Citation
Strawberry field day. February 6, 1985.

Material Information

Title:
Strawberry field day. February 6, 1985.
Series Title:
Strawberry field day.
Added title page title:
Research report - Dover, Florida Agricultural Research Center ; DOV85-1
Creator:
Albregts, E. E. ( Editor )
Howard, C. M. ( Editor )
Waters, W. E. ( Editor )
Place of Publication:
Dover, Fla.
Publisher:
Agricultural Research Center, Institute of Food and Agricultural Sciences, University of Florida
Publication Date:
Language:
English

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Subjects / Keywords:
Agricultural Research Center, Dover ( fast )
Agricultural Research & Education Center (Dover, Fla.) ( fast )
Gulf Coast Research and Education Center (Dover, Fla.) ( fast )
University of Florida. Institute of Food and Agricultural Sciences ( fast )
Strawberries ( fast )
Florida ( fast )
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serial ( sobekcm )
periodical ( marcgt )

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University of Florida
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All applicable rights reserved by the source institution and holding location.
Resource Identifier:
143121533 ( OCLC )

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FAO1:
Food and Agricultural Sciences
UFIR:
Institutional Repository at the University of Florida (IR@UF)
FLAG:
Florida Historical Agriculture and Rural Life
IUF:
University of Florida
EXPERIMENTSTATION:
University of Florida IFAS Experiment Station Publications Archive

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AGRICULTURAL RESEARCH & EDUCATION CE
INSTITUTE OF FOOD AND AGRICULTURAL SCIEN -
UNIVERSITY OF FLORIDA <'
Dover, Florida
Dover AREC Research Report DOV85-1 Feb 19

STRAWBERRY FIELD DAY PROGRAM
February 6, 1985
E. E. Albregts, C. M. Howard and W. E. Waters, Editors



PROGRAM PARTICIPANTS

W. E. Waters, Center Director (GCREC-Bradenton)
J. M. Davidson, Univ. of Fla. (Gainesville)
A. J. Overman, Nematologist (GCREC-Bradenton)
J. F. Price, Associate Entomologist (GCREC-Bradenton)
J. W. Prevatt, Associate Area Extension Economist (GCREC-Bradenton)
J. P. Gilreath, Assistant Horticulturist (GCREC-Bradenton)
C. D. Stanley, Associate Extension Water Specialist (GCREC-Bradenton)
R. L. Mitchell, Extension Agent, Hillsborough County
C. M. Howard, Plant Pathologist (AREC-Dover)
M. Sherman, Assistant Horticulturist (Univ. of Fla.)
E. E. Albregts, Soil Chemist (AREC-Dover)



Rick Mitchell, Hillsborough County Extension Agent Moderator

1:45 4:15 P.M.
Assembly and Registration
Dr. W. E. Waters, Welcome and Introduction
Dr. J. M. Davidson, Comments on IFAS Research Programs
Prof. A. J. Overman, Nematode Control in Strawberries
Dr. J. F. Price, Insects and Mites on Strawberries
Dr. J. W. Prevatt, Florida Strawberry Production Costs
Dr. J. P. Gilreath, Weed Control in Strawberries
Dr. C. D. Stanley, Water Management in Strawberries
Dr. C. M. Howard, Strawberry Breeding, Variety Trials and Diseases
Dr. M. Sherman, Harvesting and Handling of Strawberries
Dr. E. E. Albregts, Gibberellin on Strawberries
Bed Width for Fruiting Strawberries
Slow Release Fertilizer for Strawberries
Strawberry Foliar Spray Trial
Nitrogen Rate and Source for Strawberries
Potassium Rate and Sources for Strawberries
Planting Date, Day Length, and Chilling









TABLE OF CONTENTS


WELCOME AND INTRODUCTION, W. E. Waters. . . ... ... 3

PESTICIDES FOR NEW INSECT AND MITE CONTROL PRACTICES, J. F. Price . 4

FLORIDA STRAWBERRY PRODUCTION COSTS, J. W. Prevatt . . .5

SUMMARY OF RESULTS IN RECENT STRAWBERRY WEED CONTROL RESEARCH
J. P. Gilreath . . ..... . . 8

TRICKLE IRRIGATION AND WATER USE FOR STRAWBERRY PRODUCTION
E. E. Albregts, C. D. Stanley, and F. S. Zazueta . . .10

