BULLETIN 718
PANGOLAGRASS
E. M. HODGES,
O. C. RUELKE,
AND
G. B. KILLINGER, J.
R. J. ALLEN, JR., S.
A. E. KRETSCHMER,
E. McCALEB,
C. SCHANK,
JR.
AGRICULTURAL EXPERIMENT STATIONS
stitute of Food and Agricultural Sciences
diversity of Florida, Gainesville
R. Beckenbach, Director
AUGUST 1967
I -i.-'~"i
i
CONTENTS
Page
Introduction .3............. ............. ........ .. ..... .. .. 3
D escrip tion ......4 .. .......... ................ .. ........ .. 4
B reedin g ..........4.. ....... ................ ......... .............. 4
Grazing Experiments 5.......... ................. ...-.... 5
Production and Management 6
P la n tin g ..... ................................... ..................... 6
Lime .. ......... ...- ........... .. 7
F fertilizer .................................................. ............... 7
New Plantings .. .. .............
Pasture M maintenance ...................................................... ... .... 8
Fertilization for Harvest ............................................ ... 9
Factors Affecting Response to Fertilizer .......... 10
Pasture Management and Maintenance ..................................... 11
H ay and Silage .. .. ....... ......................... .............--. 12
H a y ................. .................................... ...-.. 12
S ilag e ...... .... .......... ................... ....-- 13
W in terkilling ..... ........ .......- .. . .. .. ............... 14
Sym ptom s ............................... ... ..... .......... ........ 15
Distribution ............. .............. ......... 15
Cause and Control .. ............. .......... ...... ------- 15
C old .... .. .................................... .. 15
F fertilizer E effect .. ........... ................................ ... ... 17
Rainfall ......... ............... 19
Ground Cover .................................... .... 19
Grow th Regulators .... -........... .......................... .......-. 20
Cultivation and Age of Sod ................... ..... .. 20
Management of Winter-Damaged Pangolagrass .................................... 21
Central Florida .................. ........... 21
Everglades ...........-. .......-. ...-..... ----. .... .... 22
Insects and Disease ................- -- ................-- -. 23
A phids ........ ......... ........... ...-.. 23
W orm s --..-............................ .. ...- .... ...... 25
Two-Lined Spittlebug .........................-- ....... ... 25
Other Insects ......... .............. -....----.... .. ..-..-..- 26
Insect Control .-.. .... .... ... .........-..--- -- -- .-- .- ... 26
Grazing ... .. ... ....... 26
Harvesting ................ ................-. .......--- -- ....- 26
Insecticides ....... ............. .............- ---... 27
Stunt D disease ........................... .... ..... ...---- -- .. 27
Summary and Conclusions -.. ...............-- -............. 27
Literature Cited -.~.........-... ....-... -- ...- 29
PANGOLAGRASS
E. M. Hodges, G. B. Killinger, J. E. McCaleb, O. C. Ruelke,
R. J. Allen, Jr., S. C. Schank, and A. E. Kretschmer, Jr.1
INTRODUCTION
Pangolagrass, Digitaria decumbens Stent., has become an
important species of grass for pasture, hay, and silage in penin-
sular Florida. Estimates of improved pasture area in the state
are in excess of two million acres with pangolagrass accounting
for some 25% of the whole. Virtually all commercial acreages
of this variety in Florida are located on mineral soils lying
southward of St. Augustine, Gainesville, and Chiefland.
As a part of the continuing plant introduction program car-
ried on by state and federal agencies, several new grasses were
received as vegetative material in Arlington, Virginia, in May
1935, from Dr. I. B. Pole Evans, Pretoria, South Africa (11,
24)2. These were maintained at the introduction station and in
April 1936 sent to George E. Ritchey, Agronomist, where they
were established in the forage plant introduction garden of the
Florida Agricultural Experiment Station. The most promising
one, a strain bearing the plant introduction number 111,110,
was selected for further testing. It was first widely distributed
to farmers and ranchers in 1943. First called Digit grass or
Digitaria, it was finally given the common name pangolagrass.
This is a misspelling of the name of the Pongola River which
crosses the region of South Africa where this grass is believed
to have originated. Since it came from an area in the southern
hemisphere which lies at about the same latitude south of the
equator as Lake Okeechobee does to the north, it is not surpris-
ing that pangolagrass was found to be well adapted to central
and south Florida. This grass has been established in pastures
in many subtropical and tropical areas throughout the world
(27, 33). The Gulf Coast of Mexico, where it has been planted
'Hodges: Agronomist, Range Cattle Experiment Station, Ona; Killinger:
Agronomist, Agricultural Experiment Station, Gainesville; McCaleb: As-
sociate Agronomist, Range Cattle Experiment Station; Ruelke: Associate
Agronomist, Agricultural Experiment Station, Gainesville; Allen: As-
sistant Agronomist, Everglades Experiment Station, Belle Glade; Schank:
Associate Agronomist, Agricultural Experiment Station, Gainesville;
Kretschmer: Agronomist, Indian River Field Laboratory, Ft. Pierce.
