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Group Title: Bulletin
Title: Strawberries in Florida
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Permanent Link: http://ufdc.ufl.edu/UF00094959/00001
 Material Information
Title: Strawberries in Florida culture, diseases and insects
Series Title: Bulletin - Florida Agricultural Extension Service ; 148
Physical Description: 32 p. : ill. ; 23 cm.
Language: English
Creator: Brooks, A. N ( Albert Nelson )
Kelsheimer, E. G ( Eugene Gillespie ), 1902-
University of Florida -- Agricultural Extension Service
Publisher: Agricultural Extension Service, University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 1951
Copyright Date: 1951
 Subjects
Subject: Strawberries -- Florida   ( lcsh )
Strawberries -- Diseases and pests -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
General Note: Cover title.
General Note: "February, 1951."
General Note: "A revision of bulletins 98 and 136"--P. 2 of cover.
Statement of Responsibility: by A.N. Brooks and E. G. Kelsheimer.
 Record Information
Bibliographic ID: UF00094959
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 82733666

Table of Contents
    Front Cover
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    Main
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Full Text

Subtropical Experiment Statie
Homestead
_....B ==


Bulletin 148


February, 1951


COOPERATIVE EXTENSION WORK IN
AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
AGRICULTURAL EXTENSION SERVICE, UNIVERSITY OF FLORIDA
FLORIDA STATE UNIVERSITY, AND UNITED STATES
DEPARTMENT OF AGRICULTURE, COOPERATING
H. G. CLAYTON, DIRECTOR


Strawberries in Florida

Culture, Diseases, and Insects

BY A. N. BROOKS AND E. G. KELSHEIMER


Fig. 1.-Many growers ship strawberries in refrigerated trucks to
Northern markets.


Single copies free to Florida residents upon request to
AGRICULTURAL EXTENSION SERVICE
GAINESVILLE, FLORIDA










(A Revision of Bulletins 98 and 136)


BOARD OF CONTROL
Frank M. Harris, Chairman George J. White, Sr., Mt. Dora
St. Petersburg Eli H. Fink, Jacksonville
Hollis Rinehart, Miami W. F. Powers, Secretary
N. B. Jordan, Quincy Tallahassee
STAFF, AGRICULTURAL EXTENSION SERVICE
J. Hillis Miller, Ph.D., President of the University'
J. Wayne Reitz, Ph.D., Provost for Agriculturel
H. G. Clayton, M.S.A., Director of Extension
Marshall O. Watkins, M. Agr., Assistant Director2
F. W. Parvin, B.S.A., Assistant to the Director
Agricultural Demonstration Work, Gainesville
J. Francis Cooper, M.S.A., Editor'
Clyde Beale, A.B.J., Associate Editor'
L. O. Griffith, A.B.J., Assistant Editor
L. N. Joiner, B.S.A., Assistant Editor2
J. Lee Smith, District Agent
K. S. McMullen, B.S.A., District Agent
F. S. Perry, B.S.A., District Agent
H. S. McLendon, B.A., Soil Conservationist
R. S. Dennis, B.S.A., Executive Officer, P. & M. Admin.s
C. W. Reaves, B.S.A., Dairy Husbandman
N. R. Mehrhof, M. Agr., Poultry Husbandmanl
J. S. Moore, M.S.A., Poultryman
A. W. O'Steen, B.S.A., Supervisor Egg-Laying Test, Chipley
O. F. Goen, D.V.M., Animal Husbandman
James A. McGregor, B.S., Assistant Animal Industrialist
L. T. Nieland, Farm Forester
H. G. Hamilton, Ph.D., Agricultural Economist'
Charles M. Hampson, M.S., Agricultural Economist, Farm Managementl
D. E. Timmons, M.S.A., Economist in Marketing
John M. Johnson, B.S.A., Agricultural Engineer
Fred P. Lawrence, B.S.A., Citriculturist
W. W. Brown, B.S.A., Boys' 4-H Club Agent
Joe N. Busby, B.S.A., Assistant Boys' 4-H Club Agent
A. M. Pettis, B.S.A., Farm Electrification Specialists
John D. Haynie, B.S.A., Apiculturist
V. L. Johnson, Rodent Control Specialist3
J. Russell Henderson, M.S.A., Agronomist1
F. S. Jamison, Ph.D., Vegetable Crops Specialist'
Stanley E. Rosenberger, M. Agr., Asst. Veg. Crops Specialist
Forrest E. Myers, M. Agr., Assistant Veg. Crops Specialist
Home Demonstration Work, Tallahassee
Anna Mae Sikes, M.S., State Agent
Ethyl Holloway, B.S., District Agent
Mrs. Edyth Y. Barrus, B.S.H.E., District Agent
Joyce Bevis, A.M., Clothing Specialist
Mrs. Bonnie J. Carter, B.S., Home Improvement Specialist
Grace I. Neely, M.S., Asso. Economist in Food Conservation
Mrs. Gladys Kendall, A.B., Home Industries and Marketing Specialist
Lorene Stevens, B.S., 4-H Club Specialist for Girls
Ruth Lemmon, B.S.H.E., Asst. Girls' 4-H Club Agent
Negro Extension Work, Tallahassee
Floy Britt, B.S.H.E., Negro District Agent
J. A. Gresham, B.S.A., Negro District Agent
1 Cooperative, other divisions, U. of F.
2On leave. a In cooperation with U. S.











Strawberries in Florida

BY A. N. BROOKS AND E. G. KELSHEIMER

Page Page
Varieties ................... 3 Diseases .................... 15
Yields ...................... 4 Anthracnose .............. 16
Soils ....................... 4 Rhizoctonia Bud Rot....... 17
Setting of Plants............. 6 Leaf-Spot Diseases .......... 18
Sources of Plants ........... 9 Nematodes ................. 20
Fertilizers .................. 10 Root Troubles .............. 24
Cultivation ................. 12 Fruit Rots .................. 26
Mulching ................... 12 Injurious Insects and Spiders. 28
Irrigation .................. 13 Pests of Major Importance ... 28
Picking and Packing ......... 13 Insects of Lesser Importance.. 30
Selling Methods ............. 15 Recommendations for Control 31

Strawberry growing is of major horticultural importance in
Florida. The development of this industry is based upon the
production and marketing of fruit during the winter and early
spring months, December to May. Total acreage in straw-
berries varied from 7,000 to 11,000 acres during the period
1932-33 to 1937-38. During the four years, 1940 to 1944, there
was a steady decrease in acreage until it was the lowest for a
25-year period. By 1947-48 the acreage was back to normal.
Strawberries are produced on a commercial scale mainly in
Hillsborough, Polk, Hardee, Bradford, and Union counties, al-
though smaller plantings for home use and local markets are
found in most counties. The shipping season in the Plant City-
Lakeland and other southern areas extends from December into
April and in the Starke-Lawtey area from March into May.

