Dr. Paul Mislevy
FLORAKIRK BERMUDAGRASS
Dr. Paul Mislevy
P. Mislevy, W. F. Brown, and R. S. Kalmbacher are professors at the University of Florida,
Range Cattle Research and Education Center (REC). L. S. Dunavin is an associate professor,
University of Florida, Jay REC. W. S. Judd is a professor of Botany, T. A. Kucharek is a
professor, Plant Pathology, and O. C. Ruelke is a professor emeritus Agronomy, Gainesville.
J. W. Noling is an associate professor, Citrus REC, Lake Alfred. R. M. Sonoda is a
professor, Ft. Pierce REC, and R. L. Stanley, Jr. is an associate professor, North Florida
REC, Quincy.
Florakirk bermudagrass (Cynodon dactylon) is a fine-stemmed, persistent, cold
tolerant, high yielding, good quality bermudagrass released for hay production by the
University of Florida. The grass is most adapted to the panhandle and northern part of
peninsular Florida, but also will persist well on the colder sites of central Florida.
1. Persistent, with good forage quality. Digestibility of Florakirk is about 6 to 7 percentage units greater than Coastal (C. dactylon) and Alicia (C. dactylon var. elegans).
2. Florakirk will produce good yields on central Florida wet, flatwood soils north into southern Georgia.
3. Cold tolerant to 8 F at Jay, FL.
4. With adequate fertility will produce more forage during the cool season (January-February) than most bermudagrasses in central Florida.
5. Fine stem grass which can make excellent hay that cures rapidly during favorable weather conditions.
6. Good drought tolerance.
7. Grass appears unaffected by the two- line spittle bug (Prosapia bicincla).
8. Nutritious when harvested or grazed every 4 to 5 wk.
9. Eight year average dry yield at Gainesville was 6.9 tons/acre or 10% higher than Coastal. Six year study at Jay revealed Florakirk out yielded Tifton 44 and Tifton 78 (C. dactylon) by nearly 2 to 1.
10. Leaf diseases have not limited forage
production when harvested for hay.
1. Vegetatively propagated from stem
cuttings.
2. Requires higher fertility than
limpograss (Hemarthria alissima),
digitgrass (Digitaria decumbens), and
bahiagrass (Paspalum notatum) for
best results.
3. Forage quality drops rapidly after 6-7
wk of growth and following a heavy
frost.
4. Top growth easily killed by frost.
5. Can have some rust (Puccina sp.),
leaf spot (Helminthosporum sp.) and
tar spot (Phyllachora sp.) disease
especially when harvest is delayed
beyond 5 wk.
6. High HCN-p for about a 4-wk period
following heavy N fertilization (100
lb/acre).
7. Susceptible to army worms
(Spodoptera frugiperda) and striped
grass loopers (Mocis latipes), like
other Cynodon and Digitaria grasses.
'Florakirk' bermudagrass (Cynodon dactylon) is a persistent, perennial grass that is well adapted to the panhandle and the northern part of peninsula Florida. It also grows well on south Florida flatwoods that are too cold for stargrasses. The primary use of this grass is to fill the need for a persistent, high yielding, high quality, fine-stemmed forage which can be used for hay production in north and northwest Florida and colder areas of central Florida. When vegetatively planted on a clean seed bed free of common bermudagrass (CB) (Cynodon dactylon), Florakirk spreads rapidly. When adequate moisture and fertility are available, along with good weed control, a dense stand of grass 24 in high can be obtained in 75 days or less. Florakirk, like most bermudagrasses and stargrasses, has a high fertility requirement; therefore, an intensive grazing or harvest system must be practiced to obtain maximum yield and utilization of forage. Dry matter (DM) production of Florakirk has been good in central Florida and in Gainesville where yields averaged 10% higher than for Coastal over a 10-yr period. When adequate fertility is available, this grass tends to produce good late season yields and initiates rapid spring regrowth even under drought conditions. When compared with Coastal in Gainesville, both grasses showed similar spring regrowth; however, late fall (October-November) yields favored Florakirk by 24%. Like most bermudagrasses, Florakirk matures rapidly; therefore, grazing frequency (rest period between grazings) and regrowth interval for hay production should not extend beyond 5 wks. Crude protein (CP) at this grazing frequency averaged 8 to 9% at Ona which is similar to other bermudagrass and stargrass cultivars. In vitro organic matter digestion (IVOMD) ranged from 53% (Gainesville, 1980) to 61% (Gainesville, 1989), which was 7 to 8 percentage units higher than for Coastal bermudagrass, about equal to Florona stargrass (C. nlemfuensis Vanderyst var. nlemfuesis), and 3 percentage units lower than Florico stargrass at Ona. Animal live weight gains from this grass, which have ranged from 350 to 450 lb/acre, are similar to those obtained from 'Brazos' bermudagrass (C. dactylon), but lower than those obtained on stargrass in central Florida. Florakirk bermudagrass carries a high hydrocyanic acid potential (HCN-p), especially when high levels of nitrogen are applied. However, no detrimental effects on grazing cattle at Ona have been attributed to HCN-p in this grass. Insect problems appear to be limited to fall armyworms and striped grass loopers. A foliar blight (Rhizoctonia solani) was observed on this grass twice within an 11-yr period. Leaf spot and rust have been observed, especially when plants were allowed to mature 3 to 4 wks beyond the desirable cutting stage. Tar spot on leaves, caused by Phyllachora sp., has caused leaf browning at the Range Cattle Research and Education Center (REC) when Florakirk was allowed to go ungrazed or uncut for long periods of time.
