,RCULAR 142D T MAY, 1974
42. i (FOR COMMERCIAL USE ONY)
Florida Cooperative Extension Service
Institute of Food and Agricultural Sciences
University of Florida, Gainesville
(For Commercial Use Only)
The purpose of this guide is to present general
recommendations for the production of strawber-
ries in Florida. For details on local applications of
these practices, see your county Extension agent.
Additional information on strawberry production
can be found in the following publications of the
Florida Agricultural Extension Service: (1) Cir-
cular 193, "Commercial Vegetable Insect and Dis-
ease Control Guide;" (2) Circular 225, "Commer-
cial Vegetable Fertilization Guide;" and (3) Cir-
cular 196, "Chemical Weed Control for Florida
Vegetable Crops." Also available is Florida Agri-
cultural Experiment Stations Circular S-223,
"Vegetable Variety Trial Results for 1969-1970-
1971 and Recommended Varieties." Since these
circulars are revised from time to time, be sure to
obtain the latest editions.
The following USDA Farmers Bulletins are also
available: (1) No. 1560, "Preparing Strawberries
for Market;" (2) No. 2140, "Diseases of Straw-
berries;" and (3) No. 2246, "Growing Strawber-
ries in the Southeastern and Gulf Coast States."
ACREAGE AND VALUE
Nearly 19 million pounds of strawberries were
produced from 1,400 acres in Florida during the
1972-73 season. Acreage has remained fairly con-
stant in recent years. The 1971-72 total state
yield had a value of approximately $8.1 million.
Tioga-Large, vigorous plant. High yielder
throughout the season, fruit large, firm and red.
Florida 90-Large, vigorous plant. High yielder.
Fruit red, medium size, pointed and soft.
Other varieties-Sequoia, Fresno and Torrey.
North Florida Sept. 20-Nov. 10
Central Florida Oct. 7-Nov. 1
South Florida Oct. 1-Dec. 1
Bed Between Bed In Between Plants
Type Centers Rows Rows Per Acre
(Distance in inches) (Thousands)
2 Row 48-60 8-12 12-14 15-25
4 Row 60-84 8-10 10-12 20-30
Strawberries are grown commercially on most
Florida soils except the organic soils. A soil test
should be made well enough in advance to allow
for corrections to be made. If needed, add lime
to raise the pH to 5.8 to 6.2. Mix the liming ma-
terials into the soil at least six inches deep and at
least six weeks before setting the plants.
The fertilizer may be applied all broadcast be-
fore bedding, one-half broadcast before bedding
with one-half banded in the bed, or all banded in
the bed. Banded fertilizer should be placed 2 to 4
inches below the soil surface and 4 to 6 inches to
the side of the plant row. Caution: Do not band
fertilizer directly below plants. When beds are
formed, they should be peaked 1 to 2 inches in the
center to favor accumulation of excessive fertilizer
salts away from the plant roots.
Use of natural organic nitrogen has not resulted
in increased yields or better quality of fruit. No
more than 20 percent of the nitrogen used should
be from an organic source. Twenty to 25 percent
of the initial nitrogen fertilizer should be in the
Micronutrient problems may occur in certain
situations such as on high pH soil or some new
land. In the absence of a soil history or a lack of
soil test results on the area, a grower may want
to apply all micronutrients in the basic fertilizer
application as an insurance measure. A general
guide for adequate micronutrients is to add the
equivalents of 0.3% MnO, 0.2% CuO, 0.3% Fe2O3,
0.2% ZnO, and 0.2% BO, to the fertilizer mixture.
These elements may also be added as sulfates or
fritted forms. Use micronutrients only as needed
on future crops.
Manganese deficiency has occurred under some
conditions in the past, particularly on high pH
soils or as a result of overliming. Foliar applica-
tions of manganese sulfate may correct deficiency
conditions on plants in the field. The plants can
be sprayed two or more times at five-day intervals
with 2-4 pounds of manganese sulfate in 100 gal-
lons of water per acre. Permanent correction of
this condition for future crops is generally better
accomplished by altering the soil condition or con-
Fertilizer Rates and Usage
Soils N P,05 KO N P,O, K,O
Irrigated 120 160 160 15 0 15
Non-Irrigated 72 96 96 15 0 15
Peat & Muck Strawberries not recommended.
