RESEARCH REPORT RC 1975-4
BEEF CATTLE E FIELD .i
BEEF CATTLE FIELD 0k
APRIL 18, 1975
SEP T1 1976
A.S. Univ. of Florida
Grateful appreciation is expressed to the companies
and the people that have supported the research program
at the Ona Agricultural Research Center during the past
eighteen months by their grants, gifts and assistance.
These are listed alphabetically as follows:
Abbott Laboratory Co., North Chicago, Illinois
Asgrow Florida, Wauchula, Florida
Bingham Seed Co., Jacksonville, Florida
Albert Carlton, Wauchula, Florida
Doyle Carlton, Wauchula, Florida
Dekalb Seed Company, Sanford, Florida
Dow Chemical Co., Midland, Michigan
Dupont Company, Wilmington, Delaware
Fields Equipment Company, Wauchula, Florida
Florida Seed and Feed Company, Ocala, Florida
Florida Seed Foundation, Gainesville, Florida
FMC Corporation, Tampa, Florida
Frit Industries, Inc., Ozark, Alabama
Fulton Cole Seed Company, Alturas, Florida
Haile Dean Seed Company, Orlando, Florida
Hardee County Cattleman's Association
Hardee County Commissioners
Hardee County Sheriff's Office
Lynn Harrison, Sarasota, Florida
W. A. Lesler, Sanford, Florida
Eli Lilly and Co., Greenfield, Indiana
Lykes Brothers Ranch, Okeechobee, Florida
Monsanto Company, St. Louis, Missouri
Peace River Electric Coop., Wauchula, Florida
H. G. Roberts, West Palm Beach, Florida
Sucrest Corporation, New York, N. Y.
Superior Fertilizer Company, Tampa, Florida
U. S. Sugar Corporation, Clewiston, Florida
Lat Turner, Sarasota, Florida
Velsicol Chemical Company, Chicago, Illinois
E. T. York, Gainesville, Florida
A number of other ranchers and persons have assisted in
forage testing programs and/or field tests of various types.
To them and others who have supported the Ona research
program, grateful appreciation is acknowledged.
This public document was printed at a cost of $263.30, or $0.44 per copy,
for educational use for participants of the field day.
BEEF CATTLE FIELD DAY PROGRAM
ONA AGRICULTURAL RESEARCH CENTER
April 18, 1975
8:15 Registration and coffee
8:35 Introduction and comments........................H. L. Chapman, Jr.
8:40 Welcome and comments............................H. H. Wilkowske
8:55 Use of lime on flatwoods soils...................C. L. Dantzman
9:15 Suggestions for pasture fertilization............W. G. Blue
9:35 Current situation on the bermuda and
stargrasses...............E. M. Hodges
9:55 Ways to maximize use of native range.............L. D. White
10:15 Coffee break
10:35 Smutgrass control in Florida....................P. Mislevy
10:55 Comments on Florida calf marketing situation.....Gifford Rhodes
11:15 Current status of crossbreeding research........F. M. Peacock
11:35 Problems facing the Florida cattleman............T. J. Cunha
12:10 Lunch, served by Hardee County Cattleman's Association,
1:15 Field trip to include visits to:
Freeze branding demonstration.
Calf feeding research.
Smutgrass control research.
Plant fertility research.
Forage variety testing research.
Corn and sorghum variety research.
Corn and sorghum variety research.
C. L. Dantzman
E. M. Hodges
F. M. Peacock
L. D. White
H. H. Wilkowske
Soils Chemist, Department of Soils, Gainesville.
Center Director, Ona Agricultural Research Center.
Chairman, Department of Animal Science,
Assistant Soils Chemist, Ona Agricultural
Agronomist, Ona Agricultural Research Center.
Assistant Agronomist, Ona Agricultural Research
Associate Animal Scientist, Ona Agricultural
Supervisor, Livestock Section, Division of
Marketing, Florida Department of Agriculture,
Assistant Range Management Specialist, Department
of Forestry, Gainesville.
Assistant Dean for Research, IFAS, Gainesville.
USE OF LIME ON FLATWOODS PASTURE
C. L. Dantzman
Approximately one half of the acreage in Florida is of the
flatwoods soil type. These soils can and do make good pasture lands
with proper management. The native fertility is normally very low and
can be corrected with N, P, K and the micronutrients. In addition these
soils are typically very acid and need to be changed to a higher pH
value for improved plant growth. The soil pH of flatwoods soils
normally ranges from 4.0 to 5.2. Liming with dolomite, high calcic
lime, a combination of the two or other forms of lime can correct the
A number of trials involving lime and forage plots have been
conducted at the ARC Ona. A recent trial was designed to determine
the effect of lime levels on the establishment, growth, and elemental
recovery by pangola digitgrass (Digitaria decumbens Stent.). Lime
was applied to replicated plots at rates of 0, 1, 2, 3, and 4 ton per
acre. One-half of the lime of each treatment was applied as dolomite
and one-half as high calcic lime equivalent (applied as hydrated lime).
Following application (in 1970), the lime was roto-tilled into the sur-
face six inches of the soil. The area was then planted with Pangola
The plots were fertilized with 50 pounds per acre rate of nitrogen
(N) using ammonium nitrate, 25 pounds per acre rate of P205-using
single superphosphate and 25 pounds per acre of K20 using muriate of
potash following each harvest. Double this rate was used initially
to establish the grass. Micronutrients were supplied with 20 pounds
per acre of FTE 503 each year.- The vegetation was harvested to a
3.5 inch stubble. Eleven harvests were made over the period of the
experiment. Harvest dates extended from February through October. Plant
materials were weighed, ground, digested and analyzed for Ca and Mg.
I/ FTE 503 contains 18% Fe, 7.0% Zn, 7.5% Mn, 3% Cu, 3% B, and 0.2% Mo.
Soil samples were taken each spring and soil extracts (IN
ammonium acetate at pH 4.8) analyzed for Ca, Mg, K, P, and pH by the
U. F. Soil Testing Laboratory.
The 1971 soil samples, taken nine months after the lime treatments
were applied, showed significant increases in both CaO (128 to 205%),
and MgO (115 to 148%), as compared to the no lime treatment. The 1972
soil CaO values also increased from 647/A CaO for the no lime treatment
to 1151 for the 1 ton/A rate and to 1341 lbs/A for the 4 tons per acre
rate. Magnesium oxide followed a similar pattern to that for CaO.
The pH of the native Immokalee fine sandy soil ranged from 4.5 to
4.7 in pretrial condition. Nine months after lime treatments were
applied (1971), the pH value was 4.8 for the 1 ton lime rate and 5.4
for the 3 ton rate. The pH values for 1972 were quite similar to
1971. During this time the soil of the control (no lime treatment)
became more acid to pH 4.3.
Grass yield data were not significantly different for 1971.
However in 1972 plots receiving from 1 to 4 ton/A lime had significantly
higher yields than the no lime treatment (control).
The percentages of Ca in the oven-dry forage for the eleven harvests
were 0.222%, 0.273%, 0.321%, 0.334% and 0.343% Ca for the 0, 1, 2, 3, and
4 ton lime rates, respectively. Magnesium percentages of the same
treatments were 0.173, 0.207, 0.242, 0.242, and 0.238% Mg. The levels of
Ca and Mg in the tissue were quite consistent with the treatments of lime
A second trial compared surface applied lime with soil-incorporated
lime on whiteclover-pangolagrass. Lime at the rates of 0, 2, 4, 6, and
8 ton/A (one-half as dolomite and one-half as high calcic lime equivalent)
was applied to a non-irrigated plot area that was previously rototilled
to a depth of six inches. The plot areas had the lime surface applied;
then one-half of each plot had the lime incorporated into the soil to a
depth of six inches. After establishing Pangola digitgrass, the area
was seeded with whiteclover. During the trial whiteclover was reseeded
annually in early winter.
Fertilization consisted of an application of 400 pounds per acre
rate of an 0-10-20 initially (January 11, 1972); than 0-10-20 at the
rate of 400 pounds per acre each October and 800 pounds per acre each
February. Vegetation was harvested to a height of 3.5 inches five
times each year: April, June, July, September, and October. Soil
samples were taken each spring and soil extract (lN ammonium acetate at
pH 4.8) analyzed for Ca, Mg, pH, by the U. F. Soil Testing Laboratory.
No significant differences in forage yield were evident for the
first year but application of lime at any level produced significantly
greater clover-grass yields than plots without lime during the second
year of the trial for either the surface applied lime or soil incorporated
lime. During the first year of the trial significantly greater yields
(59%) were measured for plots having lime incorporated into the upper
six inches of the soil than where it was applied to the soil surface.
Yields for the second year were not significantly different.
Clover growth was greatly aided by the addition of lime. The
benefit was more pronounced during the first three months, the period of
establishment for the clover. During the 1972 cool season clover cover
averaged 12% for the unlimed plots and for surface applied lime. This
increased to 31% for the 2 ton lime level and to 52% for the 6 ton lime
level. The percent clover cover was greater for plots having the lime
mixed to a depth of 6 inches. At the 2 ton level the percent cover was
79%, and at the 6 and 8 ton levels it was 95%. These percentages for
the incorporated lime were 2 to 4 times as great as those for surface
applied lime. During the warm season, clover cover on all treatments
ranged from 1 to 7%. Clover cover for the 1973 seasons was somewhat
less than those for 1972. The pattern for clover height was similar
to that for percent clover cover.
Lime affects the soil and forage crop as follows:
1. It adds calcium (Ca), and in the case of dolomite also adds
magnesium (Mg) to the soil. These elements are then available
for plant use.
2. It increases the pH of the soil.
3. It encourages increased root systems as compared to unlimed
soils. The larger root system then can take up more nutrients
4. It encourages increased microbiological activity. This improved
soil environment is necessary for the clover nodulating bacteria
which produce available nitrogen.
5. Solubility of micronutrients (Cu, Zn, Mn, B, Fe) is generally
decreased as pH increases.
6. In acid soils phosphorus reacts with Ca to become more soluble
and more available to plants.
7. Lime influences the soil structure.
SUGGESTIONS FOR LIMING AND FERTILIZATION OF PASTURES
W. G. Blue
Soil Science Department
University of Florida
Florida's mineral soils are derived for the most part from relatively
coarse-textured, highly weathered material. Most of the virgin soils are
acid and extremely infertile. Toxic aluminum (Al) may be a problem and
immediate deficiencies of nitrogen (N), phosphorus (P), and potassium (K) are
common. Calcium (Ca), magnesium (Mg), and one or more of the micronutrients
may be deficient at or soon after the initiation of cultivation. In spite
of multiple nutritional problems, most of these soils are highly responsive
to proper management practices, and contrary to the belief of some who have
not worked intimately with these soils, some applied nutrients accumulate.