Numbers in parentheses refer to Literature Cited.
on an estimated one million acres3, is one of the areas of most
extensive use.
DESCRIPTION
Pangolagrass resembles ordinary crabgrass [Digitaria san-
guinalis (L.) Scop] but is perennial in growth habit, forming an
abundance of decumbent stems that root at nodes which touch
the ground (Figure 1). It produces a leafy growth in early
spring followed by a profuse development of seed stalks that
reach 3 or more feet in height. The many-branched inflorescence
bears florets with less than .001% producing viable seed.
Figure 1.-Pangolagrass (Digitaria decumbens Stent.).
BREEDING
The possibilities of improving pangolagrass by selection
within the present population are poor because there is little
variation among plants. All the areas now planted have come
from vegetative division of the few original sprigs, and no
important variants have been found. The results of efforts to
produce new forms by irradiation and other treatments have
not been evaluated.
Conventional breeding methods used for forage grasses have
not been applied to pangolagrass because it is sterile. It is
3Garza, Ricardo T. Private communication. Londus No. 40. Mexico 8, D.F.
1965.
on an estimated one million acres3, is one of the areas of most
extensive use.
DESCRIPTION
Pangolagrass resembles ordinary crabgrass [Digitaria san-
guinalis (L.) Scop] but is perennial in growth habit, forming an
abundance of decumbent stems that root at nodes which touch
the ground (Figure 1). It produces a leafy growth in early
spring followed by a profuse development of seed stalks that
reach 3 or more feet in height. The many-branched inflorescence
bears florets with less than .001% producing viable seed.
Figure 1.-Pangolagrass (Digitaria decumbens Stent.).
BREEDING
The possibilities of improving pangolagrass by selection
within the present population are poor because there is little
variation among plants. All the areas now planted have come
from vegetative division of the few original sprigs, and no
important variants have been found. The results of efforts to
produce new forms by irradiation and other treatments have
not been evaluated.
Conventional breeding methods used for forage grasses have
not been applied to pangolagrass because it is sterile. It is
3Garza, Ricardo T. Private communication. Londus No. 40. Mexico 8, D.F.
1965.
believed that pangolagrass was produced by hybridization of
distantly related species4. Like most inter-specific hybrids, pan-
golagrass sterility results from meiotic irregularities which lead
to unbalanced gametes and abortive pollen. Environmental
differences which exist between the region of South Africa in
which pangolagrass originated, and the parts of Florida where
it is now grown apparently have no effect on its seed production.
Improvement must involve the use of related Digitaria
species which are fertile. These parent varieties can be crossed,
and although the hybrid may be sterile like pangolagrass, new
combinations of favorable characteristics may be incorporated
in the hybrid. Various introductions of the genus Digitaria
have different chromosome numbers ranging from 9 to 36 pairs.
Pangolagrass has an intermediate number of chromosomes,
2n=27, so its ancestors probably are species with 18 and 36
chromosomes (31).
Breeding a winter-hardy pangolagrass does not appear
possible by working directly with a sterile species. Therefore
obtaining cytogenetic information and hybridizing of related
species are the indicated methods for pangolagrass improvement.
GRAZING EXPERIMENTS
Pangolagrass, Coastal bermudagrass [Cynodon dactylon (L.)
Pers.] and Pensacola bahiagrass (Paspalum notatum Flugge)
produced similar beef daily gains and gains per acre in grazing
trials at Gainesville, Florida (Table 1).
Table 1.-Annual beef gain per acre and daily gain of steers grazing three
grasses, 1944-47.
Average Daily
Grass Variety Gain/Acre Gain/Head
lb. Ib.
Pangolagrass 212 0.75
Pensacola bahiagrass 212 0.72
Coastal bermudagrass 225 0.72
Fertilization consisted of 500 pounds per acre of 6-6-65 an-
nually in early spring and an additional 32 pounds per acre of
'Sheth, Anilkumar. Sterility problems in Digitaria decumbens, Stent. Univ.
of Fla. M. Sci. Thesis. June 1955.
nitrogen (N) during one year only. A 1-ton application of calcic
lime was made prior to the grazing trial.
Beef production in steer grazing trials at the Range Cattle
Station averaged 202 pounds per acre annually on pangolagrass
pasture treated with 6-6-6 fertilizer in March at 500 pounds per
acre (14). Production on similarly fertilized Pensacola bahia-
grass was 152 pounds per acre. Fertilization with 900 pounds
per acre of 9-6-6 put on as three equal warm-season applications
produced 338 pounds beef gain per acre on pangolagrass and 215
pounds on Pensacola bahiagrass. Animal performance data on
pastures receiving different rates of fertilization in a 2-1-1 ratio
of N, P205, and K20 are shown in Table 2 (15). Cattle were
added and removed as needed to balance stocking rate and forage
supplies.