STRAWBERRY BREEDING, C. M. Howard . . . . .. .. 11

STRAWBERRY VARIETY TRIALS, E. E. Albregts and C. M. Howard . 12

CONTROL OF STRAWBERRY DISEASE, C. M. Howard .. . . .14

APPLICATION OF GIBBERELLIN (GA) TO NURSERY PLANTS, E. E. Albregts .14

BED WIDTH FOR FRUITING STRAWBERRIES, E. E. Albregts . ... .15

SLOW RELEASE FERTILIZER FOR FRUITING STRAWBERRIES, E. E. Albregts .15

FOLIAR FERTILIZER SPRAY TRIAL, E. E. Albregts . . . .16

EFFECT OF NITROGEN PLACEMENT, SOURCE AND RATE ON STRAWBERRIES
E. E. Albregts. . ....... . . . 17

POTASSIUM RATE AND SOURCES FOR STRAWBERRIES, E. E. Albregts . .18

PLANTING DATE, DAY LENGTH AND CHILLING OF NORTH CAROLINA STRAWBERRIES
E. E. Albregts .. ... . .... .. .. 19






ACKNOWLEDGEMENTS

We would like to thank the Florida Strawberry Growers Association
for providing the coffee and soft drinks.











WELCOME AND INTRODUCTION


W. E. Waters, Center Director


On behalf of the faculty and staff, I extend to each of you a most cordial
welcome to the Dover Agricultural Research and Education Center. The Center
was initiated in 1927 as a one-man operation located southeast of Plant
City. In 1963 the Center was moved to its present location, and the programs
were expanded. This Center, with affiliated Agricultural Research Centers
located in Bradenton and Immokalee, is a Research and Education unit of
the University of Florida's Institute of Food and Agricultural Sciences.

In Dover and Bradenton, 5 research scientists and 3 extension specialists
participate in strawberry research and extension programs. Each research
scientist also holds a joint appointment with his subject matter department
at the University of Florida. This combination of a broad base of research
disciplines, industry contacts and an excellent faculty makes the inter-
disciplinary cooperative team approach to research problems far more productive
than could otherwise be accomplished with limited investment in independent
programs.

The overall mission of these Centers deals directly with the strawberry
industry in Florida through research programs in (1) genetics, breeding
and variety development and evaluation; (2) biological, chemical and mechanical
pest control; (3) production efficiency, culture, fertilization, management
and environmental stress; (4) alternate energy sources, and energy conservation
and engineering; (5) mechanization, harvesting, handling,, and postharvest
physiology; (6) food quality, safety and utilization practices; (7) water
management and conservation; (8) advancement of basic knowledge of the various
scientific disciplines represented by the faculty; and (9) assistance to
the cooperative extension service, departments in the College of Agriculture
and other Research Centers with extension, educational training and cooperative
research programs for the benefit of producers, consumers and students.

Information presented in this publication summarizes the active research
and extension projects under way this season on strawberries. We sincerely
appreciate your interest and support of these programs, and continuously
solicit your suggestion for improvement, and welcome input concerning industry
needs to keep our research and extension programs productive.










PESTICIDES FOR NEW INSECT AND MITE CONTROL PRACTICES

J. F, Price



Location: Block 15

Objective: To determine the usefulness of selected experimental and previously
registered pesticides for mite control on strawberries under the production
conditions of the Plant City area.


Treatment:


Treatment No.


Pesticide Treatment


Untreated check
Plictran 50WP at 1 lb/lOOgal
Omite CR at 3 Ib/acre
Omite CR at 6 lb/acre
Apollo 4SC at .2 lb ai/acre
Apollo + Plictran
DPX Y5893 50JP dip at 1 oz ai/100 gal;
spray ea. 4 wk after fruit set
DPX Y5893 50WP dip at 2 oz ai/100 gal;
spray ea. 4 wk after fruit set
DPX Y5893 w/o dip; spray at 1 oz ai/100
Pydrin 2.4 EC at 0.2 lb ai/acre applied
Pydrin 2.4 EC at 0.4 lb ai/acre applied
Phosdrin 4 EC at 1 qt/100 gal


gal as needed
3 times at 1 wk
3 times at 1 wk


Method of Operation: All pesticidal sprays are applied at 100 gal. of prep-
aration per acre. Most applications are made 3 times at 3 or 4 day intervals
after mite populations build up. All other pesticides are applied as the
special conditions above indicate. Yield records are maintained and phytotoxic
reactions in strawberry plants are recorded.









