Dover ARC Research Report SV78-1
AGRICULTURAL RESEARCH CENTER
DOVER, FLORIDA
OF THE
INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES
UNIVERSITY OF FLORIDA
STRAWBERRY FIELD DAY
Thursday, February 9, 1978 IJ J
** @@w********* ************* r. -'" .... 0 *
PROGRAM PARTICIPANTS
W. E. Waters, Director (AREC-Bradenton)
A. J. Overman, Nematologist (AREC-Bradenton)
D. J. Schuster and James Price, Assistant Entomologists (AREC-Bradenton)
J. A. Otte, Extension Assistant Economist (AREC-Bradenton)
G. A. Marlowe, Extension Vegetable Specialist (AREC-Bradenton)
T. Pospichal, Extension Agent I, Hillsborough County
C. M. Howard, Associate Plant Pathologist (ARC-Dover)
E. E. Albregts, Associate Soil Chemist (ARC-Dover)
** **A************* *************
Tom Pospichal, Hillsborough County Extension Agent I Moderator
P.M.
2:30 Assembly and Registration
3:00 Dr. W. E. Waters, Welcome
3:05 Mrs. A. J. Overman,- Nematode Research
3:20 Dr. George A. Marlowe Water in Agriculture
3:35 Dr. David J. Schuster and Dr. James F. Price Insects on Strawberries
3:50 Mr. John A. Otte Strawberry Production Costs
4:05 Dr. Charles M. Howard Strawberry Varieties and Diseases
4:15 Dr. Earl E. Albregts Strawberry Nutrition and Culture
4:30 Tour of Strawberry Research Plots
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Soft Drinks Courtesy of Shore Fertilizer Company, Plant City, Florida
February, 1978
TABLE OF CONTENTS
FIELD NO. PAGE
Strawberry Nematicides and Fumigants ................... 2
Determining Water for Vegetable Crops ..................... 3
Strawberry Growing Costs .......................... ....... 6
1 Miticides on Stawberries .................................. 8
Mite Tolerance of Strawberries ............................ 8
,J 8
2 Osmocote Rate and Placement Trial ......................... 9
3 Transplant Dip and Spray Trial ........................... 9
(4A Strawberry Nursery Herbicides ........................... 10
( Strawberry Variety Trial .................................. 11
6 Planting Date and Plant Chilling .......................... 12
7 Strawberry Chicken Manure Trial ......................... 12
8 & 9 Strawberry Breeding ...................................... 13
10 Strawberry Diseases ............... ..................... 14
12 Irrigation to Establish Strawberry Plants ................ 15
13 Fertilizer Source and Placement on Strawberries .......... 15
14 Comparison of Drip and Overhead Irrigation ................ 16
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THE INFORMATION AND PRODUCTS DESCRIBED HEREIN DO NOT CONSTITUTE A RECOMMENDATION
BY THE AUTHORS OR THE UNIVERSITY OF FLORIDA.
NEMATICIDES AND FUMIGANTS FOR STRAWBERRY FRUITING AND PLANT PRODUCTION FIELDS
A. J. Overman
DBCP (Fumazone, Nemagon) has been removed from the market and should not be used on
strawberries.
Chemicals available with instructions for use follow:
MATERIALS APPLICATION rate/acre Limitations and/or Directions
Nematicide-Insecticide
Dichloropropene- Broadcast: 40 gals Apply as a preplant treatment at
dichloropropane (1 pt/chisel/136 linear least 21 days prior to planting.
(D-D) ft) to 60 gals Use only on mineral soil. Space
chisels 12" apart and inject at 8"
depth. Seal soil immediately after
application. Allow additional time
before planting if temperatures are
below 600F or if soil is waterlogged.
Dichloropropene Broadcast: 24 gals Same as dichloropropene-dichloro-
(Telone II) (1 pt/chisel/136 linear propane.
ft) to 36 gals.
Ethylene dibromide Broadcast: 9 gals or Same as dichloropropene-dichloro-
(Dowfume W-85 + 1 pt/chisel/605 linear propanes. May be used on both
Soilbrom 90 EC) ft. mineral and muck soil.