The carrying capacity of a pasture is influenced by weather,
fertilization rate, supplemental feeding practices, and weight
and age of animals. Pangolagrass fertilized annually with 100-
50-50 pounds per acie of N, P205, and K0O on Immokalee fine
sandy soil at the Range Cattle Station provided forage for
mature cows stocked at the rate of one head per two acres plus
calves until weaned and a bull during the breeding season (16).
Pangolagrass and St. Augustinegrass [Stenotaphrum secun-
datum (Walt.) Kuntze.] pastures on muck soil at the Everglades
Experiment Station produced beef gains of 861 and 1,053 pounds
per acre, respectively (9).
Table 2.-Average gain on pangolagrass and Pensacola bahiagrass pastures.
Annual Annual Average Daily
Variety Fertilizer/Acre Gain/Acre Gain/Head
lb. lb. lb.
N P205 KO0
Pangolagrass 100 50 50 300 1.29
200 100 100 468 1.32
300 150 150 568 1.23
Pensacola
bahiagrass 200 100 100 343 0.84
PRODUCTION AND MANAGEMENT
Planting
Most pastures are established by spreading freshly mowed
pangolagrass stems and stolons over a well prepared seedbed
and covering with a medium weight disk harrow. Use of a
packer following the harrow produces a smoother field with
SSix% N, 6% P205 and 6% KLO, respectively.
more efficient moisture retention and quicker plant establish-
ment (14).
Broadcast planting rates vary from 500 pounds of stemmy
green grass per acre on newly prepared native land to 2,000
pounds or more on old fields which are infested with other
grasses and broadleaf weeds. A trial on virgin land at the
Range Cattle Station in 1964 showed a planting rate of 1,000
pounds of freshly cut grass to be superior to 500 pounds per
acre. Rates in excess of 1,000 pounds had no advantage in speed
or density of pangolagrass establishment. Planting can be done
whenever moisture conditions are adequate and vegetative ma-
terial is available. Herbicide treatment immediately following
planting is recommended on land infested with watergrass
(sedges) or broadleafed weeds (7, 21, 28). Either 2-chloro-4,
6 bis-(ethylamino)-5 triazene (Simazine), or 2,4-dichloro phen-
oxy acetic acid (2,4-D) on moist surface soil at 2 pounds active
ingredient per acre has given effective control in Florida trials.
Grazing of new plantings should be delayed until the ground is
covered with runners; this usually requires 60 to 90 days during
favorable weather and longer in cool or dry periods.
Lime
Pangolagrass can be established and will make vigorous
growth on sandy soils with pH 4.2 to 4.5 if it receives complete
fertilizer and necessary minor elements. However, addition of
lime using the dolomitic form if the magnesium level is low,
increases production through more efficient nutrient utilization
and makes the grass more resistant to weed invasion (16).
Initial treatment at 1 ton per acre is recommended on newly
cleared land with reliming at the same rate at 4-year intervals6.
Fertilizer
Crops with high production potentials require either naturally
fertile soils or an adequate fertilizer program to reach their full
value. The soil fertility needs of pangolagrass have been subject
to investigation from the time of its first planting in Florida.
The earlier phases of this work showed strong forage yield re-
sponses to increased N fertilization at rates from 0 to 288 pounds
per acre (2). Forage production in another study increased as
N application rose from 30 pounds to 480 pounds per acre
annually (35). Conversely there was a decrease in forage pro-
duction per pound of applied N as the fertilization rate was in-
creased.
Fertilization with phosphatic materials on sandy soils in-
creased the percentage of this element found in forage (1).
Pangolagrass pastures receiving phosphorus fertilization yielded
more forage and higher beef gains per acre than similar areas
from which this element was omitted (5). Inclusion of potas-
sium in the pangolagrass fertilizer program has been based on
its growth, vigor (1), and on the relatively high percentage of
this element in the forage (8). Trials with different levels of
nitrogen and potassium where all forage was harvested and
removed have shown forage yields from a 2-1-3 ratio (N-P205-
K20) fertilizer to be superior to those from a 2-1-1 ratio fer-
tilizer (20, 22). These results demonstrated varietal and seasonal
differences in fertilizer ratio effect.
Deficiencies of minor elements were shown to limit pangola-
grass growth on typical flatwoods soil (12). Soil treatment rec-
ommended for supplying these elements included copper, man-
ganese, zinc, and boron (1).
Fertilizer recommendations are subject to constant revision
in the light of new technical information and changing manage-
ment factors.