FLORIDA STRAWBERRY PRODUCTION COSTS


J. W. Prevatt


Putting something away for a rainy day requires a
longer stretch of clear weather than it used to.


After back-to-back severe freezes during 1983-84 and 1984-85, many Florida
strawberry growers will be taking a hard look at their costs and returns.
There is little likelihood that market prices will increase sufficiently
during the rest of this year's season to offset production losses for those
affected by the freeze. The financial stress due to the freezes will be
felt for some years to come by many growers. Hopefully, the future will
include favorable conditions such as good growing weather and market prices
which will help the industry recover.

The vagaries of the weather which resulted in lower yields and market prices
have made growers keenly concerned with not only production and prices,
but also the cost of production. Estimating costs is a necessary management
tool that will aid growers when making production and financial decisions.
The development of this information enables growers to estimate cost projections
which may be used to plant credit needs before planting a crop. Reviewing
various levels of expected yields and production costs can be used to evaluate
marketing alternatives and break-even prices. Also, a grower can compare
projected costs to records from previous seasons to determine business perfor-
mance and to aid in planning future crops. In addition, enterprise budgets
are very useful when identifying cost items that may be reduced and/or more
effectively utilized.

The estimated operating and ownership costs per acre for strawberry production
in west central Florida during the 1984-85 growing season are reported in
Table 1. This information was developed with the assistance of participating
growers, agribusiness representatives, extension specialists and researchers.
Although an effort was made to insure that the budgets are reasonably accurate,
the fact remains that individual producers often do things differently (sometimes
substantially). Because of the wide variation of alternative inputs, locations
and production systems, it is important for each grower to develop his own
budgets and understand how to utilize them when making management decisions.

Estimated break-even prices to cover operating, ownership, and total costs
were calculated for production during 1984-85, as shown in Table 2. These
break-even prices were computed by dividing the appropriate costs by the
estimated saleable yield. The break-even prices describe the price per
flat necessary to cover the various production costs associated with a particular
level of yield. For instance, assume a grower produces 2,000 flats per
acre and incurs the preharvest cost described in Table 2. The break-even
price to cover preharvest operating costs would be $1.95 per flat
($3,895.17/2,000 flats). However, a grower would harvest his strawberries
only if the market price exceeds the costs to harvest and market the straw-
berries. Therefore, a grower must receive greater-than $3.30 per flat (harvest










and market costs) before any preharvest operating costs are met. Thus,
a break-even price of $5.25 per flat would be necessary to cover first the
harvesting and marketing cost, and secondly the preharvest cost (total operating
cost). In order to cover all costs, ownership costs should be added to
total operating costs which in this example sums to $5.96 per flat. A strawberry
grower using these costs and yield would need to average $5.96 per flat
during the production season to break even. Any average value/flat greater
than $5.96 per flat should be interpreted as returns to land, management,
manager's labor, other capital improvements and risk. Obviously, most growers
will need to add. $1 to $2 per flat to the break-even price to cover family
living expenses, capital reinvestments, etc. That would mean grower needs
to average $7 to $8 per flat to cover all expenses.

Growers that accurately estimate production costs and yield will have the
information necessary to evaluate marketing alternatives as they develop. In
addition, they will have budgets to measure the profitability of growing
strawberries and for making informed decisions about future investments.







