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Januaryr y 1987
Bulletin 865 (technical)
,I
Yield and Persistence of Perennial Grasses
at Immokalee, Florida: 1981 to 1984
R. S. Kalmbacher, P. H. Everett, F. G. Martin,
K. H. Quesenberry, E. M. Hodges,
O. C. Ruelke and S. C. Schank
Agricultural Experiment Station
Institute of Food and Agricultural Sciences
University of Florida, Gainesville
J. M. Davidson, Dean for Research
Yield and Persistence of Perennial Grasses
at Immokalee, Florida: 1981 to 1984
R. S. Kalmbacher, P. H. Everett, F. G. Martin, K. H. Quesenberry
E. M. Hodges, O. C. Ruelke and S. C. Schank
R. S. Kalmbacher is Agronomist with Ona AREC; P. H. Everett is Soil
Chemist, Immokalee AREC; F. G. Martin is Statistician, Department of
Statistics, University of Florida, Gainesville; K. H. Quesenberry is Associate
Agronomist, Department of Agronomy, University of Florida, Gainesville; E.
M. Hodges is Professor Emeritus, Ona AREC; O. C. Ruelke and S. C. Schank
are Agronomists, Department of Agronomy, University of Florida,
Gainesville.
New perennial grass introductions and varieties are continually
being evaluated in Florida. Because of the range of soil and climate
within the state, these grasses need to be tested for yield, quality, and
persistence at several locations. The purpose of this publication is to
present the results of a four-year plot study designed to evaluate 20
perennial grasses in southwest Florida.
Materials and Methods
The study was conducted at the Immokalee Agricultural Research
Center (260 27'N, 810 26'W) near the Everglades. Daily minimum
temperatures during the cool season (October to March), which limit
tropical grass persistence and yield, average 56 F (13 c), and rainfall
averages 47 in. (1200 mm) annually, 75% of which falls from April to
September. Soil was an Immokalee fine sand (Arenic haplaquod)
limed to a pH of 6.6 and having an organic matter content of 1.4%. The
site was not irrigated, but because the site had been used for vegetable
production more than 10 years ago, presence of irrigation ditches
around the perimeter reduced the incidence of standing water in the
rainy season.
The following grasses were planted: nine entries of Hemarthria
altissima; three Cynodon dactylon entries (Callie, Tifton 72-81, and
Grazer bermudagrasses); three Cynodon nlemfuensis entries (Cane
Patch, Puerto Rico, and Ona stargrass); three digitgrass entries
(Transvala, Digitaria decumbens; Taiwan, D. pentzii; Survenola,
Digitaria X umfolozi); and two Pennisetum entries (P purpureum,
N-75 dwarf hybrid, and P purpureum X P americanum N-76). Eight
entries, Floralta and Bigalta Hemarthria, Grazer and Callie
bermudagrass, Ona stargrass, Taiwan, Transvala and Survenola
digitgrass, were named cultivars, and the remaining 12 were
experimental lines.
Grasses were established with stem cuttings in four randomized,
complete blocks on 6 August 1980 and 7 August 1981 (Table 1). Soil
was rotovated, weed-free and contained adequate moisture. Planting
material was disked into the seedbed, except for dwarf napiergrass
and pearlmillet X napiergrass hybrids, which were started from 12 in.
(30 cm) stalk cuttings, planted on 3 foot (91 cm) centers. The experi-
mental site in 1981 was overhead irrigated (1 inch or 2.54 cm), 2 days
after planting. Fertilization for establishment and maintenance and
herbicide usage are outlined in Table 1.
Forage harvests were scheduled on a calendar-basis (35-day), but
during the cool season forage was harvested after sufficient
accumulation. Stubble height is described in Table 1. Frequency of
harvest was often delayed by excessive rainfall during the summer
1982. Crude protein and in vitro organic matter digestibility
(IVOMD) were determined in the Forage Evaluation Support
Laboratory in Gainesville.
Table 1. General cultural information, perennial grass variety trial.
Immokalee, Florida. 1980-1984.
A. Planting (vegetative)
1. 6 August 1980, all entries except Nos. 7, 13,20. (entry nos. are in
Table 2).
2. 7 August 1981, replant entries 15,17,19 andplant entries Nos. 7,
13, 20. (entry nos. are in Table 2).
B. Fertilization a
1. Establishment
a. 5 August 1980. Dolomite at 1 t/A.
b. 29 August 1980. 50-46-92 lb/A of N-P20O-K20, resp. with 10
lb/A FTE 503 micronutrients.
c. 6 January 1981. 96-20-20 lb/A of N-P,O,-K20
d. 10 October 1981. 48-24-24 lb/A N-P20O-K20 on 7 August 1981
planted entries.