Varieties
The Missionary (Fig. 2) now is Florida's standard variety,
it being planted almost exclusively. This variety originated in
Virginia about 1900 and was introduced into the Plant City
area some 10 or 12 years later. The characteristics which make
this variety desirable are a long fruiting season, self-fertile
blossoms, and heavy production of fruit which is of good quality
and size and firm enough to withstand long shipment. It is
easily propagated because of its free production of runners.
The plants are fairly resistant to leaf-spot diseases.
Many other varieties have been tested but none found to be
as good as Missionary.







Florida Agricultural Extension Service


Yields
Strawberry yields will vary with cultural, soil and weather
conditions. No one commercial area in the state, over a period
of years, seems to have had consistently higher yields than
any other. Yearly average harvested yields range between 1,000
and 3,500 quarts per acre.
Soils
Proper soil reaction, with a pH value of from 5.5 to 6.0,
is essential for successful growth of strawberry plants. The
soil reaction should be determined from four to six weeks before
the plants are to be set. If the soil is too acid, applications of
ground limestone, dolomitic limestone, hydrated lime or basic
slag will increase the pH. If it is too alkaline, applications of
sulfur will make the soil more acid, or applications of 100 pounds
per acre of manganese sulfate generally will induce successful
plant growth even though the pH is not reduced appreciably.
In Florida the soils best adapted to strawberry culture ap-
pear to be the darker colored grades of flatwoods soils underlaid
with clay, marl or compact sand, although with proper treatment
other types can be made to produce good fruit. The best of
the present acreage is located on soils of the Scranton series.
The qualities of soil necessary for successful growing of
strawberries are: (1) Coherence without becoming too compact,


Fig. 2.-A plant of the Missionary variety.







Strawberries in Florida


(2) fairly high organic matter or humus content, (3) slightly
acid reaction, (4) sufficient but not excessive soil moisture, and
(5) adequate degree of fertility. Any soil meeting these require-
ments, either naturally or artificially by means of drainage,
irrigation, plowing under cover crops, or the application of
fertilizers, will grow strawberries.
The light sandy soils need irrigation and the plowing under
of cover crops to increase their organic content, besides ap-
plications of commercial fertilizers.
At present there is little commercial production of early
strawberries on muck soils. Such soils are more susceptible to
frosts than are the higher lands even immediately adjacent.
If found desirable to attempt the growing of strawberries on
muck soils, it is advisable to plant only lands which have been
under cultivation for several years. Strawberries produced on
muck soils tend to be too soft for shipping. In some instances on
muck soils the fruit, even before maturity, will decay on the
side in contact with the soil.
To replenish humus it is good practice to grow some good
cover crop every two or three years or oftener and plow under.
The cover should be cut with a disk harrow and plowed under
three to six weeks before the strawberries are to be planted.
During this period it is advisable to harrow the ground whenever
necessary to prevent formation of crust and to kill young weeds.
When using a velvet bean cover crop it is best to plant as
early as possible, drilling the seed in 3-foot rows so that the
crop can be cultivated to keep down weed growth. This method
of cover-cropping accomplishes two purposes. (1) It helps to
reduce root-knot by keeping down weeds which are host plants
for root-knot nematodes and at the same time allowing a crop to
grow which is resistant to the nematodes. Thus these organisms
starve to death because of lack of food material. (2) A clean
crop of velvet beans is easier to handle when the time comes
to prepare the land for the fall setting of strawberries.
Crab grass is one of the best cover crops for strawberry land.
It makes a large tonnage of plant material which, when properly
handled, results in a good supply of long-lasting humus. Humus
improves the condition of the soil by increasing its water-holding
capacity, by increasing numbers and activities of beneficial soil
organisms, and finally by preventing leaching of plant food.
Crab grass does not rot readily and hence may become an
aggravation to the grower if it is not properly handled. The







Florida Agricultural Extension Service


grass while still green should be cut thoroughly on top of the soil
by means of sharp disks. Then any one of the following fertilizer
combinations should be broadcast before the grass is turned
under: (1) Superphosphate, 600 pounds per acre; (2) mixture
of superphosphate 600 pounds, nitrate of soda 100 pounds and
muriate of potash 100 pounds per acre; or (3) granular cyanamid
300 pounds per acre.
After the fertilizer has been broadcast the grass should be
plowed under immediately. The fertilizer aids the soil organisms
in the initial steps of decomposing-the grass to form humus.
If this system of crab grass cover with broadcast fertilizer
is followed it will not be necessary to apply fertilizer in the
lay-off furrows when the beds are made. The soil will have
sufficient fertilizer present to take care of the plants from the
time they are set until they have become well established. Fur-
thermore, since the fertilizer is well distributed in the soil
there will be no danger of plant roots being burned, as is often
the case when fertilizer is added to the bed before planting time.
Setting of Plants
About 10 to 14 days before the strawberry plants are to be
set furrows are laid off the proper distance apart, and fertilizer
is distributed in these furrows. The fertilizer should be well
incorporated with the soil by means of a shovel-toothed culti-
vator or other suitable tool so that the strawberry roots in no
instance will be in direct contact with large quantities of fertil-
izer at the time of planting. The bed is made up directly over
the furrow, the height being dependent upon drainage condi-
tions. Another method is to make up the beds without fertilizer,
set the plants and make the first application of fertilizer after
the plants have become established and are growing well.
Both the single- and double-row methods of planting are
used throughout the strawberry growing areas. Single-row beds
should be 36 to 40 inches from middle to middle and double-row
beds 48 to 60 inches. The beds are dragged and allowed to
settle for a few days prior to planting.
Single Row.-Plants are set 10 to 14 inches apart in a single
row upon each bed, necessitating from 12,000 to 15,000 plants
per acre, depending upon the spacing of the beds and plants.
Double Row.-In this method two rows of plants are set on
each bed, the rows being 12 to 16 inches apart. The plants are
spaced 10 to 14 inches apart in the row; the plants in the two
rows being alternated rather than set opposite each other. It is







Strawberries in Florida


advisable to use some implement to mark the beds for setting
of plants. The number of plants required per acre is from
15,000 to 25,000 (Fig. 3).
The distance apart that plants are set will depend upon the
time of planting. When set early in the season the individual
plants will attain a larger size than when planted late, and
should, therefore, be spaced farther apart.
Strawberry plants are set most successfully during a good
"season," when the soil contains sufficient moisture without sur-
plus water being present, and during cloudy days or late in the
afternoon so that the plants have some time to establish them-
selves before being subjected to the hot sun. Setting can be
done almost any time if overhead irrigation is available.
The plants to be set should be removed from the nursery
beds by loosening the soil about the roots with a potato fork,
carefully taking up the plants by hand and, after removing all
the dead leaves and runners, tying them in small bundles. The
roots should not be allowed to dry out and, therefore, should be
protected at all times from exposure to sun and wind. At no
time should plants be dropped far in advance of the setter.
Strawberry plants should be set so that the bud and crown
are entirely above ground, while the whole of the root system is


Fig. 3.-The double-row system of planting strawberries.