To maximize the efficiency of fertilizers, correction of soil acidity by
liming with calcitic (calcium carbonate) and/or dolomitic (calcium-magnesium
carbonate) lime continues to be the first priority. Aluminum as a toxic
element has been emphasized during the past several years, primarily for finer
textured soils with large quantities of total Al. Florida's mineral soils
may have as little as a few hundred to as much as several thousand 'lb/acre
of total Al. Exchangeable (ions attached chemically tasurfaces of clay and
organic matter) and water-soluble Al will vary from insignificant quantities
if soil pH is maintained above 5.5 to toxic levels in very acid soils. Be-
cause of the low cation exchange capacities (CEC) of many sandy soils, rela-
tively small quantities of exchangeable Al can cause amounts of water-soluble
Al which will adversely affect plant root growth. As little as 1 Ib/acre in
the soil solution can cause problems with some crops.
A soil pH of 6.0 to 7,0 is frequently recommended for fine textured
soils with large nutrient reserves. Florida's sandy soils should not be
limed so heavily because micronutrient deficiencies are likely to be
accentuated. A soil pH of 6.0 is probably ideal; close attention should be
paid to prevent reduction below 5.5, the reaction at which Al begins to be-
come active. High exchangeable and water-soluble Al in subsoils may also be
detrimental to root elongation and proliferation. Subsoil liming would be
advantageous for many soils but will likely be uneconomical for most pastures
and agronomic crop. Proper liming of the surface soil will permit gradual
movement of Ca into the subsoil, diminution of soluble Al, and enlargement of
plant root systems. Phosphorus also leaches from the surface of many coarse-
textured acid soils but its retention increases as pH is increased. Reten-
tion of applied P is relatively efficient at pH 6.0. Dolomitic lime supplies
Ca and Mg. The proper balance of calcitic and dolomitic lime to maintain the
soil at pH 6 will supply adequate of these nutrients. Calcium is held
strongly by the CEC derived from organic matter which dominates the exchange
properties of many sandy soils. Magnesium and K are held relatively weakly
compared to Ca. This enables small quantities of Mg and K to supply adequate
of these elements until supplies are exhausted, but it also permits leaching,
particularly when plants are dormant or during fallow periods. Lime is
important to maximize symbiotic N fixation by pasture legumes. Symbiotic
fixation of N by legumes can satisfy the needs of these plants, provide N
for associated grasses, and permit diversion of N fertilizers to non-leguminous
crops. Maintenance of soil pH at 6.0 will satisfy the requirement of all
known potential legumes except alfalfa.
Lime should normally be applied sufficiently in advance of cropping to
bring the soil pH to near the equilibrium level ; this time interval may be
6 months or more. However, mineralization of soil N is enhanced in many acid
soils after liming. Advantage can be taken of this mineralization in the case
of acid-tolerant, warm-season grasses by liming soils shortly before planting.
Soil pH correction and enhanced N release will occur the N will be used by
the grass during its establishment.
Lime undoubtedly continues to be the best buy for improvement of soil
fertility and fertilizer efficiency. pH elevation, toxic Al reduction,
adequate Ca and Mg, improved P retention, and more efficient N fixation by
legumes, all benefits from liming, will permit more vigorous plant root
growth and improve nutrient absorption by more extensive root contact with
soil and soil water.
CONSISTENCY THE KEY TO NITROGEN EFFICIENCY FOR PASTURES
The ultimate objective of pasture fertilization is to maximize profit
per unit land area, usually through production of some animal product. The
immediate objective, in the case of fertilizer N, is to have it absorbed by
plants at the earliest possible time following fertilization. Absorption
will occur most rapidly during the period when the plant is actively growing.
The recovery of applied N in harvested forage under Florida conditions
is commonly thought to be in the range of 40 to 50%. In recent study with
Pensacola bahiagrass on flatwoods soils, recoveries were in this range for
the first 4 years (Fig. 1). Subsequently, recovery efficiencies increased
and were above 70% from the sixth through the tenth year. They were slightly
higher with a 200-lb/acre N rate than with 100 lb. Investigation of why
o00 N Applied, Ib/acre/year
1962 1964 1966 1968 1970 1972 1974
Fig. 1. Nitrogen uptake in Pensacola bahiagrass
forage from Leon fine sand as affected
by time and nitrogen rates.
recovery increased, showed that bahiagrass stolon-root weights measured in
October increased as N rates were increased. Attainment of relatively con-
stant net N content in the stolon-root system is apparently a function of time
and rate of N fertilization. Until equilibrium is achieved, part of the
applied N is retained in the stolon-root system, thus, reducing N use for
forage and protein production. However, the stolon-root system may also re-
duce the potential for N losses by leaching and volatilization following
fertilization by acting as a reservoir for rapid N absorption. Development
of stolon-root systems, whose masses and N contents are dependent on time
and rate of N fertilization, apparently is a characteristic of each perennial
plant species. Consistency of annual N fertilization, in terms of timing
and application rate, will maximize N use for forage production by main-
taining more constant stolon-root weights and N contents.
It has been a common practice in our experimental studies to fertilize
in early spring and again approximately July 1. Recovery of the N applied
in March in forage on the stolon-root system has been highly efficient.
Recovery of N from the second application in early July has been less efficient.
Moisture in the "flatwoods soils" is frequently excessive by July. Excessive
water reduces air in the soil, and microbial activity depletes the oxygen.
As a consequence, denitrification (reduction of nitrate N to volatile elemental
N and oxides of N) is known to occur. We believe this phenomenon is responsi-
ble for major N losses from pastures on flatwoods soils which are fertilized
during July and August. Therefore, it appears advisable to avoid N
fertilization during the July-August period of high rainfall. Furthermore,
forage yields are relatively high during this period with relatively lower
concentrations of N.
Since poor forage production distribution is a major limiting factor
for cattle production in Florida, the most practical and efficient approach
will likely be to fertilize in early spring to stimulate growth after the
winter season and again in September for forage production to be used for
deferred grazing or as hay.
Nitrogen is the soil-derived element needed in largest quantity by non-
leguminous pasture plants and is the most costly. There is great potential
for reduction of fertilizer N needs by inclusion of winter legumes such as
white clover with the grass on poorly drained flatwoods soils, and warm-
season, summer legumes in south Florida, The number of warm-season legumes
for the immediate future in north Florida is limited because of late flowering
and poor seed production. The N fixed by white clover can increase grass
forage production to a level equivalent to that from 200 lb of fertilizer
N/acre/year. Because N concentration in clover foliage is high and its re-
lease from clover residues is relatively slow but constant, N concentration
in the grass is increased more than yield. Protein production from white
clover-Pensacola bahiagrass pasture may be as high as that obtained with
400 lb of fertilizer N/acre. The warm-season legumes may have similar poten-
tial and a more concentrated research program is needed in this area. Proper
liming (pH 6.0), sufficient supply of other nutrients, and meticulous atten-
tion to inoculation with efficient strains of Rhizobia bacteria will insure
nodulation and symbiotic N fixation, and encourage growth of most legumes.
USE OF ACCUMULATED SOIL NUTRIENTS
As mentioned previously, some nutrients do not accumulate in sandy
soils to as high levels as in finer textured soils. Phosphorus will accumu-
late, but K does not. In soils of West Florida phosphorus is held strongly
by Al and iron (Fe). In the sandier soils of Peninsular Florida, lime is
required for efficient retention. The exact mechanism is not understood but
it is likely that Al held by the soil organic matter in the highly acid con-
dition is exposed by liming for reaction with P. In any case, fractionation
procedures indicate that most of the retained P is in the Al form. Phosphorus
that is leached from the surface of flatwoods soils will be held by the spodic
horizon (stained layer) or lower horizons which have high capacity for P reten-
tion, Studies at the Beef Research Unit near Gainesville indicated that
approximately 70% of the P applied over the past 20 years is still in the
surface soil, This P is not readily extractable with ammonium acetate and
it is not possible to predict accumulated quantities from current soil test
data. However, the accumulated P is readily available to forage plants in
terms of forage production and P concentrations,
There was no response to applied P where accumulated P was 600 Ib/acre
and only slight response where it was 300 Ib/acre. Certainly there is some
level of accumulation at which annual P fertilization can be reduced or
eliminated, and particularly where grazing cattle recycle nutrients. More.
work needs to be done concerning relationships between extractable and total
P including use of different extractants. Over the shorter term, ranchers
who have maintained soil pH in a satisfactory range and who have fertilized
well for a number of years under grazing can undoubtedly reduce P fertiliza-
tion for grass pastures.
Though K does not accumulate in large quantities in the surface of flat-
woods soils, there is some retention throughout the profile. Cation exchange
capacity is low in acid flatwoods soils because it is dependent on organic
matter which may be in low concentration; also, the CEC of organic matter is
variable depending on pH. The CEC of organic matter is quite low at pH 4.5
but it increases as pH is raised by liming. However, as the CEC is activated,
Ca from the lime is adsorbed. The large quantity of Ca and its strong attrac-
tion compared to K for the retention sites prevent efficient retention of
Data in Tables 1 and 2 show nutrients removed in harvested Pensacola bahia-
grass and analyses over a 3-year period from surface Leon fine sand that had
been limed repeatedly to maintain pH near 6,0 and fertilized annually with
phosphate and potash over a 19-year period. Experimental treatments were 1,
none; 2, N only at 400 Ib/acre in 1971 and 200 Ib/acre in 1972 and 1973; and
Table 1. Yields and nutrients in Pensacola bahiagrass forage from differential
treatments applied to Leon fine sand previously limed to maintain pH
6.0 and fertilized annually with phosphate and potash, and periodically
with micronutrients under grazing for 19 years.
Nutrients Oven-dry Nutrients in forage
Treatments applied forage N P K Ca Mg S Mn Cu Zn Fe
Ib/acre ------------------------lb/acre---------------- -------
304 53 284 139 60
538 78 348 210 96
727 113 673 266 161
Table 2. Soil analyses (0-6 inch depth) before application of
differential treatments to measure residual effects of
accumulated nutrients and after each of three growing
seasons of limed and continuously fertilized Leon fine
sand planted to white clover and Pensacola bahiagrass
under grazing for 19 years.
Nutrients Organic Soil NH40Ac(pH 4.8) Extractable
Treatments applied matter pH P K Ca Mg
Pre-experimental, March 22, 1971
Avg 4.95 5.9 26 132 3080 156
October 8, 1971
1 None 5.6 11 50 2960 130
2 N 5.5 16 26 2360 92
3 Complete 5.4 24 60 2780 178
October 6, 1972
1 None 5.9 9.2 22 2300 70
2 N 5.9 8.0 16 1820 42
3 Complete 5.6 9.0 28 2220 90
September 13, 1973
1 None 5.9 9.4 16 1800 38
2 N 5.9 7.0 14 1820 12
3 Complete 6.0 6.2 16 1660 68
3, N as in treatment P, K, Mg, sulfur (S), and fritted micronutrients as FTE
503, The only nutrients which were reduced to deficient concentrations during
the 3-year experimental period were N and K. Uptake during 1971, the first
year of residual nutrient measurement, was relatively high for all nutrients.