2. Maintenance
a. 48-24-24 lb/A (N-P2Os-KO2) applied after each harvest.
C. Herbicide
1. 7 August 1981 Lasso at 1 lb/A (active) on replanted entries.
D. Stubble height: 2" on entry No. 12; 12" on entry No. 7; 4" on all
others.
E. Harvest: generally on 35-day intervals when sufficient growth was
present. There were 3 harvests in 1981, 7 in 1982, 6 in 1983 and 5 in
1984.
a kg/ha = Ib/A x 1.12
Mg/ha = t/A x 2.24
Table 2. Yield (oven dry) of perennial grasses tested at the Immokalee 1981 to 1984.
Year
Entry
No. Cultivar No./Name 1981 1982 1983 1984 Average
--------- ------------------------- t/a ----------------------------------
1 Floralta Hemarthria 10.5 aa 9.0 ab 7.0 a 5.1 a 7.9 a
2 PI 349753 Hemarthriab 10.0 ab 9.2 a 6.6 a 4.7 ab 7.6 a
3 PI 365509 Hemarthriab 9.8 abc 9.2 a 6.8 a 4.2 abc 7.5 a
4 PI 364871 Hemarthria b 4.7 d 6.1 c-f 6.8 a 3.8 bcd 5.4 b
5 PI 364869 Hemarthriab 4.7 d 5.8 c-f 5.9 ab 3.7 bcd 5.0 bc
6 PI 364884 Hemarthria 4.4 d 6.4 cde 5.8 ab 3.4 bcd 5.0 bc
7 N-75 Dwarf Napiergrass b 0.0 6.7 b-e 6.8 a 1.6 h 5.0 be
8 Taiwan Digitgrass 5.4 bcd 6.2 c-f 4.8 bc 2.8 d-g 4.8 bc
9 Cane Patch Stargrass b 6.7 a-d 6.6 b-e 4.0 cd 1.8 gh 4.8 bc
10 Puerto Rico Stargrass (PR-2341)b 5.3 cd 6.9 a-d 4.1 cd 2.3 e-h 4.7 bcd
11 PI 367874 Hemarthria 4.1 d 4.5 def 5.0 bc 3.9 bcd 4.4 b-e
12 Grazer Bermudagrass 3.8 d 5.8 c-f 4.0 cd 3.0 def 4.2 b-f
13 Pearlmillet x Napiergrass Hybrid b 0.0 7.8 abc 3.8 cde 0.0 3.9 c-g
14 Ona Stargrass 4.4 d 4.5 def 3.4 de 0.0 3.1 e-h
15 Transvala Digitgrass 0.0 4.3 ef 4.3 cd 0.0 2.9 fgh
16 Bigalta Hemarthria 6.7 a-d 4.5 def 0.0 0.0 2.8 fgh
17 Survenola Digitgrass 0.0 4.5 def 3.9 cde 2.0 fgh 2.6 fgh
18 PI 364887 Hemarthria b 4.8 d 3.8 f 0.0 0.0 2.2 gh
19 Callie Bermudagrass 0.0 3.9 f 2.6 e 0.0 1.6 h
20 Tifton 72-81 Bermudagrass b 0.0 1.2 g 0.0 0.0 0.4 i
Average 6.1 5.9 5.0 3.3
a Means within columns followed by the same letter are not significantly different. (Waller-Duncan DMRT, K = 100).
b Experimental entries.
Table 3. Estimated plot cover a from grass entries, common bermudagrass and vaseygrass. 1981-1984.
Year
1981 1982 1983 1984
Entry name/number entry entry CB entry CB entry CB Vasey b
-----------------------------------------(- -----------------------------------------
(%)
Floralta Hemarthria 92 100 0 99 0 99 2 20
PI 349753 Hemarthria 88 100 0 98 0 97 0 3
PI 365509 Hemarthria 100 94 0 99 0 96 3 3
PI 364871 Hemarthria 85 99 0 99 0 97 0 8
PI364869 Hemarthria 76 98 0 99 0 99 0 2
PI 364884 Hemarthria 80 92 12 97 0 97 3 2
N-75 dwarf Napiergrass c 52 8 51 10 30 0 0
Taiwan Digitgrass 73 92 0 98 2 95 0 4
Cane Patch Stargrass 80 92 6 88 10 64 11 35
Puerto Rico Stargrass 93 93 3 91 12 76 9 18
PI 367874 Hemarthria 80 87 13 90 13 91 7 5
Grazer Bermudagrass 94 96 0 94 3 78 8 13
Pearlmillet x Napiergrass Hybrid c 38 14 40 10 c c
Ona Stargrass 86 97 25 88 7 c c
Transvala Digitgrass c 92 1 87 27 c c c
Survenola Digitgrass c 68 10 76 17 61 13 26
Callie Bermudagrass c 77 22 65 41 c c
a Total percentages sometimes exceed 100% of canopy overlap.
b CB is common bermudagrass, vasey is vaseygrass.
c Not evaluated: 1981, entry not established; 1984, entry died out.