Florida Agricultural Extension Service


below ground. If set higher than this the roots are exposed,
causing the plants to dry out; if set lower the buds will be
covered by soil, causing them to rot. Under Florida conditions
there is a greater tendency to set too low than too high. It is
a tiresome task to dig out about the buds of plants set too low;
be careful to set the plants at the proper depth (Fig. 4).
The holes made to receive the plants should be deep enough
and wide enough to accommodate the full length of the roots,
which should be spread out somewhat fan-wise and have the soil
packed firmly about their entire length. Extremely long roots
should be trimmed before being set, so that they fit, without
doubling up, into the holes prepared for them. Merely packing
the soil about the base of the plant by a blow with the hand
leaves the main part of the roots in an air pocket, which causes
them to dry out unless rain falls shortly after setting.
Sometimes the beds may be fairly moist but the surface
rather dry, in which case the dry soil should be scraped aside
as each plant is set. When this is done care should be taken
not to set the plant too deep in the hole thus made. At all times
the bud should not be below the surface of the bed.






















Fig. 4.-Strawberry plants should be set at the depth indicated in 2.
No. 1 is too shallow and 3 is too deep.







Strawberries in Florida


Machine Setting.-The Holland celery planter (Fig. 5) is well
adapted to setting strawberry plants. The machine is self-pro-
pelled, self-guided and has two clutch pedals so that either of the
two operators can stop the machine when necessary.
For the successful use of this planter the land must be well
prepared and all plant residue thoroughly rotted. Beds must
be laid out uniformly in width and must be uniformly moist. The









Fig. 5.-This two-row transplanter saves labor in setting strawberry plants.
planter will not work well in soil too dry or too wet. This means
that some form of overhead irrigation is desirable in connection
with the use of this machine. The planter is used also for the
setting of cabbage and pepper plants.
Sources of Plants
Plants are secured from Northern sources-mainly Arkan-
sas, Delaware and Maryland-each year during February, March,
and April. These plants start growth immediately after being set
and usually bloom and fruit before starting to form runners.
The plant beds are kept free of weeds and given frequent shallow
cultivation before the runners become too numerous, so as to
reduce the amount of hand work necessary later on. In May or
June the runner plants are removed from the beds and set out
on other beds prepared for them (Fig. 6). These newly set
plants are allowed to make plants which will be used for the
final setting in September or October for fruit production during
the season extending from December to May.
By following this procedure it is necessary to obtain but
1,000 plants in February for each acre that is to be planted to
strawberries in the fall. With careful cultivation and favorable
weather, 30,000 to 50,000 plants can be produced for fall planting
from each 1,000 set in February.
Sometimes the spring setting of plants is made fairly late,
the latter part of March through April, and the plants are set
wider apart than usual, from one to three feet apart in rows six







Florida Agricultural Extension Service


feet apart. No resetting is made in May or June but the plants
are maintained on the original beds until September or October,
at which time the runner plants are removed and set for fruit
production. This method eliminates the June or July reset
which, during most years, is quite hazardous due to spells of
hot, dry weather, unless overhead irrigation is available.
There is difference of opinion as to the relation of the time
of setting strawberry plants to the time and quantity of fruit
production. Plants are set from the latter part of August to
the first of November. Several years' tests at the Strawberry
Laboratory have shown that best production of fruit is obtained
from plants set during the latter part of September.
Fertilizers
The formulas of fertilizers used will depend upon the soils
to which they are to be applied and also the condition of the
plants at the time of application. Higher percentages of nitro-
gen are applied for plant growth and higher percentages of
potash for the coloring and firming of the fruit. Usually it is
best to divide the total quantity of fertilizer to be applied for
the season into three applications, the analyses of the fertilizers
used approximately the following: 4-7-51 for the first and
1 Percentages of nitrogen, phosphoric acid, and potash in the order given.


Fig. 6.-Method of propagating plants for fall setting.







Strawberries in Florida


second applications and 3-8-8 for the third. The quantity of
fertilizer applied each time will depend upon weather conditions
and type of soil and its previous treatment. Usually 400 to
600 pounds per acre are applied each time, thus making a total
application of 1,200-1,800 pounds per acre for the season. Tests
at the Strawberry Laboratory, near Plant City, show that a
total application per acre per season of 1,400-1,800 pounds of
commercial fertilizer gave the best yields of fruit on the type
of land used. Higher and lower applications gave decreases.
Some of the synthetic fertilizers of higher analyses have
been found satisfactory for use with strawberries. Due to the
higher analysis, a correspondingly smaller quantity of fertilizer
must be used as compared with the quantity of commercial fer-
tilizer ordinarily employed.
Method of Application-The methods of applying fertilizer
vary. The following two methods are used most commonly:
1. The beds are made up without fertilizer and the plants
set out and not fertilized until they become established. About
two or three weeks after the plants are set an application of
fertilizer is made between the rows of plants on a two-row bed
or on one side of the plants on a one-row bed. Subsequent ap-
plications are made on both sides of the two-row beds and alter-
nate sides of the one-row beds. This method lessens the danger
of the young plants being burned by the fertilizer before they
have become established.
2. The first application of fertilizer is thoroughly mixed
into the bed as it is being made up. Then one to two weeks is
allowed to elapse before the plants are set on the bed. Subse-
quent applications are made on the sides of the beds as in 1.
Time of application will vary according to moisture condi-
tions; if the soil has been dry subsequent to the last application,
the plants will have had no opportunity to utilize the fertilizer
already there. Further fertilizing will be of little or no value or
even may be harmful until soil moisture conditions are such as
to have brought the prior applications into solution, allowing this
to have been taken up, at least partially, by the plants.
It is of major importance in applying fertilizer to mix it
thoroughly with the soil and not merely apply it in drills and
then cover it. Much burning of the roots has been caused by
improper application of fertilizers.
Occasionally during February or March the fruiting plants,
evidently through an inadequate supply of available nitrogen,







