.i' L i ...
January 13, 1976
Prepared by Extension Vegetable Crops Specialists
J. F. Kelly
S. R. Kostewicz
R. K. Showalter
J. M. Stephens
G. A. Marlowe, Jr.
COUNTY EXTENSION DIRECTORS AND AGENTS (VEGETABLES AND HORTICULTURE) AND
OTHERS INTERESTED IN VEGETABLE CROPS IN FLORIDA
FROM: Stephen R. Kostewicz, Extension Vegetable Specialist
VEGETARIAN NEWSLETTER 76-1
IN THIS ISSUE:
I. NOTES OF INTEREST
Extension Specialist Vacancy
Vegetable Production Guides Control Distribution
II. COMMERCIAL VEGETABLE PRODUCTION
Good Crops Start With Good Seed
Pepper Black Spot A Fruit Disorder
Micronutrients for Watermelons Additional Information
Some Points to Consider About Low Volume, High Velocity
III. VEGETABLE GARDENING
Timely Gardening Topics
Know Your Vegetables Ginseng
is free to use the information in this newsletter.
give credit to the authors.
COOPERATIVE EXTI N0 IN VWDAORK IN AGRICUL-TURi AND HiEti ECONOMICS, STATE O- FLORIDA, IAS, UNIVERSITY
OF FLORIDAN LU. 5 tOL.ARTNMENT OF A ,RICULTUR2E ArI i0 BOARDS OF C COUNTY COrMMi ~rStO ~r E COOFPE YATiN ;
FLORIDA COOPERATIVE EXTENSI'ON- SERVICE
UNIVERSITY OF FLORIDA
INSTITUTE OF FOOD AND AGRICULTURAL SCIENICEIS
VEGETA4-LE CROPS DEPARTNiEVfi
11LE \MTGETARI1AN NFWSIBILTER
I. NOTES OF [INI'RSI I
A. Extension Specialist Vacancy
Dr. James R. Hicks, Assistant Professor and Extension Vegetable Specialist in
the area of Harvesting and Handling, resigned from his position in Vegetable Crops
effective December 26. Jim has accepted a Research-Extension-Teaching position in
the same area with the Vegetable Crops Department at Cornell University in New York.
Jim's work with growers, packers and retailers on the newly-developed red-ripe tomato
concept has done much to overcome some of the ill-informed negative images often thrust
upon our tomato industry. We hope to be able to work cooperatively with him as a
receiver of Florida winter produce.
The current position freeze brought about by the state's continuing economic
crisis prevents us from refilling the position at this time. However, we are accepting
applications so that the position can be refilled as soon as we are permitted to do so.
In the meantime, please direct all inquiries in the area of harvesting and handling of
vegetables to Mr. R. K. Showalter.
B. Vegetable Production Guides Control Distribution
We cannot overemphasize the importance of distributing our production guides to
the proper clientele. All of our production-oriented circulars are written for com-
merical growers. The latest issues of these have been so marked. Because of their cost,
and more importantly because of the pesticide recommendations contained therein, it is
important that these not be distributed to home gardeners. Since this past May, we have
completely gone through a 5000-copy printing of the "Eggplant Production Guide" (that's
enough to supply 2-3 copies for every acre of commercial eggplants in Florida). Please
look over your supplies of literature and return any unneeded materials to Gainesville.
And, guard your remaining stock as we plan to produce no more production guides until
we are able to furnish you with a gardener-oriented fact sheet for these crops.
(Montelaro and Kelly)
II. COMMI-RCIAL VEGETABLE PRODUCTION
A. Good Crops Start With Good Seed
Most growers have learned that good seed is not cheap, but is well worth the
higher cost when the final results are in at the end of the season. All growers should
use the highest quality seed available and not try to "cut corners" on this vital aspect.
Price alone does not determine whether a particular variety or brand of seed is better
than another. Fortunately, Florida as well as most other states have seed laws which
regulate the seed trade. The vast majority of seed companies take pride in handling
and selling only top-quality seeds and cooperate closely with state regulatory agencies.