No apparent Florakirk damage has been observed or associated with species of plant parasitic nematodes within the genera Helicotylenchus, Hoplolaimus, or Pratylenchus, based on a limited survey of 10 fields at the Range Cattle REC.
Because of its cold tolerance and persistence, Florakirk has been selected for release
primarily for north Florida and southern Georgia. Forage yield and quality are equal to or
better than most available forages presently grown in this region. Florakirk appears to have
good forage production during the cool-dry spring season in central and south Florida,
provided that adequate fertility is available. Florakirk is a viable option for cattle and horse
owners who desire a high quality, fine-stem grass for hay.
Florakirk bermudagrass was developed by Dr. G. W. Burton, USDA-ARS and
Georgia Coastal Plain Experiment Station, Tifton, Ga. In 1975 'Callie' bermudagrass (C.
dactylon var. aridus) was hybridized with Tifton 44 bermudagrass to create F1 hybrids with
greater cold tolerance and rust resistance than Callie. Twenty of these hybrids were
established in the field at Tifton, Ga in 1977. In 1979 one of the promising hybrids, 'Tifton
35-3' (later called 'Callie hybrid 35-3'), was sent to Dr. O. C. Ruelke, Gainesville, FL, who
sent some vegetative material to the Range Cattle REC.
In 1980 a "mob grazing" experiment was established at the Range Cattle REC consisting of
Callie hybrid 35-3 and other Cynodon entries (Mislevy et al. 1988). This 3-year study
revealed Callie hybrid 35-3, now called Florakirk, had high dry matter yields when grazed
at a 4 to 5 wk frequency, good forage quality, excellent persistence, and good drought and
cold tolerance. In 1984, pastures were established via sprigging to study grazing
management and animal performance. Many of these pastures are still persisting quite well
after 10 yr.
Florakirk bermudagrass is a long-lived, stoloniferous, and rhizomatous perennial and
a member of the genus Cynodon. Stems are much branched and leafy, 0.5 to 2.4 mm in
diameter, and reach heights of 15 to 25 in (38 to 64 cm). The nodes and internodes are
glabrous (no hairs). Leaf sheaths are loose, overlapping, and glabrous. Ligules consist of
a membrane 0.15 to 0.5 mm long, with fringed hairs 0.1 to 0.4 mm long. The junctions of
blade and sheath are often reddish and are provided with stiff hairs 1.0 to 4.5 mm long. Leaf
blades are 1.0 to 10.0 in (2.5 to 25 cm) long, 1.4 to 5.5 mm wide, flat, soft, and
succulent; they possess scattered hairs above and usually are glabrous beneath. The leaf
margins are minutely serrulate and contain a few hairs. The inflorescence is composed of
3 to 6 (occasionally 8) purplish-red (or sometimes green with a slight purple tinge)
spike-like branches; these are 1.7 to 3.5 in (4.2 to 8.8 cm) long and are arranged in a
whorl at the
apex of the stem. Spikelets are borne in 2 rows on 1 side of each spike-like branch and are
2.2 to 3.3 mm long; each spikelet possessing a single floret. Glumes are slightly unequal,
narrowly ovate, curved, 1-nerved, and 1.0 to 3.3 mm long; they are glabrous except for
minute hairs along the keel. The fertile lemma is firm, laterally compressed, 3-nerved, 2.1
to 3.1 mm long, and glabrous except for conspicuous silky hairs on the keel and lateral
nerves; the palea is narrow, 2-nerved, slightly shorter than the lemma, and glabrous. Few
if any seeds are produced, and propagation is entirely vegetative. It is difficult to differentiate
Florakirk from other bermudagrasses, especially 'Tifton 78' and 'Coastcross 1'. Therefore,
to be certain of its identity, planting sprigs must be obtained from a known source.