Marl 90 120 120 15 0 15
Rockland 90 120 120 15 0 15
'It is difficult to place supplemental fertilizer where it will greatly bene-
fit strawberry plants on plastic-mulched beds. Supplemental fertilizer
should be applied in the middles as close to the edge of the plastic as
The use of black plastic as a full-bed mulch
cover for strawberry production is a standard
practice. Use a 1 to 11/2 mil plastic in a width that
will completely cover the top and sides of the bed.
It is best to have the plastic slightly wider than
necessary for ease of application and to permit the
edges to be covered with soil to prevent the plastic
from blowing loose.
The fertilizer and a multi-purpose fumigant (if
used) should be added to the beds just before ap-
plication of the plastic. This practice reduces po-
tential leaching loss of fertilizer and prevents es-
cape of fumigant gas from the bed, thereby in-
creasing the effectiveness of the treatment.
Allow sufficient time to elapse for the fumigant
to do the job and dissipate (2-3 weeks) from the
beds before setting plants.
When setting plants, use certified disease-free
plants and make sure plants are set at the proper
depth. Plants should be set so the crown is level
with the surface of the bed. Do not remove leaves
from the plants before setting in the beds. The
loss of leaves either by removal of foliage manu-
ally or by improper care after transplanting re-
duces yield and earliness.
Irrigate with overhead sprinklers following set-
ting plants in the bed. Irrigate as needed during
the day to prevent drying of the plants and loss of
the leaves. This requires close attention for 7 to
10 days following setting.
In Florida, the sting and root-knot nematodes
are the most severe and the most widespread of
nematodes attacking strawberries. The bud and
leaf nematode causes considerable damage in loca-
Sting Nematode-Sting nematodes kill feeder
roots by sucking juices from them. Grasses, par-
ticularly crabgrass and corn, are hosts and permit
this nematode to feed and reproduce in the straw-
berry off-season. Sesbania is also a host for sting
Root-knot Nematode-This nematode causes
galls on roots which interfere with water and nu-
trient uptake. Injury is most obvious in hot, dry
Bud and Leaf Nematode-This nematode lives
in the air spaces in the leaf buds where it punc-
tures young tissue and sucks out juices. A toxin
injected into cells during feeding causes leaves to
become crimped, crinkled or "frenched." The
nematode can be controlled by soil fumigants
when it is in the soil, but not when it is in the
plant buds. Plants showing symptoms should be
removed and discarded in a manner to avoid re-
Chemicals effective in controlling nematodes,
certain soil-borne diseases, insects and weeds are
called multi-purpose soil fumigants, while chemi-
cals used only to control nematodes are called ne-
maticides. These two chemical groups vary in
their effectiveness against nematodes and other
soil-borne pests. Consequently, it is necessary for
a grower to recognize and evaluate the relative
importance of nematodes, soil-borne diseases, in-
sects and weeds before choosing one of these ma-
trials. If nematodes are the primary problem,
choose a nematicide (soil fumigant); however, if
control of other soil-borne pests is also desired,
choose a multi-purpose soil fumigant.
Fields for Fruit Production
Fl oz/chisel Fl oz/chisel
per 1000 Gal/Acre2 per 1000
Nematicides Gal/Acre linear ft (36" Row) linear ft
D-D 20-25 59-73 8-10 72-90
W-85 4.5-6.0 13-18 1.5-2.0 13-18
12.13 2.0 5.9 1.0 8.8
Oxy BBC 12:
Nemagon 8.6 3.0 8.8 1.5 13.2
Telone 15-20 44-59 6-8 54-72
Multi-Purpose per 1000 Rate/Acre per 1000
Soil Fumigants Rate/Acre linear ft (36" Row) linear ft
Chloropicrin4 35-46 gals 103-135 fl oz 12-15 gals 103-135 fl oz
Dowfume MC-33 350 lbs. 8.0 lbs 111 lbs 8.0 lbs
Vapams 40-60 gals 50-74 fl oz 6-8 gals 50-74 floz
Vorlex 30-35 gals 60-70 fl oz 7-8 gals 60-70 fl oz
'The overall rate per acre is based on a 12-inch chisel spacing.