Table 1. Estimated operating and ownership costs per acre
production, west central Florida, 1984-851.


for strawberry


Price/unit
of material


Item Month Unit Quantit

I. Operating Costs


Price/
gross acre


Pre-harvest
Dolomite
Disk
Plant
Sorghum seed
Rotovate
Lay off rows
Press beds
Fertilizer
14-5-14
Fumigate
Fumigant (MC-33)
Plastic
Labor
Transplants
Labor (transplants)
Cultivate
Spray
Captan (36 appl.)
Benlate (16 appl.)
Dibrom (6 appl.)
Plictran (6 appl.)
Phosdrin (12 appl.)
Remove plastic (labor)
Irrigation (elec.)
Interest


May
May
June
June
Sept.
Sept.
Sept.
Sept.
Sept.
Sept.
Sept.
Sept.
Sept.
Oct.
Oct.
Nov.-May
Oct.-Apr.





May
Oct.-Apr.
Sept.-May


Ton
Acre
Acre
Pound
Acre
Acre
Acre
Acre
Ton
Acre
Pound
Thou. ft.
Hour
Thousand
Hour
Acre
Acre
Pound
Pound
Gallon
Pound
Gallon
Hour
Acre
Dollar


0.33
2.00
1.00
50.00
2.00
1.00
1.00
1.00
.1.50
1.00
265.00
11.00
4.00
23.00
40.00
3.00
36.00
216.00
16.00
1.25
12.00
1.50
8.00
1.00
3,525.04


25.00
10.05
3.00
0.69
10.05
5.90
5.90
5.90

11.70
0.98
27.85
4.00
45.00
4.00
6.90
3.85
1.80
13.30
43.52
20.68
26.72
4.00
65.00
0.14


Pre-harvest operating costs


Harvest & Marketing
Picking & Packing
Containers
Miscellaneous
Transport
Marketing charge2


II. Ownership Costs/A3


Dec.-Apr.


8.25
20.10
3.00
34.50
20.10
5.90
5.90
5.90
A97.10
11.70
259.70
306.35
16.00
1,035.00
160.00
20.70
138.60
388.80
212.80
54.40
248.16
40.08
32.00
65.00
370.13

$3,895.17


$/Flat
1.45
0.70
0.55
0.10
0.50
$3.30


$1,410.00


1The estimated operating and ownership costs described in this table represent
a rationalization among sampled growers, extension specialists and researchers.
Individual growers should estimate their operating and ownership cots, since
these costs differ widely among operations.
2Marketing charge is based on handling cost per flat which was approximately
10% of the market price.
30wnership costs include depreciation, insurance, repairs, taxes and interest
on land and equipment for strawberry production.


_ _























Table 2. Estimated breakeven prices to cover operating and ownership
costs for strawberry production, west central Florida, 1984-85.


Operating costs Total
Saleable Harvest operating Ownership Total
yield/acre Preharvest & market costs costs costs

Flats1 -----------------Dollars per flat-----------------------

1400 2.78 3.30 6.08 1.01 7.09

1600 2.43 3.30 5.73 0.88 6.61

1800 2.16 3.30 5.46 0.78 6.24

2000 1.95 3.30 5.25 0.71 5.96

2200 1.77 3.30 5.07 0.64 5.71

2400 1.62 3.30 4.92 0.59 5.51



IA flat is composed of 12 pints of strawberries.





SUIMARY OF RESULTS IN RECENT STRAWBERRY WEED CONTROL RESEARCH


J. P. Gilreath and E. E. Albregts

Chcmicali weed control has been researched in both the fruiting field and summer
itlrpedy during the last two years. The following is a sumraary of these experiments.

Preplant applications of 1 and 2 lb. a.i./acre of Lasso and 2 and 4 lb. a.i./acre
of Nortron and postemergence applications of 0.5 lb. a.i./acre of Blazer and
Tackle were evaluated for weed control and crop toxicity in mulched 'Tufts'
strawberries during the 1982-83 production season. Lasso and Nortron provided
excellent early season grass and broadleaf weed control. Blazer and Tackle
provided good control of Carolina geranium, but did not control grasses. Strawberry
plant vigor was reduced by the higher rates of Lasso, Tackle and Blazer; however,
the phytotoxicity of Blazer and Tackle were confined to the foliage present
at treatment, and plants soon overcame the visible injury. None of the treatments
provided season-long weed control. Fewer fruit were produced in herbicide treated
plots than in the untreated control plots.