Fematicide-Insecticide-Fungicide
Methyl Bromide (98%) 854 lbs per acre Apply as a preplant treatment in
Chloropicrin (2%) plant beds. Prepare plant bed as
(Dowfume MC-2) if for planting. Seal with air-
tight cover. Inject material,
treating when soil temperature
above 500F. Expose to fumigation
for 48 hrs. Aerate treated area
for 2 days before planting.
Methyl bromide 500 Ibs/acre for trans- Apply as preplant treatment. Inject
(68.6%) and plant bed; 350 Ibs. per material at 6-8" depth. Seal trea-
Chloropicrin (1.4%) acre for fruit produc- ted soil with airtight cover. Ex-
(Brozone) tion. pose to fumigation for 48 hours.
Aerate for 2 days before planting
in transplant bed. Allow at least
two weeks soil aeration between
field fumigation and planting when
transplants are for fruit produc-
tion. Do not treat soil if temper-
ature is below 450F at 5" level.
-3-
Methyl bromide (67%)
and Chloropicrin (33%)
(Dowfume MC-33 or
Terr-o-Gas 67)
Methyl isothiocyanate
(20%) + Chlorinated
C3 hydrocarbons (80%)
(Vorlex)
350 lbs/acre
15 gals/acre for beds;
30 gals broadcast
Same as Brozone
Apply as preplant treatment. For
broadcast application, use shanks
spaced 6-8" apart injecting at a
depth of 6-8 in. For row applica-
tion, use 2 chisels spaced 6-8"
apart per row. Immediately after
application, seal soil. If soil
is 70*F or more at 6" depth, seal
soil surface with plastic tarp.
Keep soil moist and undisturbed
for 4-7 days. Colder soils require
longer fumigation periods. Culti-
vate soil and allow to aerate one
week for each 10 gals. per acre
of material
DETERMINING THE WATER NEEDS OF VEGETABLE CROPS
George A. Marlowe, Jr.
Of the many factors which influence effective irrigation for vegetable crops,
the following five are the most important:
The
The
The
The
The
amount of water used by the crop and soil during the growing season.
quality of water applied.
characteristics of the crop.
efficiency of the irrigation system.
soil-air-water relationship
1. Amount
The amount of water lost in transpiration by the crop and the water evaporated
from the soil surface of the crop area is referred to as evapotranspiration or ET.
Evapotranspiration is modified largely by the following factors:
a. Amount of sunshine, temperature and humidity
b. Length of daylight period
c. Length of the growing season
d. Stage and type of plant growth
e. Amount of water in the soil and nearness to the surface
Evapotranspiration is greatest during windy, clear, hot days when humidity is
low. An open body of water may evaporate as much as 0.36 inches on a peak day.
Crop land seldom equals that evaporative loss, but peak consumption may reach one-
fourth to one-third inch per day. The consumptive use of several different situ-
ations may be of interest:
-4-
Consumptive Use, Inches, Average
Situation Year Daily Peak
Open lake 54.0 0.15 0.36
Irrig. pasture 27.6 0.07 0.21
Fallow land 18.0 0.05 0.18
Weed field 30.1 0.08 0.23
Evapotranspiration figures have been estimated for most of the vegetables grown
in Florida. The calculations involved analysis of long term climatological records
which have the greatest influence over evaporation (temperature and hours of day-
light) and characteristics of the crop. Example of seasonal ET figures for some im-
portant vegetables planted on March 1 in S.W. Florida:
Radishes 30 day crop 3.2 inches
Lettuce 60 day crop 6.9 inches
Sweet corn 90 day crop 16.5 inches
Tomatoes 110 day crop 19.3 inches
The ET figure is not the irrigation requirement; it is only an index of the
water consumed by the soil and crop during the growing season. A crop with an ET of
20 inches irrigated by a method 33% efficient would require 60 inches of irrigation,
assuming zero rainfall for the growing period.
2. Water Quality
Water quality is a term used to evaluate the usefulness of water for specific
purposes. For agricultural purposes we are most concerned with the total amount of
"dissolved salts" in irrigation water and the chemical composition of this salt
effect. The following ratings, in parts per million total salts, may be of interest.
0-500 Excellent, use without reservations
500-1000 Good, use with some reservations
1000-1500 Fair, may cause some plant injury
1500-2000 Poor, may cause serious plant injury
2000-2500 Very poor, likely to cause serious plant injury
Above 3000 Substandard, should not be used for irrigation
High levels of specific chemical elements in irrigation water may cause special
problems. Excess sodium or chloride may disrupt the calcium, potassium or nitrogen
balance of the plant. High concentrations of iron or sulfur in the water may enhance
bacterial plugging of small bore irrigation tubes.