Florida Agricultural Extension Service


become sluggish. This lack of thrift can be overcome by the
application of a top-dressing of sodium nitrate, not to exceed
100 pounds per acre. Excessive amounts of quickly available
nitrogen cause a softening of the fruit, which greatly impairs
its carrying qualities. Some success has been gained by the
application of a combination of nitrate and potash, either in
the form of potassium nitrate 100 pounds per acre, or by 2
applications, first with potassium sulfate 50 to 75 pounds per
acre, followed with sodium nitrate 75 to 100 pounds per acre.
Cultivation
Cultivation is begun shortly after the plants are set and
should be frequent enough to keep down weed growth and pre-
vent packing of the soil. Deep cultivation is not necessary and
should be avoided. The amount of hoeing required will depend
on the frequency of rains and the weed growth. The manner
of hoeing is important. During the growing season, until fruit
setting, a loose soil mulch should be left over the whole bed
rather than the compact soil surface which results from the all-
too-common practice of "shaving" the beds. Continued usage of
the latter method in the early part of the season exposes some
of the roots, and by leaving the plants set too high, interferes
with the formation of new roots by the drawing away of the
soil from the crown of the plant where new roots are formed.
However, during the period of fruit production, a dirt mulch
on top of the bed is not desirable, as the fruit sinks easily
into this loose soil during rains, and subsequently rots.
Mulching
Mulching is employed to keep fruit clean by preventing its
coming in direct contact with the soil. Pine straw (needles)
and native grass straw are the materials used. Mulching is
practiced in the Starke-Lawtey area. The fruit from mulched
plants is comparatively free of sand and washing is not neces-
sary. Usually when plants are not mulched, as is the case in
the southern areas, all fruit must be washed before it is packed.
The mulching material is generally distributed through the
field by means of carts or in large boxes fitted with handles
for carrying. It is scattered over the beds, completely cover-
ing the plants which are later individually uncovered by hand.
This leaves the bed covered with the mulching to a depth of a
few inches, the mulch being in direct contact with and under
the foliage of the plants. The time of application is usually
delayed as long as possible to permit continued cultivation.







Strawberries in Florida


The material is commonly put on about the time the plants
begin to bloom.
The chief disadvantages of mulching are that it harbors
insects, particularly crickets, delays early fruiting due to lower
soil temperatures in mulched plots, and prevents cultivation,
which in some instances results in excessive weed growth.
Irrigation
To insure sufficient soil moisture in the strawberry fields at
all seasons of the year frequently it is necessary to have some
means of irrigation. Three methods are now employed.
Overhead Irrigation.-By this method water is sprayed upon
the ground from a system of pipes supported seven or eight
feet above ground. A uniform distribution of the water is se-
cured by means of automatic oscillators.
The cost of installing such a system is fairly high but this
is offset by the low cost and ease of operation.
During the past few years a light weight portable overhead
irrigation system has become available. The conductor pipes
are made in 20-foot lengths of heavy-gauge galvanized iron
sheets or aluminum tubing. The joints are simple and positive
and require a minimum of time to connect one pipe with another.
Whirler-type sprinklers may be attached to pipe or the
pipe may be perforated so that it acts as a good sprinkler.
Surface or Flood Irrigation.-This method is cheaper than
overhead as far as cost of installation is concerned, but is more
expensive to operate. The land must be brought to a proper
grade so that an even distribution of water can be effected with-
out much washing of soil or ponding of water over beds in low
places. The water is allowed to fill up the alleys to the top sur-
face of the beds. To accomplish this and to prevent loss of
water into the drainage ditches it is necessary to make use of
a series of dams between the beds throughout the patch.
Picking and Packing
Picking is done preferably in early morning when the fruit
is cool. The stems are pinched off in picking and ought not
to be more than 1/4 inch long, as longer stems interfere with
proper packing. Fruits must not be snatched from the plant
nor should a number of berries be held in the hand at one time.
After picking, it is important that fruit be carried to the pack-
ing shed before long exposure to the sun. (Fig. 7.) Close
supervision of picking generally pays dividends.
If berries are picked from unmulched plants it is commonly







Florida Agricultural Extension Service


necessary to wash the sand from the fruit. When the fruit is
washed before packing, frequent changing of the wash water
will result in less Rhizopus rot (leak) in transit. The berries
should be allowed to drain fairly dry before being packed, so
that the cups will not become wet and unsightly by the time
they reach the market. Well packed fruit, in clean white cups,
is more attractive and commands a better price.
None other than firm, ripe, fair-sized berries should be
packed. All imperfect, decayed, green, or small (less than 3/4
inches through greatest diameter) fruit should be discarded.
Culls may be packed and sold as such but it probably would
be better for the strawberry industry if no culls were packed
and only a good grade of fruit marketed.
Oblong pint boxes in 36-pint crates are standard containers.
The fruit should be packed firmly enough to prevent per-
ceptible settling in the cup before reaching destination. The
top is crowned slightly but not so much that the fruit is crushed
by the divider strips.
If a covered truck is not used for transporting the fruit to
the shipping platform the fruit should be covered with a light
colored, preferably white, cloth. Air should be allowed to cir-


Fig. 7.-A field packing shed in operation.







Strawberries in Florida


culate freely about the fruit during the trip. This circulation
will evaporate some of the water remaining on the berries from
washing and thus slightly lower the temperature.
Since Florida strawberries are sold as fancy fruit and as a
rule command a good price, it is the duty of every grower to
see that a quality pack of fruit is maintained. The U. S. Grade
No. 1 should be observed in packing strawberries.
Selling Methods
The grower brings, his fruit to the market, where it is in-
spected and bid upon by shippers consisting of local men, fruit-
brokers, or representatives of Northern commission houses. The
highest bidder pays the grower for the fruit as soon as it is
delivered to the proper car or platform for shipment.
The "Set-Off".-The grower does not take his fruit to the
market to have it bid upon but sets it off at the platform or
house of some shipper to whom he may be financially obligated
or with whom he desires to deal. He is not paid for the fruit
until the following day, when he may be given the average
market price, or slightly higher, for his fruit.
Roadside Stands.-Many growers market quantities of ber-
ries through direct sales from roadside stands. Lower grade
berries, particularly, and surplus quantities are marketed here.
"Frozen-food" Plants.-The grower can dispose of over-ripe
and slightly off-grade fruit to "frozen-food" plants where the
fruit is cleaned, stemmed, mixed with sugar and then frozen.
Strawberries are shipped to Northern markets by both
express and freight refrigerator cars, and by ventilated and re-
frigerated trucks.
Strawberry Diseases
In the strawberry-growing areas of central Florida, where
most of the work on disease identification and control measures
has been accomplished, there are several important diseases
which will be described in detail later, but which might well be
listed here according to the time of year or weather conditions
favoring their development.
During the production of runner plants, especially in the
summer period of abundant rainfall and high temperatures, a
fungous disease, anthracnose, causes a spotting of runners and
a dry rot of the fleshy part of the plants. The other two diseases
important at this time are French-bud or crimp and coarse root.
Both are caused by nematodes.
During the fruiting season plants are relatively free of






Florida Agricultural Extension Service


diseases so that fungicidal sprays are usually unnecessary. Leaf
spots are of minor importance.
Anthracnose
This disease, which is of most importance in nursery beds,
is caused by the fungus Colletotrichum fragariae Brooks. The
fungus causes a spotting and girdling of runners and leaf stems


F.






















Fig. 8.
typic


f
s


which are a part of the strawberry runner.
Control.-Since the disease occurs during the rainy season
it is most difficult to control and to keep from spreading through-
out the nursery. It is readily spread by wind-blown spores and
also quite easily spread from nursery to nursery by a man or
animal walking through a diseased nursery and then walking
into a disease-free nursery.


