
complete coverage of the fruit.
When the proliferated plantlets are scattered on a fruit, it appears
that the seeds have germinated. However, each plantlet is actually
attached to the fruit at the same point that the seed is attached. The
plantlets are formed by cells within the vascular strand that carries
nutrients to each seed.
In some areas, proliferation can be caused by the aster yellows
spiroplasm and by the green petal micoplasm-like organism. How-
ever, in Florida it appears to be caused by a change from low or
moderate temperature to high temperature at a critical time during
the initiation or development of the flower bud within the crown.
When plants of susceptible cultivars are grown in northern areas,
flower buds may be initiated in response to low temperatures or short
days during September and early October before the plants are dug.







When the plants are dug during the critical period of flower bud
initiation and planted into fruit production fields in Florida in early
October, proliferation is likely to occur in the first flush of fruit in
November and early December. In some cases, proliferation is severe
in northern-grown plants that are set within 3 or 4 days after arrival
in Florida, but much less severe in plants from the same shipment
that are kept under refrigeration for 8 to 10 days before setting.
There usually is little or no proliferation in the fall flush of fruits in
plants that are dug from northern nurseries after approximately
October 10 or in plants that are grown in nurseries in the southern
United States. However, proliferation may occur in later flushes of
fruit from these plants. In susceptible cultivars, proliferation can
occur at any time of year.
CONTROL.-Proliferation in the first flush of fruit in the fall can
be controlled by using plants grown in southern nurseries, and by
digging plants from northern nurseries after approximately October
10. Presently, the only known control for proliferation throughout
the year is the use of cultivars that are not prone to this malady. Some
cultivars are prone to proliferation, while others rarely or never show
proliferation.

DISEASE.-Yellow Leaf and White Streak
CAUSE.-Unknown
SYMPTOMS.-Entire leaves or leaflets are very light yellow or
white, or yellow or white areas occur on individual leaflets (Fig. 39).
These areas may occur in the form of streaks, or as areas of various
size and shape on individual leaflets.
DISEASE DEVELOPMENT.-This disease is first noticed as new
leaves emerge from the crowns after plants are set in the fruit
production field. In a specific year, it usually occurs only in plants
from a particular nursery, and only a very low percentage of the
plants from that nursery are affected. Occasionally most plants in a
particular fruit production field are affected to some degree when all
plants in the field come from the same nursery.
Usually only two or three of the first five or six leaves produced by
an individual plant after it is established in the fruit production field
exhibit yellow leaf or white streak or a combination of the two.
Generally all subsequently produced leaves are a normal green color.
These plants grow normally and appear to "recover" as the normal
foliage obscures the affected leaves, or as the affected areas dry and
disintegrate. However, some plants produce a few affected leaflets
any time a new flush of foliage is produced during the fruiting season.
In some cases, the first four or five leaves produced by a very low







percentage of the plants are entirely yellow or white. These plants
usually die, apparently because the extreme lack of chlorophyl in the
leaves causes them to be unable to synthesize sufficient food.
Although the exact causes of yellow leaf and white streak are not
known, they may be caused by the June yellows disease or by genetic
mutation in vegetative cells of an occasional stock plant. June yel-
lows is a disorder that occurs commonly in strawberry cultivars or
clones that have Blakemore, Howard 17 (Premier), or Auchincruive
Climax in their ancestry and is apparently of genetic origin. The
disease often does not occur in a cultivar until several years after it
has been developed. It then may appear in all stocks of the cultivar
over a period of a few years and may result in complete abandonment
of the cultivar.
If the disease is caused by mutations in vegetative cells and the
affected plants are used for propagation, then all runners produced by
these plants may be affected. If these runners are then used for
further propagation, the percentage of affected plants will increase
with each generation unless they can be rogued out of the nursery.
It is not known whether this disease, as it occurs in Florida, has any
effect on per acre yields of fruit. Yields from individual plants that
are affected severely enough to be killed or stunted obviously would
be greatly reduced. However, the percentage of affected plants in a
field is usually so low that there probably would be no effect on
overall yield.
CONTROL.-The only known control for this disease is to avoid
using plants that have exhibited symptoms for further plant prop-
agation. Frequent inspections of the nursery and destruction of any
plants that show symptoms would also aid in control. However, in
some cultivars and breeding lines, symptoms apparently do not de-
velop in summer nurseries in Florida.

NEMATODES
Plant parasitic nematodes are microscopic roundworms that live in
the soil and attack plants. Several nematodes known to parasitize
strawberries are found in Florida's sandy soils (Belonolaimus,
Meloidogyne, Aphelenchoides, Paratrichodorus, Tylenchorhynchus,
Xiphinema, Pratylenchus, Longidorus, Criconemoides). Because of
routine soil fumigation, nematodes are seldom a problem in Florida
strawberries except when infested plants are set or when nematodes
are carried into the nursery on equipment or in drainage water;
however, three important nematodes occasionally affect production
of nursery plants and reduce fruit yields.







COMMON NAME.-Sting nematode
SCIENTIFIC NAME.-Belonolaimus longicaudatus Rau
SYMPTOMS.-Root development is restricted by feeding of the
nematode on young roots. In cases of severe infestation, especially in
the nursery, many plants form a tight mat of roots 2 to 3 inches (5 to
7.5 cm) in diameter with no roots penetrating deeply into the soil
(Fig. 40). Since a restricted root system does not forage in a large
volume of soil, the foliar symptoms of nematode infestation of the
roots are wilting (due to water deficit in the plants rather than in the
soil), nutrient deficiencies of nitrogen, manganese and/or iron (due to
inefficiency of debilitated root tips, depletion of nutrients in the
severely restricted root zone, and isolation of the roots from any
banded fertilizer). Plants remain stunted, become dry and dull, and
eventually may die. Heavy infestations at transplanting in nursery
or fruiting field result in tight mats of roots composed essentially of
the roots which accompanied the transplant. New root initials gener-
ally are killed by heavy infestations of the nematode, a symptom
reminiscent of fertilizer salt burn.
Light infestations at transplanting or the developing populations
encountered late in the season following fumigation have a less
drastic effect on root volume. Since root development exceeds or at
least keeps pace with the damage caused at fewer feeding sites,
symptoms exhibited by both root and plant tops may be less apparent.
DISEASE DEVELOPMENT.-The sting nematode is a migratory,
external root parasite. It does not enter roots, but feeds from the
outside by means of a stylet through which it sucks the juices from
the tissues of the very small roots and root tips. Withdrawing juices
or injecting toxins into the tissue causes death of roots or at least
inactivation of the growing tips. Affected plants soon have no feeder
roots, only brushes of "rat-tail", coarse roots.