3. Crop Characteristics
As would be expected, crops with deep root systems have different water needs
than crops with shallow root development. A crop harvested continually for six weeks
has a different water requirement than one sacrificed at harvest. Crops which cover
the ground generally use less water than those which have an upright, compact habit
of growth.
Phosphorus application is associated with increased root development, whereas
nitrogen primarily stimulates leaf and stem growth. As soil oxygen is reduced by
such factors as poor drainage or compaction, root development and absorption of water
and nutrients is decreased.
-5-
The size, shape, and orientation of leaves modify crop water requirement, but
one of the most important leaf factors in water loss is the number and placement of
pores stomatess) in the leaf. Nearly all of the water lost and gas exchanged by the
plant occurs through the stomata.
Most of the water absorbed by the plant is taken in by the terminal portion of
the roots. It is to the vegetable growers advantage to encourage continual root
growth so that new root tips will be available for this vital function.
4. Efficiency of Irrigation System
If it were possible to apply the entire ET figure to an acre of crop land
gradually and without loss, then the irrigation requirement would be the same as
the ET. This situation is very unlikely to happen under field growing conditions.
Irrigation systems vary greatly in efficiency, due to the following factors:
a. Conveyance loss from well to field
b. Percolation during application
c. Run-off during application
d. Evaporation during application
e. Wind displacement during application
In general, irrigation workers feel that seep irrigation is approximately 30%
efficient, sprinkler irrigation 70% efficient, and drip irrigation about 85% effi-
cient. This means that a crop ET of 20 inches (zero rainfall) would require the
following irrigation applications per acre:
20 inches 30% (seep) = 66.6 inches
20 inches 70% (sprinkler) = 28.6 inches
20 inches 85% (drip) = 23.5 inches
5. Soil-Air-Water Relationships
Roots require an adequate supply of soil oxygen in order to perform their func-
tion. Excess water fills the pore spaces in the soil, thus preventing adequate gas
exchange. Good drainage must accompany sound irrigation practices to provide an
effective water management program. Good water management provides adequate soil
oxygen as well as adequate soil moisture for maximum crop production.
-6-
STRAWBERRY GROWING COSTS
John Otte
Objective:
Procedure:
To estimate production and harvest costs of strawberries.
Survey growers, suppliers, and dealers to determine equipment
requirements and production practices. Equipment and supply
costs were estimated for each practice.
Results: Table 2 shows estimated variable strawberry growing costs per
acre for a typical Plant City area 20-acre farm. Fuel, oil,
and labor costs are included with the costs for each practice.
Spray materials costs are estimated from the individual spray
program. Total variable costs are estimated at $2269/A.
The $1247 fixed costs per acre include: machinery, well, and
irrigation equipment depreciation, interest on investment,
taxes, insurance, repairs, licenses, and interest and taxes
on land.
Harvesting costs are estimated at $1.99
includes $0.55 for containers and $1.44
benefits, supervision, and packing shed
per flat. This
for picking labor,
operations.
Table 1. Estimated break-even prices to cover the fixed, variable, harvesting
and packing costs for strawberries, 1977.
Yield Variable F and Vz H and PY V H and P F, V, H, and
saleable cost cost cost costs P costs
Flats --------- -------- $ per flat ----------------------
1400 1.62 2.51 1.99 3.61 4.50
1600 1.42 2.20 1.99 3.41 4.19
1800 1.26 1.95 1.99 3.25 3.94
2000 1.13 1.76 1.99 3.12 3.75
ZF and V equal fixed and variable costs, respectively.
yH and P equal harvesting and packing costs, respectively.
-7-
Table 2. Estimated variable strawberry growing costs per acre for a typical
Plant City area 20-acre farm, 1977.