.jI



-Anthracnose, showing
al lesions on runners.


and can grow from these parts
into the fleshy part of the plant
where a dry rot is produced
which results in a wilting of the
affected plant. The disease is
most destructive during periods
of high temperatures and abun-
dant rainfall.
These runner spots are dark
brown to black in color and are
definitely sunken, with a rather
sharp line of demarcation be-
tween healthy and diseased
tissue (Fig. 81). This distin-
guishes them from similar spots
on runners caused by sand burn
during periods of hot, dry
weather. These sand burn spots
are a lighter brown and not defi-
nitely sunken. Furthermore, the
black spots caused by the fungus
can be definitely identified by
examining them under a strong
hand lens. Such spots are cov-
ered with tufts of small black
bristles which are part of the
fungus and which are readily
distinguishable from the lighter-
colored, large hairy structures







Strawberries in Florida


If the disease is noticed early, some benefit can be accom-
plished by carefully removing the diseased plants and runners
from the nursery to some place where they can be burned. Care-
ful removal and complete destruction are necessary so that the
fungous spores attached to the diseased parts of the plants may
not be scattered to healthy plants.
A spray program will to a certain extent keep the disease
from spreading. However, in the summer when rains occur daily
or even several times a day fungicidal sprays are none too effec-
tive. Bordeaux mixture 4-2-50 or fixed copper spray materials
as copper-A compound, copofilm and copotox, if used with some
good spreading and sticking agent, may be applied at weekly
intervals or oftener if necessary. All plant parts, especially run-
ners, should be covered by the spray. The fungicidal residue will
stick to the plants and remain effective if it dries thoroughly
before rain falls.
Rhizoctonia Bud Rot
The fungus which causes this disease is Rhizoctonia solani
(Kuhn), a fungus which is quite prevalent in the soils of Florida
and causes diseases on many species of plants. It can attack
any part of the plant in contact with the surface of the soil or it
can grow superficially over the plant surface and attack leaf buds
and flower buds. It is this latter phase that will be described
here. As yet it has not been found attacking the roots.
When strawberry plants with single-bud crowns are at-
tacked by the fungus the bud becomes dry-rotted and may easily
be pulled free from the remainder of the plant. The older leaves
may or may not be attacked. In the former case they become
dry-rotted at the bases of the leaf-stems, weakening the support
of the leaves and causing them to lie flat on the soil. In this case
the leaves may continue to grow and live out their normal span
of life. Death of the main bud may result in death to the plant
unless lateral buds subsequently develop and are not themselves
attacked by the fungus.
When large plants with many buds to the crown are at-
tacked the disease may go unnoticed for some time because
diseased buds are hidden by abundant foliage. Later the disease
will be observed when new vegetative growth fails to appear.
The fungus attacks not only leaf buds but also flower buds.
They attack the buds in any stage of development from the early.
forms to open blossoms. When the forms are attacked the buds
dry-rot and die. When open or nearly-open blossoms are at-







Florida Agricultural Extension Service


tacked the petals remain white but the centers become black,
similar in appearance to frosted blossoms.
Bud rot is usually more prevalent during November and
December, when air temperatures are below 75 degrees and
humidity is high. The disease is favored by foggy weather with
heavy dews which may keep the plants covered with moisture
for long periods. Large plants and plants set too closely together
on the bed tend to hold a moist atmosphere around the buds
and thus favor the disease. Moist soil surfaces favor the growth
of the fungus from plant to plant.
Control.-To control the disease it is necessary to make the
environment as unfavorable as possible for the development of
the fungus. Frequent shallow cultivations around the plants will
keep the soil surface dry. Wider spacing of plants on beds will
give better air circulation and allow foliage and buds to dry
more rapidly.
Fungicidal sprays are of no value when applied with a knap-
sack sprayer. If they are applied with power sprayers so as to
thoroughly wet the entire plant and surface of the soil surround-
ing it then some degree of control may be obtained. However,
the best control and the one which has had to be relied on most
is a change in weather, from high humidity and relatively calm
to low humidity resulting from more air movement.
Leaf-Spot Diseases
Leaf-spot diseases are of relatively minor importance in
Florida. They seldom appear on plants during the fruiting sea-
son, November to April. A true-
type Missionary is quite resistant
to these diseases. However, in re-
cent years many plants have been
sold as Missionary which
are not true to type.
Sometimes such plants
are killed out-right by
leaf spot diseases.
There are three dis-
tinct types of leaf spot
diseases.
Common Leaf Spot.-
This leaf spot is caused
by the fungus Mycospha-
erella fragariae (Tul.) Fig. 9.-Common leaf spot on strawberries.







Strawberries in Florida


Lindau. The spots are at first small, less than 1/8 inch in
diameter and puplish red in color. They increase in size to
a diameter of approximately 3/16 inch. The centers become
white or gray (Fig. 9).
The spots may number
from one to many on each
leaflet and if extremely
numerous cause the death
of the leaflet. If many
leaflets thus die, the plant
itself may be killed.
Leaf Scorch.-
This leaf spot is
caused by the fun-
gus Diplocarpon
earliana (Ell. & Ev.)
Wolf. The young
spots appear on the
upper surface of the
leaves as small pur- Fig. 10.-Leaf-scorch.
plish discolorations which rapidly enlarge into irregular purplish
blotches from 1/16 to 3/16 inch in diameter. In these spots may
be seen very small black glistening bodies which are the fruiting
structures of the fungus (Fig. 10). The spots on each leaflet may
become so numerous that they coalesce and give a dark reddish
cast to the entire leaflet. In severe cases of infection the edges
of the leaf curl upward and the leaf dries out progressively from
edge to midrib.
Leaf Blight.-This leaf spot is caused by the fungus Den-
drophoma obscurans (Ell. & Ev.) Anderson. The young spots
of this disease are larger than the mature spots of either common
leaf-spot or leaf-scorch. From one to five spots may occur on a
leaflet. The young spots are circular and reddish purple in color.
The older spots become zonated. The central zone is dark brown,
surrounded by a lighter brown zone which in turn is bordered by
a purplish zone which blends into the normal green of the leaf.
Mature spots may be circular, oval or even V-shaped (Fig. 11).
Small black dots, fruiting structures of the fungus, appear in
the central dark brown zones of older spots.
Control of Leaf Spot Diseases
It is seldom necessary to spray Missionary plants for the
control of leaf-spot diseases. It does not pay to spray plants







Florida Agricultural Extension Service


when only a few leaf spots are present on some of the older
leaves. However, if these spots tend to become numerous and
are present also on the younger leaves it shows that the plants
are susceptible to the diseases. It will then be necessary to spray
the plants once a week until the leaf spot diseases are under con-
trol. Bordeaux mixture, or any of the fixed copper spray ma-
terials such as copper-A compound, copotox, copofilm or several
others now available, may be used.
Nematodes
Three species of nematodes attack strawberries. The root-


Fig. 11.-Strawberry leaf blight, showing various types of lesions.
The leaflet at the top shows a typical fanshaped dead area. (From
Ill. Agr. Exp. Sta. Bul. 229.)