Jay Research and Education Center
Florakirk bermudagrass was established on a Red Bay sandy loam (Rhodic Paleudult)
soil in 1986 along with Tifton 78 and Tifton 44 bermudagrasses, which were used as
standards. The experiment received 290 lb/acre N annually in a 2-1-1 ratio with P2O5 and
K2O. Plants were harvested on a 4-wk cycle during the warm season over a 6-yr period, for
a total of five harvests /yr., except in 1988 when only four harvests were made. Dry matter
yields were higher for Florakirk during all 6 yr when compared with Tifton 78 and Tifton 44
(Table 1). On December 23, 24, and 25, 1989, a hard freeze occurred when temperatures
dropped to 9, 8, and 9 F, respectively. Florakirk demonstrated good cold tolerance,
yielding 5.2 tons/acre DM in 1990 compared with 0.6 and 2.6 tons/acre DM for the standard
cultivars of Tifton 78 and Tifton 44, respectively. Both standard cultivars died after 5 yr of
harvesting, but Florakirk produced 3.2 tons/acre DM. Average DM yields for Florakirk over
the 6-yr period was 5.7 tons/acre compared with 3.2 (Tifton 78) and 2.8 tons/acre (Tifton 44).
Tifton 78
Tifton 44 7.4
4.8 6.2
4.7 4.5
4.2 0.6
2.6 0.3
0.7 0.0
0.0 3.2
2.8 North Florida REC, Quincy
In August 1986 Florakirk bermudagrass was established at the North Florida REC,
Quincy and compared with standard cultivars grown by producers in the panhandle area of
Florida. Florakirk established rapidly, occupying 65% ground cover (GC) 60 days after
establishment (Table 2). In June of the following year Florakirk averaged 97% GC, which
was 60 percentage units higher GC than Coastal (37%).
Forage production from Florakirk over a 3-yr period averaged 6.5 tons/acre DM
(Table 3), which was similar to DM yields for Alicia (6.8 tons/acre), Coastal (6.4 tons/acre),
and Tifton 78 (6.1 tons/acre). Although Alicia produced slightly higher DM yields than did
Florakirk,it is generally not recommended by IFAS because its forage quality is lower than that
of most recommended bermudagrasses. Florakirk and other bermudagrasses had good cold
tolerance, especially following the 12 F temperature experienced on December 24, 1989.
The following year (1990) all grasses showed excellent DM yield, as further evidence of
good cold tolerance.
Coastal
Tifton -78
Tifton-44
Alicia
Callie
Grazer 6
Trace
Trace
40
10
15 37
25
27
85
92
67 72
50
62
97
100
100
Table 1. Dry matter yield (tons/acre) of three bermudagrass entries grown over a 6-yr period at
the Jay, REC.
Grass
entry
1987
1988
1989
1990
1991
1992
Average
Florakirk
8.7
6.6
6.7
5.2
3.6
3.2
5.7
Table 2. Development (%Ground cover) of seven bermudagrass entries established August 1986 at the North
Florida REC, Quincy.
Florakirk
65
97
100
| Table 3. Dry matter yield (tons/acre) of selected bermudagrasses at the North Florida REC, Quincy. | ||||
| Grass cultivar | Year | |||
| 1989 | 1990 | 1992 | 3-yr avg | |
| Florakirk | 5.5 | 6.7 | 7.4 | 6.5 |
| Coastal | 5.6 | 6.9 | 6.9 | 6.4 |
| Tifton 78 | 4.8 | 6.7 | 6.8 | 6.1 |
| Tifton 44 | 4.3 | 5.1 | 6.9 | 5.4 |
| Callie | 3.6 | 6.4 | 7.0 | 5.6 |
| Alicia | 5.4 | 7.3 | 7.8 | 6.8 |
| Grazer | 3.5 | 3.8 | 5.5 | 4.2 |
| Notes: Harvested every 4-5 wks from May-October. Fertilization program: 50-60-60 lbs/acre N-P2O5-K2) March; 50 lbs/acre N following harvests in May, June, July, and August; 60 lbs/acre K2O in July. | ||||
Florida Agricultural Experiment Station, Gainesville
Florakirk (compared with Coastal, Coastcross 1, Tifton 44, and Tifton 78
bermudagrass and Pensacola bahiagrass [Paspalum notatum] as standards) was established
during the summer of 1977 on an Arredondo loamy fine sand (loamy, siliceous, hyperthermic
Grossarenic Paleudult) in Gainesville. All grasses were fertilized prior to the growth of each
harvest with 60-18-35 lb/acre N-P2O5 -K2O fertilizer
containing 20 lb/ton of F 503 (contains the following elemental content: Fe, 18%; Zn, 7.0%;
Mn, 7.5%; Cu, 3.0%; and B, 3.0%). Plants
were harvested at 4 to 5 wk intervals during the warm season. Florakirk averaged 6.9
tons/acre DM, which was 8 and 10% higher than Tifton 44 and Coastal bermudagrasses,
respectively, when averaged over 8 yr (Table 4). In vitro organic matter digestion for
Florakirk during the 1980 season was 53%. This value was 2 percentage units lower than
Coastcross I (55%) but 4 and 7 percentage units higher than Tifton 44 (49%) and Coastal
bermudagrasses (46%), respectively.