Nitrogen was deficient for maximum growth from the first year and yield from
treatment 1 was significantly lower than from other treatments (Table 1).
Potassium was in adequate concentration during the first year and yield from
treatment 1 was significantly lower than from other treatments (Table 1).
Potassium was in adequate concentration during the first year and yield from
treatment 2 was not significantly lower than from treatment 3 where K was
applied. Average K concentration in forage without applied K for 1972 was
much below that in forage from treatments with K; during the latter part of
the second season concentrations were below the critical level for forage
growth. Forage yield was drastically reduced in 1972 and in 1973 when K in
oven-dry forage was 0.44% and much below the critical value of 0.70% pre-
viously established. Total uptake of K from treatment 2 with only N applied
was 348 Ib/acre for the 3-year. period (Table 1). The surface soil contained
132 Ib/acre of acid ammonium acetate extractable K at the beginning of the
study in March 1971 after 19 years of fertilization under grazing (Table 2).
Extractable K at the end of 1973 was 14 Ib/acre. The difference was 118 Ib/
acre. Total removal of 348 Ib/acre (Table 1) was almost 3 times the amount
present in the surface soil; this indicated significant K uptake from the
subsoil horizons. The effect of previous good management on supplies of other
nutrients is obvious since even with the severe stress imposed on the system
by high N levels and nutrient removal in forage, supplies were adequate over
the 3-year period. For Pensacola bahiagrass pasture with previous good manage-
ment, reasonably high yields of nutritionally adequate forage could be produced
for at least 2 years with N fertilization alone, particularly under grazing.
If the plant were Pangola or another of the digit grasses with higher K
requirement than bahia, production without K would be for shorter duration.
If one were interested in reducing N fertilization by using white clover, K
fertilization would have to be continuous since this plant must have a high
K concentration in the surface soil for rapid development of seedlings during
the winter; it is also relatively shallow rooted and requires a high K con-
centration in its vegetation to grow well.
As the term micronutrient indicates, these nutrients including manganese
(Mn),zinc (Zn), Fe, copper (Cu), boron (B), and molybdenum (Mo) are needed in
very small quantities compared with the major nutrients. However, without
proper quantities of these elements, plant growth is inhibited. Availabilities
of micronutrients are normally reduced as soil pH is increased by liming.
Molybdenum is the exception and its availability is increased. Recent pot
studies with Pangola digitgrass and Pensacola bahiagrass on Leon fine sand
have demonstrated the potential severity of micronutrient deficiencies and the
face that micronutrient availability is reduced even at soil pH 6.0. Data in
Fig. 2 show that with or without micronutrients, the highest yields occurred
at approximately pH 5.2. Yield of Pangola was severelyreduced as pH was in-
creased, particularly above 6.0. Pensacola bahiagrass was grown following
Pangola in this experiment. With fritted micronutrients (FTE 503), yield of
bahia was not affected by soil pH but without micronutrients, yield was very
poor. In fact, plant mortality was high above pH 5.5. It should be emphasiz-
ed that other essential nutrients were applied uniformly and in large quan-
tities, It is quite.obvious that micronutrient availability could markedly
0 With Micronutrients
C 70/ ---- Pangolagrass
S/ -----Pensacola bahiagrass
> I 30
4.8 5.2 Without
Leon fine sand at several rates of lime,
wit \ Micronutrients
0, -- "-T-"1
0 200 400 800 1600
Ca applied as CaCO3 ppm
I o I
4.8 5.2 5.5 6.0 6.8
Fig. 2. Pangola and Pensacola bahiagrass growth on
Leon fine sand at several rates of lime,
with and without micronutrient frit FTE 503.
affect utilization and efficiency of the major nutrients. In this particular
case, the short-term problem was Cu deficiency. Approximately 2.5 ppm in
oven-dry foliage was sufficient for maximum growth rate. Uptake of Cu in a
5 ton/acre yield of forage with this concentration would be only 0.03 Ib/acre.
The Pensacola bahiagrass, which did not grow without micronutrients, was re-
turned to a growth rate of approximately equivalent to that with the frit by
application of 1 1b/acre of Cu as copper sulfate. The short-term effect of
micronutrients will not usually be as dramatic as in this experiment since
roots can explore larger volumes of soil under field conditions. However,
more intensive use of major nutrients from increasingly refined fertilizer
materials will undoubtedly cause more widespread deficiencies. There is
currently no service facility for analyzing soils or plants for micronutrients.
Deficiencies can occur without awareness on the part of the producer. Any
indication that plant growth is less than expected can be examined by applica-
tion of micronutrient frits or soluble salts to small areas to check on rela-
tive growth rates. If experience in a particular area has indicated specific
micronutrient deficiencies, growers should apply the appropriate materials.
USE OF NATIVE SOIL NUTRIENTS
Though Florida's mineral soils are highly leached, some contain relatively
high levels of native P. Those derived from phosphatic limestone may be
relatively high concentrations of P of limited solubility in their surfaces.
Other soils in central Florida and elsewhere have relatively high native P
concentrations in their subsoils within rooting depth of deep-rooted plants.
This P is available at slow rates to plants, particularly to perennial warm-
season grasses. More attention must be paid in our soil characterization
studies to the incidence of native P in soil profiles and to delineate these
areas. With the proper liming program, P, removed by plants from subsoils,
translocated to the surface by plants, and consumed by cattle, will accumulate
in the surface soil and ultimately reduce need for P fertilization.
Most of Florida's acid, sandy soils have developed from highly weathered
parent material. They are deficient in essential plant nutrients, and many
have excessive soluble Al. -Utilization efficiency of applied nutrients is
likely to be highest when the soil biological system, including plant roots
and microorganisms, is operating at a high level of activity. Reduction of
soil acidity by liming to pH 6.0 will neutralize toxic Al, increase cation
exchange capacity, supply Ca and Mg, improve P retention, increase root growth,
and activate microbiological processes. Soil pH adjustment should have the
first priority for an efficient soil fertility program. It is important to
know what quantities of nutrients are needed by plants, and what proportion
will be supplied by the soil and what must be supplied from fertilizers. Short-
ages of any one or more of the essential nutrients will reduce efficiencies of
the others. Not only are total nutrient supplies important but so are their
availabilities at specific times in the life cycle of plants. A transient
nutrient such as N may be permanently lost from the soil-plant system if it
does not enter the organic phase through absorption by the plant. Consistency
of N fertilization will maximize N utilization for forage and protein produc-
tion. Further economy of N utilization can be achieved by eliminating its
use from most leguminous crops. Proper pH adjustment, adequate supplies of
other nutrients, and recommended methods of inoculation with efficient strains
of Rhizobia usually will preclude response of leguminous.plants to applied N.
Nitrogen fertilizer can be.diverted to non-leguminous crop use. Phosphorus
will accumulate in properly limed soils and it retains substantial availability
to crops. Potassium also will accumulate at low concentrations in the soil
profile. Previous P and K fertilization, management, and soil analyses should
be considered, particularly for deep-rooted, perennial pasture plants, in deter-
mining future fertilization programs. Micronutrient deficiencies are frequently
very subtle, but deficiencies of these nutrients can cause seriously reduced
efficiencies of major nutrients. Some Florida soils have large amounts of
native P in surface or/and subsoils. This P has some availability and can be
important, in long-term management systems particularly for perennial plants.
BERMUDAGRASS AND STARGRASS
E. M. Hodges
The botanical name for the genus which includes bermudagrasses
and stargrasses is Cynodon and the grasses discussed here can all be
referred to as 'Cynodons'. Bermudagrass (Cynodon dactylon) came to
central Florida with the first vegetable gardens and in these cultivated
and fertilized areas was the first improved pasture. The common
type of bermudagrass reproduces by seed and spreads by runners both
aboveground stolonss) and underground (rhizomes). It was included
in a grazing trial in Alachua County in the 1930's and was a low
producer. The trouble with testing this grass lies in its variability
which produces local strains that differ widely from each other. Common
bermudagrass has increased in many improved pastures and has been
particularly aggressive at the Ona ARC. Nitrogen fertilization, lime
treatment, and accumulation of plant and animal wastes all stimulate
this grass. Its value should not be put too low. While grazing
animals do not find it palatable, mature cows not supporting calves
do very well and it has special value in the fall months when growth
of Pangola and the bahiagrasses is slow.
An intensive breeding program at Tifton, Georgia, produced
Coastal and Suwannee.bermudagrasses. These were brought to Florida in
the early 1940's. The first-named grass has become the most famous
improved forage variety in the world and it has always seemed a little
strange that it has not done well in central Florida. Warm season
grazing during the 1945-1950 period with a single 500 pounds per acre
of 6-6-6 fertilizer each spring produced average beef gains of 133,
139, and 166 pounds per acre, respectively, for Coastal, Pensacola and
Pangola. Fertilization with a 9-6-6 mixture at three dates for a
total of 900 pounds per acre annually yielded beef gains of 199, 215
and 339 pounds per acre annually for these same grasses. Suwannee
bermudagrass was more productive than Coastal in a pilot comparison
but loss of stand and modest yield levels discouraged use of both
varieties. It is safe to assume that the nitrogen levels used were
inadequate although competition from other species was the biggest
problem. Coastal did not compete well even when grazed under a
200 pounds N per acre annually regime.
A new variety, Coastcross 1, was released from the Tifton
breeding program in the 1960 decade. Coastcross 1 is a sterile
hybrid between Coastal and a bermudagrass obtained from Kenya and
was selected for high digestibility. When first planted at Ona it
appeared to not compete well with other grasses and was not considered
promising. It was placed on test again in 1970 and has made a good
stand in replanted land. Substantial acreages have been planted in
central Florida and it makes vigorous fall growth with adequate
supplies of plant food.
The stargrasses are members of the Cynodon genus and have been
placed in several species by classification experts. The name
refers to the supposed 'star' outline of the flowering parts. The
name is already widely used in the African areas of origin and in
the Caribbean section of this hemisphere. Stargrasses have no rhizomes
but spread by very vigorous and rather coarse stolons. No sign of
extension by seed has been observed for the stargrasses at Ona ARC.
A plant collection made by J. L. Stevens, USDA, in southern Africa in
1955 included many stargrasses. Several of these were brought to
Ona by J. E. McCaleb in 1956 and PI 244152 was planted in 1959 in
pasture areas. This grass was rather steamy and grew slowly in the
spring. It was called variously 'African stargrass', 'Bermuda 52',
and UF No. 11. and was released in 1974 as 'McCaleb' stargrass.