Strawberries in Florida


Fig. 12.-Root-knot as it appears on strawberries.
knot nematode and the sting nematode attack the roots. The
other species attacks the buds and produces the disease known
as crimp or Frenchbud.
Root-Knot Nematode.-The type of root injury caused by
this nematode occurs on roots of many of the vegetable crops in
the South grown during periods of warm weather. On straw-
berries the disease is less severe. Fruiting plants are not much
affected, mainly because, during the fruiting season, tempera-
tures are comparatively low and the root-knot nematode some-
what dormant. The disease can become severe and cause con-
siderable root injury and even death of plants during prolonged
periods of drought and high temperatures, especially if the plants
are being grown on light, sandy soil.
The microscopic eelworm or nematode, Meloidogyne sp.,
which causes root-knot, is quite common in the soils of the South-
ern states. It enters strawberry roots and causes the formation
of galls 1/16 to 1/8 inch in diameter, much smaller than those
formed on roots of most vegetable crops (Fig. 12). These galls
interfere with normal root function, such as absorption of nu-







Florida Agricultural Extension Service


trient solutions from the soil. Plants thus attacked become un-
thrifty and may eventually die.
There are several methods which can be used to reduce the
number of root-knot nematodes in the soil. Some treatments
may even eliminate most of them. In all cases after soil has been
so treated it should not be set with plants which are themselves
infested with the nematodes.
One of the most economical methods for reducing the nema-
tode population is by the use of a resistant cover crop. Velvet
beans or crotalaria are best for this purpose. Drill the seed in
rows two feet apart and cultivate the crop as long as possible to
keep down growth of weeds which may be host plants. The ne-
matodes die of starvation because they have no suitable plant
roots upon which to feed.
Granular aero-cynamid uniformly broadcast over prepared
land and disked in to a depth of six inches will kill most of the
nematodes. Rates of application will vary from 1,000 to 1,500
pounds per acre. It will be necessary to wait 30 to 45 days after
application of cynamid before plants can be set. Cynamid breaks
down into ammonia and finally into nitrates and hence supplies
considerable nitrogen to the soil.
Good results can be obtained by fumigating the soil with
the fumigants D-D or ethylene dibromide. The latter can be
obtained under various trade names. All soils to be treated
should be well prepared and free of trash. Fumigation may be
done by commercial operators who have implements to apply the
fumigants to the soil in rows 6 inches deep and 12 inches apart.
About 22 gallons of D-D or 15 gallons of ethylene dibromide are
required to treat one acre. At time of treatment, soils should be
at optimum moisture, neither too wet nor too dry. Unless heavy
rains ensue after treatment the land can be bedded two weeks
from treating time and strawberry plants set.
Each grower can treat his land himself by a new method
which is proving satisfactory and is called the row-method or
bed-method of treatment. Costs for this method are quite low.
Full details concerning this method can be obtained from County
Agricultural Agents, Florida Agricultural Experiment Station,
or from several of the agricultural supply companies.
Sting Nematode.-The type of injury caused by this nema-
tode, Belonolaimus gracilis Steiner, is quite different from root-
knot. No galls are produced. Instead, the nematode does not
enter the roots but feeds from the outside by means of a stylet







Strawberries in Florida


or sucking tube. It feeds mainly on the very young roots and
causes them to die. The plants attacked are soon left with noth-
ing but systems of old coarse roots. This causes the plants to
die gradually. Sometimes this lingering period may last for
several weeks. Affected plants will not put out new leaf growth;
in fact leaf buds are difficult to find. The edges of the older
leaflets become dark brown in color. This coloring gradually
extends in toward the mid-rib, by which time the leaflet is dead.
Both nursery plants and fruiting plants can be affected.
The disease is worse on light sandy soils and on land which has
been continuously cropped to strawberries or vegetables with
no planting of good cover crops between times. The soils thus
managed are all low in humus.
Control measures are the same as those for the root-knot
nematode. Special emphasis might be placed upon the annual
use of cover crops and rotation of cultivated crops.
Bud Nematode. This nematode, Aphelenchoides besseyi
(Ritzema Bos) Christie, does not actually get into the plant
tissue. Instead it inhabits the air spaces in the leaf buds and
runner buds. It
feeds by punctur-
ing the young tis-
sues and sucking
the plant juices
by means of a
stylet or tube.
The saliva which
it injects into the
young growing
parts of the plant
causes these parts
to develop ab-
normally. The
young leaves are
crimped, crinkled,
darker green in
color with reddish '
coloration on
Fig. 13.-French bud, showing crimping of young
edges and veins leaves.
(Fig. 13). Plants infested with this nematode are practically
worthless for fruit production.
These nematodes are most active during late spring to early







Florida Agricultural Extension Service


fall, when temperatures are well above 75 degrees. They can
swim from place to place in the soil moisture and are readily
carried longer distances by heavy rains and floods. They enter
the buds from the soil. They are known to live in the soil from
one year to the next. Hence, infested land should not be used for
raising nursery plants unless it has been treated as for root-knot
control.
Land to be treated and used for nurseries should be so locat-
ed that it does not receive drainage from infested land. Further-
more, it would be useless to treat land and then set it with
plants which are infested with the bud nematode. At present
there are no out-of-state nurseries known to be absolutely free
of bud nematodes. Hence, if Northern-grown plants are set in
the treated land it will be necessary to inspect them from time
to time after setting and rogue out diseased plants as they
appear. These plants should be carefully dug up, placed in a
bucket and taken from the field to some place where they can
be burned, so as to destroy the nematodes in them.
One way in which a grower can be assured a clean source of
plants is to go through his fruiting field after the picking season,
preferably April 1 to 15, and select the best plants and those
known to be free of bud nematodes. These plants should be dug
carefully, the tops pruned back to the one best bud and the roots
pruned to a six-inch length and washed under running water.
These plants are then set out on the treated nursery beds.
Root Troubles
There are several abnormal root conditions, some caused by
organisms and others physiological, which may result in more
or less serious damage to plants in both nursery beds and fruit-
ing fields. Any condition which materially interferes with the
normal functioning of roots will cause noticeable changes in the
above-ground parts. The general symptoms caused by root in-
jury are, first a browning and dying of the edges of the leaflets
successively from older to younger leaves. This dying progresses
from edges to mid-rib more or less rapidly, depending upon the
type of injury to the roots.
Roots may be injured by any of the following: Various fungi
and bacteria; nematodes; insects; fertilizer; cultivation too deep
or close; soil moisture condition-too wet or dry; and soil too
acid or insufficiently acid.
Black Root.-This is not typically a root injury. The condi-
tion probably is physiological, occurring on older plants. The root