'These gallonages are given as a guide to determine the total amount
of chemical needed for a field. Row spacing closer than 36" will re-
quire more chemical per acre; wider row spacing, less.
*Where Fumazone, Nemagon or BBC is used, allow at least 55 days
between treatment and harvest. Do not use on organic soils.
'Use the high rate in fields heavily infested with nematodes. An addi-
tional 7-10 day waiting period is generally necessary when the high
rate is used.
5Do not use in fields known to have high soil-borne disease stress.
Plant Production Nurseries
Fumigant' Rate Directions
Methyl Bromide 872 lbs/acre Application method: In-
(Brom-O-Gas)2 (24 lbs/ ject to 6-8 inch depth
(Dowfume 1200 sq ft) with chisels spaced 10-
MC-2)2 12 inches apart. Cover
with plastic. Exposure
period: 48-96 hours.
Aeration before plant-
ing: 2 to 10 days.
(Dowfume 350 lbs/acre Same as above.
MC-33)2 (9.6 lbs./
(Terr-O-Gas 1200 sq ft)
Chloropicrin 35-46 gals/acre Application method: In-
(Chlor-O-Pic) (1-1.3 gal/ ject to 6-8 inch depth
(Picfume) 1200 sq ft) with chisels spaced 10-
12 inches apart or ap-
ply with handgun. Firm
bed immediately and
cover with plastic or
apply a water seal. Ex-
posure period: 24-48
hours. Aeration before
planting: 7 to 14 days.
1200 sq ft)
Application method: In-
ject to 6-inch depth with
chisels spaced 5 inches
apart. Following ap-
plication, compact the
soil surface and cover
with plastic or seal
with light watering to
help prevent gas es-
Exposure period: 7
days. Aeration before
planting: 21 days.
Drench on material in
150-250 gals of water.
Cover with plastic or
seal with light water-
ing to help prevent gas
Exposure period: 7
days. Aeration before
planting: 21 days.
Multi-Purpose Controls (Continued)
Fumiganti Rate Directions
Vorlex 34-40 gals/acre Application method: In-
(1-1.1 gal/ ject to 6-8 inch depth
1200 sq ft) with chisels spaced 6-8
inches apart. Press and
cover with plastic.
Exposure period: 7
days. Aeration before
planting: Aerate by
shallow cultivation and
wait about 4 weeks be-
'Effective in controlling nematodes, certain soil-borne diseases, insects
2Where used for nematode control at the rates listed below, it will also
control certain soil-borne diseases, insects and weeds.
PRECAUTIONS: Read pesticide labels thor-
oughly before opening container and observe all
safety precautions. Dispose of empty containers
promptly and safely. Pesticide usage is subject to
changes and cancellations. Keep current on rec-
ommendations and regulations by consulting
county agents, experiment stations and industry
Proper use of plastic mulch will reduce the need
for chemical weed control in fruiting fields. How-
ever, some weed control is still necessary in the
row middles and around the plant hole in the
The greatest need is in plant production nur-
The following table lists the recommended her-
bicides for Florida conditions:
Herbicides-Rates and Usage
Time of Lbs./Acre
Material to Crop ingredient) Remarks
DCPA Posttrans- 9
diphenamid Posttrans- 4 Plants should be
(Dymid, planting established before
Soil-borne Diseases (Plant bed and Field) Vari-
ous Root and Stem Rots-Soil treatment using one
of the multi-purpose fumigants is effective in con-
trolling many soil-borne diseases. See the nema-
tode section of this circular for materials, rates
and methods of application.
Anthracnose (Colletotrichum fragariae)-Oc-
curs most often in nursery beds, causes spotting
and girdling of runners and leaf stems. Most
severe with high temperature and humidity. After
plants are established, spray with benomyl (Ben-
late) 1 lb. of 50% WP/A at weekly intervals, or
use 3 lbs. of 48-53% metallic copper from basic
copper sulfate, plus spreader-sticker, or dust with
6% copper dust at 20 to 35 pounds per acre as a
preventative schedule. No time limit between last
application and harvest.