In 1987 many of the grasses were reestablished on a new experimental site with the
addition of Tifton 78 bermudagrass (Table 4). Results of this 2-yr study revealed Florakirk
(6.5 tons/acre) out-yielded Coastal (6.0 tons/acre) by 8% and Tifton 78 (4.9 tons/acre) by
33%. Crude protein and IVOMD were determined on forage harvested only in 1989.
Generally, CP was similar for all grass entries. Results from IVOMD analyses revealed
Florakirk and Coastcross I both averaged 61%. These values were 4, 5, and 8 percentage
units higher than for Tifton 78, Tifton 44, and Coastal bermudagrasses, respectively.
Southwest Florida REC, Immokalee
Plot studies comparing 'Florico', 'Florona', and 'Ona' stargrasses (C. nlemfuensis),
Florakirk and Tifton 78 bermudagrasses, 'Taiwan' digitgrass (Digitaria pentzii), and 'Floralta'
limpograss at the Southwest Florida Research and Education Center (SFREC), Immokalee,
revealed Florakirk was among the lowest forage yielders (Kalmbacher et al., 1989). Dry
matter yield for Florakirk averaged 1.8 tons/acre/year over a 3-yr period. These yields were
only 50 and 55% of the best yielding grasses: Taiwan digitgrass (3.7 tons/acre) and Floralta
limpograss (3.3 tons/acre). Yields were quite low even though the fertility
program was 48-24-24 lb/acre N-P2O5-K2O, prior to the first and following each
subsequent harvest. The weed CB appeared to be a major problem in Florakirk at this
location, occupying 42% of the plot area 2 yr after establishment.
Crude protein and IVOMD were determined on all forage entries sampled at 4-wk
intervals. Percentage CP for Florakirk averaged 9.1 over seven harvests, which was equal
to or slightly higher than the other cultivars tested. In vitro organic matter digestion for
Florakirk averaged 52.2% over seven harvests, which was equal to or greater than that of Florico and
Florona stargrasses, Taiwan digitgrass, and Floralta limpograss.
Range Cattle REC
Mob-grazing
In 1980 Florakirk, 4 other
bermudagrasses, and two stargrasses, were established in a mob-grazed experiment to study
the effect of cattle on DM yield, forage quality, and persistence of these grasses (Mislevy et
al., 1988). Each grass was grazed at a 2-, 4-, 5-, and 7-wk frequencies from May to
December over a 3-yr period. Grasses received a total annual application of 140-53-106
lb/acre N-P2O5-K2O. The N was applied in four equal applications from March to October,
while P2O5 and K2O were applied once annually in March. Dry matter yield of Florakirk
increased (5.5 to 7.6 tons/acre/year) as grazing frequency was delayed from 2 to 7 wk (Table
5). Average annual DM yield across grazing frequencies was 7.0 tons/acre for Florakirk,
which was similar to Florico stargrass (6.9 tons/acre).
One of the most important factors when selecting a new perennial grass is
persistence. Common bermudagrass is a very serious weed problem. Therefore, as CB
ground cover increases, the desirable grass decreases. Data in Table 6 indicate that CB
ground cover found in Florakirk ranged from 1 to 2% after 3 yr of grazing, regardless of
grazing frequency. This would indicate Florakirk is very persistent at Ona and competes well
with CB if Florakirk ground cover is nearly 100% at establishment.
Crude protein concentration and IVOMD for Florakirk bermudagrass declined as
grazing frequency was delayed from 2 wk (11.7% CP and 58.5% IVOMD) to 7 wk (7.7% CP
and 51.3% IVOMD) for May-June harvested forage (Table 7). The CP concentration of
Florakirk at Ona was about equal to most bermudagrass and stargrass entries. However, the
IVOMD of Florakirk was slightly lower than the highest digestible grasses like Tifton 68
bermudagrass and Florico stargrass, but was generally higher in digestibility than Tifton 44,
Coastal (Table 4), or Alicia bermudagrasses.
Table 4. Dry matter (DM) yield (tons/acre DM) of commercial grasses grown in Gainesville over an 8-yr period (1978-1985)
and a 2-yr period (1988-1989) along with crude protein (CP;%) and in vitro organic matter digestion (IVOMD;%)
for selected years.
