INSTITUTE OF FOOD AND
UNIVERSITY OF FLORIDA
A Vegetable Crops Extension Publication
Vegclable Crop. Department *1255 HSPP Gainesville, FL 32611 Telephone 392-2134
June 8, 1984
I. NOTES OF INTEREST
The National Agricultural
Vegetable Crops Calendar
New Telephone Listing for
II. COMMERCIAL VEGETABLE PRODUCTION
A. Herbicide Families and Symptoms of Injury
B. Selecting an Irrigation System for a Vegetable
Crop in Florida: Part III, Water and Supply
III. HOME GARDENING
St. John's County Garden Contest
Recent Field Study Results of
Anyone is free to use the information in this newsletter.
Whenever possible, please give credit to the authors.
The use of trade names in this publication is solely for
the purpose of providing information and does not
necessarily constitute a recommendation of the product.
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.
COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS, STATE OF FLORIDA. IFAS, UNIVERSITY OF
FLORIDA. U. S. DEPARTMENT OF AGRICULTURE, AND BOARDS OF COUNTY COMMISSIONERS COOPERATING
I. NOTES OF INTEREST
A. National Agricultural Plastic Assocication Meeting
The National Agricultural Plastics Association will meet in
Asheville, N.C. on October 2-4, 1984.
The call for papers has gone out with a due date of August 1.
The association is interested in any innovative or new use of agri-
cultural plastics or related products. This includes mulches, row
covers, drip irrigation, environmental structures and others. If any-
one wishes more information on the meeting or wishes to submit a title
for a paper, I can supply you with the information.
( Stall- Veg. 84-6)
B. Vegetable Crops Calendar
1. June 18-22 4-H Horticultural Institute, Cloverleaf, FL.
2. June 26-28 Vo-Ag Teachers Horticultural Update Conference,
3. July 24 State 4-H Horticultural Judging and Demonstration
Contest. 4-H Congress.
4. August 29-30 Master Gardener Advanced Training. University
of Florida, Gainesville, Fl.
5. Sept. 6 Florida Tomato Institute Marriott's Marco Beach
Resort, Marco Island, Fl.
6. October 2-4 National Agricultural Plastics Association -
Grove Park Inn Asheville, North Carolina
7. Nov. 4-7 FSHS Meeting Doral Hotel Miami Beach, Fl.
C. The Vegetable Crops Department has recently gone through a change
of telephone systems and many of the numbers have changed. Listed
below are the new phone numbers, with Extension staff noted.
Dr. Mark Bassett
Dr. Jeffrey Brecht
Dr. Dan Cantliffe
Kathleen Delate Extension (MG and Youth)
Dr. Dwain Gull Extension (Postharvest, Dist. I)
Dr. C. B. Hall
Dr. L. C. Hannah
Dr. George Hochmuth-Extension (Commercial, Dist. 2 and 3)
Dr. D. J. Huber
Dr. T. E. Humphreys
Dr. Stephen R. Kostewicz
Dr. Steven Kovach Extension (Commercial Water Program,
Dr. Michael B. Lazin
Dr. S. J. Locascio
Dr. George Marlowe Extension (Commercial Production,
Dr. D. N. Maynard Chairman
Dr. Mark Sherman Extension (Postharvest, Statewide)
Mr. James Stephens Extension (Home Garden, Statewide)
Dr. William Stall Extension (Commercial Production,
II. COMMERCIAL VEGETABLE PRODUCTION
A. Herbicide Families and Symptoms of Injury
Diagnosis of herbicide injury is often difficult and confusing.
Symptoms may vary depending on the herbicide, plant species, time or
method of application, environment and the stage of growth of the
plant. Nutritional problems, physiological disorders, diseases,
nematodes and insects may also cause symptoms that are similar to
A valuable reference is the Herbicide Injury Symptoms and
Diagnosis bulletin from North Carolina State University. In many
cases, however, there may not be a picture of the injury caused by the
particular herbicide you are concerned with.
Many herbicides can be classified into certain families of
chemistry which have similar symptoms. Even if you are not familiar
with a particular herbicide, you may be able to recognize the symptoms
by knowing its family.