Item
I. Cash costs
Remove plastic from previous crop
8 hrs. labor @ $2.66/hr
Rotovate, 1 time, 1.5 hrs. each time
tractor, driver, and rotovator @ $6.52/hr
Fertilizer for cover crop
chicken manure, 3 tons, delivered and spread
Plant cover crop, 1 time, 1/2 hr. @ $5.28/hr
sedd, 50 lbs. sorghum
Rotovate cover crop, 2 times, 1.5 hrs. each time
tractor, driver, and rotovator @ $6.52/hr
Lay off rows, 1 time, 1 hr. each time, tractor and
driver, @ $5.28/hr.
Make beds, 1 time, 1 hr. each time, tractor
and driver, $5.28/hr.
Fertilizer, 2 times, 1 hr. each time
tractor, with spreader and driver @ $5.28/hr
Fertilizer, 3000 Ibs. 6-8-8 @ $152/T
Lime, 1 ton every 3 years @ $14/T
Fumigate, 1 time, 4 hrs. each time
tractor with fumigator and driver @ $5.97/hr.
3 helpers @ $2.66/hr.
Fumigant, 175 lbs. @ $0.80 lb.
Plastic, 11,000 ft. x 44 in. @ $14/1000 ft.
Set plants
40 hrs. labor @ $2.66/hr.
23,000 plants @ $32/1000
Cultivate, 3 times, 1 hr. each time
tractor, with cultivator and driver @ $5.28/hr.
Spray, 36 sprays, 1/2 hr. each time
tractor, driver and sprayer @ $5.95/hr.
spray materials
Electricity for irrigation
Interest on above expenses, 8.5% for 7 months
Total variable costs
II. Fixed costs
III. Total production costs other than harvesting
& packing
Cos t-
$ 21.28
9.78
45.00
2.64
15.00
19.56
5.28
5.28
10.56
228.00
4.67
23.88
31.92
140.00
154.00
106.40
736.00
15.84
107.10
429.58
50.00
107.19
$2,268.96
$1,247.00
$3,515.96
Cost
-8-
MITICIDES ON STRAWBERRIES
David J. Schuster and James F. Price
FIELD #1
PURPOSE: To evaluate new materials for miticidal'activity against the two-spotted
spidermite, Tetranychus urticae Koch.
CULTIVAR: 'Florida Belle'
SET: October 28, 1977; TREATED: Weekly, beginning January 31, 1978.
TREATMENTS:
A. Check (water)
B. Plictran 50WP
C. DPX-3792 2EC
D. DPX-3792 2EC + Plictran 50WP
E. ZR-856
F. Vydate 2L
OPERATION:
lb ai/100 gal
0.5
0.25
0.125 + 0.25
4.0 lbs
0.5
Plants will be treated weekly with fungicide. Leaflets will be sampled
once a month for mite counts. Yields will be taken weekly.
SUMMARY: Plictran(R),
good control
Vendex R), and several experimental chemicals have given
of the two-spotted spidermite.
MITE TOLERANCE OF STRAWBERRIES
David J. Schuster and James F. Price
FIELD #2
PURPOSE: To evaluate the effect of control of the two-spotted spidermite on four
commercial strawberry cultivars.
CULTIVARS:
A. Florida Belle
B. Sequoia
C. Siletz
D. Tioga
SET: October 28, 1977
OPERATION:
Plants will be
receive weekly
sampled once a
treated weekly with fungicide. One-half of each plot will
sprays of Plictran for mite control. Leaflets will be
month for mite counts. Yields will be taken weekly.
SUMMARY: Last season mites were significantly controlled on all cultivars although
fewest mites were obtained from treated Sequoia plots. Treated and untreated
'Florida Belle' plots outyielded all other cultivars. 'Sequoia' and 'Florida
Belle' were most tolerant and 'Tioga' least tolerant of the mite infestation.
-9-
OSMOCOTE RATE AND PLACEMENT TRIAL
E. E. Albregts
FIELD #2
OBJECTIVE:
To determine the optimum placement
strawberries when used as the only
sprinkler irrigation.
and rate of Osmocote 16-5-16 on
fertilizer source with overhead
Fertilizer Rates
Plot no. placement (lbs/acre N & K)
A. Under plants 100
B. Under plants 150
C. Under plants 200
D. Inside plant row 100
E. Inside plant row 150
F. Inside plant row 200
G. Outside plant row 100
H. Outside plant row 150
I. Outside plant row 200
J. 1/3 mixed 2/3 banded 150
K. Regular fertilization 200
~~^"'TY: 'Florida Belle' were transplanted on October 4, 1977. All moisture
provided with overhead sprinklers.