Grass cultivar
Year
Year
8-yr(t)
avg
1980
2-yr(tt)
Avg
1989
1978
1979
1980
1981
1982
1983
1984
1985
IVOMD
1988
1989
CP
IVOMD
Florakirk
bermudagrass(c)
9.5
8.0
6.8
7.4
5.2
6.4
6.0
6.1
6.9
53
5.7
7.3
6.5
11.6
61
Coastal
bermudagrass
7.9
7.7
7.2
6.9
4.9
6.1
4.9
4.8
6.3
46
5.1
6.8
6.0
11.4
53
Coastcross 1
bermudagrass
7.0
6.7
4.7
6.3
3.7
4.9
4.7
4.2
5.3
55
5.6
5.9
5.8
12.0
61
Tifton 44
bermudagrass
7.3
8.3
7.7
7.5
5.0
5.5
4.8
4.9
6.4
49
3.5
5.7
4.6
11.7
56
Tifton 78
bermudagrass
4.1
5.7
4.9
11.5
57
Pensacola
bahiagrass
4.8
6.0
5.6
5.2
4.5
5.9
3.3
3.3
4.8
37
(t) Study established in 1977.
(tt) Study established in 1987.
(c) Five to six harvests were made during the warm season each year; 60 lb/acre N was applied prior to the growth of each harvest from a 17-5
-10 (N-P2O5-K2O) fertilizer containing 20 lb/ton F 503(R).
1 F 503(R) contains the following elemental content: iron, 18%; zinc, 7.0%; manganese, 7.5%; copper, 3.0%; and boron, 3.0%.
| Table 5. Dry matter yield (tons/acre) of bermudagrasses and stargrasses grazed at various frequencies, Ona, 1982-83. | ||||||
| Grass entries | Grazing frequency (wk) | |||||
| 2 | 4 | 5 | 7 | 2-yr Avg. | ||
| Bermudagrass | ||||||
| Florakirk | 5.5(a)* | 7.5(a) | 7.5(a) | 7.6 (b) | 7.0 | |
| Tifton 44 | 2.5 (c) | 5.2(b)(c) | 4.0 (b) | 5.1 (c)(d) | 4.2 | |
| Tifton 72-81 | 3.3(b)(c) | 6.6(a)(b) | 7.8(a) | 8.4(a)(b) | 6.5 | |
| Grazer | 2.4(c) | 3.1(d) | 3.6 (b) | 4.6 (d) | 3.4 | |
| Tifton 68 | 3.0(b)(c) | 4.6(c)(d) | 7.1 (a) | 7.3 (b) | 5.5 | |
| Stargrass | ||||||
| Florico | 5.0(a) | 5.9(a)(c) | 7.4(a) | 9.3(a) | 6.9 | |
| Ona | 4.6(a) | 4.6(c)(d) | 6.4(a) | 6.8(c) | 5.6 | |
| * Means within a column followed by different letters are different (P<0.05) according to Duncan's Multiple Range Test. | ||||||
.
| Table 6. Invasion (% ground cover) by common bermudagrass (CB) (Cynodon daclylon) in stands of improved bermudagrass and stargrass cultivars after 3 yr of grazing, at four frequencies, Ona, 1981 -1983. | ||||||
| Grass entries | Grazing frequency (wk) | |||||
| Initial CB | 2 | 4 | 5 | 7 | ||
| Bermudagrass | ||||||
| Florakirk | <1 (a)* | 2 (a) | 1 (a) | 2 (a) | 1 (a) | |
| Tifton 44 | <1 (a) | 40(b c) | 32 (b-d) | 31 (a) | 11 (a) | |
| Tifton 72-81 | <1 (a) | 63 (c) (d) | 37 (c) (d) | 15(a) | 12 (a) | |
| Grazer | <1 (a) | 10a | 10(a-c) | 23(a) | 9 (a) | |
| Tifton 68 | <1 (a) | 82 (d) | 43 (d) | 21 (a) | 42 (b) | |
| Stargrass | ||||||
| Florico | 0(a) | 7(a) | 4(a)(b) | 1(a) | 1(a) | |
| Ona | <1 (a) | 27(a)(b) | 48(d) | 8(a) | 28(a)(b) | |
| * Means within a column followed by different letters are different (P< 0.05) according to Duncan's Multiple Range Test. | ||||||
| Table 7. Crude protein (CP;%) and in vitro organic matter digestion (IVOMD;%) of bermudagrasses and stargrasses mob-grazed in May-June at different frequencies and pooled over 2 yr. | |||||
| Grass entries | Grazing frequency (wk) | ||||
| 2 | 4 | 5 | 7 | ||
| Bermudagrass | |||||
| Florakirk | 11.7 (b)* | 8.1 (b) | 9.5 (a) | 7.7 (b) | |
| Tifton 44 | 13.5 (a) | 10.2 (a) | 9.5 (a) | 9.1 (a)(b) | |
| Tifton 72-81 | 11.3(b) | 7.8 (b) | 10.0 (a) | 7.8 (b) | |
| Grazer | 9.5 (c) | 9.0 (a) (b) | 9.3 (a) | 9.7 (a) | |
| Tifton 68 | 12.7 (a)(b) | 8.2 (b) | 10.9 (a) | 8.5(a)(b) | |
| Stargrass | |||||
| Florico | 12.3 (a) (b) | 8.1 (b) | 9.2 (a) | 8.4 (a) (b) | |
| Ona | 13.6 (a) | 8.7 (a)(b) | 10.2 (a) | 8.5 (a)(b) | |
| IVOMD | |||||
| Bermudagrass | |||||
