Title: Vegetarian
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Permanent Link: http://ufdc.ufl.edu/UF00087399/00158
 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: March 1980
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Bibliographic ID: UF00087399
Volume ID: VID00158
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.


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March 7, 1980

Prepared by Extension Vegetable Crops Specialists

D. N. Maynard

R. F. Kasmire
Visiting Professor

R. K. Showalter


FROM: James Montelaro, Professor and

J. M. Stephens
Associate Professor

James Montelaro


Extension Vegetable Specialist I




Vegetable Field Day at Immokalee Another Reminder
Vegetable Field Day Belle Glade


Plastic Mulch Culture Suggestions for Refinements
Developments in Starting Vegetable Crops Sowing Primed Seed


A. Precooling Vegetable Fruits


Mini-Mulching Strawberries
Know Your Minor Vegetables Chinese Radish

NOTE: Anyone is free to use the information in this newsletter. Whenever
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. Vegetable Field Day at Immokalee Another Reminder

Dr. Paul Everett and Dr. Dave Dougherty have announced preliminary
plans for a Vegetable Field Day to be held at Immokalee. A program of items
to be discussed will follow at a later date. In the meantime, place the
following information on your calendar and make plans now to attend.

DATE: Wednesday, April 23, 1980
TIME: 1:00 pm to 4:00 pm
PLACE: Agricultural Research Center, Immokalee, Florida

B. Vegetable Field Day Belle Glade

Plans are being finalized for another Vegetable Field Day according
to Dr. Joe Good, Director and the Committee Chairman, Dr. Subramanya of the
Agricultural Research and Education Center, Belle Glade. A final program of
topics to be discussed at the field day will be issued later. In the meantime,
place the following information on your calendar, also and make plans now to

DATE: Thursday, May 8, 1980
TIME: 8:30 am (Registration)
PLAuE: Agricultural Research and Education Center, Belle Glade, Florida

A. Plastic Mulch Culture Suggestions for Refinements

Plastic mulch culture has been used extensively for over 10 years for
the production of strawberries, tomatoes, peppers, and eggplant in Florida.
It shows considerable promise for the production of many other crops including
cauliflower, lettuce and endive. The transition from open culture to plastic
mulch culture was accomplished with few, if any, major setbacks. This does
not mean that there is not room for improvements. On the contrary, many small,
but significant mistakes have been noted over the years. It might be worthwhile
to call attention to some of the more obvious in hope that the system can be
made to work even better.

Bed Height Height of bed is extremely important because it helps
regulate moisture levels in the soil. If the bed is too high in a well-drained
soil, subsurface irrigation may fail to maintain an adequate level of moisture
at the soil surface. Conversely, a flooding rain may destroy a crop planted
on low beds with poor drainage. Drainage characteristics of the soil and type
of irrigation to be used dictate the height of bed needed. Low beds (2 to 4 inches)
should be used on well-drained soils with overhead or drip irrigation. On the
poorly drained soils where subsurface irrigation is used, beds should be 6 to 8
inches high. In addition, arrangements should be made to drain excess rain water


Moisture Control Occasionally, growers pushed for time, fumigate,
apply mulch and plant in a relatively dry soil resulting in poor nematode
control and/or slow growth. Therefore, fumigants and mulch should not be applied
unless the soil is firm and moist (at field capacity level). Fertilizer that is
placed on a dry soil surface or allowed to dry subsequently cannot be utilized
by the plant efficiently. Thus, the surface should never be allowed to dry out
during the crop season.

Fertilizer Placement Much has been said and written about fertilizer
placement under plastic mulch. The most common mistake observed is the failure
to place nitrogen and potassium in complete contact with the surface soil.
Without complete contact, fertilizer materials do not go into the soil solution
sufficiently to supply plant needs. We have modified recommendations on surface
placement of fertilizer to clarify this important point. By suggesting "the
placement of the soluble N and K one-half to one inch deep and firming the soil",
the problem can be eliminated.

Bed Crown and Ridges The ideal bed shape for a one-row crop under
plastic culture is one with a perfectly flat top. On a two-row system, as used
in peppers and other crops, a slight crown in the middle of the row may be used
to advantage. Ridges, especially near the base of plants, should be avoided.
Even the low ridges developed by presser wheels in transplanting are conducive
to extra accumulations of fertilizer in the plant stem and root zone. These
slight changes in fertilizer soil movement can cause severe seedling injury.

There are many more seemingly insignificant items that affect the overall
success or failure of plastic mulch culture. The grower, more than anyone else,
has the best opportunity to observe, to study changes, and to make necessary
modifications to further improve an already successful system of culture.