New Plantings
Fertilization requirements for establishment of pangolagrass
vary with soil type and previous treatment of the area. A 10-
10-10 or similar complete fertilizer mixture should be applied
at rates of 300 to 400 pounds per acre immediately before or
after sprigging on land newly prepared from the native condi-
tion. This grass is particularly sensitive to copper deficiency
and should have an initial treatment of 0.15 to 0.25 units of
copper per acre on sandy land (14). Both copper oxide and cop-
per sulfate give satisfactory results. Manganese and zinc may
be applied to new plantings at 0.1 unit per acre of MnO and
ZnO7.
Pasture Maintenance
Annual fertilization is required to maintain pangolagrass in
a productive condition (Figure 2). Application of 400 pounds
per acre of 12-6-6 or similar fertilizer at one or more dates
annually produces excellent results. Alternate applications of
10-10-10 or similar fertilizer and ammonium nitrate or other N
source can be used on a pasture being fertilized at two or more
dates annually. The need for retreatment with minor elements
' C. L. Dantzman, Range Cattle Station Mimeo Rept. p. 15, March 1966.
Figure 2.-A 5-ton capacity custom spreader unit on pangolagrass pasture.
Solid and liquid fertilizers can be applied from the air or by ground equipment.
on mineral soils has not been fully established. Heavily grazed
or harvested pangolagrass may benefit from additional appli-
cations of copper at 0.1 units to a maximum of 0.25 units per
acre each second year.
Fertilization should be scheduled to obtain efficient use of
forage, with time and rate of application being based on cattle
needs and weather conditions. A growth period of at least 30
days between fertilization and grazing should be provided unless
the grass is 6 to 12 inches in height at time of treatment. As
much as 60 days of growing time is needed in the fall of the
year to provide forage for midwinter grazing.
Fertilization for Harvest
Harvest of a heavy crop of grass for either hay, silage, or
planting material removes as much nitrogen and potassium and
half as much phosphorus as is contained in 600 pounds of 10-
10-10 fertilizer (19). These nutrients must be replaced follow-
ing harvest to produce rapid regrowth and high quality forage.
Higher potassium fertilization rates produce the most pango-
lagrass response during the cool, low-rainfall periods of the
year, whereas nitrogen is important during all growing periods
(20, 22). One or two applications of fertilizer, each supplying 50
SC. L. Dantzman, Range Cattle Station Mimeo Rept. p. 15, March 1966.
L~lbkk..I~U~1I(ISb(llllP
C e "klC~j
pounds per acre of N are recommended for a crop of hay or
silage. Fertilization to produce maximum growth either before
or after forage harvest in central and south Florida may be
varied according to the date of application, using the following
schedule:
Date of Application Fertilizer, pounds per acre
Oct. 1 Mar. 31 10-10-10 500
Apr. 1 May 15 12-6-6 400
May 16 Aug. 15 Ammonium nitrate 150
Aug. 16 Sept. 30 12-6-6 400
Summer applications of N should be used in combination
with complete fertilizer at other seasons, never as a single yearly
treatment.
Most fall-harvested hay is medium to low in protein content,
but application of N approximately three weeks prior to mowing
has been shown to increase digestible crude protein and con-
sumption rate of pangolagrass hay (4).
Factors Affecting Response to Fertilizer
Applications of either complete fertilizer or N materials on
pangolagrass sod sometimes fail to give the expected results.
Low quality fertilizer, lack of lime, and minor element de-
ficiencies are often blamed but seldom responsible for poor per-
formance. The most frequent causes of poor results from
fertilization may be described as follows:
1. Heavy rainfall within 48 hours after fertilization reduces
effect of N treatment and delays response. Treatment of dif-
ferent pastures at different dates lessens the risk of rain loss on
a large area; limiting application to a maximum of 50 pounds
N per acre at one date is recommended.
2. Extended periods of cold or dry weather retard grass
response but most plant food remains available for later growth.
Supplemental feeding of cattle usually has more value than at-
tempts to force pasture growth during unfavorable weather.
3. Continued close grazing immediately after fertilization
reduces yields and causes apparent lack of growth response.
Most of the available N is taken into the plant within 7 to 14
days after application; removal of this growth represents a
severe drain on the fertility of the pasture. Complete removal
of cattle for a reasonable period should be practiced.
4. Soil fertility is depleted by continued close grazing or by
removal of large tonnages of grass for hay or planting. A run-
down sod does not respond strongly to treatment with 500
pounds of 10-10-10 fertilizer or its equivalent, and much dis-
satisfaction has resulted. Prompt retreatment with more fertil-
izer will prevent further delay of forage growth.
Pasture Management and Maintenance
The successful use of pangolagrass as pasture requires an
orderly grazing system. It has the potential to use intensive
rates of fertilization but will remain productive at a low annual
level of fertilization if grazing pressure is regulated accordingly.