The factors which are used to determine or define good seed are:
(1) Germination percentage. Seed "lots" do not germinate 100 percent because of
many factors beyond this discussion. Additionally, there are differences in "expected
germinations" between kinds of crops. Some crops do, however, germinate 95-98% con-
sistently while others characteristically germinate lower. Standards have been developed
for the various crops. Thus, if a crop has a gennination standard percentage of 85%,
"lots" of seed with a tested germination of below that figure cannot be offered for sale.
There are exceptions to this, but certainly one would not consider that lot as quality
THE VEGETARIAN NEWSLETTER
(2) Seedling vigor. High-quality seeds should not only germinate, but also
should develop healthy, vigorous seedlings. This factor is hard if not impossible to
"pre-test" and indeed in some cases to define, but is as important as any other factor
one can use to describe good seed.
(3) Content of weed seeds or debris. Quality seed should be "free" of these,
firstly, since seed is sold by weight and one expects crop seed for one's money and not
trash, and secondly, most growers have plenty of weed problems without bringing in new
(4) True to type. There should not be a mixture of types within the lot. If
one were to plant round, red radishes and instead ended up with long red, long white and/
or round black radishes, it would be reasonable to assume that the particular seed lot
was of low quality.
(5) Free of diseases and/or insects. Many diseases can be seed-borne and thereby
introduce problems for the maturing crop. Commercial seed producers usually take advan-
tage of climatic conditions in specific production areas to reduce or eliminate seed-
borne disease problems.
A seed is essentially a live plant in a dormant state, the quality of which is
(1) Preharvest treatment,
(2) Storage and handling, and
(3) Environmental factors during and following planting.
The best way to maintain seed quality is with low temperatures and low humidity.
Normal seed packaging in the trade involves a good many light, moisture and air-tight
containers such as cans, foil packs, etc., that do an adequate job of protecting the seed
When the package or container is opened, the seed then is subjected to potentially
quality-degrading factors. Some of the things a grower can do to protect his seed may
be the following:
(1) Reclose opened containers as thoroughly as possible and store at low tempera-
tures and low humidity.
(2) If planting is delayed by weather, etc., place seed in proper storage con-
ditions as rapidly as possible. Don't let the seed ride around on the back of a pick-up
(3) Don't store seed near chemicals or materials which can contaminate the
seed and affect its subsequent germination.
(4) Avoid harsh handling of the seeds at all levels of handling. This is
especially critical for large-seeded crops such as beans. Mechanical damage of seeds can
reduce the quality of the seed drastically.
How does one get good seed? Generally, reputable seed companies take pride in
putting up a quality pack. But, some guidelines can be drawn up to help in selecting
(1) Don't purchase "old" seed. Most seed containers are dated and should be
selected. However, some seed retain good germination and vitality if kept under proper
THE VEGETARIAN NEWSLETTER
(2) Don't be fooled by specials! Some are legitimate, but they can be old seed,
poor germination, full of weed seeds, the wrong variety, etc. A few dollars saved on
seed can come back and cost one many dollars if it results in poor stand, yield, etc.
(3) Use only varieties and strains you know will do well in your area.
(4) Do not attempt to save your own seed.
(5) Make sure that only treated seed is used for planting. If the purchased
seed is not treated, treat it with one of several seed treatment materials available
in most seed stores.
B. Pepper Black Spot A Fruit Disorder
A recent outbreak of "black spot" of pepper in a field is of sufficient concern
to be called to the attention of all interested in pepper growing in this state. In a
recent report, Dr. Villalon (Black Spot--A Nonparasitic Disease of Bell Pepper Fruit in
the Lower Rio Grande Valley of Texas, Ben Villalon, Assistant Professor, Texas A & M
University Agricultural Research & Extension Center, Weslaco, Texas, Plant Disease
Reporter, Volume 59, No. 11, November, 1975) described the disorder as follows:
"Black spots occur on mature green pods, but are more noticeable
on red ripe fruit. The fruit pericarp remains smooth and unblemished
except for conspicuous round to irregular-shaped subcutaneous black spots
2 to 7 mm in diameter below the epidermal layer. Soft to dry internal
chlorotic lesions extend deep into and through the thick pericarp. Black
spots may or may not be sunken. Necrotic tissue appears to be localized.