Results and Discussion
Establishment
All Hemarthria entries were quick to establish. Although there was
competition from annual grasses in the year of planting, they over-
came the competition and were well established by spring 1981. Most
Hemarthria entries had good ground cover, and there was little
encroachment from common bermudagrass by the end of the second
year. Only PI364887 and Bigalta appeared to be weak entries and had
66 and 65% common bermudagrass cover. All other Hemarthria
entries had 87% cover with less than 13% common bermudagrass.
Entries 1,2,3, which were the highest yielding (Table 2), had 98%
cover with little common bermudagrass. (Table 3).
Callie bermudagrass failed to establish in 1980 in three of four
replications and was replanted in 1981. Stands from the second plant-
ing were weak, and common bermudagrass covered 22% of the plot
area (Table 3). Other Cynodon entries were quick to establish and
were persistent, especially Cane Patch and Puerto Rico stargrass
(Table 3). These entries spread faster than Ona stargrass, and plots of
Cane Patch and Puerto Rico stargrass contained less common
bermudagrass than Ona stargrass. Grazer bermudagrass was quick
to establish and was persistent due to its decumbent growth habit.
Tifton 72-81 was a weak entry with 60% cover one year after planting.
Taiwan digitgrass was quick to establish and proved to be persistent
with 92% cover and no common bermudagrass after two years of cut-
ting (Table 3). Transvala and Survenola required replanting in 1981
because annual weeds crowded out these varieties in the initial year,
but use of herbicide in 1981 resulted in good establishment.
Napiergrass entries were slower to establish. After one year, plot
cover from these bunch-type plants was 38% and 52%, respectively.
These entries were planted on 3-ft. (91 cm) centers, which were too far
apart. Planting on 15 (38 cm) to 20 in. (50 cm) centers would probably
increase yield and reduce interplant spaces and weed competition.
Weeds had to be hoed from around these entries, which explains the low
common bermudagrass and vaseygrass (Paspalum urvillei) cover in
1983 and 1984 (Table 3).
Yield and Persistence
Significant differences in dry matter yields between entries were
found in each year. Hemarthria entries, Floralta, PI 349753 and PI
365509, were highest yielding with four-year averages of 7.9, 7.6 and
7.5 t/A, respectively (Mg/ha = t/A x 2.24). Hemarthria entries PI
364871 and PI 364869 were quite decumbent and therefore not high
yielding, but they were consistent. Entry PI 364869 declined 2.2 t/A
between 1983 and 1984 compared to an average 2.6 t/A for all other
grasses. It may have potential for heavy grazing because considerable
leaf area remained close to the soil surface after cutting. Stargrass and
bermudagrass yields averaged 3.7 t/A (range was 1.6 to 4.8 t/A), while
digitgrasses averaged 3.4 t/A (range was 2.6 to 4.8 t/A). Average yield of
the napiergrass hybrids was 4.5 t/A for the three years they were tested.
These yields do not represent the amount of forage that cattle would
consume by grazing, but forage available for harvest as hay or silage.
They are meant to serve as a relative index of productivity, and because
they represent whole plant yields measured at specific times, the
averages should be used carefully.
No grass was able to sustain uniform yields through the four years
(Table 2). Entries 13, 14, 15, 16, 18, 19 and 20 died out by 1984, while
others (entries 4, 5, 6, 11, 12) were producing almost as much forage in
1984 as in 1981(80,79,78,95, and 78% of 1981 yields, respectively). This
was a reflection of harvest method, which placed stress on the plants
beyond that which would be realized through grazing. The reduction in
yield, especially in the Hemarthria entries mentioned above, was the
result of a decline in plant vigor. The Hemarthria spp. had 91 to 99% plot
cover after the four years (Table 3), which indicates the entry was still
present but not vigorous.