Mature or frosted forage is consumed readily by grazing cattle
(Figure 3). Extremely close grazing for 30 to 60 days will not
weaken the sod if regrowth to a height of at least 12 to 18
inches is allowed. Pangolagrass should be grazed rotationally
whenever possible, allowing a minimum of one week between
periods in mid-summer and two to three weeks during the rest
of the growing season.
The high level of palatability of pangolagrass often results
in cattle grazing it in preference to all other vegetation, thus
allowing weeds and less acceptable grasses to occupy an increas-
ing percentage of the area. Management which accumulates as
'-; k'*W t -.
Figure 3.-Breeding cows grazing pangolagrass in December. Mature non-
lactating cows maintain weight whenever forage is available.
c--4
much as 18 inches of grass at one date during the year greatly
increases the competitive position of pangolagrass. Pastures in
which more than 50% of the area is occupied by pangolagrass
can be effectively renovated by thorough cultivation during the
growing season. Thorough disking or cutting with a rotary
tiller during June stimulates vigorous regrowth with no need
for replanting. Spring renovation is desirable because pango-
lagrass then recovers at the maximum rate and there is no
reduction in fall and winter forage. Reestablishment of severely
degraded pangolagrass, with less than 50% cover or infested
with bahiagrass, requires replanting after complete destruction
of the sod. Intercropping and dry weather tillage usually are
necessary in this process.
Pangolagrass grown in combination with whiteclover makes
productive and nutritious grazing while receiving little or no N
fertilizer. Such pasture is grazed closely during August and
September to reduce grass competition, then fertilized with 300
pounds per acre of 0-10-20 fertilizer. Rotational and deferred
grazing and complete water control are important for successful
production of pangolagrass-clover pastures.
Hay and Silage
Hay
Pangolagrass mowed in the early heading stage can be cured
into high quality hay that is readily eaten by livestock. Hay
made from mature grass has a substantial feed value although
chemical analysis indicates the need for a protein supplement
to provide nutritional balance. Digestibility data (3,4) reveal
a comparatively low level of protein utilization in forage having
a dry basis protein content of 5% or less.
Superior yield is the primary reason for using pangolagrass
for hay in areas of Florida where it is well-adapted (Figure 4).
It produced 3 tons of air-dry forage per acre as compared with
1 ton for improved bermudagrass at the Range Cattle Station in
a spring harvest, both varieties receiving 120 pounds of N per
acre.
Field curing of pangolagrass is slow, requiring three days to
attain the same dryness reached by bermudagrass in one day.
Heavy yields of forage have been a partial cause for excessive
drying time, but even a light crop of pangolagrass requires extra
time for field curing. Use of mower-conditioners shortens the
ready-for-baling time by one to two days. Rotary mowing
hastens drying but increases loss because some grass is cut too
fine to be raked and baled. A high-clearance rotary mower can
Figure 4.-Harvesting a 3-ton per acre yield of pangolagrass hay. Mechani-
cal advances in haymaking machinery have increased the storing and feeding of
this crop in Florida.
be used with good results to condition sickle-cut grass. Equip-
ment for harvesting pangolagrass must be in excellent condition.
Special precautions are required to avoid breakdowns caused by
stems wrapping on universal joints, shafts, and wheels.
Grass for high quality hay can be produced by means of early
spring fertilization and complete protection from grazing. This
permits harvest by June 1, which ordinarily is early enough to
avoid rainy weather in central and south Florida. Most hay is
made from October 1 to November 15, when damage by rain is
less likely than in the spring. Hay harvest may be planned as
late as January if work and weather conditions are suitable.
Silage
Silage made from pangolagrass has the excellent palatability
which is characteristic of this forage species. Large supplies can
be produced during midsummer when curing hay is difficult or
impossible (34). Silage made during July and August adds to
the feed-producing potential of grassland areas.
Grass cut at the full-heading stage will yield 6 to 12 tons per
acre of green material having approximately 25% dry matter.
Loading directly into the silo without wilting or use of pre-
servative produces silage of satisfactory feeding quality. Addi-
tives are not necessary for preservation and palatability when
compaction is thorough and moisture levels are adequate (23).
~qt~f:
YC~-~
r.
c
7'
cit~_rSlrl~
iitr Ihi~.
* ^SU _,e__ *'' .. .. .* v -. .
Figure 5.-This bunker silo is 16 x 100 feet and has a maximum depth of 7
feet; total capacity is approximately 225 tons of grass silage. The walls are
plastic-lined and the black plastic cover is held in place with discarded tires.
Grass in the preheading stage should not be cut for silage be-
cause of excessive shrinkage and loss of nutrients. Methods of
producing and handling wilted or low-moisture pangolagrass
for silage have not been evaluated in Florida. Prevention of
surface and internal spoilage is an important factor in efficient
production of pangolagrass silage. Covering exposed surfaces
with black polyethylene film, to be held in place by discarded
tires, is effective in reducing spoilage and nutrient loss (Figure
5).