B. Developments in Starting Vegetable Crops Sowing Primed Seed

Seed priming consists of placing seeds in an osmotic solution with a
concentration that allows seeds to imbibe water and go through the first steps
of germination but does not permit radicle protrusion through the seed coat.
Such treatments have been referred to as 'advancing', invigorationn', 'hardening'
or 'vigorization' (particularly when salts are used). In many species tested,
seed priming has caused a marked increase in germination rate, total germination
and seedling uniformity, especially at below optimum environmental conditions.
This process has been shown to overcome such problems as thermodormancy in
lettuce and celery. Priming causes 'slow' and 'fast' germinating seeds of a
single lot to attain the same stage of germination readiness. This is of
considerable importance in obtaining uniform emergence of seedlings. Major
advantages of this system over pregerminating seed for fluid drilling is that
seed can be primed without specialized equipment, redried and then stored for
extended periods of time, and finally planted using conventional planting

There are several factors involved in order to successfully prime seed.
These include osmotic source, the amount of available water (water potential),
duration of the soak, temperature, air supply, need for light and redrying
procedure. One of the major disadvantages with seed priming is that all these
variables have to be studied and determined Tor each species because the degree
of acceleration in germination may differ with species, cultivar, and seed lot.


Much research to date has been conducted in an attempt to standardize the
procedures as much as possible.

Osmotic source This can be a salt such as KN03 or an inert material
such as polyethylene glycol (PEG). The use of salt solutions may add some
nutritional value to the treatment, however, extended soaking in the salt
solution can damage the germinating seed. The major advantage of PEG is that
it is chemically inert and does not have an adverse effect on seed and seedling

Osmotic concentration This depends on how much water is to become
available to the seed. Usually osmotic solutions of -6 to -12 bars are used
(-6 bars means that more water is available).

Aeration In general, priming treatments which involve immersion of
the seeds have been successful only in cases where the soak duration was short
or extra aeration was provided. Aeration for a small amount of seed can be
provided by spreading a single layer of seeds on a moist surface (paper)
supplied with the osmotic solution or by 'floating' the seeds on a PEG solution.
Large quantities of seed may be treated by using external air pumps or by frequent
pumping and draining of the solution.

Temperature Radicle emergence during the soak treatment may be prevented
by priming the seed at temperature below the optimum range for germination of
the species. Generally, temperatures of 50 to 200C are best, with 150C being
established by many as a suitable prime-temperature for most seeds. High soaking
temperature may be detrimental to the seed.

Soak duration The duration of the soak is dependent on the species being
treated, soak temperature, osmotic potential and the type of aeration. It is
generally felt that the shorter the duration the less problems with pathogens
and radicle emergence.

Need for light during seed priming Even though most vegetable seeds
do not require light for germination some respond Detter when light is used
during priming. The reasons for this are unknown at present. It is suggested
that light always be used in cases where it is needed for normal germination,
i.e. celery.

Redrying of primed seeds This is one of the most important aspects
of priming. If the seeds are primed (germinated) too long then redrying may
kill the seed. Redrying should be slow usually at normal room temperature
and at a relative humidity of 50-70%. Rapid drying with hot air may drastically
reduce seed vigor and viability.

Storage Primed seeds should be stored as any fresh seed, at low
temperature and low relative humidity (10C, 50% R.H.)

In summary, osmotic preconditioning of seed under controlled temperature
conditions or "seed priming" may be useful in promoting better seed germination,
seedling emergence and plant uniformity under adverse environmental conditions.
However, the priming technique has shown variable results from species to species
and even among cultivars of the same species. This variation, in response to
priming, may be due to factors inherent in the seed, the osmotic source being
used or other conditions prevailing during soaking. Therefore, the conditions
for priming that will give the best results when the seed is sown should be
considered on small quantities of seed before being placed in a large operation.
(Cantliffe & Montelaro)


NOTE: This is the second of three articles on seed germination to be
presented this season. The first was published in the May, 1979 issue of
this newsletter. Dr. D. J. Cantliffe, Associate Professor in our department,
is doing extensive research in seed physiology.


A. Precooling Vegetable Fruits

Prompt, thorough cooling of fresh fruits and vegetables after harvest to
desirable transit temperatures helps maintain product quality and slows their
deterioration rate by slowing the rates of respiration, water loss, ripening,
softening, growth of decay causing organisms, rates of ethylene production,
and reduces the sensitivity of products to ethylene in the atmosphere.

Of the several cooling methods available forced-air cooling is most
adaptable for precooling fruits, including vegetable fruits. Forced-air cooling
can be used for cooling products in field containers (boxes or bins) or in packed
shipping containers. Most presently used cold rooms, including small ones, used
for cooling can be easily and inexpensively modified for forced-air cooling, which
can provide cooling rates 6 to 10 times faster than room cooling. Although forced-
air cooling requires more space, the faster cooling rates achieved provide more
product cooling per unit of space, and therefore is more efficient than room
cooling and requires less total space.

Fruit type vegetables are especially adapted to forced-air cooling
because most have a relatively low bulk-density in packed shipping containers.
They have regular shapes that allows cooling air to easily pass over and around
each fruit and absorb heat from its surface. Sufficient venting (5% to 7%) of
side or end panels of shipping containers is necessary to permit enough air to
move through containers for rapid cooling.