Establishment after planting is rapid and forage production is high
under heavy fertilization. McCaleb makes good fall growth, competes
well against other grasses and has had no serious disease or
insect problems. Like all members of the bermudagrass group, it
has a high plant food requirement. It matures more rapidly than
digitgrasses and should be used for grazing or hay when in the
immature stages. More information is available in IFAS circular
S-231, January 1975.
Other promising grasses of the stargrass type are under test and
will be released when their value is proven.
A number of other Cynodons are known which are of interest to
the local situation. One of these is a bermudagrass named 'Alicia'
which has been widely distributed in the last several years. This
is a fine-stemmed, narrow-leafed grass that has yielded varying
results when compared with other varieties. Difficulty in obtaining
material for testing has limited our supply of data.
A release from the Mississippi Experiment Station, named 'Callie
Giant Bermudagrass', has not been evaluated in Florida at this date.
Several other vigorous, coarse-stemmed grasses of the stargrass type
are being planted. They generally share the characteristics of
McCaleb stargrass and their place in our forage system will be
measured by their production performance.
The Cynodon grasses as a group have a little more frost tolerance
than the digitgrasses but none hold up under sub-freezing temperatures.
Stage of growth and local moisture conditions cause wide variations in
apparent cold tolerance. None of these grasses should be expected to
be "wondergrasses"! Quite possibly they will find a valuable niche
in our future forage program.
No new forage variety has been tested in all the varied conditions
present in our state or even in a county. Neither experiment station
test nor commercial statement proves or disproves what will happen on
a local farm or ranch. Trial plots or small pasture plantings are
recommended when new and promising varieties are available.
Ways to Maximize Use of Range
Larry D. White
Range Ecosystem Management
School of Forest Resources and Conservation
The management of range resources for optimum yields from cattle
and secondary products require a well balanced year round supply of for-
age of sufficient nutritional quality and palatability to maintain high
herd health and good calf crops. Nutritional needs can be maintained on
lower quality roughage by free-choice supplements and/or supplemental-
fertilized pastures. Also, quality and quantity of forage can be mani-
pulated to advantage by altering kinds of plants utilizing ecological
principles. Desirable native plants are palatable, productive and adap-
ted to local environments. This paper will discuss ways of increasing
livestock forage production from Florida's rangelands and maximizing
sustained yields. Very few of us really need to be told ways to maxi-
mize use of any resource. This is the thing most of us do best. What
we are weakest at is the longer term objective of sustaining high or
optimum yields. This past winter has seen many ranchers attempting to
maximize short term use of rangelands. Maximum use does not have to mean
resource depletion. Rather, application of range management principles
can provide proper planning and direction for range use to obtain sustained
maximum animal production, consistent with perpetuation of the natural
resources (ASRM, Range Term Glossary Comm. 1964).
Some Basic Range Management Principles Applicable
1. Rangelands are usually a mixture of plants requiring management stra-
tegies adapted to desirable forages.
2. Desirable forage plants require management providing a competitive
advantage over undesirable plants for water, sunlight, and soil
,3. Individual plants can sustain grazing if their ability to: (a)
produce food, (b) renew topgrowth, (c) maintain a healthy root
system, and (d) produce reproductive organs are provided by planned
4. Planned utilization should properly harvest available forage resources
to best advantage for livestock and forage production incorporating
a period of rest allowing forage plants to grow unmolested follow-
ing a systematic grazing schedule.
5. Insure nutritional needs of animals are met at all seasons, especially
to flush cows to increase conception.
6. Provide adequate clean water and necessary pest and parasite control.
7. Adapt the livestock operation to take advantage of forage re-
sources and economic situations.
8. Balance animal numbers with the forage resources, graze at proper
seasons and obtain proper distribution within pastures.
"Successful production of red meat depends upon careful handling of both
(forage and livestock) and upon the greatest possible harmony between
the two (Stoddard, Smith, and Box. 1975. Range Management. McGraw-
Hill, Inc. N.Y.).
Past Management of Florida Ranges
Historicallyuse of range resources has been for livestock production
and wildlife habitat. The Florida beef cattle industry was founded on
ranges with recent advances in beef production possible through agronomic
(tame pastures) and animal husbandry advances. The advances occurred dur-
ing an era of low energy and fertilizer costs with ranges badly depleted
and management strategies based on wiregrass and "annual" burning. Range
livestock numbers were determined by "growing to fit the land" or survival
of the fittest. These range practices have produced a generally recognized
overgrazed range dominated by undesirable grasses, such as wiregrass, and
carpetgrass, and shrubs such as sawpalmetto.
The potential of Florida's rangelands for production of quality cow-
calf operations has not been widely recognized until recently. Past range
livestock practices developed without ecological or range specialist in-
puts. These practices resulted in marginal operations which were most
often destructive to the basic range forage resource. Such prevailing con-
ditions has lead to a generally accepted concept that Florida's rangelands
have marginal cattle production values. On the other hand, a few excep-
tional range operators show that good management increases cattle grazing
capacity to 6-8 acres/animal unit year while maintaining high calf crops.
Range management for wiregrass results in calf percentages averaging
40-50 with cows calving in alternate years (Hughes 1974). "Providing
about half the diet through the grazing of improved pasture in combina-
tion with wiregrass range offers one method of obtaining satisfactory
percentages of calving and weaned weights." Another alternative many
ranchers are choosing, is to develop management programs that favor the
most palatable forage species (bluestems, panicums, and paspalums) and
discourage wiregrass and sawpalmetto.
A 1974 survey from Florida county agents indicated approximately
3200 cattle operations with combination range and tame pastures, 288
with only range, and 4171 with only improved pastures. The range operations
occurred on an estimated 8.5 million acres. A recent USDA study of U.S.
ranges conclude "... a considerable increased demand for red meat, prin-
cipally beef, the higher demands for, and costs of, feed and food grains
probably will mean a higher dependence of the beef industry on forage,
particularly that from range" (USDA 1974). The study further identified
at least a decade of high fossil fuel costs which will "create a need
in some situations for the substitution of low energy using production
activities for those of high energy use ..."
Increasing Range Forage Production
Two major management situations affect range forage production pro-
grams and utilization strategies:
1. management and use of depleted ranges where desirable forage
plants are not dominant require rehabilitation practices to
achieve maximum production, and
2. management and use of ranges where desirable forage plants are
at full production potential require utilization planning and
maintenance practices to maintain high yields.
A first principle in range management is to take full advantage of
natural production cycles with the minimum necessary "manpower" input.
This would mean allowing natural reseeding of desirable forages, reducing
competition from undesirable plants by chopping and discing, reduced
livestock numbers, rotating season of use, burning, water level control,
Research is currently underway on undesirable plant control, recover
of desirable plants, management characteristics of desirable plants, re-
growth potential following harvesting, fertilization, water management
for maximizing marsh forage production, and development of grazing sys-
Control of Undesirable Plants
Careful planning and evaluation of the need for plant control, methods
of control, best areas for treatment and potential economic returns
are needed before embarking on expensive manipulation programs. Control
of less desirable plants such as wiregrass, saw palmetto, wax myrtle, sand
cordgrass, rush, carpetgrass, etc. are often desirable to increase forage,
livestock, and economic production. Plant control applied without adequate
planning often results in short term gains but long term resource depletion.
Desirable plants protected by shrubs are easily destroyed by overgrazing
following brush control. Brush control is not a substitute for good
management, rather it is an aid to management allowing depleted ranges
to recover to their full potential, too many ranchers want immediate re-
sults (increased livestock grazing capacity) without longer term planning
of year round forage needs. This too often results in the further demise
of desirable plants before they are allowed to recover from the control
program and past grazing pressure. Also, no opportunity is allowed for
the desirable plants to reproduce and occupy the pasture.
Before a rancher implements a brush control program, he must evaluate
the need for treatment and potential return by area. Research on the Golden
Rainbow Ranch near Myaaka City show the relationship between shrub and
grass production. This type of results illustrate the need for brush
controlwhen saw palmetto production reaches moderate to high levels. Wire-
grass (pineland threeawn) production was highest without a saw palmetto cover
but high yields remained even with saw palmetto production of 1000 pounds per
acre (Figure 1). This further substantiates that what is good for wire-
grass is probably good for saw palmetto. Chalky bluestem production was
greatly reduced by production of saw palmetto above 100 pounds per acre
(Figure 2). Production of indiangrass (wild oats) was not greatly affected
by saw palmetto production until about 500 pounds per acre was present
(Figure 3). Creeping bluestem production was reduced when saw palmetto
produced more than 100-300 pounds per acre (Figure 4). Management for
anyone of these four grass species would require different densities of
saw palmetto for effective control and establishing the need for treat-
ment. Saw palmetto coverage of less than about 300 pounds per acre would
probably not provide an economic return from brush control. Other factors
may be preventing effective establishment of desirable forage plants.
Maximum yields of the three desirable grasses could be achieved by re-
ducing saw palmetto to an open scattered stand. The scattered palmetto
would still provide cover and food for wildlife.
Several studies have shown chopping controls saw palmetto and wire-
grass (Lewis 1970) releasing creeping bluestem and increasing herbage
production from 200 pounds per acre to 6,000 pounds per acre (Yarlett
1965). A chopping study established in 1971 on Golden Rainbow Ranch
resulted in decreased production of wiregrass and saw palmetto still
evident today. There was an immediate decrease in these plants and creep-
ing bluestem. Creeping bluestem is recovering rapidly, spreading over
more study plots. Chalky bluestem and indiangrass increased dramatically
the first year but has since decreased. Results of this year's clippings
are not currently available. The first year response of creeping bluestem
may indicate the need for rest from grazing before applying chopping. This
FIGURE 1. F
POUNDS PER ACRE
RELATIONSHIP BETWEEN PINELANDTHREEAWN AND SAW PALMETTO
PRODUCTION PRIOR TO TREATMENT ON GOLDEN RAINBOW RANCH.
(f 60 300 540 780 1020 1260
POUNDS PER ACRE
RELATIONSHIP BETWEEN CHALKY BLUESTEM AND SAW PALMETTO
PRODUCTION PRIOR TO TREATMENT ON GOLDEN RAINBOW RANCH.
I~.IIUIIU~ II __ _ _~ ~_arm~n~- I ~I~ F 1811~ 1
.iad,3..f tgfl t^& l ^^A i r
0 60 300 540 780
POUNDS PER ACRE
RELATIONSHIP BETWEEN INDIANGRASS AND
PRIOR TO TREATMENT ON GOLDEN RAINBOW
0 60 300 510 780 1020 1260
POUNDS PER ACRE
RELATIONSHIP BETWEEN BLUESTEM AND SAW PALMETTO PRODUCTION
PRIOR TO TREATMENT ON GOLDEN RAINBOW RANCH.