COMMON NAME.-Root-Knot
SCIENTIFIC NAME.-Meloidogyne hapla Chitwood
This nematode generally appears on nursery plants from more
northern states; however, either this or a new strain of the Northern
root-knot nematode has adapted to the environmental conditions of
central Florida.
SYMPTOMS.-Root-knot nematodes, as the name implies, cause
swollen areas (galls) on the roots of infected plants. The galls range
from /Vi to 1/s inch (1.6 to 3.2 mm) in diameter (Fig. 41); they may
occur as spherical swellings or as elongate, convoluted tumors which
result from multiple infections. Characteristic of the Northern root-
knot nematode are the secondary roots which emanate from the gall







itself. When plants become severely infested, they become unthrifty
and may eventually die.
DISEASE DEVELOPMENT.-When juvenile root-knot nema-
todes enter strawberry plant roots and remain sedentary to maturity,
they cause characteristic root galls or knots involving the entire root
volume in the area of invasion. This reaction of the plant to nematode
invasion differs markedly from the reaction to infection of legumi-
nous roots by nitrifying bacteria wherein nodules or knots formed on
roots are easily removed from the surface without destroying the
integrity of the root. Subsequent generations of the nematode, pro-
duced each 25 to 40 days depending on soil temperature and mois-
ture, may result in elongate, spindle-shaped galls containing several
life stages.
The amount of yield loss is dependent not only on the severity of
nematode attack, but also on the range of additional stress the plant
encounters from other factors such as root-infecting fungi, and in-
appropriate levels of nutrients, water, and temperature.

COMMON NAME.-Bud or summer crimp nematode
SCIENTIFIC NAME.-Aphelenchoides besseyi (Ritzema Bos)
Christie
SYMPTOMS.-Leaves are crinkled and dark green, often with
reddish coloration in the veins and around the edges of the leaflets.
Some leaflets may be narrow and elongate with much distorted
mid-ribs.
DISEASE DEVELOPMENT.-This nematode lives as an ecto-
parasite in the air spaces in the leaf buds. It feeds by puncturing the
young tissues with its stylet and extracting the plant juices. The
salivary secretions which it injects into the young growing parts
cause them to develop abnormally.
CONTROL OF NEMATODES.-A11 soil in which strawberries are
to be planted should be treated with an approved nematicide or soil
fumigant. Cultivation of the area should begin 6 to 8 weeks before
treatment to ensure that all plant debris is well decayed before the
nematicide or fumigant is applied. The soil should be damp, but not
excessively wet, for at least two weeks prior to treatment and at the
time of treatment. Since strawberries are in the field 6 to 7 months,
label instructions must be carefully followed to obtain maximum crop
protection during the long growing season.
In the fruit production field, only the row area needs to be treated.
In the nursery, the entire area must be treated, and every possible
effort should be made to avoid contamination from nontreated soil or
drainage water. Although roots in fruiting fields may be protected








from gross contamination by the full-bed plastic mulch, nurseries are
particularly vulnerable to contamination. Ditching or construction of
plastic covered beds along the high side of the nursery may reduce
flooding problems.
Only nematode-free plants should be used. This is especially im-
portant in the nursery. If plants with even light infestations of
nematodes are set in the nursery, the nematodes will reproduce
rapidly, and many or all the daughter plants will become infected.

MITES AND INSECTS
Mites and insects are animals that comprise portions of the larger
group, arthropods. Numerous arthropods are normally associated
with strawberry crops. Some are economically damaging to strawber-
ries and will be discussed individually in this bulletin. Other arthro-
pods, such as Collembola, saprophytic mites, and certain beetles, may
serve to decompose dead plant material, aerate the soil, or provide
food sources to predators when a pest arthropod food source is not
available, but otherwise may have little economic relationship to the
crop.
A non-pest group of arthropods normally associated with strawber-
ry crops is the group of beneficial parasites and predators. This group
in Florida strawberries includes an important predatory mite (Phy-
toseiulus macropilis (Banks)), an earwig (Labidura riparia (Pallas)),
wolf spiders (including Pardosa milvins (Hentz)), jumping spiders,
big-eyed bugs (Geocoris spp.), ants, carabid beetles, syrphid flies, and
numerous parasitic wasps. These arthropods, living in strawberry
fields, survive principally or entirely on other arthropods, including
those that would damage the crop. Efforts to conserve this beneficial
group through integrated pest management (IPM) practices, includ-
ing wise use of pesticides, are important to successful strawberry
production.
This section of the bulletin discusses the important arthropod pests
that may be found in Florida strawberries produced through cur-
rently accepted systems. Components of those systems which have
major influence on pest arthropods status are fumigation of beds in
the fruiting field and broadcast fumigation in the nursery, use of
plastic mulch to cover beds in the fruiting field, use of fruiting plants
for one season only, and timing of fruit production for winter and
early spring harvests. Changes in strawberry production systems
may bring about changes in the pest status of arthropods.
The arthropods discussed are presented in four groups: mites, in-
sects that may produce their damage primarily by feeding on leaves,







insects that feed on fruit and flowers, and insects that feed on straw-
berry roots or crowns. For each arthropod presented, a description of
its appearance, the development of the problem, and control methods
will be discussed.