| Florakirk | 58.5 (a) (b) | 55.0 (a) (b) | 54.8(b)(c) | 51.3 (b) | |
| Tifton 44 | 58.3 (a)(b) | 52.9 (b)(c) | 51.5(c) | 50.4 (b) | |
| Tifton 72-81 | 55.7 (b) | 49.7 (c) | 54.2 (b) (c) | 49.0 (b) | |
| Grazer | 55.8 (b) | 57.8 (a)(b) | 56.3 (b)(c) | 58.8 (a) | |
| Tifton 68 | 63.1 (a) | 57.6 (a) (b) | 62.6 (a) | 59.5 (a) | |
| Stargrass | |||||
| Florico | 58.6 (a)(b) | 58.0 (a) | 58.5 (a)(b) | 58.2 (a) | |
| Ona | 59.9 (a)(b) | 54.8 (a)(b) | 57.0 (b) | 51.1 (b) | |
| * Means within a column (CP and IVOMD separately) followed by different letters are different (P< 0.05) according to Duncan's Multiple Range Test. | |||||
Small pasture grazing
A grazing study with Florakirk bermudagrass was conducted from May 1986 to December 1988 at the Ona REC. The fertility program on these pastures was 175-47-95 lb/acre N-P2O5-K2O annually, plus 18 lb/acre of micronutrient mix IPI 303 (contains the following elemental content: iron, 18%; zinc, 7.0%; manganese, 7.5%; copper, 3.0%; boron, 3.0%; and molybdemum, 0.2%). Nitrogen was applied in four equal applications (March to September), and P2O5 and K2O were applied once annually in the spring. Each pasture was divided into three equal parts, allowing 2-wk grazing and 4-wk regrowth. The stocking rate was four yearling steers (500 lb/animal) per 1.25 acres. Average daily gain (ADG) was 0.8 lb, and total live weight gain per acre per grazing season (208 days) was 461 lb.
A 3-yr study was conducted on Florakirk and Brazos bermudagrass to compare a 1- and 2-wk cattle rotation for live weight gain and average daily gain. Cattle that were rotated every week were on a 5-pasture rotation, and cattle that were rotated every 2 wk were on a 3-pasture rotation. Both rotation treatments were allowed a 4-wk regrowth period between grazings. The fertility program was similar to the above grazing study. Cattle rotated weekly averaged 5 and 18% higher live weight gain/acre for Florakirk and Brazos, respectively, when compared with a 2 wk rotation (Table 8). Average daily gain of cattle grazing Florakirk and Brazos and rotated every week was 0.62 and 0.93 lb, respectively, compared to 0.59 and 0.73 lb, respectively, with the 2-wk rotation schedule. Florakirk showed little response (5%) compared with Brazos (27%) in favor of the fast rotation, possibly due to the higher quality forage of Florakirk. The animal performance increase from grazing Brazos on the 1-wk rotation may be due to its low digestibility. Consequently, the forage is higher in quality and better utilized when cattle are rotated more frequently. Average daily gain of cattle grazing Brazos on the 1-wk rotation was 0.31 lb higher compared to Florakirk, mainly due to a lower stocking rate on Brazos. Ruelke (1990), clipping grasses on a 4 to 5-wk schedule, showed Brazos (52% IVOMD) averaged 9 percentage units below Florakirk (61% IVOMD). Brazos, unlike Florakirk is more susceptible to the two-lined spittlebug, which was detrimental to stocking in mid and late summer.
| Table 8. Comparison of weekly and biweekly cattle rotation on live weight gain and average daily gain of Florakirk and Brazos bermudagrass (1988 to 1990), Ona. | ||||||
| Grass entry | Live weight gain (lb/acre) | Average daily gain (lb) | ||||
| Rotation (wk) % | Rotation (wk) % | |||||
| 1 | 2 | change | 1 | 2 | change | |
| Florakirk | 380 | 360 | 5 | 0.62 | 0.59 | 5 |
| Bravos(t) | 390 | 330 | 18 | 0.93 | 0.73 | 27 |
| (t) Average over 2 yr. | ||||||
.