The following information is intended to help you classify
herbicides by families, give some general types of symptoms, and if
used with the Herbicide Injury and Symptom publication may be of help
in identifying symptoms of herbicide injury or eliminating certain
herbicides as probable cause of injury.
In the next several months the commonly used herbicides in
vegetables and other herbicides that may be used in Florida will be
Herbicide Families and Injury Symptoms
Mode of Action and Symptoms: These herbicides generally inter-
fere with cell division or cell enlargment in the terminal leaves,
leaves, shoots or root meristems; generally termed meristematic in-
hibitors. Symptoms vary but are usually associated with root growth
inhibition, stunted, malformed seedlings. Most amide herbicides are
used either preemergence or preplant. This group does not
translocate. Control is usually better for grasses than broadleaf
weeds. Misapplication of these herbicides to corn can cause leafing
out under ground and cause leaves not to unfurl properly.
Misapplication in beans (bush or soybeans) causes heart-shaped leaves.
Naptalam has the unusual property of altering the geotropic
response of plants, often resulting in roots growing upward out of the
Mode of Action and Symptoms
Acetanilides are related to Amides in mode of action and
symptoms. Both are meristematic inhibitors. Acetanilides, however,
translocate in the plant, amides do not.
Family: Arsenical s
Mode of Action and Symptoms: These herbicides are generally thought
to interfere with phosphorous metabolism or by completing with sulfur
containing enzymes. Symptoms are leaf chlorosis followed by necrosis.
Common Name Trade Name
cacodylic acid Several products
MAA Several products
MSMA Several products
DSMA Several products
(Stall- Veg. 84-6)
B. Selecting an Irrigation System for a Vegetable Crop in Florida:
Part III, Water and Supply Systems.
As water control capability becomes more sophisticated and as
components are added to an irrigation system to reduce the labor
required for operation, generally the capital investment costs for an
irrigation system increase. Therefore it is important to evaluate
available capital and labor during the planning and selecting process
of an irrigation system so that possible trade-offs can be determined.
Available Labor and Technical Skill
If labor is either difficult to secure, relatively unskilled,
and/or expensive the trend is to select irrigation systems which use
lesser amounts of labor. Many irrigation systems with lower labor
requirement also require greater maintenance and repair skills.
Therefore, when systems with labor saving capabilities are selected
the level of technical skill available to maintain and operate such
systems must be considered. Due to the present emphasis on improving
the efficiency of irrigation water use, the need exists to develop
technical skills necessary to apply water efficiently.
The following labor requirements (man hours/acre inch of water
pumped) apply to the various irrigation systems used in Florida:
Type of System Man Hours/Acre Inch
of Water Pumped
Solid set 0.04
Center Pivot 0.05
An economic feasibility of an irrigation system requires
estimating all of the costs and returns expected from the planned
system. When determining irrigation cost and return on investment, a
comparison is made of the average annual cost of irrigating to the
value of the estimated annual increase in production.
Fixed costs for an irrigation system consist of depreciation,
insurance, repairs, taxes and interest.
Variable costs for an irrigation system consist of those costs
that vary with output and during the period of crop production.
Examples of variable costs are fuel, oil, lubricants, electricity and
A sensitivity analysis should be done on inputs the costs of
which may escalate faster than other inputs. Two inputs that may have
costs that escalate faster than other inputs are labor and fuel. The
initial design (size of the pipeline and pumping plant) and system
selection may be influenced by the analysis.
Economic Evaluation (Benefit-costs)
Benefit-costs is determined by comparing the estimated annual
costs of owning and operating the farm to the projected increase in
the returns, or benefits, the irrigation system will create by
increasing crop yields and other products sold from the farm.
The goal of the financial feasibility evaluation is to identify
the actual year-by-year costs and revenues which can be expected by
installing the irrigation system. The annual repayments for loans
secured to purchase and install the irrigation system including all
annual variable costs expected for operating the enterprise must be
determined. The annual costs are then compared with the projected
revenue from the enterprise to determine whether cash-flow problems
will occur. An irrigation system may be profitable for a farm but it
does not mean that the grower can afford it. If the irrigation system
is estimated to last 15-20 years, the lending institution may require
that the loan be paid back in 6-10 years. If this is the case, the
grower may find himself with an annual payment that is more than the
value of the expected increase in yield per year with installing the
irrigation system or replacing his old system.