Strawberries in Florida


cortex or bark may become dark brown to black in color. This
dark-colored cortex readily peels off, showing that the central
cylinder is still white and alive. Such roots have been found to
be capable of putting out new lateral roots and under favorable
growing conditions will support a vigorously growing plant which
will put on a good crop of fruit.
Black root occurs mainly on older plants in the nursery beds.
Two or three weeks before such plants are to be set in the field
it is well to loosen the soil around them by means of a potato
fork or pitchfork. Then the loosened soil should be lightly irri-
gated. The old black roots will put out new laterals and within
the two or three weeks the plants will be in much better condi-
tion for setting in the field.
Sclerotium Rot.-This rot is caused by a soil-inhabiting
fungus, Sclerotium rolfsii Sacc., which develops most rapidly
during hot, moist weather. For this reason the disease is found
mainly during the summer months on plants in the nursery
beds. The fungus grows through the soil and attacks the plant
at the soil line. From there it progresses upward into the fleshy
part of the plant and downward into the roots. Complete death
of the plant may be quite sudden. Under moist conditions a
white mat of compressed cottony growth of the fungus may be
found around the base of the plant. Small round bodies, sclero-
tia, which are white at first and later dark brown appear scat-
tered over the surface of the white mat.
If such a plant is carefully dug up the root system will be
found to be heavily infected with the fungus and part or all of
the roots in a state of soft rot.
This fungus can attack plants of most of the cultivated
crops and weeds in central Florida. However, infection seldom
takes place over a wide area. In strawberry nurseries it is
usually quite localized. Hence, some good can be accomplished
by carefully removing such infected plants together with some
of the surrounding soil, placing both in a bucket and taking
them from the field to a place where they can be burned.
Other Root Rots.-Several other fungi and bacteria may be
capable of causing root rots but are not found frequently in
fields in Central Florida, especially in fields which have been
under cultivation for any length of time. On recently cleared
ground where pieces of oak roots may be scattered through the
soil the fungus Armillaria mellea (Vahl) ex Fr., may infect straw-
berry roots and cause death of plants. Other microorganisms







Florida Agricultural Extension Service


have been isolated from rotted roots of strawberry but their
ability to produce root rots has not been definitely established.
Fruit Rots
There are four different fungous rots of strawberry fruit
in Florida.
Leaks or Whiskers and Control.-This rot, caused by
the fungus Rhizopus nigricans Ehreub. ex Fr., is of most import-
ance during the transportation and marketing of strawberries,
although it may rarely be found in the field. It develops most
rapidly under conditions of high temperature and moisture.
The fungus readily attacks fruit that has been injured and
causes a collapse of the tissues and rapid extraction of the fruit
juice which accumulates in the bottom of the container and
drips out, thus giving rise to the common name, "leaks." The
fruit settles down until it fills about one-half of the container.
A loose cottony growth of fungus appears over the surface of
the fruit. This is the "whiskers" stage (Fig. 14). This growth
may hold the fruit together so firmly that when the container
is inverted the fruit falls out in one solid block. Black dots
appear scattered amongst the cottony mass. These dots are the
spore-bearing cases of the fungus.
In picking, preparing and transporting fruit to the market
it should always be handled carefully to avoid bruising. Fre-
quent changing of the water used in washing fruit will greatly
reduce the source of infectious material. Since high tempera-
tures favor the development of this rot, fruit should be picked
during the morning and protected at all times from exposure to
the sun until the fruit reaches market, where it should be rapidly
cooled to a temperature of 35 to 40 degrees before being shipped
to Northern markets by rail or by truck. Fruit thus handled
will not develop Rhizopus rot.
Brown Rot or Gray Mold and Control.-This rot, caused by
the fungus Botrytis cinerea P., occurs both in the field and dur-
ing transportation of fruit. During prolonged periods of cool,
wet weather this rot may become of prime importance in the
field where it attacks strawberries in all stages of development
from blossom-stage to fully-ripe. At such times a high percent-
age of the fruit is covered with "gray mold" and has to be dis-
carded.
Under less severe conditions the fruit may be spotted. These
spots are at first light brown, later dark brown in color. -The
flesh may become slightly soft at first, then hard and dry; never







Strawberries in Florida


Fig. 14.-"Whiskers" or "leaks".
"leaky." There is no distinct line of demarcation between dis-
eased and healthy tissue. Under moist conditions the infected
fruit is covered with "gray mold," which is the spore-bearing
stage of the fungus.
At present weather is the only factor capable of controlling
this disease in the field. In preparing fruit for market all in-
fected fruit should be discarded because this rot will develop
slowly, even at temperatures of 35-40 degrees.
Hard Brown Rot.-The fungus which causes this rot of
strawberry fruit is the same one causing bud-rot, Rhizoctonia
solani. The fungus is present in the soil and attacks the fruit
on the side in contact with the soil. Fruit in all stages of
maturity may be attacked. The spots are light tan in color unless
soil has become enmeshed in the fungal growth. In this case
the spots are of the same color as the soil adhering to them.


,-------







Florida Agricultural Extension Service


The line of demarcation between the tan-colored diseased tissue
and the pink healthy tissue is so sharp that the diseased tissue
can be cut away and the remainder of the fruit will be edible.
Light Tan Rot.-This fruit rot is the least important of the
four rots in Florida. It is caused by the fungus Pezizella lythri
Shear & Dodge and is easily distinguishable from the other rots.
The spots produced on the fruit are small, sunken, and tan
in color. They increase but slowly in size. The infected tissue
is a cone-shaped core which, due to its corky texture and to the
disintegration of the cells adjoining, can be removed intact from
the sound tissue.
Injurious Insects and Spiders
Insects and spider mites cause more damage than do plant
diseases in those fields set to strawberry plants for fruit pro-
duction. Insects are of less importance than plant diseases in
strawberry nurseries. The pests are listed in the order of their
importance, the first six of which should always be considered as
an annual menace to the strawberry grower.
Pests of Major Importance
Red Spider.-Red spiders (mites), Tetranychus sp., are red-
dish or yellowish in color and although small, are visible to the
S eye. They spin strands of silk which web
up both surfaces of the leaves. They use
This web to travel over the leaves and also
Sto hold their eggs to the leaves. Spread is
by crawling from one plant to another and
by wind currents. Injury is caused by the
spiders sucking the plant juice from the
foliage and the fruit. The leaves turn a
pale ashen color and, if the infestation is
heavy, become dry, shrivel up and die. The
Young unripe berries turn a brown color,
Become hard and dry and fail to develop.
The spiders occur in the field in late fall
and early spring.
Fig. 15.-Strawberry Pameras.-Three species have been
pamera (X5). recorded in Florida, but Orthaea bilobata
(Say) is the most prevalent (Fig. 15). Pameras belong to the
chinch bug family. In size and color the young resemble small
yellow ants but they are much more rapid in their movements.
The adults have dark-colored wings. They breed so rapidly and
are so inconspicuous in color, size and habits that they often be-