MITES
COMMON NAME.-Twospotted spider mite
SCIENTIFIC NAME.-Tetranychus urticae Koch
DESCRIPTION.-The twospotted spider mite (Fig. 42) is about the
size of a pencil point. Walking forms have three or four pairs of legs
(the number depends on the mite's developmental stage). This mite is
usually greenish yellow, although many members of a population
may be purplish red during or following cold weather. A prominent
dark area is usually present on each lateral side of the abdomen.
DEVELOPMENT OF THE PROBLEM.-Spider mite populations
do not usually become sufficiently dense to cause damage in winter
and summer nurseries in Florida. Plants grown in nurseries outside
Florida are more likely to be infested with spider mites when planted
in fruiting beds than are locally grown plants. When infested plants
are set in fruiting beds, spider mite damage can appear as early as
November. Mites do not fly, but adults produce strands of silk that
can be blown by the wind to carry the mites in a process called
"ballooning." Mites can infest a strawberry field after plants are set
by ballooning from another host such as weeds on ditch banks or farm
perimeters.
Mites generally remain below damaging levels in the fruiting field
until warm spring weather arrives. At that time, less than five days
is required for mites to complete their life cycles. Short life cycles in
warm weather and the ability of females to produce many eggs
require that the fields be inspected twice weekly during this time.
A hand lens should be used to locate the mites on the undersides of
the older leaves. Unthrifty leaves (mottled, chlorotic, russety or par-
tially red) (Fig. 43) or russety berries may indicate that spider mites
are present. Dense populations of spider mites on leaves can reduce
the ability of the plant to grow and to produce fruit. Under extreme
conditions, spider mites can feed on blooms and the developing fruit,
reducing fruit size and quality.
The twospotted spider mite is the most frequently encountered
arthropod pest of strawberries in Florida. Most growers must take
measures to control this pest each year in fruit production fields.
CONTROL.-
1. Set mite-free strawberry plants.







2. Maintain the strawberry field and its environs free of weeds
that could be hosts.
3. Conserve naturally occurring predatory mites by eliminating
unneeded insecticide or miticide applications.
4. Scout fields and apply recommended miticides only after mites
are found.
5. Ensure that miticides used reach the undersides of the lower
leaves where mites live.

COMMON NAME.-Cyclamen mite
SCIENTIFIC NAME.-Stenotarsonemus pallidus (Banks)
DESCRIPTION.-Eggs, larvae, and adult females are the forms
most frequently observed. All forms are so small that they are only
faintly visible without optical magnification. Eggs are about half as
large as adult females; they are oval and opaque white. Several eggs
may be found together. Mobile larvae and non-mobile nymphs are
opaque white, while adult females are light brown, about /loo inch
(0.25 mm) long, and about half as wide.
DEVELOPMENT OF THE PROBLEM.-Damage to strawberries
in Florida develops from setting of infested plants. In infested nurs-
eries, mother plants are usually more infested than are daughter
plants and should not be set in a fruiting field. The cyclamen mite
moves along runners to colonize new plants and feeds on strawberry
crowns, flowers, and fruit in addition to leaves. Bees, other insects,
birds, field workers, or machinery can move cyclamen mites among
fields.
Leaves of colonized plants are small, chlorotic, and wrinkled, with
short petioles (Fig. 44). Runners may have tiny thorns (Fig. 45)
rather than a smooth texture. Infested plants may also have dry,
brown flowers, russety fruits and poorly developed root systems.
Cyclamen mites had not been an economic problem in Florida's
strawberries until the 1982-83 season. In a few fields, this mite was
the most damaging arthropod pest in the Plant City area during that
season.
CONTROL.-
1. Use inspected plants free of cyclamen mites.
2. Use only first-year daughter plants.
3. Inspect fields regularly for outbreaks.
4. Restrict movement of possibly contaminated personnel and
machinery out of infested sites and into noninfested sites.
5. Provide the greatest separation in time and distance that is
practical between infested fruiting fields and summer nurseries. This
may require an agreement from managers of infested farms to de-
stroy their completed crop as early as possible.







6. Since the cyclamen mite has few weed hosts on which to survive
the noncropped summer, eliminate cultivated and noncultivated
strawberry plants from the area of an infested farm to prevent rein-
festation in the following year.
7. Inspect summer nurseries carefully after a season in which the
cyclamen mite was present on strawberries in the community.
8. Apply recommended miticides in large volumes of water per
acre to ensure penetration into the bud.


INSECTS PRIMARILY AFFECTING FOLIAGE
COMMON NAME.-Fall armyworm
SCIENTIFIC NAME.-Spodoptera fruqiperda (J. E. Smith)
DESCRIPTION.-The fall armyworm is one of the several noctuid
insects that may be present on strawberries. The adult stage is a
moth which is usually less than 3/4 inch (19 mm) long and frequently
brown or gray. Larvae are up to 11/ inches (38 mm) long. They are
soft-bodied, brown caterpillars with faint longitudinal stripes. An
important distinguishing feature is the presence of a prominent,
light colored, inverted "Y" on the head.
DEVELOPMENT OF THE PROBLEM.-Since fall armyworm
adults fly at night, they may not be noticed. Adults fly into straw-
berry fields or develop from pupae already inside the field from
previous immigrations. The adult female deposits its eggs in masses
containing many eggs covered with "hairs" from the female.
Fall armyworms occur in summer nurseries and in fruit production
fields. The larvae feed on strawberry leaves, especially the develop-
ing leaves in the center of the plant. Cultivated grassy crops such as
sorghum are important hosts of the fall armyworm; thus this species
may be more prevalent following or in close proximity to grassy
crops.
CONTROL.-
1. Do not plant strawberries following or near crops that have been f
or currently are infested heavily with the fall armyworm.
2. Scout the strawberries weekly, particularly during September
through early December.
3. Apply recommended pesticides as required to ensure coverage
in the area of developing leaves.