PESULTS: Last year showed few differences because of rate. Osmocote banded under
plants was not toxic.
-------------------------------
TRANSPLANT DIP.AND SPRAY'TRIAL
E. E. Albregts
FIELD #3
OBJECTIVE: To determine if immersing the roots or spraying foliage at transplanting
or a combination of both procedures enhance early plant growth or yield.
To compare these treatments with a check and two fertilizer spray treat-
ments.
Plot no. Treatment
A. Plant roots dipped at transplanting with growth stimulant.
B. Foliage sprayed after plants established with growth stimulant.
C. Combination of treatments in plots A and B.
D. Applied 5 g/gallon of Nutri-Leaf for 10 days after transplanting.
E. As plot D except 25 g/gallon.
PLANTING DATE: 'Florida Belle' plants set on October 5, 1977.
RESULTS: Greenhouse trials indicated that more root growth appeared earlier with
the growth stimulant.
-10-
EFFECT OF HERBICIDES APPLIED IN NURSERY ON PLANT GROWTH AND FRUITING
IN THE FRUITING FIELD
E. E. Albregts
FIELD #4
OBJECTIVE:
PLANTING DATE:
To determine the effect of various herbicides applied in strawberry
nursery on the growth and fruiting response of the plant when placed
in the fruiting field.
Plot no. Herbicides applied in nursery
A. No herbicide
B. Prowl
C. Dacthal and Tenoran low rate
D. Dacthal and Tenoran high rate
E. CIPC and Dacthal
'Florida Belle' plants which had been sprayed three times
in the summer nursery with the above herbicides were set
on October 5, 1977.
RESULTS: Plants which received the high rate of Dacthal and Tenoran in the
nursery were slower in their growth rate in November and December
than plants in other treatments.
-11-
STRAWBERRY VARIETY TRIAL
E. E. Albregts and C. M. Howard
FIELD #5
OBJECTIVE: To determine the growth characteristics, fruit quality, earliness,
and yields of advanced breeding lines.
Plot no. Cultivar or breeding line
A. 1965
B. 1872
C. Florida Belle
D. Tioga
E. Tufts
Small stakes in plots have the breeding line number or cultivar name written on them.
FIELD DATA: Plants were set on October 12, 1977.
1978 RESULTS: None as yet.
PREVIOUS RESULTS:
Marketable yields in flats/acre and weight of fruit in
grams/fruit for 5 clones for two years.
Yield Cultivar or breeding line
(flats acre) Tioga #1965 #1872 Tufts Florida Belle
1976 Yield 2256 2840 2090 1411 2400
1977 Yield 1516 2508 2274 2033
Fruit wt (g/fruit)
1976 fruit wt 10.7 12.9 11.6 12.9 15.1
1977 fruit wt 10.9 13.2 11.9 15.1
FRUIT QUALITY:
The fruit of 1965 are firm and have good appearance and shape and
are seldom malformed. The fruit of 1872 are very firm, have gen-
erally good appearance and shape with some slight misshapen fruit
early in season. Clone 1965 produces fruit earlier and in greater
amounts early in the season than does 1872.
-12-
PLANTING DATE AND PLANT CHILLING
E. E. Albregts
FIELD #6
OBJECTIVE: To determine the planting date and amount of chilling needed for locally
grown clones of 1965 and 1872 for optimum fruit quality and yields.
Plot no. Date of planting Line Chilling
A. October 3 1965 0
B. October 3 1965 15
C. October 3 1965 30
D. October 17 1965 0
E. October 17 1965 15
F. October 17 1965 30
G. November 1 1965 0
H. November 1 1965 15
I. November 1 1965 30
RESULTS: Thirty days chilling of both clones caused heavy runner production and de-
layed flowering. First yields came from those plants not chilled and set
on October 3. Clone #1965 produced fruit earlier than clone 1872.
CHICKEN MANURE AS FERTILIZER SOURCE ON STRAWBERRIES
E. E. Albregts
FIELD #7
OBJECTIVE:
To determine
composition.
effect of chicken manure on yields and on soil elemental
Plot no. Treatment
A. Check no fertilizer
B. Regular fertilization
C. 4 tons chicken manure/acre
D. 4 tons chicken manure/acre + 40 lbs N & K
E. 8 tons chicken manure/acre
F. 16 tons chicken manure/acre
G. 32 tons chicken manure/acre
PLANTING DATE:
'Florida Belle' plants were set on October 5, 1977. Received 6 inches
of rain from time of chicken manure application to date of fumigation
and mulch application.
