• TABLE OF CONTENTS
HIDE
 Program
 Table of Contents
 Drip irrigation and hematicide...
 Considerations for spider mite...
 Fungicide trial
 Strawberry diseases
 Strawberry variety trial
 Paraquat herbicide trial
 Strawberry irrigation and fertilizer...
 Strawberry breeding
 Bed height and nitrogen fertilizer...
 Date of planting and plant chilling...
 Intermittent irrigation after...
 Field map






Group Title: Strawberry field day.
Title: Strawberry field day. February 20, 1975.
ALL VOLUMES CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00076494/00002
 Material Information
Title: Strawberry field day. February 20, 1975.
Series Title: Strawberry field day.
Alternate Title: Research report - Dover, Florida Agricultural Research Center ; SV75-1
Physical Description: Serial
Language: English
Publisher: Agricultural Research Center, Institute of Food and Agricultural Sciences, University of Florida
Publication Date: 1975
 Record Information
Bibliographic ID: UF00076494
Volume ID: VID00002
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 143121533

Table of Contents
    Program
        Program
    Table of Contents
        Page 1
    Drip irrigation and hematicides
        Page 2
    Considerations for spider mite control on strawberries
        Page 3
        Page 4
        Page 5
    Fungicide trial
        Page 6
    Strawberry diseases
        Page 7
    Strawberry variety trial
        Page 8
    Paraquat herbicide trial
        Page 9
    Strawberry irrigation and fertilizer trial
        Page 10
    Strawberry breeding
        Page 11
    Bed height and nitrogen fertilizer source
        Page 12
    Date of planting and plant chilling trial
        Page 13
    Intermittent irrigation after transplanting
        Page 14
    Field map
        Page 15
Full Text




c- Dover ARC Research Report SV75-1


February, 1975


AGRICULTURAL RESEARCH CENTER
DOVER, FLORIDA

OF THE

INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES

STRAWBERRY FIELD DAY

Thursday, February 20, 1975


PROGRAII


P. M.




2:45

2:50

3:00

3:20

3:35

3:50

4:05


Florida Coop. Ext.


Dean SH. f st h Planning
lNFAS. on
A enrman Nematode Research

Dr. S. L. Poe Insect and Mite Research

Dr. C. M. Howard Plant Breeding and Strawberry Disease Research

Dr. E. E. Albregts Soil Fertility and Horticultural Research

Tour of research plots and greenhouse


THE INFORMATION AUD PRODUCTS DESCRIBED HEREIN DO NOT CONSTITUTE A RECOMMENDATION
BY THE AUTHORS OR THE UNIVERSITY OF FLORIDA


















TABLE OF CONTENtS


PAGE

Drip Irrigation and Nematicides A. J. Overman ................ 2

Considerations for spider mite control on strawberries
S. L. Poe ................................................. 3

Fungicide Trial (Field 1) C. M. Howard ....................... 6

Strawberry Diseases C. M. Howard ............................. 7

Strawberry Variety Trial E. E. Albregts & C. M. Howard ....... 8

Paraquat Herbicide Trial E. E. Albregts .................... 9

Strawberry Irrigation and Fertilizer Trial E. E. Albregts .... 10

Strawberry Breeding C. I. Howard ........................... 11

Bed height and nitrogen fertilizer source E. E. Albregts ..... 12

Date of planting and plant chilling trial E. E. Albregts ..... 13

Intermittent irrigation after transplanting E. E. Albregts ... 14

Field diagram ................................................. 15






-2-


DRIP IRRIGATION AND NEMATICIDES

A. J. dverman
Professor (Nematolbgist)

Sdrface-applied neriaticides with ViAfio for strawberry
Sarah Bay C. 13


Purpose: To deetmine the efficacy of nematicides broadcast on bed surface
wheh Viatio is used,


Procedure:


Chemicals
(2 levels
shoulder,


bkbadcast over the prepared bed surface. Fertilizer
N) banded middle row, 2 sArips Viaflo 1 on each
mulch applied. Berry transplants from 3 sources set.