COMMON NAME.-Southern armyworm
SCIENTIFIC NAME.-Spodoptera eridania (Cramer)
DESCRIPTION.-The southern armyworm is one of the noctuids







described in general under "fall armyworm." Larval southern army-
worms are marked with purple triangles on their backs (Fig. 46);
each lateral side has a faint yellow, longitudinal stripe broken above
the middle pair of true legs (near the head) by a dark, almost round
spot.
DEVELOPMENT OF THE PROBLEM.-Southern armyworm in-
festations occur in the manner of the general noctuids. Eggs are laid
in masses in summer nurseries and fruiting fields but are without the
dense covering of hair typical of the fall armyworm. As do the fall
armyworms, these larvae feed on leaves and prefer those developing
in the bud. Although the southern armyworm is a pest of many crops
in the strawberry growing regions of Florida, it rarely reaches eco-
nomic levels in strawberries.
CONTROL.-
1. Scout strawberries weekly, particularly during September
through early December.
2. Apply recommended pesticides as required to ensure coverage
in the area of developing leaves. Pesticides applied to control the
more prevalent fall armyworm should also control the southern
armyworm.

COMMON NAME.-Cabbage looper
SCIENTIFIC NAME.-Trichoplusia ni (Hubner)
DESCRIPTION.-The larval cabbage looper is a green caterpillar
with white longitudinal stripes. This caterpillar is easily distin-
guished from other caterpillars found on strawberries by the pre-
sence of only three pairs of false legs on the rear half of the abdomen
rather than four or more pairs. This noctuid is usually smaller in
cross section than are caterpillars of similar length that may be found
on strawberries.
DEVELOPMENT OF THE PROBLEM.-Adult cabbage looper
moths lay eggs singly on strawberry plants. Larvae developing on the
strawberries may be found on outer leaves as frequently as on the
central leaves. Cabbage loopers are not routinely found in strawber-
ries grown in Florida, although they may occur from time to time.
CONTROL.-Cabbage loopers are usually controlled by insecti-
cides applied to control several other insects. Special applications for
cabbage looper control are rarely required.

COMMON NAME.-Granulate cutworm
SCIENTIFIC NAME.-Feltia subterranea (Fabricius)
DESCRIPTION.-Granulate cutworms are much like the other
foliage feeding noctuids discussed. These caterpillars are brown with







faint chevron markings (Fig. 47). Granulate cutworms curl into a
C-shape when at rest or when disturbed.
DEVELOPMENT OF THE PROBLEM.-Adult cutworms are
small moths. The female lays eggs singly on strawberry leaves. When
larvae are found, they are usually at rest on the plastic mulch under
the strawberry leaves.
This species is usually found each season in winter and summer
nurseries and in fruit production fields; however, granulate cut-
worms rarely cause economic damage. They occasionally cause sig-
nificant damage in nurseries by eating from the central buds of
plants, causing the plants to produce few runners. When these plants
are transplanted, numerous side crowns develop and form plants
with large masses of leaves that are smaller than normal. In fruit
production fields, these plants produce small, late fruit and an overall
low yield.
CONTROL.-Usually insecticides applied to control other insects
will also kill granulate cutworms. For that reason, and since densi-
ties are rarely high and each larva causes little damage, treatments
applied specifically for the granulate cutworm are rarely necessary.

COMMON NAME.-Tiger moth larvae, including woolly-
bear and saltmarsh caterpillars
SCIENTIFIC NAME.-Arctiidae
DESCRIPTION.-Tiger moth larvae are heavily clothed in long
"hairs" (Fig. 48) and may appear larger than the noctuid caterpillars
found in strawberries. They can be found in nurseries and fruit
production fields.
DEVELOPMENT OF THE PROBLEM.-Tiger moth caterpillars
are frequently abundant in weeds growing near strawberry fields.
Consequently, these larvae may be most numerous on border rows
and near ditch banks. Adult tiger moths lay their eggs in masses of up
to 100 eggs. When an egg mass has been laid on a strawberry plant,
that and adjacent plants may be fully defoliated.
CONTROL.-Applied controls are rarely required for this infre- f
quent pest.
1. Control weeds along ditch banks and field margins.
2. Scout field portions near ditch banks and perimeters, then spot-
treat infested areas with recommended insecticides.

COMMON NAME.-Strawberry root aphid
SCIENTIFIC NAME.-Aphis forbesi Weed
DESCRIPTION.-Aphids in general are usually about 1/16 inch
(1.6 mm) long and slightly less in width. They have two pipe-like
projections extending from their posterior ends. Most are wingless,







but winged forms occur. The strawberry root aphid is bluish green.
DEVELOPMENT OF THE PROBLEM.-In the late fall, winged
adult aphids fly into strawberry fruiting fields where they come to
rest on strawberry leaves. Winged adults produce female young that
usually produce young without mating. The aphid life cycle is com-
pleted within a few days in warm weather; thus numbers of aphids
can increase quickly. Under the cultural conditions of strawberries in
Florida, the strawberry root aphid develops on leaves. It ingests plant
juices, and can devitalize the plant when present in large numbers.
This aphid is found in low numbers every year on strawberries grown
without pesticides in the Plant City area; it is rarely an important
pest.
CONTROL.-Scout fields weekly and apply recommended insecti-
cides when populations warrant. Insecticides applied to control other
insects usually control the strawberry root aphid.

