Title: Vegetarian
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00087399/00161
 Material Information
Title: Vegetarian
Series Title: Vegetarian
Physical Description: Serial
Creator: Horticultural Sciences Department, Institute of Food and Agricultural Sciences, University of Florida
Publisher: Horticultural Sciences Department, Institute of Food and Agricultural Sciences, University of Florida
Publication Date: June 1980
 Record Information
Bibliographic ID: UF00087399
Volume ID: VID00161
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.


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June 9, 1980

Prepared by Extension Vegetable Crops Specialists

D.N. Maynard

R.F. Kasmire
Visiting Professor

James Montelaro

Mark Sherman
Assistant Professor

R.K. Showalter

J.11. Stephens
Associate Professor


FROMt: J.M. Stephens, Extension Vegetable Specialist






Jim Montelaro Ill
New Faculty Member
Research Reports From Sanford


(No Articles)


A. Ethylene in Postharvest Biology:

An Overview


woundingg Tomatoes for Better Yields
Know Your Minor Vegetables Angelica

NOTE: Anyone is free to use the information in this newsletter.
possible please give credit to the authors.


The Institute of Food and Agricultural Sciences is an Equal Employment Opportunity Affirmative Action Employer authorized to provide research,
educational information and other services only to individuals and institutions that function without regard to race, color, sex, or national origin.



A. Jim Montelaro Ill

It is with sadness that I report that Dr. Jim Montelaro suffered a stroke on
May 16. Jim is still confined to the Alachua General Hospital in Gainesville where
he is receiving physical therapy treatment to restore use of his left arm and leg
presently immobilized. I'm sure that he would appreciate a note of encouragement
from his many friends throughout the state. He is able to receive visitors. We
look forward to a complete recovery. His address is Room 355, Alachua General
Hospital, 801 SW 2nd Avenue, Gainesville, Florida 32602.


B. New Faculty Member

Michael B. Lazin joined the Vegetable Crops faculty at Gainesville on May 8.
He has a joint teaching-research appointment. A native of Philadelphia, Mike
received the BS from Delaware Valley College and the Ph.D. in Vegetable Crops from
Cornell University. We are pleased that Mike has joined us and we welcome him to


C. Research Reports From Sanford

Three recent Research Reports have been released from the Sanford AREC that
may be on interest.

1. White, J.M. 1980. Cauliflower cultivar evaluation. Res. Rpt. CF-80-4.

2. White, J.M. and J.O. Strandberg. 1980. Broccoli cultivar evaluation.
Res. Rpt. CF-80-6.

3. White, J.M. and E.A. Wolf. 1980. Celery bolting trials. Res. Rpt.

Copies can be obtained from the Vegetable Crops Department or Sanford AREC.






A. Ethylene in Postharvest Biology -- An Overview

Ethylene, one of the simplest organic compounds, causes many responses to
horticultural crops and products. It probably causes some of the problems
that county Extension Agents are asked to solve. We can probably be most effective
in helping our commercial horticultural industry, home gardeners, and consumers
by increasing our own knowledge of ethylene and its roles. The following
article on Ethylene in Postharvest Biology -- An Overview by Dr. Adel A. Kader should
be helpful to all county horticultural agents. This article was first published in
the University of California Perishables Handling Newsletter, Issue #44, December,
1979. Other articles related to ethylene also appear in that issue. Horticultural
agents interested in single copies can obtain them from Dr. Mark Sherman, Vegetable
Crops Department, University of Florida, Gainesville, FL 32611.

by Adel A. Kader, Extension Pomologist, University of California

Ethylene is one of the simplest organic compounds which have an effect on
physiological processes of plants. It is a natural product of plant metabolism
and is produced by all tissues of higher plants and by some microorganisms.
Ethylene is considered the natural aging and ripening hormone and is physiologically
active in trace amounts (0.1 ppm). Its effects on harvested horticultural
commodities can be desirable or undesirable. Thus, it is of major concern to all
handlers of fruits, vegetables, and ornamentals.

