Title: Krome Memorial Section, Florida State Horticultural Society, including symposium
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00094987/00001
 Material Information
Title: Krome Memorial Section, Florida State Horticultural Society, including symposium Florida's role in the development of tropical horticulture, November 4-6, 1969
Alternate Title: Florida's role in the development of tropical horticulture
Physical Description: 5 leaves : ; 28 cm.
Language: English
Creator: Florida State Horticultural Society
Donor: unknown ( endowment ) ( endowment )
Publisher: Florida State Horticultural Society
Publication Date: 1969?
Copyright Date: 1969
Subject: Horticulture -- Research -- Congresses -- Florida   ( lcsh )
Tropical plants -- Research -- Congresses -- Florida   ( lcsh )
Peach -- Research -- Congresses -- Florida   ( lcsh )
Mango -- Research -- Congresses -- Florida   ( lcsh )
Genre: non-fiction   ( marcgt )
conference publication   ( marcgt )
 Record Information
Bibliographic ID: UF00094987
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 436444951

Full Text
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(Including Symposium: .-lorida's Role in the Development of Tropical Horticulture

November 4-6, 1969

Hugh Popenoe, Vice-President


Endosperm Cytokinesis in 'Early Amber' Peach

W. B. Sherman and D. W. Buchanan
Department of Fruit Crops
University of Florida
Gainesville, Florida

Fruit samples of 'Early Amber' peach were taken at various intervals
to determine the stages of the transition from free nuclear to completely
cellular endosperm. Fruit diameter and seed length had a positive, linear
relationship and may be used as indicators for stages of morphological
development of endosperm. A third of the fruit were in the completely
cellular endosperm stage 33 days after full bloom. This is the suggested
optimum time for chemical thinning. Fruit diameter and seed length were
25.3 and 12.1 mm, respectively, at this time.

Post-Bloom Thinning of Florida Peaches with 2-Chloroethylphosphonic Acid

James A. Blake, R. H. Biggs, and D. W. Buchanan
Department of Fruit Crops
University of Florida
Gcinesville, Florida

A new growth regulator, 2-chloroethylphosphonic acid (Ethrel), applied
as a post-bloom spray to 'Early Amber' peaches, was found to result in ade-
quate thinning when compared to commercially hand-thinned trees. The appli-
cation was timed to coincide with a critical stage in seed development,
(seed length 11-14 mm), a stage characterized by cytokinesis in the endosperm
and initial growth of the embryo beyond the pro-embryo stage. Evidence was
also obtained that Ethrel significantly influenced date of harvest, color
development, flesh firmness, and pit-splitting.

Peach Fruit Maturity as Influenced by Growth Regulators

G. F. martin, D. W. Buchanan and R. H. Biggs
Department of Fruit Crops
University of Florida
Guinesville, Florida

Growth regulating chemicals were applied to 'Maygold' and 'Florida Sun'
peach trees to test their influence on fruit development and maturity.
2-Chloroeth.ne phosphonic acid (Ethrel) resulted in substantial acceleration
of maturity and enhanced color without adversely affecting quality. Treat-
ments of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) increased red color,
but the coloration was splotchy. Fruit firmness and storage life were not
changed by 2,4,5-T treatments. Neither Mt-benzyladenine (BA) nor naphtha-
lIneacetamide (NAD) caused any definite changes in the maturity indices
measured. Gibberellic acid (GA) reduced yields and indicated trends of
delaying maturity.

Field Testing Petroleum Coke Heaters for Frost Protection of Peaches

J. F. Gerber, D. W. Buchanan and G. R. Davis
Department of Fruit Crops
University of Florida
Gainesville, Florida

Petroleum coke heaters, trade name "Tree Heet' were used in a field
test on February 19, 1969 in a young orchard of 'Early Amber' peach trees.
Two adjacent plots of 2 1/4 acres each were used. The north plot was the
unheated control and the south plot was the heated test plot. One 4-pound
package of Tree Heet per tree was lit at 8:45 p.m. which produced an imme-
diate temperature rise that occurred in'the test plot. A second package
was lit at 10:45 p.m. which produced a second but smaller temperature rise.
An average temperature difference of 20 F was maintained throughout the
test period. The small trees in the test plot bore fruit whereas the fruit
was lost in the control plot.

Ethylene Produced by Tropical and Subtropical Fruit Plants

W. C. Cooper and P. C. Reece
Horticultural Field Station
Orlando, Florida

Small plants of avocado, mango, lychee, citrus, pineapples, bananas,
and peaches were held for 4 weeks at programmed climates of 40-600 F,
50-70 F, and 70-900 F. Leaves and fruit were harvested and incubated at
70 F for 24 hours in sealed flasks. Ethylene produced was measured by
gas chromatography. Low night temperatures caused injury to banana and
Mexican avocado leaves and to fruit of certain avocado varieties. Enhanced
ethylene production was associated with this chilling injury.