Three entries died out after 2 years (Table 2). One of these was Bigalta
Hemarthria, which had little persistence when compared to the newly
released and much higher yielding Floralta. Four entries (Ona
stargrass, Callie bermudagrass, Transvala digitgrass and the
pearlmillet x napiergrass hybrid) died out by 1984. Other than Hemar-
thria entries, the only other entries still productive in 1984 were
Taiwan digitgrass, Puerto Rico stargrass, and Grazer bermudagrass.
As a group, Hemarthria entries appeared to be much more efficient in
fertilizer use. Application of 50 lb/A (56 kg/ha) of N would easily carry
these grasses over to the next harvest, and during the long period
between the last fall harvest and the first spring harvest these entries
maintained good color and relatively dense stands. On the other
extreme, stargrass entries (except for Puerto Rico) were very pale at
harvest, and canopies were open. Stargrasses appeared to be heavily
dependent on nitrogen and were definitely at a disadvantage with rates
applied.
Encroachment by other grasses was a major problem for stargrasses
because of their open canopy (Table 3). Common bermudagrass and
vaseygrass were the major weeds. Vaseygrass plants were rogued from
all plots in 1981 and 1982, but became so numerous that they grew
unchecked thereafter. Vaseygrass plot coverage averaged 20% in 1984
and was even a problem weed in Floralta.
Diseases and insects were not problems on any entry. Spittlebugs
(Lepyronia spp.) were often found on the two napiergrass entries, but
there was no apparent damage due to their presence.
Forage Quality
Crude protein content was consistently high on N-75 dwarf
napiergrass and Grazer bermudagrass because these samples were
mostly leaves (Table 4). N-75 napiergrass digestibility was also
superior to most other entries for this same reason (Table 5). Another
entry with good protein and digestibility was PI 364869 Hemarthria,
which was a persistent, low growing entry. Puerto Rico stargrass was
Table 4. Seasonal crude protein of grass entries tested at Immokalee,
1982.
Season
Entry Name or Number Spring8 Summer Fall Winter
N-75 Dwarf Napiergrass d
Grazer Bermudagrass
Pearlmillet x
Napiergrass Hybrid d
PI 364869 Hemarthria d
Puerto Rico Stargrass d
PI 364887 Hemarthria d
Ona Stargrass
Tifton 72-81
Bermudagrass d
Cane Patch Stargrass d
Bigalta Hemarthria
Taiwan Digitgrass
PI 364871 Hemarthria d
Transvala Digitgrass
Callie Bermudagrass
PI 367874 Hemarthria d
Survenola Digitgrass
PI 365509 Hemarthria d
PI 349753 Hemarthria d
Floralta Hermarthria d
PI 364884 Hemarthriad
Average
10.4 abb 13.2 a
S 12.8 a
c
5.9 c
8.4 abc
c
C
c
10.8 a
11.1 a
9.0 ab
10.6 ab
11.2 a
c
8.1 abc
10.2 ab
9.4 ab
7.8 bc
8.2 abc
9.3
11.5 b
10,6 bed
10.9 be
9.6 c-g
10.1 cde
e
11.0 be
9.6 c-g
9.8 c-f
8.5 g
8.4 g
11.1 bc
9.2 efg
10.4 b-e
9.9 cf
9.6 d-g
9.9 cde
8.6 fg
10.3
a Spring is late February, Summer, mid-July, Fall, mid-October, Winter, December after
frost.
b Means followed by the same letter are not different (Waller-Duncan DMRT, K = 100).
c Entries had not resumed growth.
d Experimental entries.
e Not included because of poor stand.
(%)------
9.6 a
9.4 a
6.2 de
6.5 de
8.3 ab
8.6 ab
7.6 bed
8.2 cde
7.9 be
6.6 cde
7.2 bcd
6.2 de
6.7 cde
6.9 cd
6.2 de
6.5 cde
6.9 cd
5.4 e
6.1 e
6.2 de
7.1
8.8 a
6.7 ade
6.9 bed
5.3 fgh
6.1 def
5.4 e-h
6.3 de
e
6.9 bcd
5.7efg
6.0 ef
4.9 gh
6.1 def
7.5 be
5.0 gh
7.8 ab
4.2 h
4.3 h
4.6 h
4.8 gh
6.0
often higher in protein and digestibility than other stargrasses,
especially Ona.
Crude protein and IVOMD in Hemarthria depended on the entry, as
the full range of both quality parameters was covered by this group of
grasses. High yielding entries like Floralta and PI 365509 were low in
crude protein, probably because plant N was diluted by the large mass
of forage. Digestibility of Floralta and other high-yielding Hemarthria
entries was usually good.
Table 5. Seasonal in vitro organic matter digestibility (IVOMD) of
grass entries tested in Immokalee, 1982.