Rhizoctonia Bud Rot (Rhizoctonia solani)--
Most prevalent during cool, humid weather. Fa-
vored by fog and heavy dew. Avoid areas where
this disease has been prevalent on previous crops
particularly where heavy legume cover crops have
been grown. Cut and allow cover crops to thor-
oughly dry before turning under. Set plants at
Leaf Spots (common, scorch and blight)-In
the nursery spray with three to four pounds of 48-
53% metallic copper from basic copper in 100 gal-
lons of water at 75 to 150 gallons per acre or
Captan 50% WP, 3 lbs./100 gals., or benomyl 50%
WP, 1/2 lb./100 gals./A, or dust with 6% copper
dust at 20 to 35 pounds per acre at seven- to 10-
In production fields, benomyl, or zineb, or captain
may be used. Use two pounds of zineb in 100
gallons of water, or 20 to 35 pounds of 61/2% zineb
dust per acre at seven-day intervals until full
bloom, then switch to three pounds of 50% captain
in 100 gallons of water, using 100 to 200 gallons
per acre, or 20 to 40 pounds of 6% captain dust per
acre at seven-day intervals, throughout fruiting
season. Do not apply zineb within seven days of
harvest, no time limitation for captain and be-
nomyl. The captain treatment may be used
throughout the season. Benomyl should be ap-
plied at one lb. of 50% material/A at 10% bloom
and again at full bloom, and additional applications
of 1/2 lb./A at seven- to 14-day intervals as needed.
Black Root-This condition occurs on older
plants in the nursery. These plants will produce
new lateral roots and vigorous plants when trans-
planted. Good soil aeration two to three weeks
prior to digging aids in new root initiation.
Red Stele (Phytophthora fragariae)-PUR-
CHASE DISEASE-FREE, CERTIFIED TRANS-
PLANTS. This disease has occurred in Florida
only when uncertified plants were purchased. It
has not survived in Florida.
Sclerotium Rot (Southern Blight) (Sclerotium
rolfsii)--Develops during hot, wet weather and is
most severe in the nursery during the summer.
This fungus attacks plants at the soil line and in-
vades both the crown and roots, causing sudden
death of plants. Avoid areas where this disease
has been prevalent on previous crops, particularly
where heavy legume cover crops have been grown.
Cut and allow cover crops to thoroughly dry, then
bury plant debris at least six inches deep.
Gray Mold Fruit Rot-Use 3 lbs. captain, 50%
WP as a spray or 20 to 40 lbs. of 6% dust at
seven-day intervals or spray benomyl 50% WP,
1 lb/A at 10% bloom, at full bloom, then 1/2 lb./A
at 10- to 14-day intervals as needed. No time
limitation between last application and harvest.
Verticillium Wilt (Verticillium albo-atrum)-
No chemical control. Use new land or rotate with
Insecticides-Rates and Usage
Insecticides and Amounts Days to
Insect Formulations' Per Acre Harvest
Flower Malathion 5E 1% pts. 3
Thrips Parathion 4E 1/ pt. 14
Field Parathion 4E % pt. 14
Insecticides-Rates and Usage (Cont.)
Insecticides and Amounts Days to
Insect Formulations1 Per Acre Harvest
Spider Mites Dicofol
35% WP 2-3 lbs 2
4E 1 qt. 2
Omite 30% WP 2-3 lbs 3
(Dibrom) 8E 1 pt. 1
Cutworms Apply toxaphene or chlordane at 2 pounds
active ingredient (5 pounds of 40% WP or
20 pounds of 10% dust or granules) per
acre to the soil surface before planting if
cutworms are known to be present. Do not
disturb soil for three to five days. A 2%%
toxaphene or 2% chlordane bait can be used
as above at 20 to 40 pounds per acre. If
cutworm damage to young plants is noted
baits should be used at once.
Mole Broadcast aldrin or diazinon at 2 pounds or
Crickets chlordane at 4 pounds active ingredient per
acre as a spray, dust, or granule or a 2%
chlordane or aldrin bait evenly over the soil
surface at 20 to 40 pounds per acre before
seeding or transplanting if insects are pres-
Wireworms Apply parathion or diazinon at 2 pounds
and active ingredient per acre. Distribute even-
Citrus ly over the soil surface 2 to 3 weeks before
Root planting and immediately mix into the up-
Weevil per 6 inches of soil.