The following initial and operating costs apply to
irrigation systems used in Florida:
Type of System
(Kovach- Veg. 84-6)
III. HOME GARDENING
A. St. John's County
The traditional spring garden contest in the St. Augustine -
Hastings area was held May 17 under the direction of County Director
Jim Dilbeck. Twenty-eight gardens were subjected to the scrutiny
ofjudges Terry DelValle (Urban Gardening -Jacksonville), Kathleen
Delate and Jim Stephens. Gardens were divided into small (less than
1000 square feet), large, and market garden categories and graded on
the basis of aesthetics, suitability based on the gardener's
resources, production techniques and productivity. Plaques and
ribbons were awarded to the top three gardens in each category.
Garden size ranged from 200 square feet to over one acre (for the
only garden in the market garden category). Most of the gardens fared
well despite the extended cool weather this year and a period of
minimal rainfall. Some excellent crops of tomatoes, cabbage, cucumber
and onion were observed, with zucchini and Daikon radish receiving
points for the largest specimens. No unusual pest problems were
detected in the gardens. Of particular interest were the gardens of
the Hartley School 4-H Club, the Center for Living ( a facility for
mentally retarded adults ), and a winning garden located one block
from the salt spray of the Atlantic Ocean.
(Delate- Veg. 84-6)
B. Recent Field Study Results of Interest to Gardeners
Researchers at Gainesville have just completed another year of
field trials whose results were reported during the Vegetable Crops
Department Field Day in May. The following is a summary of some of
these and other observations which are applicable to home gardeners in
1. Beans/weed competition preliminary studies showed that bean
yields were reduced by 15 to 25 percent when one to one ratios of
goosegrass to beans were maintained. Weeds are detrimental in several
ways, although yield reduction is the bottom-line problem.
2. Planting pre-germinated seeds Pepper seeds germinated
faster and the seedlings grew better with a combination of
pregerminated seed, plugmix, water and gel. This method is called the
gel-mix seeding technique.
3. Broccoli variety trial Broccoli seeds were planted Jan. 25,
and seedlings transplanted March 1. Out of 31 varieties and lines,
'Packman' was observed to be the earliest. At the first harvest,
April 19 (60 days after transplanting) 76% of the mature heads
harvested came from 'Packman', 18% from 'Green Beret', 16% from
'Cleopatra', and 10% from 'Kwik-green'. The standard 'Green Duke'
variety, also in the trial, was later.
4. Cold Protection in Strawberries woven polystyrene row
covers were tested for frost protection and production of early fruit.
On Feb. 15 the row covers were placed over early blooming plants and
left on until March 15. Temperatures were below freezing on several
nights during this covered period. Temperperatures were the same
under cover and outside; however, covered plants produced slightly
greater at the early harvest times.
5. A southern pea variety trial conducted at Live Oak (North
Florida) by W. C. Smith, the County Extension Director, and Shepherd,
his technician, in the spring 1983, showed highest yields in the
following order: Mississippi Silver, Mississippi Purple, Colossus,
California Blackeye, Pinkeye Purplehull, Knucklehull Purplehull, and
6. A mulching trial was conducted at Florida A & M University.
Tomatoes, peppers, and southern peas were grown on black, clear, and
biodegradable black plastic, plastic plus new paper, and the natural
organic oak and pine needles. Of particular note was the failure of
the oak and pine mulch to control weeds due to their lack of
thickness. Enough leaves must be maintained to exclude light. Also,
the close spacing of the holes for the peas allowed grassy weeds to
proliferate around the row centers. The black non-degradable gave
best control as expected.
( Stephens- Veg. 84-6)
Prepared by Extension Vegetable Crops Specialists
D. N. Maynard
G. A. Marlowe
J. M. Stephens
S. P. Kovach
S. M. 01son
W. M. Stall
K. M. Delate
Visiting Extension Agent I