Results:


Kemicyclio- RtKt !t. of
Treatment Yield (g) phora Index dead leaves

Ck 10948 1334 2.6 191
Mocap 10G 10 paa 8815 530 1.0 159
Furadan 10G 10 paa 10204 504 1.3 167
CGA-12223 5G 4 paa 11150 377 3.1 150
LoN 20 lb 18-0-25/100 ft 24685 1691 3.8 153
HiN 20 lb 18-0-25
+ 11 lb (114)2S04 16433 1054 1.7 222

Source:
Dover 11454 1042 2.0 385
Calif. 14849 1084 1.7 12
Dover 14815 619 2.3 268


NOTE: Calif. plants survived better. Lost less foliage to mites.





CONSIDERATIONS FOR SIDER WHITE CONTROL ON STRAWBERRIES


S. L. Poe
Associate Professor (Entomologist)


Adequate control of spider mite populations on Florida grown strawberries
achieved in an acceptable and practical manner must be achieved through application
of principles based on knowledge of several determinant factors. These factors
are outlined in this paper and the knowledge necessary for better understanding
each is summarized as what the farmer, pest control operator or management specia-
list should know to control spidermites.

1. Knowledge of the life history and biology of the mite. The two-spotted
spidermite may invade strawberry fields from nearby non-crop plants, weeds, ornamen-
tals, ttees, or crop plants, eggplant, peas, beans, etc. The development of large
populations is dependent upon an adequate source of nutrition which is readily
available from the fruiting berry plant but which appears to be absent fron non-
fruiting vegetative plants. The mite lays tiny eggs which hatch into larvae,
these then progress through growth stages of protonymph and deutonymph before
reaching the adult stage. The cycle is completed in from 10-14 days in warm weather.
As large numbers of mites develop on plants, many will begin to migrate away from
their birthplace and in so doing form webs and groups of swarming mites on the tips
if leaves. Mlites may crawl across the ground or be blown by wind, moved by hand or
by machine. Under a good management program, the migratory stage of the population
should never appear since the desirable level of control to prevent damage is below
the level for migration.

An estimate of 10-20 mites/leaf during Jan., Feb., and March is the tolerable
level to avoid undue damage to plants. The absolute average value tolerated depends
on variety; 'Sequoia' or 'Apollo' will tolerate more mites than 'Tioga' or 'Fla. 90'.

Because mites inhabit the lower leaf surfaces it is necessary to look there
for them. Their many stages of development place undue burdens for control on
any material used, so the most advantageous use of all methods is desirable.

2. Knowledge of basic approaches to control mites;
A. Chemical toxicants
The use of chemical toxicants proceeds logically from the 4-Rs of pesticide
use pointed out by the extension service.
1. Right way seek out the right way to apply a toxicant with consider-
ation for formulation, concentration, or amount to be applied to best reach mites
on the lower leaf surfaces. Contact toxicants must touch the pest to be effective.
Sprays should thoroughly wet the lower foliage.
2. Right amount use the material in accordance with the instructions
written on the label or instructions supplied by your extension service. Because
many formulations vary the concentration of technical material it is essential to
study each label to determine what amount to use.
3. Right material make sure the material chosen for use is one that will
do the job, that it has not been stored too long and is still active. This choice
is one which must be made based on research data provided to the extension service.
Several compounds are available for use on strawberries. The next few remarks
pertain to recent field experience with these materials.

Dicofol or Kelthane, a chlorinated hydrocarbon, is probably the most common
acaricide used for mite control. It has been used for several years, and conse-
quently, some populations of mites appear to be resistant to its action. In tests
of the two formulations the emulsifiable liquid gave better control than the
wettable powder.







Naled or Dibrom, also commonly used, is an organic phosphate chemical which
is also insecticidal and thus may also serve for aphid or pamera control. Like
dicofol, some populations of mites are tolerant of its use and only low mortality
results.

Omite, a sulfone chemical compound, is now widely used and appears more effec-
tive than either of the two older materials above. There is no evidence of resis-
tance to Omite in spidermites but in a few cases control has been less than that
desired. One of the great advantages of Omite is its safety to mammals and birds
and to beneficial or predaceous mite species.

Plictran, an organotin compound, is a recent introduction which in tests has
been a most potent chemical for spidermite control at 0.25-0.5 lb. ai/A. It is
now labeled for use and should be available. A similar compound, Vendex, is soon
to be registered also for mite control on strawberries.

In view of the hazard and destructiveness of parathion to beneficial organisms
and lack of effect on mites its use should be limited to extreme cases where no
other material is available.