'Other formulations may be registered and available.
HARVESTING AND HANDLING
Strawberries should be harvested early in the
morning to prevent heat build-up in the fruit. Do
not pick wet berries. Free water on the fruit
favors development of fruit rots. Pickers should
be closely supervised to be sure they harvest all
ripe berries since these will become over-ripe and
soft by the next harvest. Immature berries will
not ripen properly and will not have good quality.
Berries should be picked with stems and without
Berries may be harvested and brought to a shed
for grading and packing or grading may also be
done during harvest if the pickers are experienced
and reliable and if fruit quality is good. The first
method allows more supervision of the packers
and better quality control. The second method
causes less damage to the fruit because the ber-
ries are picked and packed for marketing in one
Strawberries should never be left exposed to the
sun after harvest, they should be precooled im-
mediately after packing, and all subsequent opera-
tions should be carried out as near to 320 F (0 C)
as possible. The best method of precooling straw-
berries is by forcing cold air directly through the
container where it comes into contact with each
berry. This method cools berries five to 10 times
faster than just placing them in a cold room.
Protection of open blossoms and fruit down to
20 F can be accomplished with the use of over-
head sprinkler irrigation by following these simple
Use brass sprinkler heads that deliver at least
0.2 inches of water per hour.
Sprinklers should rotate at least one revolu-
tion per minute.
Space sprinklers to cover not more than 50
percent of their effective diameter.
Turn on when the temperature falls to 340 F
and run system until the temperature returns to
above 340 F or when the wet bulb temperature
rises above 32 F.
Have accurate thermometers placed in the
field at plant height.
Clear ice forming means good cold protection.
Milky ice means no protection and the water appli-
cation rate should be increased by using a larger
nozzle orifice opening.
PROPAGATING RUNNER PLANTS
Most growers have switched away from grow-
ing their own plants because of disease and labor
supply problems that have developed. Plants are
generally purchased from out-of-state plant pro-
ducers, but a few in-state sources still remain.
The Institute of Food and Agricultural Sciences
researchers are working to develop varieties re-
sistant to diseases which have presented problems
to Florida growers. At a future time, a return to
the practice of growing one's own plants may oc-
As guidelines to those growers who have an in-
terest in growing their own plants, the following
Select a clean well-drained site for the nur-
Use a multi-purpose soil fumigant (see Nem-
atode Section) to treat the area.
Prepare the unmulched beds and use a fertili-
zation rate of 500 to 600 pounds of 6-8-8 per acre.
Sidedress as needed during the season.
Select and use "mother" plants which are free
of nematodes and diseases.
Keep weeds controlled.
Start and stay on a good disease and insect
control program as outlined in the respective sec-
tions of this guide.
The use of trade names in this publication is solely for
the purpose of providing specific information. It is not
a guarantee or warranty of the products named and does
not signify that they are recommended to the exclusion of
others of suitable composition.
Stephen R. Kostewicz and James Montelaro
Acknowledgements: The authors wish to express their
sincere thanks to the many faculty members of the Insti-
tute of Food and Agricultural Sciences who made many
helpful suggestions in the preparation of this circular.
Special contributions were made by:
J. R. Hicks-Harvesting and Handling
J. E. Brogdon and F. A. Johnson-Insect control
R. S. Mullin and T. A. Kucharek-Disease control
W. L. Currey-Weed control
D. W. Dickson-Nematode control
SInstitute of Food and Agricultural Sciences
TEACHING I FAS
Single copies free to residents of Florida. Bulk rates
available upon request. Please submit details on
request to Chairman, Editorial Department, Institute
of Food and Agricultural Sciences, University of
Florida, Gainesville, Florida 32611.
This public document was promulgated at an
annual cost of $552.75 or .11 cents per copy
to inform commercial producers about straw-
COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 nd Jun 30, 1914)
Cooperative Extension Servce, IFAS, Unversity of Flonda
and United States Department of Agrculture, Cooprating
Jo N. Busby, Dean