RESULTS: Past year's results indicate that 8 tons/acre of good quality chicken manure
will raise a good crop of fruit if heavy rain does not leach out fertility
between time of application and mulching. Calcium levels must be monitored
in soils with high levels of chicken manure.
-13-
STRAWBERRY BREEDING
C. M. Howard
FIELDS #8 and 9
OBJECTIVES: To develop new strawberry varieties that are specifically adapted to
Florida growing conditions.
Table 1. Numbers of seedling clones tested in 1973-74 through 1977-78 seasons.
No. clones No. selected No. of clones
Season fruited for observation in rep. trial
1973-74 2,596 181 16
1974-75 1,956 497 12
1975-76 1,258 112 20
1976-77 1,185 213 18
1977-78 1,051 17
First year (Field 8): Crosses are made in the greenhouse during the winter and seeds
are sown in flats in late March or early April. Seedlings are transplanted into indi-
vidual peat pots in May or early June and set in the nursery in late June where they
form runners. In October, clones are selected from the nursery on the basis of runner
production and resistance to anthracnose, leaf spot and leaf blight. Four plants of
each selection are transplanted into the fruiting field where records are kept on
fruit yield and other characteristics. Specific clones are selected primarily on the
basis of early (through Jan.) and total (through March) yields, and fruit color, size,
appearance and ripening characteristics. Some clones are selected for specific charac-
teristics such as long fruit stems or concentrated ripening in an effort to develop
clones that may be useful for mechanical harvesting.
Second year (Field 9): The clones that have been selected are transplanted into the
summer nursery where they are again observed for runner production and resistance to
anthracnose. In October, selections are made from this group and transplanted into
10-plant observation plots. In this trial the clones are compared with currently
grown varieties and the fruit and plants are observed more closely for any defects
such as poor color or soft fruit. Specific clones are selected on the basis of plant
type, early and total fruit yield, and fruit firmness, color, size, ripening charac-
teristics and general appearance. These clones are transplanted into the nursery in
April where they are again observed for runner production and resistance to diseases
(especially anthracnose).
Third and Fourth years: The most promising clones from the second year observational
trials are placed in replicated trials where they can be thoroughly compared with var-
ieties currently being grown in Florida. After a clone has shown sufficient promise
at least 2 years in replicated trials, a variety release committee may be formed. If
the committee, after reviewing all the accumulated date, agrees that the specific clone
should be an improvement over currently grown varieties, then it can be named and re-
leased as a new variety.
Grower trials: When we feel that a line shows real promise of becoming a new variety,
we get a few plants out to growers to see how the line reacts on various soil types
and under various cultural systems. This way we get the opinions of many growers
(because several growers observe each small lot of plants) and the handlers.
-------------------------------
-14-
STRAWBERRY DISEASES
C. M. Howard
FIELD #10
OBJECTIVES: To determine the cause, importance and control of strawberry diseases.
Colletotrichum fruit rot: Round, dark spots which are firm and sunken. Very severe
in some fields during warm periods. This fungus also causes anthracnose and wilt.
Dendrophoma fruit rot: Round, light pink or gray spots which are soft and not sunken.
Small black fruiting bodies often form in these lesions. Very severe in some fields
during some periods. This fungus also causes leaf blight.
Pestalotia fruit rot: Lesions variable. The most typical lesion has a round, light
tan central area which is slightly sunken below the original fruit surface and a sur-
rounding band of soft tissue which is definitely sunken. Rarely serious in commer-
cial fields.
Alternaria fruit rot: Lesions round or irregular in shape and light green to nearly
black, depending on the stage of development. Rarely serious in commercial fields.
Fruit rot control: The only fungicides presently registered for use on strawberries
which have a short enough required interval between application and harvest for use
under Florida's conditions are Captan, Benlate and Copper sulfate. If regular spray
intervals are maintained and good coverage is achieved, Captan will usually give good
control of all these fruit rots, but during periods of severe disease incidence Ben-
late usually gives better control of the Colletotrichum and Dendrophoma fruit rots.