With four different types of Chemical toxicants available the choice of the
right one depends upon effectiveness. When one material is used exclusively,
mites soon are unaffected by it, therefore, alternate use of the compounds from
the classes mentioned should provide adequate mite control. Each chemical has some
disadvantages, all may cause some fruit or foliage injury, formulations may not mix
well or powdery residues nay persist on the fruit. These things should be weighed
to make a choice of the right material for a given situation.

4. Right time this is perhaps the most critical of the 4 R's in some ways.
Mites are not always vulnerable to acaricides and in many cases the damage has been
caused before they are noticed. For this reason a good detection system should be
in operation routinely and when inspections reveal the presence of mites, begin a
treatment to eradicate the "hot spots" or local areas in a field with mites. Timing
is also important to avoid injury and to allow for tolerance before harvest.

B. Integrated Controls and Managment
A second approach to mite control is through integrating the best known prac-
tices to retard mite damage. This approach could involve the use of more tolerant
varieties, such as 'Apollo' or 'Sequoia'; however, these varieties appear to be
inferior to 'Tioga' in yield and earliness. Development of an early bearing
variety with mite tolerance would make this initial step a reality.

Mite populations may be controlled by other mites which feed on their eggs and
young. These predators, when released along the guidelines for use of chemicals
could be most important to control.

1. Right Way Release of predators should be made as needed and on plants
with spider mites present. If no host mites are present the predators soon starve
and are lost.

2. Right Humber The number of predators released may depend upon the
number of spider mites present on the foliage. Release of predators to form a
ratio of from 3:1 to 5:1 prey to predator seem adequate at the present time. Large
populations of spider mites could be lowered with chemical treatment to reduce
the numbers of predators needed. Concurrent release of prey and predator is prac-
ticed with some crops and might be feasible with strawberries.








3. Right material Integration of biological methods with chemical con-
trols involves judicious use of toxicants, both types of materials and rates which
will conserve the natural enemies. Omite, and in some cases Plictran, have been
used successfully in such a program. Other toxicants, fungicides, should also
be studied for their effect on predators.

4. Right time The time to release predators for spider mite control
is initially when the plants are transplanted, or at the first evidence of invas-
ion of the fields. Because the biological method works best when a balance is
established, the earlier predators are released the sooner the balance is reached
and biological control effected.

3. Knowledge of options available for control:
The future without doubt holds options for the farmer with regard to choices
of control. With current restrictive legislation, curtailed use of toxicants and
licensing required for commercial applicators there will come the professional
consultant or pest management specialist who will provide a service in agricul-
tural pest control. The farmer thus must know what routes he should take rela-
tive to equipment, pesticide, and relative to a question of knowledge to achieve
the control he desires. Should the farmer become his own pest management specia-
list or contract for the service? The answer to this question will doubtless
be provided by the success of his control efforts and by underlying economic
consideration.












FUNGICIDE TRIAL
(Field 1)


C. H. Howard
Associate Professor (Plant Pathologist)


Objective:


To determine the potential of new fungicides for control of strawberry
fruit rots and foliar diseases.


KEY TO TREATMENTS (FIELD 1):


Plot No. Treatment Lbs/A Applications/week

1 Control
2 Captan 4 1
3 Benlate 1 1
4 Benlate 2 1
5 DPX 10 1 1
6 DPX 10 2 1
7 Captan + Benlate 4 + 1 1
8 Captan + DPX 10 4 + 1 1
9 Captan 4 2
10 Benlate 1 2






-7-


STRAWBERRY DISEASES

C. M1 Hlowatd
Associate Professor (Plant Pathologist)


Objectives: To determine the cause and importance of new 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
sunken. Small black fruiting bodies
in some fields during some periods.


pink or gray spots which are
often form in these lesions.
This fungus also causes leaf


soft and not
Very severe
blight.


Pestalotia fruit rot:
light tan central area
and a surrounding band
in commercial fields.


Lesions variable. The most typical lesion has a round,
which is slightly sunken below the original fruit surface
of soft tissue which is definitely sunken. Rarely serious


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 straw-
berries 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 Benlate 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.






-8-


STRAWBERRY VARIETY TRIAL

E. E. Albregts and C. H. Howard
Associate Professor (Horticulturist) and Associate Professor (Plant Pathologist)

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

Table 1. Fruit yields of 1973-74 trials.