Number of lesions on the fruit may vary from 1 to 5 or more. Black spot
first appears at the mature green stage of fruit development. Some
plants may bear fruit with or without black spots. Ninety- to 120-day-old
plants with black-spotted fruit may appear perfectly healthy; some others
may show mild mosaic or virus-like symptoms. Fruit size, shape and yield
do not seem to be affected by black spot."
Dr. Villalon investigated black spot during the 1971 and 1974 seasons when it
developed in pepper fields in Texas. From these studies, he concluded, "Attempts to
isolate fungi, bacteria, nematodes, and insects were unsuccessful. Attempts to transmit
viruses reported on pepper through artificial inoculations from extracted fruit juice
to a wide pepper virus host range also yielded negative results." Speculating on
probable causes, he stated: "The part that environmental conditions and mineral fertility
play in the development of black spot symptoms has not been determined. It is possible
that black spot on pepper fruits may be caused by a combination of factors. Further
studies are justified in the area of mineral deficiencies, phytotoxicity, and environ-
mental conditions (nutrition, light, temperature, and so forth)."
Having made an "on-the-spot" survey of the problem in the field, we concur with
Dr. Villalon's last statement. Based on our limited survey, we feel that variety and
nutrition might interact under certain environmental conditions to trigger the disorder.
We need to "stay on top" of this potentially serious problem. For that reason, we are
asking anyone who finds black spot in pepper fields to please report it to us. In this
way, we may not only help the one grower overcome the problem, but keep it from becoming
a serious threat to pepper growing in Florida.
'11E VLGETARIAN NEWSLETTER
C. Mircronutrients for Wateniljons Additional Information
In last month's issue of the Vegetarian Newsletter, we suggested an application
of 20 to 30 Ibs/acre of FTE 503 or equivalent from a mix of the salts with the regular
fertilizer. The equivalent amount of actual micronutrients can be obtained from
TEM-300, a mix of the elemental salts. According to soils scientists, minor element
mix like TEM-300 is just as golod as the glass fritted material suggested above.
D. Some Points to Consider About Low Volume, High Velocity Concentrate Spraying
Something new has been added to low volume, concentrate spraying. The new com-
bination, referred to as the LVHVC system (low volume, high velocity, concentrate sprayer)
provides more unifonn spray droplets of smaller size at greater velocity than the older
air-blast sprayers. Previously, droplet size was greatly controlled by high pump pressure
and nozzles of the disc and swirl type. The new system utilizes a low pressure pump and
a high velocity fan to produce air-sheared droplets of uniform, small size.
The LVHVC sprayers are reported to generate air velocities of 120-200 mph or
almost twice the speed of the former air-blast machines (60-115 mph). The pump used in
the new system requires about one-half the pressure of the dilute sprayer and is of the
less expensive diaphragm or impellor type.
Low volume, concentrate sprayers frist gained popularity about 20 years ago. They
offered greater savings of time, labor and weight than the dilute sprayers; factors
which may be even more important now than in years past. Older spray methods often con-
sidered "spray to the point of run-off' as a rule of thumb. This axiom is now being
questioned from the standpoint of spray efficiency, economics and environmental pollution.
The old method of covering to the point of run-off often wasted 90% of the liquid and
contributed to the contamination of soil and ground water. This was not all bad, however,
as it did contribute to partial control of root inhabiting insects such as wireworms,
rootworms, and the lesser cornstalk borer. In the future, we may be thinking more about
dynamic catch (adherence), zone of kill (radius of activity of pesticide), and soak
(coverage just short of run-off) than just "visible coverage".
The new L\HVC system produces spray droplets from 5 to 150 microns in size (micron
= one millionth of a meter). The velocity encourages adequate turbulence to help over-
come the electrostatic charge of the foliage and promotes deposit. Retention by the
ledf is, of course, primarily a function of the kind of surface and the physical
characteristics of the spray formulation.
Droplet size is of great importance to agriculturists. It influences spray
efficiency, cost relationships, .and drift. A brief comparison of some common droplet
sizes may be of interest. It should be noted that droplets cover a range of sizes within
any spray or dust system. (Size expressed in microns, from Frazer, Advances in Pest
Control Research, 1969).