Physical Properties:

Ethylene is a two-carbon hydrocarbon with a double bond (CH2=CH2) and it
is a gas at normal temperatures and pressures. It is a colorless gas with a
faint sweetish odor that can be detected in parts per million concentrations.
Ethylene gas is flammable at 3.1 to 32% (by volume) in air. At high concentrations,
ethylene is both an anesthetic and asplxiant. Thus, adequate safety measures
should be practiced when ethylene is added in ripening rooms. The minimum explosive
concentration of ethylene (31,000 ppm) is at least 3000 times the concentration
needed for stimulation of fruit ripening and should never be used commercially.

Ethylene as an air pollutant:

Ethylene can be a major component of air pollution and it comes from:

1. Natural sources: plants, soil, natural gas, burning vegetation.

2. Man-made sources: industrial, combustion of coal and oil, refuse burning,
operation of motor vehicles, cigarette smoke, fluorescent ballasts, rubber
materials exposed to heat or UV radiation, etc.

Ethylene production by horticultural crops:

The amounts of ethylene produced by horticultural crops vary greatly. Climacteric
fruits produce large quantities of ethylene coincident with their ripening. The rate of
ethylene production by fruits is influenced by many factors including the following:


1. Physiological age -- higher rates with advanced maturity and ripeness stage.

2. Temperature -- higher rates with increased temperatures between 320F (00C)
Sand 770F (25C); temperatures of 86F (300C) or higher inhibit ethylene

3. Oxygen level -- reduced rates with low 02 levels especially below 8%; elevated
(>21%) 02 levels increase C2H4 production rates.

4. Carbon dioxide level -- elevated C02 levels may either increase or decrease
C2H4 production rates depending on the commodity.
5. Other hydrocarbons -- propylene, acetylene, etc., can enhance ethylene
production by plant tissues.

6. Stresses -- physical damage, disease, waterlogging, fumigation, etc., are
all stresses which stimulate C2H4 production by plant tissues.

7. Inhibitors -- some chemicals (i.e., amino-ethoxyvinylglycine) inhibit
C2H4 production by plant tissues.
Biosynthesis of ethylene in fruits:

Research by several postharvest biologist for many years has helped expand
our knowledge of where does ethylene come from in fruits. Some important discoveries
were recently made by Dr. S.F. Yang and his associates (UCD Dept. of Vegetable
Crops) in relation to intermediate compounds and enzymes involved in ethylene
biosynthesis. We now know that ethylene is synthesized from the amino acid methionine
via S-adenosylmethionine (SAM) as an intermediate. SAM fragments to 2 components
including 1 aminocyclopropane-l-carboxylic acid (ACC) which is an amino acid.
This is converted, with the help of ethylne synthase enzyme, to ethylene, format, CO2,
and ammonium ion. Oxygen 'is required for the latter step to take place. It was
also found that treating plant tissues with ACC stimulates their ethylene production.

Mechanism of ethylene action in fruits:

Various proposals have been made as to how ethylene exerts all of its effects
in fruits but more research is needed before its mode of action can be understood.
Many of the factors mentioned above which influence C2H4 production also affect
its action. For example, decreased temperatures, reduced 02 levels, elevated CO2
levels, and some inhibitors (i.e., silver ion) reduce ethylene effects on harvested
horticultural commodities.

Ethylene production by pathogens:

Ethylene is produced by many species of bacteria and fungi which are pathogenic
to harvested horticultural commodities. Also, diseased plant tissues produce
higher levels of ethylene than healthy ones. Banana fruits infected by
Pseudomonas solanacearum bacteria lose their green color faster than healthy fruits.
Carrot and sweet potatoes infected by Ceratocystis fimbriata fungus produce more
C2H4 than non-infected roots. Tulip bulbs infected by Fusarium oxysporum f. sp.
tulipae fungus can produce enough C2H4 to cause gummosis when diseased and healthy
bulbs are stored in the same room. Ethylene produced by Pencillium digitatum
fungus promotes degreening of citrus fruits.