Variety or line January February March April May Total

October 1 Planting
Tioga 4327 4085 5483 2157 1564 17772c
69-253 8786 5001 7017 4910 4088 29814a
69-712 3474 5436 5273 4649 1684 20559b
Florida Belle 10334 2138 8890 3665 5264 30358a

October 15 Planting
Tioga 4135 2644 6147 5190 2327 20440
69-253 6477 2093 7753 3510 2617 22450
Florida Belle 7373 1017 8017 1970 1187 19563

November 1 Planting
Tioga 796 5770 3262 3079 1228 14135d
69-253 5101 5388 4768 3771 1833 20857ab
71-729 6776 8179 5935 2094 1560 24537a
Florida Belle 3151 4418 5375 1544 1107 15590c


The 1975 January yields (Ibs/acre) for this trial are Tioga
Florida Belle (7461), 71-729 (8258).


(6337),No. 10(6684),


KEY TO BREEDING LINES AND VARIETIES IN STRAWBERRY VARIETY TRIAL IN FIELD 2


Breeding line
Plot No. or variety

1 Florida Belle
2 Tioga
3 No. 10
4 71-729
5 69-266







-9-


PARAQUAT HERBICIDE TRIAL

E. E. Albregts
Associate Professor (Horticulturist)


Objective: To evaluate different paraquat application rates to bed middles for
control of weeds and to obtain residue samples of fruit.

Previous years results: If weeds are small (1-2 inches) at first application of
paraquat, weeds were fairly well controlled with 1/4 lb/acre rate. Row middles
were sprayed three times during season. The 1/2 lb/acre rate gave good weed
control.


1974-75 results to January 31: Weeds were not well controlled in the 1/4 lb/acre
rate plots especially if weeds were 4 to 5 inches tall before spraying. Best re-
sults have been with the 1/2 and one lb/acre rates.

KEY TO TREATMENTS IN STRAWBERRY HERBICIDE TRIAL, FIELDS 3 AND 8.


Plot No. Treatment

1 No herbicide & no cultivation
2 Cultivated
3 1/8 lb/acre
4 1/4 Ib/acre
5 1/2 lb/acre
6 1 lb/acre


Field 3 planted with the variety Tioga and Field 8
planted with the variety Florida Belle.






-10-


STRAWBERRY IRRIGATION AND FERTILIZER TRIAL

E. E. Albregts
Associate Professor (Horticulturist)


Objective:


To determine water application rates with drip irrigation on several
nitrogen fertilizer sources and to monitor fertilizer availability
and leaching as well as crop response.


A drip irrigation system using Viaflo tubing is placed in center of all beds.
This is the sole source of water for the beds except for rain and when plants are
protected from frost. The 3 rows on west receive 0.8 inches of water a week while
the 3 rows on the east receive 0.4 inches of water per week. The tubing, in all
instances but one, is placed above the fertilizer. Fertilizer nitrogen was applied
at 200 lbs/acre.

KEY TO TREATMENTS FOR IRRIGATION AND FERTILIZER TRIAL, FIELD 4




Plot No. Fertilizer Source Fertilizer Placement

1 Uramite Middle of bed
2 Osmocote Middle of bed
3 Urea Middle of bed
4 Ammonium nitrate Middle of bed
5 Ammonium nitrate with barrier Middle of bed
6 Ammonium nitrate with barrier Middle of bed
7 Uramite Side
3 Osmocote Side
9 Urea Side
10 Ammonium nitrate Side
11 Ammonium nitrate with barrier Side






-11-


STRATIBERRY BREEDING

C. II. Howard
Associate Professor (Plant Pathologist)

Objectives: To develop new strawberry varieties that are specifically adapted to
Florida growing conditions.

Table 1. Numbers of seedling clones tested in 1972-73, 1973-74 and 1974-75 seasons.

No. clones No. selected No. of clones
Season fruited for observation in rep. trial

1972-73 2,339 134 18
1973-74 2,596 181 16
1974-75 1,956 12


First year (Field 5): 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 Hfay 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 rec-
ords are kept on fruit yield and other characteristics. Specific clones are se-
lected primarily on the basis of early (through Jan.) and total (through Harch)
yields, and fruit color, size, appearance and ripening characteristics. Some clones
are selected for specific characteristics such as long fruit stems or concentrated
ripening in an effort to develop lines that may be useful for mechanical harvesting.