Although they reduced yields, Lasso and Nortron may be acceptable compounds
for weed control in strawberries when applied to row middles. They would be
especially useful in row middles since they were only mildly injurious to strawberry
plants placed in direct contact with soil treated with these compounds. Blazer
and Tackle were somewhat more phytotoxic; however, the plants recovered rapidly
from the injury. In addition, they did not reduce fruit number relative to
the other herbicide treatments, and for these reasons may be useful for control
of difficult to suppress winter annuals such as Carolina geranium, especially
when applied with a shielded sprayer.

In 1984, a combination of herbicides which had looked promising in previous
research were evaluated for weed control and plant injury in a summer nursery
planting of 'Dover' and 'Florida Belle' strawberry plants. The herbicide treatments
were pre-transplant applications of 2.0 lb. a.i./acre Devrinol, 9.0 lb. a.i./acre
Dacthal and 1.5 lb. a.i./acre Lasso. These were followed by 3 additional post--
transplant applications of the above herbicides with 0.25 lb. a.i./acre Fusilade
included as a tank mix in combination with the last 2 applications of each treatment
to provide control of established grass weeds. Several difficult-to-control
broadleaf weed species were in the experimental area. Since previous experience
had established that the preemergence herbicides in this experiment would not
control these weeds (coffee weed, beggartick, sicklepod), a 33% solution of
Roundup was applied 3 times with a wiper applicator to kill these weeds once
their height exceeded that of the strawberry plants. A weedy or untreated check
and a hand weeded check were included for comparison purposes.

All of the herbicide treatments reduced strawberry plant vigor. Weed control
was determined several times during the season by counting the number of weeds
of each species in each plot. The herbicide treatments reduced the numbers
of beggartick, sicklepod, and goosegrass plants equally well, and had populations
of these weeds comparable to the hand weeded check. Control of hairy indigo
was acceptable with the Devrinol + Fusilade + Roundup treatment only.

Strawberry plants were dug October 31, 1934 and graded by size. Fewer 'Florida
Belle' plants were dug in plots treated with the Devrinol and Lasso combinations.
The number of plants dug in plots treated with the Dacthal combination was not
different from the weedy check or the hand weeded check. Numbers of l-rge and
extra snall plants were not affected by any of the herbicide trn-rments; however,
ewer s.ll and medium size plants were produced in plots treated with the herbicide
combinat-.0ons. Production of 'Dover' plants (both total number of plants and
numbers pse s-i.z grade) was reduced by all herbicide ti.eatments. Evcn the best
herbicide i:reatrent, the Dacthal combination, o.ly had half as many plants as







the hand weeded check.


It is apparent from this and previous research that mechanical and hand weeding
are presently best for weed control in the summer nursery. The herbicide treatments
evaluated represent what is currently felt to be the best chemical alternatives.
If the cost or availability of labor changed drastically, then these treatments
would be worth considering.











TRICKLE IRRIGATION AND WATER USE FOR STRAWBERRY PRODUCTION

E. E. Albregts, C. D. Stanley and F. S. Zazueta


Location: Block 14

Objectives: 1) To evaluate the effect of different trickle irrigation rates
on strawberry production and 2) determine strawberry crop water use with field--
located drainage lysimeters.

Treatments:

Treatment No. Irrigation Rates

1 0.75 x Pan*
2 1.0 x Pan
-3 Constant 0.3 in./day

*Pan = Daily evaporation from Class A Evaporation Pan.

Cultivar: Dover

Methods of Operation: Trickle irrigation treatments were established using
dual chamber tubing with an emiter spacing of 12 inches. Water application
is maintained by electronic controllers, programmed for proper application times,
operating solenoid valves. Plots are 25 feet long and replicated four times.
Each plot contains a drainage lysimeter which is exempt from the automated trickle
irrigation system. Each lysimeter consists of a 30-gallon polyethylene garbage
can containing (from the bottom upward) 8-10 inches of gravel, 3 inches of pea-size
gravel, and local soil making up the remaining volume. An access tube for removing
drained, unused irrigation water is present in each lysimeter. Water applications
are made by hand according to rate treatments for surrounding plots. The difference
between the amount of water applied and amount of water drained is assumed to
be the water use for a specific time period of measurement. This amount will
be compared to the estimated amount of evapotranspiration (crop water use) for
the same time period in order to develop a relationship useful for predicting
water requirements based on environmental data.