Overhead irrigation 575-1820 Rain 250-1000
High volume sprayers 5-1100 Clouds 15-30
Low volume sprayers 2-150 Fog 5-10
Thermal aerosols 0.1-50 Smoke 0.01-1.0
Herbicide sprayers 130-740 Ground sprays 70-200
THE VEGETARIAN NEWSLETTER
If the droplet size is too small, excessive drift may be encountered. A 50
micron diplet will drift 478 feet in an 8 mph wind from a 10 ft. height; whereas, a
20 micron droplet will drift 2956 feet before settling under the same conditions. A
droplet size of approximately 100 microns is considered by many plant pathologists and
entomologists to give the highest index of deposit with an adequate kill zone. Spray-
ing with small droplets should be restricted to quiet days or nights with winds less
than 8 mph.
The LVHVC system has great versatility in gallonage delivered per acre, ranging
from 3 to 400 gpa. Research on potato blight and insect control showed that 20 gallons
per acre was better than 10 gpa and as effective as 30 gallons of spray. Some tomato
growers in West Florida spray 6-8 rows by the LVIVC when plants are small, 3-4 rows when
several feet high, and drop back to two rows of coverage per swath when the crop is
near harvest stage.
Insect and disease control studies at various universities have noted that low
volume spraying properly done can achieve results equal to high volume spraying. The
lighter weight of equipment and water; the cost saving of labor, material, and time;
and reduction in run-off of spray materials make this new system worthy of consideration
by growers and intensive study by researchers under Florida conditions.
III. VEGETABLE GARDENING
A. Timely Gardening Topics
These questions and answers are suggested for agents' use in developing periodic
(weekly) radio or newspaper briefs. They are based on letters of inquiry from Florida
(1) Timely Topic for Week of January 18-24
Are there certain varieties of vegetables I can plant which are resistant to
Sane varieties of the same kind of vegetables have been observed to be bothered
by certain insects less than other varieties. For example, Shogoin is a turnip variety
which is claimed to have resistance to the turnip aphid. We recommend it for Florida
home gardeners. Tests were conducted to test its resistance, comparing it to a variety
aphids seemed to like. From the tests, it was obvious that when given a choice the
aphids greatly preferred the susceptible to the resistant variety. However, the tests
did not show why the aphids were more destructive on one than the other. Some possible
explanations were (1) that hairs on the leaves of the susceptible variety provided good
foot-holds to the aphids; (2) light reflections from the different colored leaf surfaces
attracted aphids in different degrees, or (3) that the variety might just be more tolerant
of the insect's attack.
In any case, insect resistance in varieties plays only a minor role in practical
control of insects in Florida home gardens. One still needs to keep an eye open for
early detection of infestations, then apply a recommended dust or spray.
THE VEGETARIAN N ISL:iTER
(2) Timely Topic for Week of January 25-31
I have heard that vegetables can be gro.,wn in a bail of hay. Is this true and
if so, please explain the procedure?
Hay bales are being used in northern greenhouse culture for cucumbers. Their use
might be the answer for a person who has a problem soil or no soil at all. A hay bale
provides a well-aerated disease-free growing medium which can be placed on top of a
concrete floor or over a very sandy spot. To make ioe bale productive, it needs to be
well prepared by watering and fertilizing it for about 10 days before planting. One
schedule in practice is to heavily water the bale for the first 3 days, then apply five
ounces of ammonium nitrate fertilizer, then water for two days, then more (2 1/2 oz.)
anmoniumn nitrate on the 7th day, then water again for a couple of days, then apply a
complete fertilizer on the tenth day (or 2 1/2 oz. ammonium nitrate plus 7 oz. triple
superphosphate, plus 13 oz. potassium nitrate). On the llth day, apply a 3 to 4 inch
layer of top soil or good potting mix into which you set the plants. Other crops
besides cucumbers are a possibility.
(3) Timely Topic for Week of February 1-7
Can you tell me what is causing the very tips and edges of my garden lettuce leaves
to turn brown and die while the rest of the leaf is healthy?