The region of maximum production of ethylene in pineapple plants was
the growing point of tiny etiolated leaves. In these tests we were un-
able to detect an enhanced ethylene production by chilling.

The leaves of peaches and trifoliate oranges produced copious quan-
tities of ethylene, turned yellow, and abscised when plants were held at
40 to 600 F.

Correcting Magnesium deficiency of Limes Grown on Calcareous Soils with
Magnesium Nitrate

R. C. J. Koo
Associate Horticulturist
University of Florida, IFAS
Citrus Experiment Station
Lake Alfred, Florida 33850
T. W. Young
University of Florida, IFAS
Sub-Tropical Station
Homestead, Florida 33030

Magnesium deficiency is a perennial problem of limes grown on Rockdale
soil. Soil applications of magnesium fertilizer have not controlled mag-
nesium deficiency satisfactorily, especially on marcotted lime trees. Mar-
cotted lime trees with severe magnesium deficiency were sprayed with mag-
nesium nitrate at 3 concentrations (1.75, 3.50, and 5.25 pounds of MgO/100
gallons of water). Three applications were made between March and September,
1967. Most of the magnesium deficiency symptoms disappeared after 2 sprays.
The trees were completely green after the third spray, regardless of the
rates used. The control trees remained chlorotic, Treated trees remained
green for about 18 months after the last spray, when some magnesium defi-
ciency symptoms began to appear on trees sprayed with the low rate (1.75
pounds MgO/100 gallons of water).

The practical applications of magnesium nitrate for control of mag-
nesium deficiency are discussed with respect to rates and frequency of ap-
plication, compatibility with other compounds, and effects of weather con-

Final Report on Some Mango Hybrids

David Sturrock
Horticulturist (Retired)

The work on this series of mango hybrids was started in 1956 and
concluded in 1969.

This work was a follow-up of Peter J. Wester's suggestion to
hybridize the small, prolific Philippine mango of fine quality with
the large bright colored East Indian mangos. Work along this line
by the late Edward Simmonds, of the USDA Station at Miami, was left
only part done at the time of his death. This is a continuation of
his work, going a step further with his Edward hybrid.

The results show promise for this unorthodox method of hybri-
dizing mangos. Time from seed to fruiting of these seedlings is
reduced by inarching the seedlings to strong sprouts on cut-over ma-
ture trees. In the present case fruiting of all the seedlings was
delayed by hurricanes.

Degenerate Mango Ovaries

Thomas T. Sturrock
Florida Atlantic University
Boca Raton, Florida

Two types of blossoms are generally recognized in mango panicles.
Some are staminate with functional stamens and no pistil. Others are
considered perfect with a globular ovary being present in addition to
the functional stamens. The number of fruits set on these panicles does
not approach the number of ovaries present. Investigations show that
many of these ovaries are degenerate in varying degrees. The unknown
causes of this breakdown are concluded to be contributing factors to
the poor fruit-set of this species.

Mineral Content of Florida l'ango Leaves

T. W. Young
Sub-Tropical Experiment Station
R. C. J. Koo
Citrus Experiment Station

Results of analysis of 274 mango leaf samples for N, P, K, Ca and
Mg are given. The leaves were collected between 1958 and 1968 from'.Kent',
'Parvin', 'Haden' and 'ZilIl variety trees on Lakewood sand and from 'Kent'
and lHaden' trees on Rockdale soil. The trees were fertilized during the
collection period with as wide a range in levels of these 5 elements as
likely ever would be used in commercial practice. The desirable range in
level in the leaf for each element for satisfactory performance is sug-
gested tentatively.

Response of Iron Chlorotlc Avocado Trees on Rockdale
Soil to Certain Iron Treatments

T. W. Young
Sub-Tropical Experiment Station

Iron Chlorosis of avocado trees on Rockdale soil can be corrected by
soil applications of Sequestrene 138, but treatment is relatively expen-
sive. In a search for a more economical treatment, several iron compounds
were tested. One of these, NaFeEDTA, when used in combination with aluminum
sulphate, corrected the chlorosis satisfactorily on about 80% of the trees
treated, but there were exceptions where there was little improvement.
Perhaps it would be feasible to use this mixture in place of the more ex-
pensive Sequestrene 138 for general overall treatment of iron chlorotic
avocado groves, and later spot-treat any trees that did not respond satis-
factorily with Sequestrene 138.

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