INSECTS PRIMARILY AFFECTING
FRUITS AND FLOWERS
COMMON NAME.-Field cricket
SCIENTIFIC NAME.-Gryllus firmus (Walker) and G. rubens
(Scudder)
DESCRIPTION.-Field crickets are the frequently encountered,
dark brown insects with long legs and long antennae, much like the
crickets sold for fish bait (Fig. 49). Males of this species may be noted
in warm weather by their songs, a series of short chirps, from under
the plastic mulch. Adult field crickets are winged. The young are
wingless but otherwise similar to adults.
DEVELOPMENT OF THE PROBLEM.-Soon after strawberry
beds are covered with plastic mulch, field crickets crawl through
planting holes in the plastic and hide in the protected environment
on top of the soil bed. Adult females lay eggs there, and nymphs
develop in the early spring. Adults and nymphs feed similarly. They
occasionally may chew around strawberry crowns, but they inflict
their most serious damage upon the fruit (Fig. 50). Field crickets
scrape seeds and some outer fruit tissue from hard fruit, rendering
the strawberries unsaleable.
This insect group has caused economic damage on some farms in
the Plant City area in recent years. The damage has been attributed
mistakenly to seed-cracking birds. The most serious damage occurs
two to five months after beds are covered with mulch.
CONTROL.-
1. Apply residual insecticides to the plant bed before plastic mulch
is installed.







2. Scout fields when strawberries are present. Piles of cracked
seeds and small fecal pellets under damaged, hard strawberries indi-
cate the presence of this insect.
3. Apply recommended insecticides to plants upon which crickets
may later feed. Approved cricket baits in row middles should reduce
cricket numbers considerably.
4. Apply insecticides to ditch banks and field margins that may
harbor crickets.

COMMON NAME.-Flower thrips
SCIENTIFIC NAME.-Frankliniella cephalica (Crawford)
DESCRIPTION.-Flower thrips in strawberries are usually yel-
low. They are 1/2o inch (1.3 mm) long and much more narrow than
long. Adult thrips have wings while nymphal thrips do not.
DEVELOPMENT OF THE PROBLEM.-Thrips invade straw-
berry fields from blooming citrus, clover, and wild flowers. Although
thrips are not strong fliers, winds aid their movement into flowering
strawberry fields. Thrips rasp the portions of the strawberry flower
that develop into fruit, causing it to develop poorly. Damaged green
fruits may become bronze or grayish (Fig. 51), and very fine shallow
cracks may develop in their surfaces. As these fruits ripen, they
remain dull in appearance. Thrips damage can easily be mistaken for
damage caused by powdery mildew or by spray burn. This insect
occurs on every farm in every year and may require control mea-
sures.
CONTROL.-
1. Scout fields at least once a week when strawberries are in
bloom. This is particularly important in the late winter and early
spring when thrips activity is at its peak. Thrips may be detected by
thumping opened flowers onto the observer's hand or by blowing
lightly into the flowers. A magnifying lens may be required to see the
insect.
2. Apply recommended pesticides when populations warrant.

COMMON NAME.-Plant bugs, including the tarnished
plant bug.
SCIENTIFIC NAME.-Taylorilyqus pallidulus (Blanchard) and
Lyqus liniolaris (Palisot de Beauvois)
DESCRIPTION.-Plant bugs are usually brown, grayish brown, or
green (Fig. 52). They are about /4 inch (6.4 mm) long and about half
as wide. Since they are true bugs, they have sucking mouth parts,
and their forewings are hard at the basal half and membranous at the
distal half. Immature plant bugs (nymphs) look like adults but do not
have wings.







DEVELOPMENT OF THE PROBLEM.-Plant bug adults can
enter a strawberry field and cause economic damage at any time that
strawberry flowers or very small fruit are present. Adults may repro-
duce within the field, resulting in the presence of nymphs. Both
nymphs and adults feed by inserting their sucking mouthparts into
flowers or small fruit, causing the fruit to develop with a catface.
CONTROL.-
1. Scout fields weekly during the blooming period.
2. Apply recommended insecticides when populations warrant.

COMMON NAME.-Sap beetle
SCIENTIFIC NAME.-Nitidulidae
DESCRIPTION.-Sap beetle adults found on strawberries are
usually 1/s inch (3.2 mm) to 1/4 inch (6.4 mm) long and brown or tan.
Their larvae are about the same size as the adults, but are soft and
white and may have lateral projections on abdominal segments.
These are the same beetles found in citrus fruits that have fallen from
trees and rotted.
DEVELOPMENT OF THE PROBLEM.-Sap beetle adults are
attracted to damaged or overripe strawberries fermenting in the
field. Adults feed on and lay their eggs in the deteriorated fruit. The
eggs hatch, and larvae develop also to feed there and in nearby
overripe or damaged fruit. Sap beetles do not normally damage a
sound strawberry. Sap beetles can be present at any time that over-
ripe fruits are present; however, the beetles become most numerous
in warm weather and when large numbers of fruits have been aban-
doned in fields.
Sap beetles are not usually economically important in fresh mar-
ket strawberries. However, when overripe fruits are harvested for
processing, sap beetles may infest the fruit and render the crop
unmarketable.
CONTROL.-
1. Maintain sound fruit through good disease and insect control
practices and through preventing damage from birds.
2. Pick fruits before they become overripe.
3. Remove all damaged or overripe fruit from the field, particu-
larly in warm weather.
4. Do not cease picking from portions of a field while continuing to
harvest from other portions.
5. Scout fields for the presence of sap beetles or for conditions
favorable for sap beetles development.
6. Be informed when neighboring strawberry fields are aban-
doned.
7. Apply recommended insecticides when conditions warrant.







COMMON NAME.-Tomato fruitworm or corn earworm
SCIENTIFIC NAME.-Heliothis zea (Boddie)
DESCRIPTION.-The tomato fruitworm is a noctuid similar to the
generalized noctuid described under the section "Fall armyworm."
The color of the larval form varies greatly, but yellow or pale green
often dominates; sometimes tomato fruitworms that have fed on ripe
strawberries have pink among their colors. Small spines with flat,
circular bases over most of the body distinguish these larvae from
other noctuids in strawberries.
DEVELOPMENT OF THE PROBLEM.-Adult tomato fruitworm
moths can fly into strawberry fields in almost any month. Female
moths lay eggs singly on leaves, where the eggs develop into caterpil-
lers that feed on leaves and fruit.
CONTROL.-
1. Scout fields weekly, especially during the fruiting season.
2. Apply recommended insecticides as populations warrant.