I-~I I;~A~~a-~~-i~u~~~~~;~----~--- ~-------- -~-~----
is further substantiated by a rapid improvement of herbage production
on ungrazed control plots the first year.
Studies in north Florida further indicate soil disturbance reduces
wiregrass (pineland threeawn) (Table 1). These results indicate bedding
for establishment of pine plantations reduces wiregrass approximately
50 percent, and saw palmetto 90 percent; increases dogfennel, grassleaf
aster, blackberry, gallberry, greenbriar and ground blueberry.
The use of fire to control saw palmetto crown cover, "freshen
forage," and provide high quality range for winter and spring grazing
has been widely accepted. This practice has been especially adapted
to wiregrass management systems. Prescribed fire was reintroduced on the
Agricultural Research Center at Ona during the winter of 1973-74. Several
burns were established to provide control of wax myrtle, and reduce saw
palmetto and grass rough. The range areas had not been heavily grazed
for approximately 5-7 years nor burned for 12 years. In october, 1974
adjacent 40 acre blocks were observed for control of wax myrtle and
recovery of creeping bluestem. Results indicate most wax myrtles
were effectively killed to ground level but were resprouting at the base
(85%). Creeping bluestem leaf production was reduced to 1/5th of that
of the unburned area (6.5% LAI vs 31.5%, respectively).. Most of the burned
creeping bluestem plants produced reproductive stems rather than leaves
as compared to the unburned plants. Since the areas were not grazed
following the fires, massive flowering occurred without cattle removing
terminal buds which can greatly affect individual plant health. Repro-
ductive stems usually occur when creeping bluestem plants are in a low
vigor stage. Hence, if "normal" grazing practices were followed,com-
petitive selection would have been in favor of wiregrass, saw palmetto and
Table 1. Significant understory vegetation response to niche location
on Leon f.s. flatwoods near Lake Butler, Florida.*
Niche location Level of
Species Top of Bed Midway between Beds Significance
Pounds per acrel
Pineland.Threeawn 406 712 .01
Dogfennel 14 5 .20
Grassy Leaf Aster .8 1 .01
Blackberry 170 53 .01
Gallberry 550 378 .01
Greenbriar 5 2 .20
Ground Blueberry 42 20 .10
Saw Palmetto 6 59 .20
Total Shrubs 831 588 .01
Total Live Biomass 3726 3509 .10
Dead 113 55 .05
*CRIFF A-23 study established .1968, sampled October 1973 by State
Division of Forestry in cooperation with Owens-Illinois.
SRounding to the nearest whole number makes some means the same even
though the ANOVA may have indicated a difference.
other less desirable plants. Burning followed by rest during the spring
and summer growing season might be used to enhance spread of creeping
bluestem throughout a pasture. In cooperation with the Soil Conservation
Service, the seed crop was harvested as a pilot test of a range seed stripper
and for establishment of a range plant nursery at Gainesville.
Range fertilization is usually considered as a potential alternative
for increasing forage quality and quantity. Maximum benefit can be derived
from ranges with good production of desirable plants. Fertilization is
one way of increasing production beyond the normal capability of an area.
Before current high fertilizer pricesjconsiderable interest existed for
possible use of fertilizers on Florida rangelands. Lewis (1970) reported
increased range forage production and quality following application of
rock phosphate to flatwoods. A north Florida study showed application
of 50 pounds of nitrogen per acre increased bluestem production tenfold
in a 25 year-old pine plantation (Duval and Hilmon 1965). Incorporated
with the chopping study on Golden Rainbow Ranch was the application of
rock phosphate, dolomite, and/or nitrogen. Fertilizers were applied
in all combinations. Preliminary first year results are not sufficient
to recommend application of fertilizers to rangelands at the time brush
control is needed. A forest pine plantation fertilization study in north
Florida showed increased yields of broomsedge with fertilization, especially
nitrogen (Table 2). (Kilograms per hectare times 0.89 equals pounds
per acre) Wiregrass was reduced by fertilization. Blackberry usually
increased. Considering the present situation, fertilizers should be
applied only to existing tame pastures and select situations. Third
year results are currently being evaluated.
Table 2. Significant understory vegetation responses to fertilization on Leon f.s. flatwoods near Lake Butler,
1 2 3 4 5 6 7 8
Kilograms per Hectare
Fetterbush 0 0
Gallberry 453 399
Ground Blueberry 44 14
Oak sp. 3 40
Wax Myrtle 0 0
Total Live Biomass 3393 3809
CRIFF A-23 study established
** Fertilizer Treatments were:
N P K
1- 0 0 5
2- 20 0 0 6
3 80 0 0 7
4- 0 20 -0 8
10 11 12
1968, samples October 1973 by State Division of Forestry in cooperation with
- 20 20 0
- 80 20 0
- 20 80 0
- 20 80 0
9 80 80 0
10 80 80 80
11 80 80 80EE
12 20 20 80
Other Research Studies
Research on Paynes Prairie, a marsh near Gainesville, is now being
summarized in a final report. Results show the normal production curves
for maidencane, cutgrass and other species. Also, regrowth following
seasonal harvest and production of ungrazed marsh in relation to water
depth will provide needed information on maximizing forage yields.
Research is currently underway on developing grazing systems for
rangeland in north and south Florida. The north Florida work is in
cooperation with the Animal Science Department and Beef Research Unit.
The south Florida research will be centered at the Agricultural Research
Center at Ona, the Diamond Circle Q near Parrish, the Cecil Webb and
Green Swamp wildlife management areas.
Conclusions and Summary
Maximizing use of rangelands require a sound utilization program
adapted to native forage plants. Contrary to tamepasture plants, native
plants may require periodic rests of 4-6 months to recover from grazing.
Plant control should only be implemented after proper grazing management
and needs for control are established. Use of drum choppers can effectively
control saw palmetto and wiregrass at costs varying from $3-12 per acre.
The economic benefit derived is much dependent on existence of a remnant
desirable forage plant population, proper care following treatment, proper
utilization of the resource and the current economic situation. Range burn-
ing followed by intense grazing provides only short term quality forage
often in insufficient quantity to meet daily intake needs. Use of protein
and energy supplement during the winter months can allow utilization of
rough herbage. Sufficient protein should be supplied to meet animal daily
requirements (approximately 3 pounds per day). In order to maintain high
livestock yields, non-producers should be culled heavily.
Long term increase in livestock yield from rangeland can best result
from management for more desirable forages than the current often applied
management for wiregrass. High cost tame pastures are losing their past
competitive edge once range forage production approaches potential. The
long term success of Florida ranching probably required a diversified
operations with several forage production alternatives available. Range-
land can be a valuable asset for livestock forage if properly planned
for and utilized. In addition, wildlife resources from rangelands can
be a major economic asset without decreasing livestock returns.
ASRM, Range Committee. 1964. Range term glossary. American Society of
Range Mgt., Denver, Colo.
Duval, V. L. and J. B. Hilmon. 1965. New grazing research programs for
southern forest ranges. J. Range Mgt. 18:132-136.
Hughes, R. H. 1974. Management and utilization of pineland threeawn range
in south Florida. J. Range Mgt., 27:186-192.
Lewis, C. E. 1970. Response chopping and phosphate on south Florida
range. J. Range Mgt. 23:276-282.
Stoddard, L. A., A. D. Smith and T. W. Box. 1975. Range Management.
McGraw-Hill, Inc., N.Y.
USDA. 1974. Opportunities to increase red meat production from ranges of
the United States. U.S.D.A., Washington, D.C.
Yarlett, L. L. 1965. Control of saw palmetto and recovery of native grasses.
J. Range Mgt. 18:334-345.
Smutgrass Control in Florida Pastures
Smutgrass (Sporobolus poiretii) a native of tropical Asia, has
become a serious pasture weed problem in southeastern United States,
particularly in peninsular Florida. A recent survey of selected
central and south Florida counties indicated that 75 percent of the
improved pasture was infested with smutgrass and the average level of
infestation was 39 percent. Smutgrass also occurs in tropical regions
of Central and South America.
The plant is a perennial bunch-type grass and is named for the
black fungus (Helminthosporium ravenelii) which often attacks the
infloresence and at times is found in patches on the leaves. The
seeds are smut-free, reddish when mature and may remain on the panicle
for some time or may shatter quickly depending on weather. Seeds are
spread by wind, water and livestock and reportedly have remained
viable for more than two years.
A recent study showed that mature plants could produce in excess
of 45,000 seeds per plant with over 1400 seeds per panicle. Seed
production takes place continually throughout the growing season.
Seed maturation is a continual process with flowering, immature seed,
mature seed and seed shattering occurring simultaneously on each seed
head of the same plant. Fortunately, the natural germination percen-
tage averages less than 9 percent due to a very hard seed coat.
Mature smutgrass is unpalatable to cattle in the southeastern United
States. One reason for the unpalatability may be the high fiber (82%)
found in mature plants. However cattle will consume young immature
plants or developing tillers (sprouts) of mature smutgrass plants
that were mowed earlier.
Research on control of smutgrass began at the Agricultural
Research Center (ARC) Ona in 1955 by Drs. John McCaleb and E. M.
Hodges who studied various control methods. They reported mowing did
not control smutgrass; however it did decrease plant size temporarily
while the number of plants increased and all recovered to former
density when mowing terminated. Complete renovation was expensive and
gave unsatisfactory smutgrass control. Studies to determine the effect
of herbicides on smutgrass were variable. Of all herbicides tested
in the early studies Dalapon (the active ingredient in Dowpon Me grass
killer) provided most complete control of smutgrass with minimal
damage to pangolagrass and bahiagrass.
Studies of various aspects of smutgrass control are presently
being continued at the ARC, Ona to evaluate the performance of Dalapon
for smutgrass control under different management systems. The influ-
ence of rates and time of application, cultural practices following
herbicidal treatment and its effect on the duration of control are
Results of current research indicate that a single application of
4 lb/A Dowpon M will give consistent results at the least cost,
provided the smutgrass plants are actively growing. Excellent control
resulted from Dowpon M applied from late April to early June followed
by mowing and fertilization 4 to 5 weeks later. This allows the less
sensitive pangolagrass and bahiagrass to respond to fertilization
better during this time of year, because moisture is not excessive.
These forage grasses spread rapidly, providing competition with treated
mature smutgrass and germinating smutgrass seedlings. Mowing or
chopping 4 to 5 weeks after herbicidal application provided superior
control as compared with no cultural practices following treatment.
However, smutgrass control was further improved when fertilization
was applied several weeks after herbicidal treatment, and especially
when applied in conjunction with mowing or chopping.