STRAWBERRY BREEDING


C. M. Howard

Location: Blocks 1, 2, 13

Objective: To develop new strawberry varieties which are specifically adapted
to Florida growing conditions.

Method of Operation:

First year (Block 2): 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 individual 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.
Two 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 appearance, ripening
characteristics, yield, earliness, and fruit size. Emphasis is also
placed on selecting for long, large diameter, single fruit stems to
improve uniformity of fruit size and ease of harvest.

Second year (Block 1): 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 and soft fruit. Specific clones are selected on the
basis of plant type, early and total fruit yield, type of fruit stems,
fruit firmness, color, size, ripening characteristics 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 year (Block 13): The most promising clones from the second year
observational trials are placed in replicated trials where they can
be thoroughly compared with varieties currently being grown in Florida.
After a clone has shown sufficient promise for at least two years in
replicated trials, a variety release committee may be formed. If the
committee, after reviewing all the accumulated data, agrees that the
specific clone should be an improvement over currently grown varieties,
then the clone can be named and released as a new variety.





STRAWBERRY VARIETY TRIALS FOR 1984-85 SEASON

E. E. Albregts and C. M. Howard
Location: Block 13

Objective: To evaluate all promising breeding lines and out-of-state varieties
for, earliness, yield, fruit size, ripening characteristics, and plant growth
characteristics.


Treatment


Clone


Treatment


Clone


Treatment


Clone


1........77-198
2........79-1125
3 .......79-1126
S4........80-456
5........80-1232
6........81-149P
7........81-166P
8........81-318
9........81-1183
10........81-2465
11........81-2553
12 ........81-2689
13........82-101
14 ........82-135P
15........82-136
16........82-144
17........82-174


18........82-197
19........82-415P
20........82-421
21........82-434P
22........82-533
23........82-542
24........82-576
25........82-594P
26........82-670
27........82-820
28........82-946
29........82-1070
30.........82-1072
31.........82-1078P
32........82-1113P
33........82-1115P


34........82-1127P
35........82-1143P
36........82-1163P
37........82-1300P
38........82-1454P
39........82-1486
40........82-1499P
41........82-1560
42.........82-1615P
43........82-1652
44........M82-1864
45........Tufts
46.........Pajaro
47........Chandler
48 ........Douglas
49.........Parker







STRAWBERRY VARIETY TRIAL (CONT'D)


Results: Yields of marketable fruit from selected clones in 1983-84 trials.


Cultivara
Sor line 'December


February March April Seasonalb


Seasonal
av. fruit wt.


Marketable yield (flats/acre)


334
243
751
651
306
337
263
126
307
451
498
219
608
692
315
270
577
164
366
280
173
151
297
347


1518
2124
1616
1740
1624
.2047
2089
.1841
2083
2164
2127
2800
1934
1702
1824
1201
2291
1027
1085
1244
1350
1025
1465
1360


998
538
S107
320
300
760
423
395
767
537
932
615
367
386
427
1038
227
115
1348
673
1004
264
1112
682


aForty-two breeding lines were
the 15 most promising ones.


tested, but data are shown only for


bThe 1984 Christmas freeze makes it difficult to make comparisons
among entries because of differing stages of development of entries
at the time of the freeze, and because of differing degrees of plant
damage among plots.


81-149
77-198
81-318
80-866
77-869
81-872
79-1120
79-1125
79-1126
81-1183
80-1340
81-2465
81-2553
81-2689
81-3114
Chandler
Dover
Fern
Pajaro
Parker
Santana
Selva
Tufts
Tuston


2850
2905
2480
2711
2230
3144
2786
2362
3157
3152
3557
3634
2909
2780
2566
2509
3095
1306
2799
2197
2527
1440
2874
2389


g/fruit


14.56
15.00
13.79
15.26
12.79
13.90
13.81
13.86
15..20
14.19
13.18
14.27.
14.20
15.53
13.69
14.99'
13.24
12.24
14.29
15.31
15.79
12.44
13.82
14.91


---


g/fruit






CONTROL OF STRAWBERRY DISEASE

C. M. Howard


Location: Block 3

Objective: To test new fungicides for control of strawberry diseases.
(Especially, two new fungicides for control of graymold, and two for
control of anthracnose on fruit).