Desirable effects of ethylene:

1. Ethylene can stimulate abscission of fruits and help facilitate their harvesting.

2. Ethylene can be used to stimulate sprouting of seed potatoes before planting.

3. Ethylene can be used to promote faster and more uniform ripening in fruits
picked horticulturally mature. This is the most important desirable effect
of CXH4, which is the natural regulator of fruit ripening. It influences most
of the processes associated with ripening and not only color. Faster ripening
can mean reduced time between harvest and consumption of fruits which also
means better quality and nutritive value to the consumer.

Commercial application of ethylene:

Ethylene may be used commercially to achieve faster and more uniform ripening
of fruits, i.e., bananas, tomatoes, honeydew melons, casaba melons, mangos,
papayas, persimmons, etc. It is effective only if applied to fruits before ripening
is initiated. In this case, ethylene enchances maturation and triggers subsequent
ripening. If the fruits have already begun to ripen, they will produce their own
ethylene and any added C2H4 will be useless.

A concentration of 100 ppm C2H4 for 24 to 48 hours is generally adequate for
most fruits. The optimum temperature range for fruit ripening is between 20C
(680F) and 250C (770F) with a relative humidity of 85-95%. Adequate air circulation
within the room to insure uniform distribution of the gas is important. It is also
essential to insure that CO2 produced by respiration does not accumulate in the room
by using adequate continuous air exchange or by opening the room for air change
every 24 hours, then regassing.

Degreening of citrus fruits by C2H4 treatment helps remove chlorophyll (green
color) from the rind without affecting other components of the fruit.

Ethylene can be applied by one of the following methods:

1. Addition of measured quantities of ethylene from gas cylinders or lecture bottles.
Banana gas is diluted ethylene (with an inert gas) which is not flammable and
thus more safe to use.

2. Use of ethylene generators where a liquid is heated to produce ethylene. The
number and location of these generators to achieve desired concentration
depend upon room size.

3. Use of ethylene-releasing chemicals such as Ethephon (2-chloroethanephosphonic
acid) which release ethylene upon changing the pH to the alkaline side. This
is widely used on processing tomatoes before harvest. None of these chemicals
are approved yet for postharvest application.

Undesirable effects of ethylene:

There are numerous examples of undesirable effects of ethylene on harvested
horticultural crops. These include:

1. Accelerated ripening and softening of fruits during storage when not desired.

2. Accelerated senescence and loss of green color in some immature fruits (cucumbers,
squash, etc.) and leafy vegetables.



3. Russet spotting on lettuce.

4. Formation of bitter principle (isocoumarin) in carrots.

5. Induction of stress metabolities, i.e., impomeamarone in sweet potato roots.

6. Sprouting of potatoes either stimulation or retardation depending on
concentration and duration of exposure to ethylene.

7. Abscission of leaves (cauliflower, cabbage, foliage ornamentals, etc.)

8. Toughening of asparagus.

9. Abbreviated storage life and reduced quality of cut flowers e.g. "sleepiness"
of carnations.

10. Physiological disorders in flowering bulbs: C2H4 (0.1 ul/l or higher) inhibits
elongation of shoots and roots in several bulb species; induces gummosis, bud
necrosis, and flower-bud blasting in tulips, promotes flower-bud abscission in
lily and leaf abscission in hyancinth.

Sources of ethylene during postharvest hadnling:

Based on a survey of ethylene concentrations and its possible sources during
postharvest handling of lettuce, it is clear that the problem areas are cold storage
rooms used for holding the commodity at various points in the handling and
distribution system.

Avoiding exposure to ethylene:

A. Exclusion of ethylene from storage rooms.

1. Use of electric fork-lifts.

2. Use of C2H4-absorber on the exhaust system of fork-lifts.

3. Avoiding.other pollution sources.

4. Avoiding mixing C2H4-producing commodities with those which are sensitive
to C2H4.
B. Removal of ethylene from storage rooms.