Fans used in forced-air cooling must move enough air against the resistance
offered in the system (known as static pressure) from containers and product to
provide cooling rates desired. Effective channeling of the cooling air is
essential for forced-air cooling. This requires a basic understanding of the
method. Therefore, some engineering assistance would be helpful in modifying
present cold rooms for forced-air cooling. We can help you plan for this type
of conversion. Planning and designing new forced-air coolers definitely requires
professional engineering if the system is to operate efficiently.

Although vacuum cooling is used as supplement to cooling sweet peppers
its main use is to dry the stems and thus retard stem end decay. Limited, though
often adequate pepper cooling is achieved by vacuum cooling. Unless stem end
decay is a major problem (as is common in Florida) vacuum cooling would not be
the preferred cooling method for peppers because of large capital investment
required for this method.

Effective vacuum cooling requires a high surface-to-mass ratio of
products to be cooled. Thus, leafy vegetables are adapted to vacuum cooling
but fruits (except peppers) are not. Sweet peppers have a large amount of
surface in proportion to their mass and are therefore somewhat adaptable.
However, water is not readily transpired through nor evaporated from the surfaces
of sweet peppers, which limits their adaptability to vacuum cooling. The amount


of cooling achieved (to 500F or 550F) is enough. They should not be cooled
to lower temperatures because they are susceptible to chilling injury.

Hydro-cooling is less desirable for cooling fruits, even though it is
used, because of water beating damage and the opportunities for spreading
decay. Hydrocoolers should be drained and cleaned daily and the cooling water
should be chlorinated.

Package-icing is not adaptable for cooling most fruits, even though
it is used to a limited extent for cooling cantaloupes.


A. Mini-Mulching Strawberries

If you did not get around to mulching your strawberries with plastic when
you set them out, you might want to consider "mini-mulching" them now. The
mini-mulch technique utilizes a small square of plastic placed around each
strawberry plant. Cut 1.5 to 4 mil thick, black plastic mulch into one-foot
square pieces. Make a three to four-inch slit in the center of each piece of
plastic. Place one plastic square over each plant and pull the leaves, fruit
and flowers through the slit. Snug the plastic flat against the ground beneath
the plant.

The plastic mini-mulch acts as a barrier between the soil and all above
ground parts, thus reducing rots and possible insect injury. Weed growth is
reduced although not completely eliminated. The edges of the plastic may be
raised to allow any needed cultivation, watering or fertilizing.

An additional utilization for the mini-mulch mats is for cold protection.
During the day of an impending cold front moving in, pull the four corners of
each mat together over the top of each plant. Make sure the corners and sides
overlap to eliminate air leakage, then tape the corners together. Heat absorbed
by the soil beneath the plant will slowly release and be trapped to some extent
by the overlapping plastic cover. Cold protection by this method should not be
expected to prevent injury altogether, especially when freeze conditions are
severe enough to freeze the berries. However, frost-bite to tender blossoms and
young berries can be greatly minimized by this procedure. Placing hay, styrofoam
chips, or other insulative material over the plant before wrapping it up would
provide additional protection. Of course, untapeing, unwrapping and removing
insulating material from each plant after the cold has passed would be a simple
operation in the home garden.

From a mulching standpoint, materials other than black plastic might be
used, not only on strawberries but other crops as well.

B. Know Your Minor Vegetables Chinese Radish

The Chinese radish (Raphanus sativus L. Longipinnatus Group) is also
known as Daikon, Japanese radish, Oriental radish, and winter radish.


Chinese radishes originated in the Orient (Asia), as did the common
spring or summer radishes. Chinese radishes have extremely large roots,
some weighing up to 100 pounds. Most however, are in the ten to twenty
pound class at full maturity. These big, late maturing radishes were known
in Europe much earlier than the smaller kinds. Chinese radishes grown in
Florida vegetable gardens have reached twenty to thirty pounds in our sandy

It is quite common for Chinese radishes to have a leaf-spread of more
than two feet. The leaves differ from common types by being greatly notched
and spreading from the tops of roots in a rosette fashion.

Some varieties form large round to top-shaped roots, while others
are elongated and cylindrical in shape. Some commonly available varieties
offered by U. S. Seed companies are Chinese Rose (round), Chinese White
(cylindrical), and Celestial (same as White Chinese).

This type of radish is usually cooked rather than eaten fresh. As
a cooked vegetable, they are a major food item in the Orient and in the U. S.
by Orientals. Chinese radishes are seldom grown in Florida gardens, but are
grown by a handful of commercial growers of oriental vegetables.

Their culture is quite similar to that for the common radish. Seeds
should be planted 3/4 inch deep in the fall (September through October) so that
the roots enlarge in the cool months. Due to the size of the mature plants,
they should be spaced from four to six inches in rows spaced three feet
apart. To accommodate the large root size, plant on high raised beds fortified
with liberal amounts of organic matter (compost). At each cultivation, work
the soil around the root higher and higher as it grows. Some of these roots
are 18 to 24 inches in length, so require a loose, friable soil.

Chinese radishes take up to 6 months to reach full size. Most reach
best usable size in 60 to 70 days. They are pithy and pungent when overmature,
but are still tender and edible even when quite large.


Statement: "This public document was promulgated at a cost of $1h.4n or
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to extension, research and industry personnel.

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