COMMON NAME.-Pamera
SCIENTIFIC NAME.-Pachybrachius vinctus (Say) and P. bi-
lobatus (Say)
DESCRIPTION.-Pamera adults and nymphs are tan or brown
bugs (Fig. 53) about 1/s to 1/4 inch (3.2 to 6.4 mm) long with narrow
bodies and long antennae. The upper portions of the first pairs of legs
are enlarged. The basal half of the forward pair of wings is hard, and
the distal half is membranous. The bugs feed with piercing and
sucking mouth parts.
DEVELOPMENT OF THE PROBLEM.-Pameras are very com-
mon on many of the weeds found associated with strawberry fields
and their environs and are therefore most numerous in rows border-
ing the weeds. These insects are particularly noticeable beginning in
the late winter when young fruit is present. In fields not treated with
insecticides, pameras accumulate in large numbers on the plastic
mulch around individual plants. Although pameras are capable of
flight, they rarely fly, but quickly crawl under a plant when dis-
turbed.
The insect's mouthparts are inserted into leaf petioles and fruit,
sometimes causing the young fruit to fail to develop fully. Little is
known about the numbers of pameras that are required to cause
economic losses, but significant losses appear unlikely when only a
few bugs per plant are present.
CONTROL.-
1. Practice weed control in row middles and along field margins.
2. If insecticides applied to control other arthropods do not main-







tain populations below moderate levels, apply approved insecticides
specifically to control pameras.

INSECTS PRIMARILY AFFECTING
ROOTS AND CROWNS
COMMON NAME.-Lesser cornstalk borer (mistakenly
called bud worm)
SCIENTIFIC NAME.-Elasmopalpus liqnosellus (Zeller)
DESCRIPTION.-The damaging larval stage of this insect is
about 1/2 inch (12.7 mm) long. It is bluish green with purple or brown
bands encircling the body (Fig. 54). The adult is a tiny moth.
DEVELOPMENT OF THE PROBLEM.-The lesser cornstalk
borer can cause extensive damage in summer nurseries and in fruit
production fields. Adult borers deposit single green or white eggs on
strawberry leaves. Larvae developing from these eggs bore into the
crown of the strawberry plant at the soil line. A silk tube (Fig. 55) is
often formed between this hole and the soil. During an active infesta-
tion, frass may be pushed to the outside of the plant. Larvae usually
leave the plant within three weeks and pupate at the soil line inside a
silk cocoon.
Lesser cornstalk borers attack mother and daughter plants in the
summer nursery. Mother plants and large, rooted daughter plants
are girdled just below the bud, resulting in wilting (Fig. 56) and death
of affected plants. A longitudinal cut through the crown of such a
plant reveals a small tunnel extending around the crown just below
the bud (Fig. 57). Young, unrooted daughter plants are also attacked.
The borer generally enters these plants from underneath and hollows
out the crown area, resulting in wilting and death.
In fruit production fields, usually the first signs of damage by the
lesser cornstalk borer are very small, round holes in the youngest
leaves. (Small armyworms may cause similar damage.) These holes
are made by the very small larvae tunneling through the bud. As the
larva enlarges, it moves into the crown and girdles the plant below
the bud, resulting in wilting and death of the plant. Wilting caused
by the lesser cornstalk borer may be mistaken for anthracnose dis-
ease.
The attack by the lesser cornstalk borer in corn, sorghum, peanut,
and some other crops is usually more severe in areas of fields that are
dry and sandy. However, it is not known just what conditions favor
this pest in strawberries. Strawberries grown in fields previously
planted in corn, sorghum, peanut, pea, cowpea, or bean may be
attacked by the lesser cornstalk borers that survived in crop residues.







CONTROL.-
1. Do not plant strawberries in or near fields recently planted in
hosts of the lesser cornstalk borer-corn, sorghum, peanut, pea, cow-
pea, or bean. This is especially important if those crops were known to
have had an infestation of the lesser cornstalk borer.
2. Scout for damaged plants (wilted or brown leaves in the center;
holes, frass, or tunnels at the base).
3. Apply recommended pesticides when signs of an infestation are
found.

COMMON NAME.-Mole cricket
SCIENTIFIC NAME.-Scapteriscus acletus Rehn and Hebard and
S. vicinus Scudder
DESCRIPTION.-These unusual crickets are tan and are as large
as 11/2 inches (38.1 mm) long. They have front legs that are short and
broad for digging (Fig. 58). Their raised tunnels, found in moist soil,
are more easily seen than are the insects. On warm nights, male mole
crickets can be detected by their songs, which are much like those of
field crickets except that the song of the mole cricket continues for
long periods without a pause.
DEVELOPMENT OF THE PROBLEM.-Female mole crickets lay
eggs in the soil during the warm days of spring. The eggs produce
small, wingless nymphs that are otherwise similar in appearance
and behavior to the adult. Before early July, most nymphs develop to
adults that later enter the soil bed of the fruiting field through
planting holes in the plastic mulch. There they feed on roots and
crowns of strawberry plants. Since strawberries are planted with a
developing root system, the plants quickly extend their roots and
usually withstand the below-ground damage from this insect.
Crowns are more vulnerable and are susceptible to damage by the
mole cricket.
CONTROL.-
1. Do not locate strawberries near bahia pastures or other crops
that are suitable hosts for the mole cricket.
2. Apply a residual insecticide to the soil bed before installing the
plastic mulch.
3. Scout for mole crickets and their tunnels.
4. Apply recommended insecticides to plants when conditions war-
rant. Since many mole crickets remain under the plastic mulch, this
measure has limitations.
5. Apply recommended insecticidal baits to row middles.
6. Apply recommended insecticides to ditch banks and field mar-
gins to reduce further invasion of mole crickets.