Second year (Field 6): The clones that have been selected are transplanted into
the summer nursery where they are again observed for runner production and resis-
tance to anthracnose. In October, selections are made from this group and trans-
planted into 10-plant observation plots. Two plantings of most of these are made
two weeks apart to obtain some information on the best date of planting for each
clone. 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 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 (Field 2): 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 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 it can be named and released as a new variety. Hopefully, more extensive
grower testing of varietal candidates will be done in the future even though
manpower and time limitations make it very difficult for us to grow the large
numbers of plants that are required for these tests.






-12-


BED HEIGHT AND NITROGEN FERTILIZER SOURCE

E. E. Albregts
Associate Professor (Horticulturist)


Objective: To determine effect of nitrogen fertilizer sources and bed height on
nitrogen availability during season and crop response. Also to determine the
extent of leaching of these fertilizer sources.

Fertilizer was applied at top bed center. The same amount of N, P, and K was
applied to all treatments. Soil samples were taken in 6 inch increments to 24
inches before fertilizer was applied, after plants were started. These plots will
be sampled in February and at end of season at same depths to measure nitrogen
availability and leaching.


KEY TO TREATMENTS FOR BED HEIGHT & N FERTILIZER SOURCE TRIAL, FIELD 7



Plot No. Fertilizer Source Bed Height

1 Ammonium nitrate 12 inches
2 Urea 12 inches
3 Osmocote 12 inches
4 Sludge 12 inches
5 Uramite 12 inches
6 1/2 sludge & 1/2 ammonium nitrate 12 inches
7 No fertilizer 12 inches
8 Ammonium nitrate 9 inches
9 Urea 9 inches
10 Osmocote 9 inches
11 Sludge 9 inches
12 Uramite 9 inches
13 1/2 sludge & 1/2 ammonium nitrate 9 inches
14 Ho fertilizer 9 inches
15 Ammonium nitrate 6 inches
16 Urea 6 inches
17 Osmocote 6 inches
18 Sludge 6 inches
19 Uranite 6 inches
20 1/2 sludge & 1/2 ammonium nitrate 6 inches
21 No fertilizer 6 inches





-13-


DATE OF PLANTING AND PLANT CHILLING TRIAL

E. E. Albregts
Associate Professor (Horticulturist)


Objective:


To determine if date of planting and amount of chilling that Florida
Belle, No. 10 and 71-729 receive before transplanting affects time of
fruiting, fruit yield, fruit quality, and plant growth.


Previous Trials:
With the Tioga variety 15 days of chilling was optimum for fruit yield without
delaying fruit production. Delaying the transplanting date into November delayed
fruiting and can reduce yields.

Since observations here indicated that other varieties were also affected by
planting date and chilling these three varieties or lines should also be evaluated
for these treatments.


KEY TO TREATMENTS IN PLANTING DATE AND PRE-PLANT CHILLING TRIAL, FIELD 8




Plot No. Variety Chilling Date of Planting

A September 15
B October 1
C October 15
D November 1
1 No. 10 0
2 No. 10 15
3 Florida Belle 0
4 Florida Belle 15
5 Florida Belle 30
6 71-729 0
7 71-729 15






-14-


INTERMITTENT IRRIGATION AFTER TRANSPLANTING

E. E. Albregts
Associate Professor (Horticulturist)


Objective:


To determine if irrigating plants intermittently at 15 or 30 minute
intervals after transplanting will give a response equal to that of
continuous irrigation during the day. Also to determine if anti-
transpirants will enhance the plants response during this starting
period.


Previous years results:
Only 30 minutes intermittent or continuous irrigation was used in 1973-74.
There were no yield response differences because of irrigation method. The use
of anti-transpirants did not appear to enhance the overall growth or yield response
of the plants.



KEY TO TREATMENTS IN IRRIGATION AFTER TRANSPLANTING TRIAL FIELD 9


Plot No. Anti-transpirant Irrigation period

1 None A. Plots were continuously
2 2% Vapor Gard irrigated, B. Plots were irri-
3 5% Vapor Gard gated at 30 minute intervals,
4 5% Folocote and C. Plots were irrigated at
5 10% Folocote 15 minute intervals.






-15-


FI-ELD 5 N FIELD 6
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Office




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