1. Use of adequate ventilation (air exchange).

2. Use of ethylene absorbers.

a. Potassium permanganate (for example, "Purafil" which is alkaline KMnO4
on aluminum silicate pellets).

b. Activated and brominated charcoal alone or in combination with KMnO4
(such as "Stay-Fresh absorbers).

3. Use of ozone or ultraviolet radiation (which oxidizes 02 to ozone) to
oxidize ethylene: C2H4 + [0] CO2 + H20

In this system, UV at 185 nm produces ozone which oxidizes ethylene while
UV at 254 nm destroys the remaining ozone which is very harmful at very low


concentrations to all commodities.

4. Use of low pressure system (hypobaric storage).

Methods of determining ethylene concentration:

Generally ethylene is analyzed by gas chromatography which is a very sensitive
method (10 parts per billion can be routinely detected). However, this is strictly
a laboratory technique and air samples will have to be collected then transported
to the laboratory for analysis.

Two methods are available for determination of ethylene concentration away
from the laboratory. Although less accurate than gas chromatography, they are
much less expensive and probably adequate for commercial use. These methods are:

1. Use of the Kitagawa gas detector system which includes a piston-type volumetric
pump into which direct-reading detector tubes are inserted. Analysis is based
on chemical reaction of a reagent in the detector tube with ethylene in the air
sample. The extent of this reaction is then translated into concentration from
a calibration chart. Detectable ethylene concentration range is 0.1-100 ppm
and accuracy is +10% for this method.

2. Snoopy Electronic Ethylene Detector is a new portable instrument which is
capable of detecting 0.1 ppm C?H4 in a 1 ml gas sample with +5% accuracy.
For more information contact Bio-Gas Detector Corporation, 4245 Okemos Rd.,
Okemos, MI 48864.


It is clear from this overview that ethylene plays a major role in postharvest
biology of harvested horticultural commodities. Because of the wide range of
desirable and undesirable effects of ethylene, it is very important to understand
specific responses including physiological disorders of each commodity to ethylene.
Then, the postharvest handling systems currently used for horticultural crops must
be evaluated in relation to their sensitivity to ethylene action, and must be modified

Research should continue to further identify the mode of ethylene action, its
possible involvement in various physiological disorders, its effect on pathogens,
etc. Also, new effective and economical methods for ethylene removal must be
given high priority in research and development efforts.
-End of Kader article-



A. Mounding Tomatoes For Better Yields

A Florida gardener and Urban Gardening Program Aide, Mr. Wade Ellis, has
innovated a technique for growing home garden tomatoes that has proven so successful
that I am going to pass it on to others with his permission.

Using tomato mounds prepared in his unique way, Ellis has consistently grown
plants which produce almost unbelievable yields of quality fruits. It is not


unusual on each plant to find 40 to 60 tomato fruits ranging in size from large
to small. He relies on the 'Flora-Dade' variety transplanted about mid-March in
the Jacksonville area. By late May and early June, the plants are literally
breaking-over with the abundance of fruit. Of course, he supports the plants up-
right with string and two or three stakes per mound.

The simple technique involves building a mound of soil over a pile of cow
manure. Here is how to construct the mound and plant the tomato.

(1) Prepare the soil into seed bed condition as usual, liming if need is
indicated by soil test, and treating for nematodes if necessary.

(2) On the selected site or row for the tomatoes, measure three feet
between each mound center.

(3) Place a double layer of unfolded newspaper flat on the soil surface at
each planting site. The paper appears to reduce the leaching away of
moisture and nutrients.

(4) In the center of the paper, place a shovelful (one gallon) of rotted cow

(5) Depress the center of the pile with the fist or trowel, making a central
cavity almost down to the newspaper.

(6) Measure one and one half cups of common garden fertilizer (6-6-6, 6-8-8
or 8-8-8) and place it in the central cavity. Do not mix the fertilizer
with the manure.