The striped grass looper and fall armyworm both will feed on Florakirk bermudagrass
and may destroy the entire crop if not controlled. Florakirk should be monitored for
armyworms from mid-June and loopers from mid-August to early November. When
scouting the bermudagrass field for armyworms and loopers, kneel to the ground and count
the number of worms (1 inch to hair-like) per ft2 at random locations throughout the field.
If the number of worms per ft2 is 6 to 8 or greater and the size is 0.5 in or smaller, spray
immediately with an appropriate insecticide (contact County Extension Office for
recommendations). Occasionally, the two-lined spittle bug is found on Florakirk; however,
the plants appear unaffected.
The impact of nematodes on perennial crop productivity usually begins in the seedling stage and continues through to crop termination. In many cases, however, the impact may not be immediately obvious or cannot be completely described by the results of a single harvest but must rather be continually measured over the productive life of the crop. The severity of the problem often is also defined by the presence of other soilborne pest and disease problems, which may interact with nematodes to accentuate the problem. Progressive reductions in crop growth, stand density, and harvest yields are therefore generally reflective of the prolonged exposure of perennial crops to plant parasitic nematodes.
At present, no data has been obtained implicating plant parasitic nematodes as
economically important pests of this grass. In a limited survey of 10 Florakirk fields of
different ages at the Range Cattle REC, major problems with nematodes have not developed.
In some of the fields, populations of nematode species within
the genera Helicotylenchus, Hoplolaimus, and Pratylenchus have apparently increased to
moderate levels on Florakirk. However, no obvious symptoms of nematode damage, such
as poor stand establishment, reduced growth, or reduced plant density, have been observed. Continued observation and further research is necessary to establish the
importance and damage potential of other nematode species to Florakirk. Therefore, if a
nematode problem is suspected in a field, soil and root tissue samples should be removed for
diagnosis and submitted to a reputable nematode assay laboratory for analysis.
A 'leaf blight' disease (Sonoda and Mislevy, 1985) was found on Florakirk bermudagrass in grazing studies during August and September 1983 and again in 1994 at Ona, Florida. Florakirk bermudagrass grazed to a 3-4 in stubble under a continuous system, or under a rotational system with a 4-wk grazing frequency, revealed no foliar blight. The incidence of blight seemed to be associated with dense stands of tall, uncut, ungrazed forage and tended to disappear after October 15. Cattle consumed infected plants relatively well with no signs of rejection. This disease does not appear to be of economic importance.
Rust has been found periodically on Florakirk when plants were allowed to mature 8 to 10 wk before harvest. The rust seemed to be associated with dense stands of tall, uncut, ungrazed forage. No indication of rust has been reported in north Florida when Florakirk was cut at 4- to 5-wk intervals.
Tar spot has occurred on Florakirk at the Range Cattle REC. Numerous lesions coalesce
and cause leaf browning on lower leaves with the disease progressing to higher leaves over
time. Tar spot tends to be more severe in plantings when cutting or grazing is delayed. Tar
spot has not prevented good regrowth of Florakirk after a cutting even though the disease
was prevalent one half to two thirds up the plants. Increasing the cutting or grazing
frequency should minimize the impact of tar spot. In fact, utilizing Florakirk in an intensive
hay harvest system results in little or no leaf diseases.
Florakirk bermudagrass is established vegetatively from crowns and rhizomes or mature stem pieces including stolons (runners). When placed in a moist, firm seed bed, roots develop from nodes in 5 to 10 days. Freshly harvested planting material (1000 to 1200 lb/acre) should be distributed on clean cultivated soil and covered by disking 2 to 4 in deep (75% of each stem covered with soil) or crimping (roller with a series of 14 disks 0.25 in thick welded perpendicular to roller axis and extending 8 in beyond roller drum) by pushing vegetative material lying on the soil surface 4 in into the well-prepared seed bed. Freshly harvested vegetative material must be disked or crimped into the seed bed within 30 minutes after distribution to prevent drying of plant material. The seed bed should be firmed with a heavy roller, passing one to three times depending on soil moisture.
To establish Florakirk or any other grass successfully, the seed bed must be clean (free of CB and all other vegetation) and moist. If CB had been growing on the field, the planting rate should be increased to 1500 lb/acre. It is also important to spread the plant material uniformly across the field with no voids larger than 3 ft in diameter.
Seven to 10 days after planting Florakirk, when signs of growth are evident, the field
should be sprayed with 1.0 lb/acre Weedmaster® (0.25 lb/acre dicamba + 0.72 lb/acre 2,4-D
amine) or equivalent even though the field may appear weed-free. The herbicide will
control many sedges and broadleaves that are just emerging (< 1 in tall). Follow label
directions on all pesticide usage.