Preliminary data, 3 years after herbicidal application, indicate
very little smutgrass encroachment in pangola and bahiagrass pasture
provided the treated pasture is fertilized properly and rotationally
grazed. Proper pasture fertilization will allow pangola and
bahiagrass to attain a dense stand, therefore providing maximum
competition for developing smutgrass seedlings.
Preliminary data has also indicated that double chopping as
compared with mowing treated smutgrass 4 to 5 weeks following
herbicidal application resulted in good smutgrass control. However
fertilization must be applied. If the treated smutgrass is not
fertilized, poor smutgrass control will be obtained.
Research is also being conducted to study smutgrass control in
late September and seeding treated area to ryegrass 5 weeks later,
followed by irrigation.
In summary, research as indicated that smutgrass can be
controlled by spraying with 4 Ib/A Dowpon M when the smutgrass is
growing actively, provided additional cultural practices are followed.
Mowing smutgrass back to a 2 inch stubble or double chopping smutgrass
3-5 weeks following herbicidal application, and then fertilizing,
resulted in a dense stand of pangolagrass.
Current Status of Beef Cattle Breeding
F. M. Peacock
Breeding Research at the Range Cattle Station is designed to
evaluate the genetic potential of beef breeds as purebreds and in
breeding systems. Research has been with the Shorthorn, Brahman,
Angus and Charolais breeds.
The beef cattle breeder has the opportunity of increasing beef
production by various breeding systems, utilizing production traits
unique to particular breeds, as a means of increasing production.
The use of breeds or breed combinations adapted to the particular
environment and utilizing heterosis effects is a means of combating
the cost-price squeeze facing cattlemen.
Improvement in beef production can be accomplished by utilizing
(1) the additive breed effects characteristic of the various breeds
and (2) heterosis which accompanies certain parental combinations by
breeding systems toward specific goals. The environment furnished the
animal determines whether or not the genetic potential is fulfilled
but for this presentation only breeding will be discussed.
The genetic pool available for improvements in beef production
consists of breeds with wide variations in production triats. The
mature size, growthiness and muscling of the large breeds, the ability
to fatten and carcass quality of the British and the adaptability
and crossbreeding potential of the Brahman provide a pool of raw
materials for improvements in beef production.
Reproduction and mothering ability are the two most important
traits in the beef cow. For optimal performance the cow has to be
adapted to her environment. This is not only necessary for the cow
but the calf also must be genetically adapted for optimal performance.
The following table includes examples of additive breed effects
for weaning weight and carcass grade after 180 days in feedlot,
Weaning Weight Carcass grade
Angus 411 Low Choice
IAngus x Charolais
\Charolais x Angus) F 463 High Good
Charolais 501 Good
We see from these data on crossing the Charolais and Angus
that breed effects are additive since the crossbred fits close to
the average of the two straightbred in weaning weight and carcass
grade. This shows that breeding bulls of genetically larger breeds
to cows of the smaller breeds will improve weaning weight, even though
heterosis was not present. If heterosis for these traits had been
present there would have been a significant increase over the average.
An example of heterosis for weaning weight and additive breed
effects for carcass grade is shown in the following tabulation of
Angus, Brahman and F1 A-B cattle.
of calf Weaning Weight Carcass grade
Angus 411 Low Choice
Angus x Brahman\ 459 Hh
\Brahman x Angus/ 1
Brahman 415 Good
Heterosis is present in the Brahman-Angus cross for weaning
weight as the crossbred exceeds the average of the parents breeds.
However, there is no heterosis for carcass grade since the crossbred
is half way between the two straightbred, the same as in the
Charolais x Angus cross.
The full benefits from heterosis by crossbreeding are not fully
utilized until the crossbred females come-into production. The
following is an example of the advanced generation effect.
To further increase weaning weights of calves the three-breed
cross can be utilized. This combines the growthiness and muscling
of the Charolais and the mothering ability of the Fl Angus x Brahman
cow. An example is as follows:
Angus / 1
These results show both breed effects and heterosis for
This example demonstrates the benefit for weaning weight of the
three-breed cross when characteristics of each breed are complementary.
However, it demonstrates also the effect of growthiness on carcass
grade when length of feeding period is fixed and not relative to the
growth curve of the particular breed combination.
Reproduction is probably the trait most affected by adaptability
to environment. The following example demonstrates both adaptability
and heterosis when the Angus and Brahman breeds are combined.
Breed of cow
Weaning rate %
If the three-way cross is too complicated, satisfactory results
may be obtained by the use of complementary breeds in a criss-cross
program. An example of this is presented in the following tabulation:
of Sire of Dam Weaning Weight Wean Rate
Shorthorn Shorthorn 380 59
Brahman Brahman 392 79
Brahman Shorthorn) Fl 480
Shorthorn Fl 501
Brahman F 527 83
Brahman 314 Brahman-1/4 Shorthorn 453
Shorthorn 3/4 Brahman-1/4 Shorthorn 482
Shorthorn 3/4 Shorthorn-1/4 Brahman 416
Brahman 3/4 Shorthorn-1/4 Brahman 497
These results show the superiority of the F1 product over the
straightbred and the product of the Fl cow over the Fl product for
weaning weight. The criss-cross program is the result of the back-
crossing to the opposite breed of bull when breeding in a cow reaches
three-fourth to maintain certain blood proportions in the offspring.
By breeding Brahman bulls to 3/4 Shorthorn-1/4 Brahman cows instead
of Shorthorn weaning weights were 497 instead of 416 lbs. Breeding
Shorthorn bulls instead of Brahman to 3/4 Brahman-1/4 Shorthorn cows
resulted in weaning weights being 482 instead of 453 Ibs.
The knowledge and breeding stock are available in Florida that
will enable the cattleman to produce the type of beef animal the
Problems Facing Florida Cattlemen
T. J. Cunha
Department of Animal Science
University of Florida
Cattlemen are now facing the most serious financial squeeze of
modern times. Cattle are selling at very depressed prices and the
cost of every item used in producing cattle is at an all time high.
The whole situation is further exaggerated by having beef cattle
numbers at an all time high. The January 1, 1975, cattle number
figures recently released, show that the total cattle population
increased 3% in the U. S. during last year but increased 9% in the
Southeast and 18% in Florida. All indications are that it will take
at least two years, and possibly three years, before cattle numbers
decrease appreciably. Many suggestions are being made concerning what
cattlemen should do. Following are some suggestions which can be
considered as cattlemen in Florida weigh the various alternatives
available to them:
1. Tighten up the management and production program. Eliminate
all unnecessary expenses and increase efficiency of operation.
2. Decrease cattle numbers. This can be done by culling approxi-
mately the bottom 20% of the open cows and those producing the
poorer quality calves. This will result in more feed being
available for the remaining cows and may actually result in
more total beef produced on the ranch.
3. Keep only the top 10% of the heifers for replacements for a
few years. This will decrease herd size and reduce cattle
4. Where possible, sell cows and replace them with top quality
weaned heifers. The heifers will eat less feed and will not
have calves ready for sale for about two years when cattle
prices may be better.
5. Increase herd productivity by rigidly culling and selecting
for weaning weight, ability to calve early every year and
produce a heavy, quality calf. Pregnancy test cows and
eliminate the free boarders. Fertility test bulls and
eliminate the sterile bull or poor breeder. Use only high
6. Self-feed minerals to make sure cattle do not become
deficient in them. It is false economy to try to save money
by not feeding minerals since they cost only 1 to 3% of
total production costs. Also use the protein supplementation
needed. One or two pounds of a high protein supplement daily
will help growth and reproduction and will increase efficiency
of roughage utilization.
7. Develop programs to produce a two-way calf that can be sold as.
a slaughter calf for "baby beef" or "light beef" or to go into
the feedlot. Cattlemen cannot depend on the feedlots to take
all their calves, at least for a time. Therefore, one market
for these calves will be for slaughter as baby beef (approxi-
mately 400 to 600 lbs liveweight) and light beef (approximately
600 to 800 Ibs liveweight). Recommendations for programs for
producing these calves in Florida will be given at the Beef
Cattle Short Course to be held at Gainesville on May 1-3, 1975.
More detailed information on these programs can be obtained by
contacting the beef cattle scientists at the University of Florida
IFAS Research Stations nearest your farm.
8. Develop programs to have "baby beef" or "light beef" calves
available over a longer period of time during the year. For
this program to be most successful, the auction market, feeder,
packer and retailer need to have them available on a year
9. Produce heavy slaughter calves suitable for "baby beef" at
weaning, either by some creep feeding or by giving these cows
some access to a high quality temporary pasture to stimulate
milk production and thus produce a heavier calf at weaning.
Cows which are in good enough condition to breed back after
calving, might suckle their calves a little longer to about
eight months of age, as a means of producing a heavier,
better conditioned calf for slaughter at weaning.
10. Use as much forage as possible to produce the two-way calf
which can be slaughtered as "baby beef" or"light beef" or
sold to the feedlot.
11. The demand for a lightweight calf is very low. Therefore,
develop production programs to intensify beef production and
thus increase weaning weight, cows that calve every year and
produce a heavy, quality calf at weaning.
12. Develop a fertilization-management program for forage prod-
uction based on the latest recommendations from University of
Florida IFAS scientists. Maximum forage production per unit
cost is essential.
13. Keep abreast of new developments and use them in evaluating the
present status and whether it needs some change.
Cattlemen need to increase their efficiency of operation and lower
production costs. Therefore, they need to follow every avenue which
increases efficiency of production. At the same time, they need to
decrease cattle numbers and thus get to the point where the demand for
beef by the consumer will allow the producer, feeder, packer and retailer
a profit. Some changes in the cattle industry, as it has operated here-
tofore, may occur and cattlemen (as well as those in related industries)
need to adapt to them. Fortunately, the American people like beef.
Therefore, it is hoped the present situation will soon be corrected.
The more everyone concerned cooperates to this end the sooner this will
occur. In the meantime, let's all "eat more beef" and help correct the
REPORT OF PROGRESS
ACTIVE RESEARCH PROJECTS
AGRICULTURAL RESEARCH CENTER
During 1974 research was conducted under 13 active projects
covering work with beef cattle breeding and nutrition, forage
evaluation and soil fertility. In addition cooperative studies
were conducted with the School of Forestry in Gainesville.
During 1974 emphasis was continued on forage and field crop
research at the Ona and Immokalee Research Centers as well as
in Manatee, Orange, Collier and Polk counties. Buildings on
the research center were painted and about 5 miles of fence
was replaced. Approximately 100 acres of pasture was renovated.
Over 20,000 bales of hay were made. A controlled burning program
was established under the supervision of personnel from the
School of Forestry.
Rainfall totaled 48.02 inches during 1974. Temperatures ranged
from a low of 260F on December 10 to a high of 94F on May 31,
June 1 and July 20.