(7) Using a hoe or rake, pull the soil from around the edges of the newspaper
up over the manure until a mound is formed three to four inches above the
manure pile. Again, do not mix the soil, manure, and fertilizer.

(8) Now, dig a planting hole on top of the mound just deep and large enough
to accommodate the root ball of the tomato plant. Place the plant in the
hole, water, and firm soil around the stem. Keep roots at least one
inch above the fertilizer. A slight depression round base of plant will
help hold water until it soaks into the soil.

(9) Water the plant root zone with a little liquid fertilizer solution for a
week or two until the plant starts to grow. Then, no more fertilizer is
needed for the rest of the time the tomato is alive.

(10) Insert two or three sturdy 4 to 6 foot tomato stakes around each mound.
Confine and support the single plant to these stakes with cord as it
grows. It is important that the plant be staked or supported by a wire
cage, for the plant is growing primarily above the ground. Wind or other
forces can easily topple non-supported plants.

(11) Water and care for the growing plants as usual. Roots will penetrate the
paper and grow into the soil beneath, but most of the roots will be con-
centrated in the mound. With the 'Flora-Dade' variety, it is not
necessary to prune the plants.


B. Know Your Minor Vegetables Angelica

Angelica (Angelica archangelica) ia a European perennial plant sometimes grown
in this country as a culinary herb. In addition to garden angelica, other common
names are archangel and masterwort.

History This member of the parsley family, related to carrots, grows in
fields and damp places, from Labrador to Delaware and west to Minnesota. Syria is
believed to be its point of origination.

Many species have been used since early times where it has been regarded most
highly for its medicinal and magical properties, especially in counteracting poison
and plague and warding off evil. Its name probably derives from these properties.
One species is called "Holy Ghost", (A. sylvestris), while the common is A. archangalica.

Uses Fresh angelica has a powerful, peculiar, pleasant soft musky odor and
a sweet taste (pungent after-effect). The odd flavor and odor are due to a volatile
oil contained in all parts of the plant.

The fresh stems and leafstalks are used as garnish and for making candied
angelica. The seeds and the oil distilled from them are used in flavoring foods, and
the aromatic roots are used in medicine. People in the north, particularly the
Lapps use it as a foodstuff, condiment, medicine, and even chew it like tobacco.
The Norwegians use the crushed roots in their bread. Laplanders eat the stalks and
Icelanders both the roots and stems, raw with butter. In Finland, the stems are
cooked with flavoring provided by the leaves, while in Norway a bread is made from
its roots. Eskimos in North America use the stalks like celery.

Wild angelica (Angelica sylvestris) has a lot of uses related to its hollow stems.
Children squirt water through them, they are used like a pea-shooter, and the hollow
stems have even been used in espionage for spying through holes in curtains.

Description The robust growing angelica plant is five to six feet tall and
resembles wild carrot. It has large petioles and a purple colored root. Leaves are
compound and flowers are borne in umbels like the carrot. It is a perennial plant
that flowers every two years.

Cultural The plant thrives best in a moderately cool climate in semi-shade;
therefore, it is unlikely to grow well in Florida. The plant is most readily
propagated from division of old roots, which can be set either in the fall or
spring about 18 inches apart in 3 foot rows. Seeds germinate very poorly, especially
if more than a year old. When seeds are obtained, start seedlings in a seed bed,
then transplant to the garden. In order to increase root development, the plants
are often transplanted a second time, at the end of the first year's growth. For
the same reason, the tops are often cut back to prevent the formation of seed.

Harvest Roots, stems, and seeds are harvested and used as needed, with some parts
being ready 3 to 4 months after planting. Sometimes the roots of the first-year
plants are dug, but usually the harvest of roots is deferred until fall of the
second year. The roots are then washed and dried in open air. Estimat of yields
are not available. Dried roots should be kept in tightly closed containers to
preserve the aroma.

Seeds/Plants Several herb supply catalogs list angelica starting material for


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