Soil test results should be used in determining lime and fertilizer requirements. Bermudagrass generally performs well at a pH range of 5.5 to 6.5, with available calcium at 1000 to 1200 lb/acre. The bermudagrass fertilization program should be divided into two parts: establishment and maintenance.
Establishment Fertilization
Most flatwood soils in Florida are deficient in plant nutrients, therefore Florakirk
bermudagrass needs to be fertilized about 7 days after planting. When new shoots are
approximately 1 to 3 in tall, fertilize with about 35-35-35 lb/acre N-P2O5-K2O plus
micronutrients, if needed. About 30 to 40 days after the initial application, plants should
receive additional 40 to 50 lb/acre N when fields are not in standing water. This
establishment fertilization and herbicide program should allow Florakirk to attain a height
of 24 in or more in 75 days or less.
Maintenance fertilization
All bermudagrasses require a high level of fertility. Under an intensive grazing
program, Florakirk should receive 60-15-30 lb/acre N-P2O5-K2O (unless otherwise indicated
by soil test), at least three times per year (early March, late June, and mid September) to
encourage continuous forage production throughout the warm season. When the
bermudagrass is harvested for hay, about 70-30-60 lb/acre N-P2O5-K2O should be applied 4
to 5 wks before each cutting. If micronutrients have not been applied within 3 to 4 yr or the
bermudagrass is planted on new land (recently developed from the native condition), about
10 lb/acre IPI 303 or equivalent may be required. This fertilization program should be adequate
to produce about 1.5 to 2.0 tons/acre hay after 4 to 5 wk of regrowth, provided suitable
environmental conditions occur.
Clipping and grazing studies have demonstrated that Florakirk bermudagrass should
be allowed a rest period of 4 wk between grazing and 4 to 5 wk between hay cutting. If the
rest period is shorter, forage quality increases, but persistence of the stand may decrease. If
the rest period between grazing is increased to 7 wk, yield and persistence could improve,
but forage quality and palatability will decrease. Unlike stargrasses, bermudagrasses tend
to perform well under a relatively short stubble height.
Florakirk has been released for hay production basically for north Florida and south Georgia growers because of its fine stems, persistence, high yields, and good quality. To make good quality Florakirk bermudagrass hay or silage is both a timely and an intensive process. If 7 wk or more are allowed between harvests, the quality of this fine stemmed grass will be low and cattle may reject considerable amounts. Commercial growers must harvest bermudagrasses on a 4 to 5 wk schedule. Generally, two spring (May and June) harvests can be obtained in central Florida provided cattle are removed by early March and the field is fertilized by mid-March, when moisture is still available in central Florida soils. Florakirk tends to produce spring DM yields similar to Coastal; however, fall yields were 24% higher for Florakirk than for Coastal in Gainesville.
In central Florida, Florakirk (0.74 tons/acre) will produce about double the DM yield
of Pensacola bahiagrass (0.35 tons/acre) during October and November. These fall Florakirk
yields are similar to or slightly better than for Florona and Florico stargrasses under similar
conditions. Remember, to obtain maximum fall yields, Florakirk must be well fertilized in
mid-September. All dates and rates of fertilizer may require adjustment to meet weather and
soil fertility variables.
Florakirk bermudagrass has persisted well under grazing at the Range Cattle REC; however, leaf spot diseases tend to be more prevalent under grazing than hay harvest systems. Unlike the stargrasses, which require a 6 to 10 in stubble for best persistence, Florakirk tends to persist well and have less leaf spot disease when grazed to a short (3 to 4 in) stubble height. For best results, Florakirk should be rotationally grazed, allowing a 4-wk rest period between grazing. Remember, bermudagrass, like stargrass, has a high fertility requirement. Therefore, frequent fertilization is necessary for continued growth and production.
Information regarding planting material of Florakirk bermudagrass can be obtained from the following offices:
Florida Foundation Seed Producers, Inc.
P.O. Box 309
Greenwood, Florida 33443
Telephone 904-594-4721
Range Cattle Research and Education Center
Rt 1, Box 62
Ona, Florida 33865
Telephone 813-735-1314
Kalmbacher, R., P. Mislevy, and F. G. Martin. 1989. Evaluation of new stargrasses and bermudagrasses at Immokalee. IFAS, Agricultural Research and Education Center, Ona Research Report RC-1989-6.
Mislevy, P., O. C. Ruelke, and F. G. Martin. 1988. Grazing evaluation of Cynodon species. Soil and Crop Sci. Soc. Florida Proc. 47:207-212.
Ruelke, O. C. 1990. Florida field and forage crop variety report, 1989. IFAS, Agronomy Research Report Ay 90-93.
Sonoda, R. M., and P. Mislevy. 1985. Foliar blight of Cynodon spp. forage caused by
Rhizoctonia solani in Florida. Plant Dis. 69:811.
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