COMMON NAME.-Wireworm or click beetle
SCIENTIFIC NAME.-Elateridae
DESCRIPTION.-Adults are beetles, usually about /2 inch (12.7
mm) long, with sides that are conspicuously parallel and distinctly
rounded at both ends. They are brown, gray, or black. When placed on
their backs, adults will flip themselves over with an accompanying
"click"; thus the name "click beetle." Larval wireworms are white,
light brown or yellow, as much as 3/4 inch (19 mm) long, distinctly
round in cross section, and generally look like small sections of wires
(Fig. 59).
DEVELOPMENT OF THE PROBLEM.-Wireworm adults may
feed on above-ground strawberry plant parts, but their damage is
rarely important in strawberries. A single generation of their larvae
may occur in the soil of strawberry beds during one crop cycle. Since
beds are normally fumigated and covered with plastic mulch in
Florida's commercial strawberry production, larvae usually do not
develop in sufficient numbers or size to threaten strawberry plants.
Larvae may feed on strawberry roots and crowns occasionally.
CONTROL.-Apply residual insecticides to the soil before install-
ing plastic mulch.

MISCELLANEOUS INSECTS
Other arthropod species may damage strawberry plants or fruit on
occasions. Although details of these arthropods will not be discussed,
it is wise to be aware of their status as potential pests. Among this
group are flea beetles, leaf hoppers, leaf rollers, leaf tiers (Fig. 60),
grasshoppers, stink bugs, ants, May beetle larvae, rice beetles, and
fruit flies.
One other potential insect pest has the unusual status of being
normally a beneficial predator. A species of carabid beetle, Harpalus
sp., sometimes may eat seeds from strawberries, as does the field
cricket, although this beetle more frequently feeds on other insects.
Snails and slugs, known as gastropods rather than arthropods,
sometimes may damage strawberries. Damage from this group is
unusual in Florida's commercial strawberry production. However,
pesticides are available for control of snails and slugs if needed.

TIME OF APPLICATION OF PESTICIDES
Since it is important to prevent build-up of diseases rather than to
try to control them after they occur, fungicides should be applied on a
regular schedule throughout the season. Insecticides and miticides







COMMON NAME.-Wireworm or click beetle
SCIENTIFIC NAME.-Elateridae
DESCRIPTION.-Adults are beetles, usually about /2 inch (12.7
mm) long, with sides that are conspicuously parallel and distinctly
rounded at both ends. They are brown, gray, or black. When placed on
their backs, adults will flip themselves over with an accompanying
"click"; thus the name "click beetle." Larval wireworms are white,
light brown or yellow, as much as 3/4 inch (19 mm) long, distinctly
round in cross section, and generally look like small sections of wires
(Fig. 59).
DEVELOPMENT OF THE PROBLEM.-Wireworm adults may
feed on above-ground strawberry plant parts, but their damage is
rarely important in strawberries. A single generation of their larvae
may occur in the soil of strawberry beds during one crop cycle. Since
beds are normally fumigated and covered with plastic mulch in
Florida's commercial strawberry production, larvae usually do not
develop in sufficient numbers or size to threaten strawberry plants.
Larvae may feed on strawberry roots and crowns occasionally.
CONTROL.-Apply residual insecticides to the soil before install-
ing plastic mulch.

MISCELLANEOUS INSECTS
Other arthropod species may damage strawberry plants or fruit on
occasions. Although details of these arthropods will not be discussed,
it is wise to be aware of their status as potential pests. Among this
group are flea beetles, leaf hoppers, leaf rollers, leaf tiers (Fig. 60),
grasshoppers, stink bugs, ants, May beetle larvae, rice beetles, and
fruit flies.
One other potential insect pest has the unusual status of being
normally a beneficial predator. A species of carabid beetle, Harpalus
sp., sometimes may eat seeds from strawberries, as does the field
cricket, although this beetle more frequently feeds on other insects.
Snails and slugs, known as gastropods rather than arthropods,
sometimes may damage strawberries. Damage from this group is
unusual in Florida's commercial strawberry production. However,
pesticides are available for control of snails and slugs if needed.

TIME OF APPLICATION OF PESTICIDES
Since it is important to prevent build-up of diseases rather than to
try to control them after they occur, fungicides should be applied on a
regular schedule throughout the season. Insecticides and miticides







may be omitted until signs of a particular pest are noticed. However,
fields should be inspected closely and frequently in order to detect
insects or mites in the early stages of infestations, and appropriate
pesticides should be applied as soon as conditions warrant. Mites are
much easier to control while populations are sparse rather than
dense.

PRECAUTIONS TO BE FOLLOWED
WITH PESTICIDES
Keep all pesticides in a locked building or cabinet at all times; read
the entire label on any pesticide before using the product. Handle all
pesticides with care and heed directions and precautions on the label.
Wear protective masks, gloves, and clothing as recommended for the
specific pesticide whenever any pesticide is being handled or applied.
Never eat, chew tobacco, or smoke while handling or applying pesti-
cides; always wash hands and arms with soap immediately after
handling any pesticide. Take precautions to ensure that no one enters
a treated area before the safe reentry time has elapsed.
In case of accidental contact with any of these products, remove
contaminated clothing and wash the pesticide off the body as quickly
and thoroughly as possible.
Do not wear contaminated clothing again until it has been washed
thoroughly. In cases off suspected pesticide poisoning, see a doctor
immediately, tell him what pesticide is suspected and show him the
label from the pesticide container if possible.