Season
Entry Name or Number Spring Summer Fall Winter
N-75 Dwarf Napiergrass d
Pearlmillet x
Napiergrass Hybrid d
Bigalta Hemarthria
Floralta Hermarthria
PI 364869 Hemarthria d
Survenola Digitgrass
PI 349753 Hemarthria d
PI 365509 Hemarthria d
Grazer Bermudagrass d
PI 367874 Hemarthria d
Transvala Digitgrass
Taiwan Digitgrass
Puerto Rico Stargrass d
PI 364871 Hemarthria d
Callie Bermudagrass
PI 364887 Hemarthria d
Cane Patch Stargrass d
Tifton 72-81
Bermudagrass d
PI 364884 Hemarthriad
Ona Stargrass
Average
35.9 e b 67.5 ab
c
53.9 a
54.3 a
49.9 a-e
49.2 a-e
51.0 abc
50.8 a-d
C
c
49.2 a-e
C
46.1 b-e
53.2 ab
39.9 d-e
c
43.4 c-e
c
43.4 c-e
c
47.7
65.4 ab
61.9 bc
63.2 abc
70.3 a
68.9 ab
61.8 bcd
62.5 be
64.3 ab
59.7 bcd
60.6 bcd
65.1 ab
63.5 ab
52.7 d
64.5 ab
61.3 bcd
62.8 be
e
55.4 cd
62.3 bc
62.8
a Spring is late February, Summer, mid-June, Fall, mid-October, Winter, December
after frost.
b Means within columns followed by the same letter are not different (Waller-Duncan
DMRT, K = 100).
c Entries had not resumed growth.
d Experimental entries.
e Not included because of poor stand.
(%)--
62.9 a
60.5 b
58.2 bc
56.0 cde
54.7 def
57.2 cd
57.0 cd
53.0 fg
51.0 ghi
52.6 fg
52.3 fgh
52.4 fg
54.3 ef
48.9 ij
52.8 fg
49.0 ij
46.9j
47.9 ij
49.6 hij
48.4 ij
53.3
59.1 a
57.1 ab
49.4 efg
54.1 bcd
57.2 ab
50.3 def
55.5 be
51.0 de
50.2 ef
50.0 ef
52.0 cde
49.3 efg
46.5 fgh
49.8 ef
42.4 i
48.5 a-h
42.3 i
e
45.8 ghi
45.7 hi
50.3
Forage quality depended on season (Table 5). Protein content and
IVOMD in very early spring averaged 9.3% and 47.7%, respectively.
These percentages represented both new growth and frosted herbage.
Early summer quality was better than other seasons with 10.3%
protein and 62.8% IVOMD. Both quality parameters declined on all
entries, especially in August (data not in table), but increased in
September. Crude protein and IVOMD in October, when most hay is
made, averaged 7.1% and 53.3%. After the first frost in December, both
protein and IVOMD parameters declined on almost all entries and
averaged 6.0% and 50.3%, respectively.
Conclusions
Twenty perennial grasses were tested for dry matter yield and
persistence over a four-year period at Immokalee. The Hemarthria
entries as a group were superior to stargrass, bermudagrass, digitgrass
or napiergrass entries and were shown to be better adapted to the
Immokalee area. Floralta was shown to be a high yielding and persist-
ent cultivar with satisfactory digestibility and is recommended for use
in the Immokalee area. Other desirable experimental Hemarthria
entries were PI 349753, PI 365509, PI 364871 and PI 364869.
Stargrass and bermudagrass entries were not persistent nor was
yield sustained at a satisfactory level during the four years. They did
not respond well to the levels of fertility used in this study, which were
quite high compared to those used on commercial cattle ranches.
Stargrasses and bermudagrasses are not recommended for use in the
Immokalee area.
Taiwan digitgrass was the only digitgrass that was persistent and
rather consistent in yield. It is the only digitgrass which warrants
recommendation in Immokalee.
N-75 dwarf napiergrass may have potential and seems promising
because of its high quality. Methods of propagation and management
should be developed.
Mention of a trade name does not constitute a guarantee or warranty of the product and
does not imply its approval or recommendation by the Florida Agricultural Experi-
ment Station to the exclusion of other products that may be suitable.
UNIVERSITY OF FLORIDA
This publication was produced at an annual cost of $671.45 or
26.9 cents per copy to provide information for making recom-
mendations and planning research about perennial grasses.
All programs and related activities sponsored or assisted by the Florida
Agricultural Experiment Station are open to all persons regardless of race,
color, national origin, age, sex, or handicap.
ISSN0096-607X
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