WINTERKILLING
The term "winterkilling" is used in this bulletin to charac-
terize the death of previously viable grass crowns during the
November to March period. There is a constant process of
crown death and replacement in pangolagrass sods more than
one year old, with the death rate being highest during times of
unfavorable weather. The susceptibility of pangolagrass to
crown killing during the winter was observed during the first
10 years of culture in north Florida but was not then recognized
as an important factor in the peninsular sections of the state.
There was increasing awareness of this problem during the
1950's, and a drastic southward extension of damage occurred
in the extremely cold 1957-58 winter (13).
41110 A,
I
Symptoms
The normal thinning which takes place during the winter
often passes unnoticed, and such fractional winter damage may
be confused with the slow growth rate associated with cool or
dry spring weather. Severely winterkilled pangolagrass sod,
having 75% or higher mortality, fails to make a spurt of growth
when moisture and temperature conditions become favorable.
Instead, it remains the uniform gray-brown color characteristic
of dead and weathered pangolagrass forage. Winter injury ap-
proaching the 100% level can be identified by a weakening of
the grass crown that permits pulling it loose from the ground
by handfuls-which cannot be done on a living sod. This con-
dition does not develop until one to two months after the actual
date of damage. Surviving buds in heavily damaged areas often
are weak and slow to develop. Recognition of extensive winter-
killing may be obscured when the sod contains a mixture of
weeds or grasses that renew growth in a normal manner.
Distribution
Winter damage to pangolagrass often is severe in north and
central Florida, with Alachua and neighboring counties being
the northern limit of adaptation. Injury is less common to the
south, and the zone of transition from frequent winter losses
to the area having virtually no damage on sandy land passes
through Hillsborough, Hardee and Osceola Counties (Figure 6).
The map shows the number of times the temperature fell
to 280F or lower from November 1937 to March 1957. It can
be seen that temperatures of 28'F or lower occurred a total of
25 times during 20 seasons, as far south as Charlotte, Glades,
and Okeechobee Counties. In addition there was an area south
of Lake Okeechobee where temperatures of 280F or lower oc-
curred 25 times or more. Data from the coldest frost pockets
were not included in this summary.
The 28'F temperature has no special significance as a critical
point in connection with winter damage to pangolagrass. Rather,
it is used as a means of showing the distribution of subfreezing
weather in the Florida peninsula and to illustrate the relation-
ship between severity of winter temperatures and pangolagrass
injury.
Cause and Control
Cold
Winterkilling of pangolagrass is associated with a combina-
tion of frost and freezing temperatures. Severe damage has
TO MONROE COUNTY -
Figure 6.-Map of peninsular Florida showing the number of times tempera-
ture fell to 28 F or lower from November 1937 to March 1957 (20 seasons)
(17). Shaded area indicates zone of severe pongolograss winter damage.
occurred when the winter minimum ranged between 28 and
320F, although temperatures of 25F and lower are commonly
associated with winterkill. In the Gainesville-Ocala area con-
siderable winterkilling or depletion of stand has been noted in
the early spring for many years. From 1945 through 1952 it
was observed that five or more killing frosts during the winter
with one week or more of mild temperatures (400 to 50F at
night and 60 to 80F daytime) between frosts caused severe
loss of pangolagrass plants.
Fertilizer Effect
There is ample evidence that rate of N fertilization, espe-
cially in late summer and fall, influences the severity of winter-
killing. An experiment started in February 1954 at Gainesville
included plots sprigged to pangolagrass and given N applica-
tions of 0 to 540 pounds per acre between May 28 and Septem-
ber 23 (25). These yielded from 2,000 to 15,000 pounds of
oven-dry forage per acre in five harvests. By March 1955 it was
evident that plants receiving 447 pounds or more of N annually
had a greater tendency to resume growth during warm periods
of winter than those receiving lesser amounts. It was also ob-
served that plots receiving the high rates of N had very few
living plants. With the same fertilization practices continued
through 1955, root yields of pangolagrass plots were reduced at
N rates above 112 pounds per acre (Table 3), and plant survival
data for spring 1956 revealed the effect of increased N rates.
The phosphorus and potassium fertilization rates were variable
in this experiment, but no increase in cold resistance was ob-
tained from extra increments of either fertilizer component.
Table 3.-Effect of N rate on pangolagrass root development and winterkill
(25).
N/Acre Dry Roots/Acre, Living Plants/Acre,
Annually Fall, 1953 Spring, 1956
lb. lb.
0 7,600 304,000
56 6,400 256,000
112 7,100 152,000
224 5,600 76,000
447 5,600 28,000
666 3,700 20,000
1113 2,400 4,000
1560 1,400 0
251
NUMBER
OF
FIELDS
77
^iI
I '_ 'o U
20 40 60 80 100
PERCENT WINTERKILL
Figure 7.-Number of pangolagrass pastures, Range Cattle Station, in differ-
ent percentage classes.
ol
'''''~''''''''''~
J
F
A damage survey including 59 fields at the Range Cattle
Station following the 1957-58 winter is summarized in Figure 7.