Strawberries in Florida 29

come very abundant before they are noticed. They cause "but-
tons"-berries in the early stage of development that cease to
grow and become hard, dry and brown. Later the insects attack
the crown of the plant, which withers rapidly and dies if the bugs
are numerous. The outer leaves of the plant die first and dry up,
turning a brownish color. If these leaves are disturbed the
pameras scatter in all directions. They are prevalent in late
spring but sometimes as early as late November and December.
Lesser Cornstalk Borer.-The lesser cornstalk borer, Elas-
mopalpus lignosellus (Zell.), at times is a serious pest of straw-
berries. The larva is a bluish-green caterpillar that bores into
the stem at the surface of the ground and completely circles the
plant at the fleshy part, causing the newly set plant to wilt and
die. The larvae do not remain in their tunnels except for feeding
but are usually found in the soil in a thin silken tube which is
covered with sand and excrement. The first indication of their
presence is the wilting of the younger leaves. In the nursery,
old plants and new runner plants are attacked. They can tunnel
any place along the runner. A young plant is killed if it has not
rooted.


Fig. 16.-Left, Puerto Rican mole-cricket (Scapteriscus vicinus Scudd.);
right, Southern mole-cricket (S. acletus R. & H.).


71







Florida Agricultural Extension Service


Flower Thrips.-This sucking insect, Frankliniella cephalica
Crawford, is minute, soft-bodied, yellowish in color and quite
active. The insects sometimes are found in considerable num-
bers in blossoms, where they feed on stamens, pistils and young
berries. When numerous they can cause blossom drop or the
young berry may remain hard and brown and fail to grow. They
usually occur in the field in the late spring after the picking sea-
son, but may sometimes infest blossoms during the season.
Mole-Crickets.-Two species, the Southern mole-cricket,
Scapteriscus acletus R. & H., and the Puerto Rican mole-cricket
or change, S. vicinus Scudd. (Fig. 16), quite often cause consider-
able damage to strawberry plants. They are most destructive
in the field in the fall. They can also be destructive in nurseries.
They affect the plant by destruction of roots and drying out of
soil.
Cutworms.-Several species of cutworms attack strawber-
ries but no attempt is made to separate the species. Damage is
caused by the larvae cutting off the young plants. They also
feed on the berries, sometimes cutting the fruits from the plants.
They also cut off the leaves. They occur in the field and in the
nursery, especially in early fall.
Insects of Lesser Importance
Crickets.-Field crickets, Gryllus sp., in the past have been
destructive but now are seldom seen since the new organic in-
secticides have been in use.
Strawberry Flea-Beetle.-This flea-beetle, Altica ignita (Illi-
ger), is a bronze-colored insect about 1/ inch long that damages
strawberry leaves by eating round holes in them. They are most
frequently found in the fall on early set plants.
Strawberry Leaf-Roller.-The destructive stage of the leaf-
roller, Ancylis comptana fragariae (W. & R.), is a small cater-
pillar about 1/2 inch long that folds the strawberry leaf along
the midrib and lives in this folded portion, feeding upon the leaf.
It may occur at any time of the year.
Root-worms.-The adult, Paria carrella Fab., acts as a leaf
beetle in the fall on early set plants. Nothing is known of the
larval habits.
Grasshoppers.-The young nymphs are usually the most
destructive.
Negro Bugs.-These small round, shiny black bugs, Corimel-
aena pulicaria (Germ.), may damage the roots or berries. These







Strawberries in Florida


insects have sucking mouth parts. They are frequently over-
looked, occurring in the late fall. Damage from these insects is
debatable.
Ants.-Several species of ants damage plants by building
mounds over the buds, causing them to rot. Ants are carriers
for aphids.
Root Aphids.-Aphis forbesi Weed, the root aphid, attacks
strawberry plants by sucking the plant juice from the roots.
They are considered a very minor pest.
Recommendations for Control
General.-Fortunately, very few insecticides are needed to
control such a formidable array of insect pests that attack straw-
berries. A strawberry dust mixture consisting of 5 percent
chlordane in a dusting sulfur base has proven very satisfactory.
Apply the dust at the rate of 15 pounds per acre for a single
row or 20 to 25 pounds per acre for a double row. Chlordane
is also used in a bait made from a feed base containing mostly
wheat products, to which enough chlordane is added to 100
pounds of bait to make a 11/2 percent bait. If one wishes to make
his own bait, use three pounds of a 50 percent chlordane formu-
lation in 100 pounds of wheat feed. If it is a 40 percent formula-
tion, use 33/4 pounds. Add enough citrus molasses to dampen it
but not make it soggy. Amyl acetate (banana oil) may be added
at the rate of 1 ounce to 100 pounds of the bait if an attractant
is thought to be necessary.
DDT is usually applied as a 5 percent dust with or without
sulfur as a base.
Nicotine is applied as a 3 percent dust.
Specific Control for Each Pest
Red Spider.-Apply sulfur dust only when the mites appear
on the older leaves.
Pameras.-Apply 5 percent DDT or 5 percent chlordane dust.
Lesser Cornstalk Borer.-Apply 5 percent DDT or 5 per-
cent chlordane dust or 11/ percent chlordane bait. Apply directly
to bud.
Flower Thrip.-Apply 3 percent nicotine dust.
Mole-Cricket.-5 percent chlordane dust or 1 percent
chlordane bait.
Cutworms.-5 percent DDT or 5 percent chlordane dust or
1/2 percent chlordane bait.







Florida Agricultural Extension Service


Crickets.-5 percent chlordane or 5 percent DDT dust or 11/
percent chlordane bait.
Strawberry Flea-beetle.-5 percent DDT dust.
Strawberry Leaf-Roller.-5 percent DDT or 5 percent chlor-
dane dust.
Rootworms.-5 percent DDT dust.
Grasshopper.-5 percent chlordane dust or 11% percent
chlordane bait.
Negro Bugs.-5 percent DDT or 5 percent chlordane dust.
Ants.-5 percent chlordane dust.
Root Aphis.-Control of ants.
Time of Application
Do not dust when the plants are damp. Foliage burn may
be produced on wet plants, especially if a heavy dust application
remains on the plant. It is preferred to dust in the late afternoon
and evening. Dust immediately after picking the berries, which
is usually 2 to 3 days before they are picked again. Do not dust
too frequently with DDT or chlordane at blossoming time as it
will injure the blossoms and reduce the yield. Do not apply
the chlordane-sulfur dust oftener than once every three weeks.
Insect Control Summary
DDT and chlordane applied as 5 percent dusts or chlordane
applied as a 11/ percent bait control practically all of the insect
pests. The exceptions are red spider, which requires sulfur,
and the flower thrips, for which nicotine still remains the most
effective control.
The grower is given his choice of preventing a build-up
in population by applying insecticides on a schedule or the use
of insecticides for control only when needed, as determined by
careful inspection of the plants.




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