Treatments:

Treatment Fungicide

1 Untreated check
2 Captan 50WP 6 lb/acre twice/week
3 Captan 50WP 6 Ib/acre once/week
4 Benlate 50WP 1 Ib/acre twice/week
5 Drawifol 50WP 2 Ib/acre once/week
6 DPX-H4921 40EC 2.5 oz/acre every 2 weeks
7 DPX-H4921 40EC 1.25 oz/acre every 2 weeks
8 DPX-H4921 40EC 2.5 oz/acre once/week
9 Tilt 3.6E 4 oz/acre once/week
10 CGA 449 50WP 2 lbs/acre twice/week




APPLICATION OF GIBBERELLIN (GA) TO NURSERY PLANTS

E. E. Albregts


Location: Block 6

Objective: Application of GA in nursery normally enhances daughter
plant production. For those cultivars with low runner production,
GA application may be a viable method to enhance plant numbers in
the nursery. Before this is attempted, the fruiting response as related
to rate and time of application needs to be evaluated.

Cultivars: 'Dover' on south end and 'Florida Belle' on north end
of plots.

Treatments GA Rate (PPM) When applied to nursery

1 100 June, July, August
2 50 June, July, August
3 50 June, July
4 50 August, September
5 0

Method of Operation: GA was applied at rates and dates listed above
to 'Dover' and 'Florida Belle' cultivars. Plants were then dug in
October, 1984 and set into fruiting field.













BED WIDTH FOR FRUITING STRAWBERRIES

E. E. Albregts


Location: Block 7

Objective: To evaluate the effect of bed width and plant spacing
on strawberry fruiting response, ease of harvesting, and disease problems.

Cultivars: 'Dover' on south end and 'Chandler' on north end of plots.

Treatments Bed width Plant spacing Rows/bed
Inches Inches

1 14 4 1
2 14 6 1
3 14 8 1
4 18 4 1
5 18 6 1
6 18 8 1
7 24 11 2










SLOW RELEASE FERTILIZER FOR FRUITING STRAWBERRIES

E. E. Albregts


Location: Block 8

.Objective: To evaluate the nitrogen release rate of melamine for strawberries
and determine if any growth regulator effects are present.

Cultivars: 'Dover' on south end and breeding line 79-1126 on north end of plots.


Total nitrogen
applied (lbs/acre)


200
150
200
150
200
150
200


Total pounds of
N/acre from melamine
0
0
50
50
100
100
0


Method of Operation: Melamine is a 50/50 combination of urea and triazine.
Treatment number 7 has 50 lbs/acre of urea, but no triazine. All other nitrogen
is derived from ammonium nitrate. All melamine was applied broadcast.

Summary: Fruit yield results were not different among melamine treatments and
not different from the standard fertilizer treatment during the 1983-84 season.


Treatments










FOLIAR FERTILIZER SPRAY TRIAL


E. E. Albregts


Location: Block 9

Objective: To evaluate foliar fertilizer spray rates and soil fertilizer
rates on fruiting response of strawberries.

Cultivars: 'Dover' on south end and breeding line 79-1126 on north end
of plots.

Treatments Soil fertilizer rates (Ibs/acre) Foliar spray rate
Nitrogen Phosphorus Potassium

1 200 50 170 None
2 200 50 170 One qt acre Stoller*/wk
3 200 50 170 2 qt/acre Helena** once/2 v"
4 200 50 170 2/qt/acre Stoller*/wk
5 50 12 43 10 qt/acre Helena**/wk
6 50 12 43 None

Summary: Previous studies indicated that foliar fertilization generally
enhanced fruit yields when soil fertilization was insufficient. However,
yields were considerably less than obtained when sufficient soil fertilizer
was available. Foliage burn usually prevents sufficient foliar application
of fertilizer when soil fertility is low.