LIST OF FIGURES


Figure 1.-Anthracnose on stolons.
Figure 2.-Anthracnose on petiole.
Figure 3.-Rhizoctonia rot on
petioles.
Figure 4.-Bud rot caused by
S. rolfsii (arrow-sclerotia).
Figure 5.-Verticillium wilt.
Figure 6.-Common leaf spot.
Figure 7.-Leaf blight.
Figure 8.-Leaf scorch.
Figure 9.-Leaf blotch.
Figure 10.-Powdery mildew.
Figure 11.-Leaf roll caused by
powdery mildew.
Figure 12.-Bacterial leaf spot.
Figure 13.-Black leaf spot.
Figure 14.-Graymold: early (left)
and advanced (right) on green
fruit.
Figure 15.-Graymold on ripe fruit.
Figure 16.-Colletotrichum rot.
Figure 17.-Colletotrichum flower
blight.
Figure 18.-Dendrophoma fruit rot.
Figure 19.-Leaks (whiskers).
Figure 20.-Hard brown rot.
Figure 21.-Rhizoctonia flower
blight.
Figure 22.-White rot.
Figure 23.-Alternaria fruit rot.
Figure 24.-Stem end rot.
Figure 25.-Pestalotia fruit rot.
Figure 26.-Powdery mildew of
fruit.
Figure 27.-Anther and pistil
blight.
Figure 28.-Brown cap.
Figure 29.-Mottle virus (severe).
Figure 30.-Mottle virus
(moderate).
Figure 31.-Mild albinism.
Figure 32.-Weather burn.
Figure 33.-Sunscald.
Figure 34.-Fasciation.


Figure 35.-Tip burn.
Figure 36.-Tip burn caused by high fer-
tility.
Figure 37.-Catface.
Figure 38.-Proliferation.
Figure 39.-Yellow leaf.
Figure 40.-Roots affected by sting nem-
atode (right); healthy (left).
Figure 41.-Root knot.
Figure 42.-Twospotted mite (top); pred-
ator mite (bottom).
Figure 43.-Damage from twospotted
mite (left); healthy (right).
Figure 44.-Plant affected by cyclamen
mite.
Figure 45.-Thorn-like growth on stolon
caused by cyclamen mite infestation.
Figure 46.-Southern armyworm and
feeding damage.
Figure 47.-Cutworm.
Figure 48.-Saltmarsh caterpillar.
Figure 49.-Field cricket.
Figure 50.-Fruit damaged by field
cricket feeding.
Figure 51.-Fruits damaged by thrips.
Figure 52.-Tarnished plant bug on
chrysanthemum.
Figure 53.-Pamera.
Figure 54.-Lesser cornstalk borer.
Figure 55.-Silk tube of lesser cornstalk
borer.
Figure 56.-Plant wilting because of gir-
dling by lesser cornstalk borer.
Figure 57.-Girdling of crown by lesser
cornstalk borer.
Figure 58.-Mole cricket.
Figure 59.-Wireworm.
Figure 60.-Leaf tier and feeding dam-
age.
























Figure 1.-Anthracnose on stolons.


Figure 3.-Rhizoctonia rot on petioles.


Figure 4.-Bud rot caused by S. rolfsii
(arrow-sclerotia).


Figure 6.-Common leaf spot.


Figure 2.--Anthracnose on petiole.


Figure 5i.--Verticillium wilt.























Figure 8.-Leaf scorch.


Figure 9.-Leaf blotch.


Figure 11.-Leaf roll caused by powdery
mildew.


Figure 10.-Powdery mildew.


Figure 12.-Bacterial leaf spot.


Figure 7.-Leaf blight.






















Figure 13.-Black leaf spot.


Figure 15.-Graymold on ripe fruit.


Figure 17.-Colletotrichum flower
blight.


Figure 14.-Graymold: early (right) and
advanced (left) on green fruit.


Figure 16.-Colletotrichum rot.


Figure 18.-Dendrophoma fruit rot.























Figure 19.-Leaks (whiskers).


Figure 21.-Rhizoctonia flower blight.


Figure 20.-Hard brown rot.


Figure 22.-White rot.


Figure 23.-Alternaria fruit rot.


Figure 24.-Stem end rot.























Figure 26.-Powdery mildew of fruit.


Figure 27.-Anther and pistil blight.


Figure 28.-Brown cap.


Figure 30.-Mottle virus (moderate).


Figure 25.-Pestalotia fruit rot.


Figure 29.-Mottle virus (severe).























Figure 31.-Mild albinism.


Figure 33.-Sunscald.


Figure 35.-Tip burn.


Figure 34.-Fasciation.


Figure 36.-Tip burn caused by high fer-
tility.


Figure 32.-Weather burn.























Figure 38.-Proliferation.


Figure 39.-Yellow leaf.


Figure 41.-Root knot.


Figure 40.-Roots affected by sting
nematode (left); healthy (right).

. .; ^ ,,...
i 4..











Figure 42.-Twospotted mite (top); pred-
ator mite (bottom).


Figure 37.--Catface.























Figure 43.-Damage from two-spotted
mite (left); healthy (right).


Figure 45.-Thorn-like growth on stolon
caused by cyclamen mite infestation.


Figure 44.-Plant affected by cyclamen
mite.


Figure 46.-Southern armyworm and
feeding damage.


Figure 48.-Saltmarsh caterpillar.


LFigure 47.--Cutworm.























Figure 49.-Field cricket.


Figure 51.-Fruits damaged by thrips.


Figure 50.-Fruit damaged by field
cricket feeding.


Figure 52.-Tarnished plant bug on
chrysanthemum.


Figure 54.-Lesser cornstalk borer.


Figure 53.-Pamera.
























Figure 55.-Silk tube of lesser cornstalk
borer.


Figure 57.-Girdling of crown by lesser
cornstalk borer.


Figure 59.-Wireworm.


Figure 56.-Plant wilting because of gir-
dling by lesser cornstalk borer.


Figure 58.-Mole cricket.


Figure 60.-Leaf tier and feeding dam-
age.







































This public document was promulgated at a cost of 10,226.28,
1.28 a copy, to provide a means by which growers, extension
personnel and industry advisors may diagnose strawberry
problems in the field.



All programs and related activities sponsored or assisted by the Florida
Agricultural Experiment Stations are open to all persons regardless of race,
color, national origin, age, sex, or handicap.


ISSN 0096-607X


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