Tipburn and edgeburn are two common disorders of lettuce. Actually, dieback of
the leaf n-n-rgins is a condition that had been noticed on many crops, from cantaloupes
to beans to lettuce. Although in some cases a disease organism is associated as the
caIus;.1l :IgLr~-t, in general such disorders are the result of root injury bringing about
moisture stress at the leaf margin. Fertilizer root burn, nematode injury, even root
pruning from too close cultivating, all generally result in brown dead edges of the
leaves. Furthermore, deficiencies of certain nutrients such as potash and calcium, or
excesses of certain nutrients such as manganese and boron have been suggested quite
reliably as causes of tip and edgeburn.
In the case of lettuce, a recent study showed tipburn to be associated with low
soil moisture. The idea is that as the lettuce approaches harvest, which is a high
water-use time, cells at the leaf edge die due to leaves using more water than roots can
take up. Constantly maintaining good soil moisture helps prevent tip dieback of leaves.
Low moisture could cause slow calcium translocation and result in calcium deficiency in
rapidly developing young tissues, as has been suggested.
(1) Timely Topic for Week of February 8-14
Are '.Legetables more nutritious when grown with organic fertilizers than with
chiem, i cal ferti i i elrs?
THE VEGETARIAN NEWSLETTER
There has always been a small controversy over this subject. The usual answer
has been that vegetables are similar in nutritional content when they receive the same
plant foods from either source--organic or inorganic. Of course, this answer is too
simplified. It is certain that the nutrient content of vegetables does increase or
decrease according to many factors including soil fertilization. Therefore, the kinds
of fertilizers used and the way one uses them can have an effect on the nutritive
content of the plant. In general, it is more a matter of amounts and availability of
nutrients to plants rather than the source of these nutrients that counts.
For example, an experiment has shown that nitrate nitrogen increased in spinach
leaves when amounts of nitrogen applied to the soil was increased. However, the amounts
in the leaves were the same whether the source was organic or inorganic. The one
exception was where cow manure was used, apparently the nitrogen it contained was so
slowly released that the leaves could not take it up. So, here is an example of source
affecting the nutrient level of the plant because it affected availability. Keep in
mind that this relationship is never as simple and direct as has been inferred, and other
environmental effects may override the effects of nutrient supply.
B. Know Your Vegetables Ginseng
Ginseng (Panax quinquefoluis) is not a vegetable but is a fleshy-rooted herb.
It is also called sang, ninsin, five fingers and seng. Ginseng plants are about 12 to
18 inches tall. Each leaf stem has three or more compound leaves, with each leaf com-
posed of five oblong-pointed leaflets. The fruit is a bright crimson berry. The mature
root, which is the part used, is 3 to 4 inches long, up to one inch thick, and usually
forked with circular wrinkles. It somewhat resembles a young parsnip or parsley root
that is branched three, four or more times.
Ginseng is native to the cool and shady woodlands from Canada to Northern Florida.
The native ginseng seems to be much preferred by oriental users who claim to be able to
distinguish wild from cultivated types. Reports indicate ginseng roots often decay when
attempts are made to grow them under warm humid Florida summer conditions.
Ginseng requires S to 7 years to mature its roots. It needs shade and may be
grown in shady wooded areas or in lath houses. Seeds may be planted, but require a
longer period from planting to harvest than from seedlings. Set seedlings 8 inches apart.
These will produce seed the first year, which then also can be planted. Another way to
start ginseng is to plant roots which are obtained either from the woods or from another
The main users of ginseng are orientals who believe the dried roots have stimula-
tive properties. Beverages, such as tea, are often flavored with ground ginseng root.
Very high prices per pound of dried root have caused many persons to consider growing it
in their wooded areas. And, the woodlands of the eastern U. S. mountains are often
scoured by "sang" hunters. Those wishing to try it in Florida should consider it a risky
endeavor due to (1) mostly an export market; (2) takes so long to mature; (3) wild roots
preferred; (4) our warm climate makes poor-quality roots; and (5) high cost of planting
material (seeds, plants, or roots). U.S.D.A. Farmers Bulletin No. 2201, "Growing Ginseng"
has been available from U. S. Government Printing Office (1973 issue), and probably