*Stoller material is a 14-4-6 liquid


**Helena material is a 11-8-5 liquid fertilizer







EFFECT OF NITROGEN PLACEMENT, SOURCE, AND RATE
ON LEACHING AND FRUIT YIELD
OF STRAWBERRIES

E. E. Albregts


Location: Block 10


Objective: To correlate nitrogen fertilizer rate, source,
with fruit yield and fertility analysis.


Cultivars:


Treatments


and placement


'Dover' on north end and 'Douglas' on south end of plots.


Fertilizer placement


Broadcast
Broadcast
Broadcast
Broadcast
Broadcast
Broadcast
Band
Band
Band
Band
Band
Band
Band & Broadcast
Band & Broadcast
Band & Broadcast
Band & Broadcast
Band & Broadcast
Band & Broadcast


Fertilizer source*

All NH4N03'
All NH4N03'
All NH4NO3
I NH4N03, 4 SCU
I NH4NO3, 1 SCU
4 NH4NO3, 4 SCU
All NH4NO3
All NH4NO3
All NH4NO3
4 NH4N03, 4 SCU
4 NH4NO3, 4 SCU
I NH4N03, 2 SCU
NH4NO3
NH4NO3
NH4NO3
2 NH4N03, I SCU
1 NH4NO3, 4 SCU
SNH14N03, 4 SCU


Nitrogen rate
(lbs/acre)


70
135
200
70
135
200
70
135
200
70
135
200
70
135
200
70
135
200


Method of Operation: Treatments 1 through 6 had all fertilizer broadcast a
mixed in bed. In treatments 7 through 12 all fertilizer was banded in bed cent
2 inches deep. One-fourth of fertilizer was applied broadcast and 3/4 band;
in treatments 13 through 19. Soil samples are taken monthly.

Summary: Previous work showed that a 100 Ib rate of nitrogen gave very low nitrc,
levels in April. Broadcast application generally gave the lowest soil nitrcg
levels.


*NH4NO3 = Ammonium nitrate; SCU = sulfur coated urea.








POTASSIUM RATE AND SOURCES FOR STRAWBERRIES


E, E. Albregts


Location: Block 11

Objective: To correlate potassium rate and sources with foliar and soil
analyses and strawberry fruit yields.

Cultivars: 'Dover' on north end and breeding line 79-1126 on south end
of plots.

Treatments Lbs K/acre Potassium source

1 0 Potassium chloride
2 50 Potassium chloride
3 100 Potassium chloride
4 150 Potassium chloride
5 200 Potassium chloride
6 50 Osmocote
7 100 Osmocote
8 150 Osmocote
9 50 Sulfur coated K2S04
10 100 Sulfur coated K2S04
11 150 Sulfur coated K2S04

Method of Operation: 'Dover' and breeding line 79-1126 plants were set
on 10/27 and 10/26, respectively.

Summary: In the 1983-84 season the 200 lbs/acre rate of potassium reduced
yields for both 'Tufts' and 'Dover'. 'Dover' yields increased with increasing
potassium rates to 150 lbs/acre. 'Tufts' yields were not affected by potassium
rates except at the highest rate. The potassium rate correlated well with
potassium present in the soil saturated extracts, with amount in the double
acid (Melich) soil tests, and with potassium in the foliage of the 'Dover'
cultivar.


r\/










PLANTING DATE, DAY LENGTH, AND CHILLING OF
NORTH CAROLINA STRAWBERRY TRANSPLANTS

E. E. Albregts

Location: Block 12

Objective: To evaluate effect of planting date and amount of chilling below
450F received in nursery on growth and fruiting response.

Treatments:

Section Cultivars

Red Chandler
Blue Douglas
Green Pajaro
Black Tufts

Row Planting date

1 September 14, 1984
2 September 26, 1984
3 October 12, 1984
4 October 28, 1984


Chilling # Hours


None
12
72
144
None
None
None
None
None
12
72
144
None
12
72
144


Method of Operation: Plants were given the chilling and
in a phytotron at the North Carolina State University by
and then shipped to AREC-Dover for immediate planting.


Day length # Hours

Field conditions4'
14
14
14
Field conditions*
14
14
14
Field conditions*
12
12
12
Field conditions*
12
12
12

day length treatments
Dr. Barclay Poling,


*Day length prior to harvest from nursery in North Carolina.


Treatments


Plot