A summary of 1974 research results at the Ona Agricultural
Research Center are presented on the following pages of the
AGRONOMY RESEARCH E. M. HODGES AND PAUL MISLEVY
State Project 1167. Evaluation of Introduced and Native Plant
Species for Pasture, Forage and Other Uses.
American Jointvetch (Aeschynomene americana) summer-seeded and chopped into
Pensacola bahiagrass (Paspalum notatum) sod produced two tons of mixed
hay per acre without nitrogen fertilization. Planting material of
McCaleb stargrass (Cynodon aethiopicus) was released to growers, recommended
for use south of Leesburg, Florida. Forage yield and cattle day responses
to Gibberallic acid treatment of newly planted Pangola digitgrass
(Digitaria decumbens) pastures were inconclusive. Nursery plantings of
Hemarthria, Chloris, Digitaria, and Cynodon accessions were evaluated for
persistence, forage yield, nutritional value, and cold tolerance.
At Immokalee, irrigation had little effect on perennial forage yield.
Harvesting all species back to 2 inch stubble resulted in a significant
increase over species cut back to a 4 inch stubble. However, species cut
at a 2 inch stubble were less vigorous and many species died. For the
second consecutive year U. F. 5 stargrass was among the top yielders.
No significant difference in yield was observed among digitgrasscs or
bahiagrass at the Ona clipping study, however clipping digitgrasses and
bahia each time they attain 12-14 inch and 9 inches respectively resulted
in highest yield. Mob grazing perennial grasses every 4 or 5 weeks
results in highest yield and Estimated TDN, with the Cynodon species
being the highest yielders. U. F. 5 was the highest individual yielder
and contained least number of weeds after 2 years. In a 1/2 acre
pasture study grazing digitgrass and bahia each time plants attained a
height of 14-16 inches and 8-10 inches respectively resulted in highest
D. M. yields.
State Project 1241. Herbicides in Forage Production.
A recent survey in South Central Florida indicated approximately 75%
of improved pastures were infested with an average of 38% smutgrass
(Sporobolus poiretii). A split block experiment involving herbicidal
rates and cultural practices was established in 1972', repeated in 73
and 74. Commercial Dowpon M was applied at 2, 4 and 6 Ib/A with 0, 1,
2 and 4 gal/A of Sunoco 11E spraying oil to study their effects on
smutgrass control. Five weeks following herbicidal application mowing
(mow vs non mowed) and nitrogen (0 vs 100 lb/A) treatments were applied.
Smutgrass was controlled by spraying 4 Ib dowpon commercial product/A
when plants were growing actively. Mowing smutgrass back to a 2 inch
stubble and fertilizing, 4 to 5 weeks following herbicidal appli-
cation allowed the growth of a dense sward of pangolagrass in 70 days,
when spraying was done in May or early June. In another experiment
the effect of chopping, mowing and fertilization at different times
folLcir. Dowpon treatment on smutgrass control was studied. Pre-
liminary data indicate equal smutgrass control was obtained from
chopping or mowing. Fertilization within 6 weeks following Dowpon
treatment was also necessary to obtain superior smutgrass control.
Another experiment was initiated to study the effect of herbicides
on forage quality. Preliminary data indicates little difference in
Argentine bahiagrass yield and In vitro organic matter digestion from
State Project 1358. Pasture Grass and Legume Variety Evaluation
Under Varied Fertilization and Management Practices.
Commercial corn, silage sorghum, millet and sorghum x sudangrass, small
grain, clover and ryegrass variety experiments were conducted at the
ARC, Ona. Silage corn variety testing was also conducted in Orange,
Manatee and Polk counties. No significant differences were observed
among silage sorghum varieties, however Acco PS-531 produced the
highest yield averaging 6.4 tons/A D. M. with 95% of that yield coming
from the first harvest. Lodging for this variety was only 5% while
average for all sorghum varieties was 32%. S-S hybrids significantly
outyielded pearlmillets, with Dekalb SX-16 and Funk Millet III
producing 8.1 and 5.0 T/A D, M. with Dekalb XL 399 producing 7.7 T/A;
the Manatee county experiment averaged 7.0 T/A D.M., with Dekalb XL
99 yielding 8.6 T/A. The Polk county experiment, on reclaimed phosphate
land, averaged 4,9 T/A with Pioneer 3030 producing 6.1 T/A D. M. Corn
silage production at Ona averaged 9.2 T/A D.M. with Pioneer 3030 pro-
ducing 10.6 T/A D.M. Dry matter yields of small grains at Ona averaged
3.3 T/A, with Coker 227 oats yielding 4.6 T/A over 5 harvests. In
Immokalee the average small grain yield was 1.8 T/A with Coker 227 oats
yielding 2.5 T/A. Ryegrass production at Ona averaged 2.8 T/A D. M.,
with no significant differences among varieties. Dry matter production
of 5 clover varieties seeded at Ona averaged 2.3 T/A D.M. with Tillman
white and Pennscott red clover producing the highest yield over 7
harvests. Tillman white clover continued to-persist the following
State Project 1368. Yearlong Grazing on Grass and Grass-Legume Varieties.
Pangola digitgrass (Digitaria decumbens), Transvala digitgrass (D.
decumbens), Coastcross I bermudagrass (Cynodon dactylon), and U. F. 4
experimental stargrass (C. Nlemfuensis) were grazed from October to
October, beginning with weanling steer calves. Annual fertilization
consisted of three equal applications (early spring, summer and fall)
of a mixture supplying 50-25-50 pounds per acre of N, P2 0 and K20.
The cool season stocking rate was one animal per acre; cattle were added
to utilize the increased warm season growth. Cool season daily gains,
with each animal receiving a total of 300 pounds dried citrus pulp
as supplement, averaged .96, .71, 1.03, and .95 pounds respectively
for Pangola, Transvala, Coastcross I, and U. F. 4. Warm season daily
gains, with no supplemental feed, averaged .94, 1.19, 1.04, 1.19 pounds.
Annual gain per acre ranged from 550 pounds on U. F. 4 stargrass to 490
on Coastcross I, 417 on Pangola, and 397 on Transvala. Low daily gain on
Transvala during this cool season indicated the effect of near-freezing
temperatures on this cultivar. Stocking rate during the warm season
averaged 28% higher on the Cynodon pastures than on the Digitaria
varieties and was directly related to the higher productivity of U. F.
4 and Coastcross I.
State Project 1403. Management Systems for Beef Cows.
Breeding herds of European x Brahman cows were grazed year-round on
40-acre pasture units to evaluate forage management systems for beef
production. Perennial grass pastures included pure and mixed Pangola
digitgrass (Digitaria decumbens), Pensacola bahiagrass (Paspalum notatum),
and common bermudagrass (Cynodon dactylon). Each treatment was in
duplicate, stocked at 1.6 acres per cow unit. Treatment 1 (Check)
included four 10-acre pastures of perennial grass, fertilized twice
annually with 400 pounds per acre of 16-8-8. Treatment 2 repeated the
check plus 64 Ib/A nitrogen. Treatment 3 included three 10-acre
perennial grass units and one 10-acre area fall-planted to rust-
resistant ryegrass (Lolium multiflorum). Treatment 4 included two
10-acre units of perennial grass, 10 acres of ryegrass, and 10 acres of
irrigated grass-white clover (Trifolium repens). Hay and dried citrus
pulp supplement was fed at 470, 358, and 364 and 309 pounds per cow in
Treatments 1, 2, 3, and 4. Weaning percentages averaged 86, 92, 76, and
84 on these treatments and weaned calf production per cow was 378,
440, 345, and 400 pounds. Annual total weight gain per acre, including
calf production and gain or loss by cows, was 229, 270, 224, and 232
pounds respectively. The calf production data indicate that additional
N was the most effective treatment while ryegrass was the lowest.
Inclusion of cow gains and losses shows additional N as top producer
with the other treatments at a lower level.
State Project 1590. Field Crop Variety Testing.
With high grain prices in recent years, there has been considerable
interest in grain production in South Central Florida. Commercial
corn and grain sorghum variety testing was conducted at the ARC, Ona.
The experimental design was a randomized complete block with four
replications. Fourteen commercial corn varieties were tested for
grain production. Dekalb XL 399 produced the highest yield of 15.5%
moisture shelled corn, averaging 175 bu/A. This variety was signifi-
cantly higher yielding than the six lowest yielding varieties. Signi-
ficantly less Southern corn rust (Preccinia polysore Underw.) was
observed on corn varieties in 1974 as compared with 1973, however,
Dekalb XL 80 and Funks G 4762 contained an average of 20% and 16%
respectively. No significant differences were observed among the 11
grain sorghum varieties tested. However, Funk G-516 BR did produce
5260 Ib/A grain. Bird damage on Dekalb F-64 and Asgrow Dorado M was
12 and 10% respectively, with many varieties having no bird damage.
Average disease for all varieties was 30% and lodging was not a
ANIMAL BREEDING RESEARCH F. M. PEACOCK
State Project 1120. Charolais, Brahman, Angus and Their Crosses.
This project is designed to evaluate the three breeds and their
crosses for beef production in central and south Florida. Each breed of
sire was bred to P1 and Fl cows of the three breeds. Calves by
Charolais sires has weaning weights as follows: x Charbray cows, 501 Ibs;
x Angus, 430 Ibs; x Brahman, 543 Ibs; x Angus-Charolais, 529 lbs; x Angus-
Brahman, 571 Ibs; and x Charolais-Brahman, 557 lbs. Angus sired calves
had weaning weights as follows: x Angus, 419 lbs; x Brahman, 463 lbs;
x Charbray, 464 Ibs; x Angus-Charolais, 439 lbs; x Angus-Brahman, 479
Ibs; and x Charolais-Brahman, 534 Ibs. Brahman sired calves had weaning
weights as follows: x Brahman, 394 Ibs; x Angus, 469 Ibs; x Charbray,
478 lbs; x Angus-Charolais, 511 lbs; x Angus-Brahman, 503 Ibs; and
x Charolais-Brahman, 449 Ibs. Charbray cows produced highest weights
of the straightbreds while the Angus-Brahman cows was highest of the
crossbreds. Charolais bulls produced the heaviest weight calves of the
three breeds of sires used.
State Project 1261. Feedlot Performance and Carcass Characteristics
of Brahman, Angus, Charolais, and Their Crosses.