This was the first injury over an extensive area recorded in
south Florida. It can be seen that in spite of severe losses, more
than half the pastures had in excess of 20% survival. These
were returned to grazing by June 1, and even the most severely
damaged areas were in use by July 1, after fertilization and
favorable moisture conditions. There was no consistent relation-
ship between fertilizer rate and stand loss observed in 1958 ex-
cept on several small pastures which received 300 pounds N per
acre annually and suffered more winter damage than ones
treated at lower rates.
Levels of fertilization above 200 pounds N per acre annually
should be avoided where winterkilling of pangolagrass is an
important factor. Control of N fertilization holds little promise
for cold damage reduction in the main pangolagrass-growing
areas of the state since few pastures receive more than 200
pounds N per acre. Added to this is the fact that winterkilling
in unfavorable years shows limited relationship to N fertilization
below this level. It is doubtful that a build-up of plant health
and vigor can be used to increase the winter hardiness of pango-
lagrass sod. Lack of dormancy is associated with the problem,
and any condition which encourages cool season growth increases
susceptibility to cold damage.
Rainfall
The winterkilling noted in 1958 occurred during a high rain-
fall period which was thought to be at least partially responsible
for the damage (13). Subsequent mortality observations made
in the spring periods of 1962, 1963, and 1964, following normal
to dry winters, showed that excess moisture is, at most, a minor
factor in winterkilling.
Ground Cover
Effect of amount of ground cover on extent of cold damage
is variable, but evidence shows that damage is increased by the
presence of large amounts of mature or dead grass, particularly
under heavy N fertilization (30). This gives rise to the descrip-
tion of winterkilling as "smothering". Tall grass protects
underlying leaves and stems from light frost damage but is not
effective against severe cold temperatures. Trials with Coastal
bermudagrass in Gainesville in December 1962 indicated that
minimum temperatures in 12-inch grass did not fall as low as in
3-inch grass, but warming was retarded and maximum tempera-
tures were not as high in the taller grass (30). Observations on
muck soil at the Everglades Experiment Station during the
1963-64 winter showed that temperature readings at 12 inch
above the soil surface were similar in tall and short pangolagrass
and that there was no appreciable time lag in temperature
changes under the tall grass. It seems probable that effect of
forage accumulation on crown temperature and survival is in-
fluenced by soil type, soil moisture, and severity of cold. Fall
production of 1 to 2 tons of dry matter per acre for midwinter
grazing is not likely to affect winter survival in central and south
Florida, although heavily matted growth increases the hazard
of winterkilling. Removal of forage by grazing or hay harvest
not later than January 1 is suggested.
Growth Regulators
The relationship of dormancy to damage reduction led to
experiments with chemical treatment to prevent growth during
the winter. Plots in the Gainesville area fertilized with N in the
fall were sprayed with maleic hydrazide after the forage was
removed (29). It was found that pangolagrass treated with the
growth retardant remained dormant during alternating periods
of warm weather and frost, and that as a result more of the
pangolagrass was alive in the spring. No measurable advantage
was found during prolonged or uninterrupted cold winters.
Maleic hydrazide applied at the rate of 4 pounds per acre in
November at the Range Cattle Station retarded pangolagrass
growth until March, but a 2-pound rate had no effect on growth
renewal. No appreciable winterkilling occurred on either treated
or untreated areas. The per-acre cost of this material is high,
and it is not recommended for preventing winter damage on
pangolagrass.
Cultivation and Age of Sod
Seven pangolagrass pastures at the Range Cattle Station
were renovated in June 1963 by cutting with a heavy-duty roto-
tiller followed by levelling disk and packer. The grass in these
fields made vigorous growth after renovation and fertilization
and was grazed in October and November of 1963. When frosted
in mid-November they had 2 to 3 tons per acre more mature
herbage than adjoining areas similarly fertilized and managed
but not renovated. Survival in March 1964 was 90% or higher
on the renovated pastures, and less than 1 % on the undisturbed
sod (Figure 8).
Figure 8.-The winterkilled pangolagrass sod on the left had not been culti-
vated for 10 years prior to photographing on April 10, 1964. The field on the
right had been thoroughly cultivated in June 1963.
Management of Winter-Damaged Pangolagrass
Central Florida
The stand in severely winterkilled pangolagrass may be re-
duced to the point that living buds remain at 3 to 6-foot inter-
vals. These survivors are adequate to renew the sod without
replanting if pangolagrass made up most of the ground cover
prior to injury. Heavy grazing of damaged sods during the
winter and early spring is usually practiced because of feed
shortage. This can be beneficial to recovery of pangolagrass by
keeping other grasses and weeds from filling in the vacant
spaces during the cool season before pangolagrass growth be-
comes rapid. Severely winterkilled pasture should remain un-
grazed for 30 to 60 days after rapid growth begins or until a
stand has been reestablished. Rapid growth usually occurs dur-
ing May and June and damaged areas can be renewed if sur-
viving plants are given full opportunity to spread. Pangolagrass
runners root through thickly matted dead grass without diffi-
culty.