Copper sprays become toxic to the plants after repeated applications and can not be
used for long periods. Colletotrichum and Dendrophoma rots usually become most severe
after some interruption of the picking schedule results in large numbers of overripe
fruit accumulating in the field. At times these two rots become extremely difficult
to control. In those cases, the quickest and most effective control consists of pick-
ing all fruit that is ripe or beginning to ripen (even those in the early pink stage)
and discarding them in the middles, then immediately following this with an applica-
tion of Captan or Captan plus Benlate.
-------~---------------~---------
-15-
INTERMITTENT IRRIGATION TO ESTABLISH PLANTS
E. E. Albregts
FIELD #12
OBJECTIVES:
To reduce the irrigation requirements needed to establish strawberry
plants after transplanting by applying overhead irrigation intermit-
tently.
Row no. Treatment
A. Irrigation on 15 minutes, off 15 minutes
B. Irrigation on 10 minutes, off 20 minutes
C. Irrigation on 5 minutes, off 25 minutes
D. Irrigation on 3 minutes, off 17 minutes
E. Irrigation on 5 minutes,'off 15 minutes
F. Continuous irrigation
PLANTING DATE:
'Florida Belle', and clones 1965 and 318 were set on October 19,
1977 and given the above irrigation treatments until October 31,1977.
RESULTS: Previous results indicate that one can apply irrigation in 15 minute inter-
vals even in hot, windy and dry weather and not increase leaf loss or plant
mortality and not reduce yields.
FERTILIZER SOURCE AND PLACEMENT ON STRAWBERRIES
E. E. Albregts
FIELD #13
OBJECTIVES;
To evaluate four fertilizer sources and eight fertilizer placements on
strawberry fruit quality and yield.
Plot no. Source Placement
coated
coated
coated
coated
coated
coated
coated
coated
Bed center 2" band near surface
As plot A with 10 lbs TH & K in plant hole
As plot A with 20 lbs N & K in plant hole
As plot A with 40 lbs N & K in plant hole
3/4 rate of plot A with 20 lbs U & K in plant hole
As plot A, but band 6" wide
As plot A, but 1/4 mixed in top 3" of bed
As plot G, but 1/2 mixed in top 3" of bed
Fertilizer sources of urea, Osmocote, and IBDU also used and applied in same manner
as sulfur coated fertilizer.
RESULTS: Mixing part of the fertilizer in the bed or applying slow release fertili-
zer in the plant hole has increased earliness and seasonal yields as well
as the plant growth.
Sulfur
Sulfur
Sulfur
Sulfur
Sulfur
Sulfur
Sulfur
Sulfur
-16-
COMPARISON OF DRIP AND OVERHEAD IRRIGATION
E. E. Albregts
FIELD #14
OBJECTIVES:
To determine optimum moisture content or irrigation rate plus
fertilization rate with drip irrigation. In addition, to com-
pare overhead and drip irrigation and to evaluate fertilizer
source under drip irrigation with two and four row beds.
Plot no. Treatment
A. Overhead irrigation
B. Drip irrigation low moisture, 6 Ibs N&K/wk
C. Drip irrigation high moisture, 6 Ibs N&K/wk
D. Drip irrigation low moisture, 8 lbs N&K/wk
E. Drip irrigation high moisture, 8 Ibs N&K/wk
F. Drip irrigation low moisture, 10 Ibs N&K/wk
G. Drip irrigation high moisture, 10 Ibs N&K/wk
RESULTS: Previous results indicate that after plants begin to flower 8 Ibs/acre
(injected in drip tubes) of N & K are needed per week for best yields.
Dry fertilizer can be used in place of injection of fertilizer if placed
in bed properly and some slow-release materials is used.
FIELD 6
DATE OF
PLANTING
AND
CHILLING
I P
Ln
m -
>- cc
-,a
.JL
Ijw
Lrc,
FIELD 7
CHICKEN
IiANURE
RATES
FIELD 8
OBSERVATIONS
BARN
MEETING AREA
I1-1
UJ CD
U- iU
,l V
0 a
u.
FIELD 9
SEEDLINfGS
ow
i-
Lz -1
GREENHOUSE
_IFI
OFFICE E
FIELD 1
MITICIDES
BLDG 7
Li-
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