This project is designed to evaluate the relative performance and
carcass characteristics of steers from the three breeds and their
crosses in project 1120, when fed in drylot for 180 days. Weight
gains were obtained by subtracting beginning weight (normal fill)
from end weight, based on 60% chilled carcass. Animals had the
following daily gain and carcass grade by breed: Angus, 1.66 lbs,
High Good; Brahman, 1.82 Ibs, Good; Charolais, 2.45 lbs, High Good;
1/2 Angus-1/2 Brahman, 2.29 Ibs, Good; 1/2 Brahman-1/2 Angus, 2.25 lbs,
Low Choice; 1/2 Angus-1/2 Charolais, 2.04 Ibs, High Good; 1/2 Charolais--
1/2 Angus, 2.37 lbs, Good; 1/2 Charolais-1/2 Brahman, 2.38 Ibs, Good;
1/2 Brahman-1/2 Charolais, 2.40 Ibs, High Good; 3/4 Angus-l/4 Brahman,
2.15 lbs, Low Choice; 3/4 Brahman-1/4 Angus, 2.01 lbs, Good; 3/4 Angus-
1/4 Charolais, 2.12 Ibs, Low Choice; 3/4 Charolais-1/4 Angus, 2.35 Ibs,
Low Choice; 3/4 Charolais-l/4 Brahman, 2.30 lbs, High Good; 3/4 Brahman-
1/4 Charolais, 1.99 Ibs, Good; 1/2 Angus-1/4 Charolais-1/4 Brahman,
2.29 Ibs, Low Choice; 1/2 Charolais-1/4 Angus-1/4 Brahman, 2.34 lbs,
Good; 1/2 Brahman-1/4 Angus-1/4 Charolais, 2.40 lbs, Good. Highest
gains were obtained by the Charolais sired calves. Carcass grade was
highest from calves sired by Angus sires.
State Project 1679. Fertility, Growth and Maternal Ability in Angus,
Brahman, Charolais and Crosses of These Breeds.
This project was initiated in 1974. Research data will not be avail-
able until the 1975 report. It is designed to compare fertility and
maternal ability in straightbred, firstcross, backcross and three-
breed cross dams utilizing all possible combinations of the three
parent breeds; levels of heterosis for weaning performance in straight-
breds, F2, backcross, three-breed crosses, two-breed rotation cross
calves; breed value of the three breed combinations of Fl bulls
(Angus x Brahman, Charolais x Angus; Charolais x Brahman) used for the
production of backcross, three-breed and F2 progeny.
ANIMAL MANAGEMENT AND NUTRITION RESEARCH H. L. CHAPMAN, JR.
State Project 001 Preliminary Research at Ona, Florida.
Two concurrent trials were conducted to evaluate the use of Trolene 40
for horn fly control when incorporated into a loose mineral mixture
and the same mineral made into a block. Trial one involved 69 head
of long yearling cattle grazing unimproved range and trial two involved
89 head of mature cows grazing pangolagrass pasture. In both trials
there were less horn flies on the cattle receiving the mineral contain-
ing Trolene 40 as compared to the control cattle. The mineral containing
the Trolene 40 was less palatable and intake was reduced as compared
to the mineral with no Trolene 40. There were no adverse reactions
noted on any cattle during the trial.
State Project 1369. Evaluation of Nutritional Quality of Forages
Grown on Mineral Soils.
Grazing and green chop experiments were conducted simultaneously every
28 days during a 6-month period to estimate the seasonal variation in
nutritive value of Pensacola bahiagrass and to relate this to rate of
gain of steers, intake of forage and sampling technics used to estimate
forage quality. Estimates of organic matter (OM) intake by grazing
steers were lower than actual intake by steers fed green chop. Estimates
of OM intake from IVOMD of esophageal fistulated steers, hand plucked
forage and caged forage samples were all highly correlated with animal
gain. IVOMD of hand plucked samples was the most highly correlated
with animal gain.
State Project 1386. Post-Weaning Management for Beef Calves.
Ninety, yearling, crossbred heifers were divided into six groups and
randomly assigned to experimental liquid feed mixtures containing
0, 5, 10, 15, 20 and 25% of ammonium lignin sulfonate (ALS). Each
LFM contained an estimated 13.5% CP and 50% TDN. The heifers were
fed in confinement for 95 days, with pangolagrass hay and the LFM fed
ad libitum. Daily gain was inversely related to the percent of ALS
in the LFM. Intake of LFM was decreased by all but the 5% level of
ALS. Hay intake was approximately the same for all groups.
In a second study 108 crossbred steer calves were divided into 6 groups
on the basis of grade, weight and source and placed on an experiment tc
evaluate various management procedures for producing feedlot cattle in
south Florida. Feed costs were approximately 1/3 less on pasture as
compared to drylot. Performance of calves varied approximately 22%
between source of calves.
SOILS RESEARCH C. L. DANTZMAN
State Project 404. The Maintenance of Soil Fertility Under Permanent
A plot study (pangolagrass) was continued to study the recovery
efficiency of fall and winter applied K, and to investigate the
possibility of applying nutrients to permanent pastures during the
cool season thereby extending the use of fertilizer distributing
equipment. Harvest results for 1974 ranged from 3.6 to 3.9 T/A (not
significantly different) for plots treated at one of the dates:
October, December, April, July.
A second study was continued to further determine the effect of lime
and micronutrients on white clover-grass production. Plant yields
(pangolagrass) for 1974 varied from 1.4 to 1.9 T/A (not significantly
different). Dry conditions during the cool seasons were not favorable
to clover growth.
In a third study lime level plot study to investigate recovery of Ca
and Mg by pangolagrass. Fourth year data (5.6 to 6.5 T/A) indicate
no significant differences in yield.
In another study the phosphorus level plot study made to test recovery
of native subsoil P by grass. Yield data for 1974 indicate little
differences (3.7 to 4.9 T/A). No analytical data is available at this
A sulfur level plot study done to test need for sulfur by forage grass.
1974 yield data (5.3 to 6.4 T/A)show little differences.
LIST OF 1974 PUBLICATIONS
AGRICULTURAL RESEARCH CENTER
Chapman, H. L., Jr. 1974. Value of ammonium lignin sulfonate in
liquid feed mixtures. ARC Ona Research Report RC-1974-3.
Chapman, H. L., Jr. 1974. What about energy and agriculture?
Hardee Farm Bureau News. February, p. 4.
Chapman, H. L., Jr. 1974. Pros and cons of liquid feeds. Proceedings
of Beef Cattle Shortcourse, Gainesville.
Chapman, H. L., Jr.and J. E. Pace. 1974. Liquid feed mixtures for
beef cattle. Fla. Agr. Exp. Sta. Circular 229.
Chapman, H. L., Jr. 1974. Use of liquid feeds. The Shorthorn World.
August p. 152-160.
Chapman, H. L., Jr. 1974. Supplementacion de ganada de came y leche
con urea y otros fuentes de nitrogeno no proteico. Proceedings
3rd Central American Shortcourse on Beef and Dairy Cattle.
Chapman, H. L., Jr. and J. E. Pace. 1974. Non-protein-nitrogen for
beef cattle. Fla. Agr. Exp. Sta. Circular S230.
Currey, W. L. and P. Mislevy. 1974. Smutgrass control in Florida.
Down to Earth. Vol. 29, No. 4, Spring, 1974, pg 6-9.
Dantzman, C. L. 1974. 1973 Climatological Report. Agricultural
Research Center, Ona Research Report RC-1974-1.
Dantzman, C. L. and H. L. Breland. 1973. Chemical levels of some
streams in southwest central Florida. Soil and Crop Sci. Soc.
of Florida Proc. Vol. 32:102-105.
Gonzales, J. S., W. G. Blue, and C. L. Dantzman. 1973. Availability of
native subsoil phosphorus in flatwoods soils from central Florida.
Soil and Crop Sci. Soc. of Florida Proc. Vol. 32:138-141.
Hodges, E. M. 1974. McCaleb stargrass. Florida Cattleman. Vol. 38(1).
Hodges, E. M., F. T. Boyd, L. S. Dunavin, A. E. Kretschmer, Jr., P.
Mislevy, R. L. Stanley. 1974. McCaleb Stargrass. Fla. Agr. Exp.
Sta. Cir. S231.
Hodges, E. M., F. M. Peacock, H. L. Chapman, Jr., and R. E. L. Greene.
1974. Forage and supplement systems for beef cows in south
central Florida. Soil and Crop Sci. Soc. of Florida Proc.
Kirk, W. G., E. M. Hodges, J. W. Carpenter, F. M. Peacock and
F. G. Martin. 1974. Supplemental feeding of steers on
Pangola digitgrass and Pensacola bahiagrass pastures. Soil
and Crop Sci. Soc. of Florida Proceedings. Vol. 33:53-55.
Kirk, W. G., E. M. Hodges, F. M. Peacock, L. L. Yarlett, and
F. G. Martin. 1974. Production of cow-calf herds: effect of
burning native range and supplemental feeding. J. Range
Kirk, W. G., G. K. Davis, F. G. Martin, E. M. Hodges and J. F. Easley.
1974. Effect of burning and mowing on composition of pinelawn
threeawn. J. Range Management. 27(6):420-424.
Mislevy, P. and C. L. Dantzman. 1974. Comparison of ammonium nitrate
and sulfur-coated urea on ryegrass production in south central
Florida. Soil and Crop Sci. Soc. of Florida Proc. Vol.33:199-201.
Mislevy, P., P. H. Everett and R. D. Barnett. 1974. Winter annual
forage production at Ona and Immokalee, 1973-74. ARC, Ona
Research Report RC-1974-5.
Mislevy, P. (Ona) and V. E. Green (Gainesville). 1974. Grain sorghum
x sudangrass hybrid and pearlmillet testing in south central
Florida. 1973 Sorghum Newsletter Vol. 17, pg 75-76.
Mislevy, P. and V. E. Green. 1974. Commercial sorghum, sorghum-
sudangrass hybrid and pearlmillet variety testing in south
central Florida, 1973 ARC, Ona Research Report RC-1974-2.
Mislevy, P. and E. M. Hodges. 1974. Performance of selected tropical
and subtropical forage grasses in south central Florida. ARC, Ona,
Research Report RC-1974-4.
Mislevy, P., E. M. Hodges and G. 0. Mott. 1974. The use of mob grazing
technique to evaluate perennial grasses and legumes. Agronomy
Abstracts. 1974 Annual Meeting, Chicago, Illinois, November 10-15,
Mislevy, P. and D. W. Jones. 1974. Commercial corn variety production
in south central Florida, ARC, Ona Research Report RC-1974-6.
Peacock, F. M. E. M. Hodges, W. G. Kirk and M. Koger. 1974.
Increase cow production with improved pastures. Progressive
Peacock, F. M., M. Koger, E. M. Hodges and W. G. Kirk. 1974. Beef
cattle production as affected by breed composition and forage
systems. Soil and Crop Sci. Soc. of Florida Proc. 33:50-53.
Peacock, F. M., A. C. Warnick, M. Koger and W. G. Kirk. 1974.
Brahman and breeding. Progressive Farmer 89(6):28.
Prates, E. R. 1974. Nutritional evaluation of Pensacola bahiagrass
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