Cultivation and burning treatments on damaged pangola-
grass at Range Cattle Station in the spring of 1958 showed that
911111106
71 1- "' ",4 -, ,
7 7: RPR
both were harmful to rapid recovery. These practices removed
surface mulch, opened the way for spread of Common bermuda-
grass [Cynodon dactylon (L.) Pers.], and increased weed seed
germination. Recovery from winterkilling was most rapid on
undisturbed plots treated with 300 pounds per acre of complete
fertilizer. The same treatments on damaged grass in 1963 pro-
duced only limited differences in pangolagrass recovery because
the sod had been almost pure pangolagrass and there were few
weed seeds in the soil. Cultivation in addition to fertilization
and protection from grazing was of no benefit.
Vigorous measures are required to renew winterkilled pango-
lagrass already invaded heavily by other grasses and weeds.
One method consists of winter and early spring cultivation of
the damaged sod to subdue surviving grasses, followed in June
by planting 1 ton per acre of pangolagrass cuttings. Harvesting
one or more of the succeeding crops for hay or silage favors
establishment.
An alternative to cultivation and replanting of severely
thinned sod is fertilization and subsequent harvest of the spring
and summer growth for hay or silage. The upright growth of
pangolagrass under these conditions gives it a competitive ad-
vantage over lower growing grasses. This method is slower than
replanting but may be useful where substantial amounts of har-
vested forage are used in the year-around forage plan.
Everglades
Pangolagrass is used on a relatively small percentage of the
pasture acreage of the peat and muck soils of the Everglades
agricultural area. The principal problem on pangolagrass pas-
ture is invasion by weeds and other grasses, primarily Common
bermudagrass. Aphid attacks in November often weaken or al-
most kill pangolagrass, and later periods of frost kill tender
new growth. This permits small patches of bermudagrass to
grow during winter months.
The problem of maintaining pangolagrass in a pasture exists
in direct proportion to the intensity of grazing. Cattle eat
pangolagrass in preference to bermudagrass, permitting the
latter to persist in the pasture through the summer and to ex-
pand its coverage during the winter and spring. When bermuda-
grass areas become solid, pangolagrass does not reestablish even
if cattle are removed, because the pangolagrass runners lie on
top of the bermudagrass with little chance of rooting down.
A 20-acre pasture on the Everglades Experiment Station
planted to pangolagrass in 1950 was renovated twice in a 10-
year period by plowing in midwinter, planting to field corn, and
replanting to pangolagrass in midsummer. After the last reno-
vation this pasture was lightly grazed or rested in late winter
and spring and the pangolagrass held its own. However, with
heavier grazing in 1963 and 1964, Common bermudagrass again
took over the pasture.
It has been observed that pangolagrass and other grasses
used on organic soil pastures are more susceptible to cold dam-
age and slower in spring recovery when they go into the winter
in a tall, undergrazed, or unmowed condition than when they
are moderately grazed or harvested in late fall. It appears that
cold damage is a less important factor in the maintenance of
grass stands on these soils than is pasture management.
Pangolagrass grown primarily for harvest is comparatively
unaffected by winterkilling or invasion by weeds and other
grasses. It is highly competitive when provided adequate fer-
tilizer and harvested at the early heading stage.
INSECTS AND DISEASE
Aphids
The yellow sugarcane aphid [Sipha flava (Forbes)] (Figure
9) (18) is a major pest of pangolagrass, especially in the south-
central and southern parts of Florida. Other kinds of aphids
found on pangolagrass often are highly parasitized and fre-
quently brought under control by natural enemies. This is not
true of the yellow sugarcane aphid. Attack by these insects is
common in spring and fall months and especially when nights
are cool and days are warm. Affected grass leaves change from
green to yellow or red in color and growth is severely retarded.
Reduction in protein content and feeding quality is greater than
would be expected, even with light infestation. The protein
contents of aphid-infested and aphid-free pangolagrass on muck-
land pasture averaged 12% and 23%, respectively8. Severe
infestations turn the entire field brown and may cause thinning
of the sod. Damage is most apparent on actively growing grass,
but it has been shown that fertilization may actually reduce
aphid infestation (10). Aphids are easily detected by examining
boots and trouser cuffs after walking through suspected areas.
Shaking grass into the cupped palm will reveal the presence of
aphids more quickly than examination of individual leaves.
SGenung, W. G. Pasture and livestock insects and their control. Everglades
Exp. Sta. Mimeo Rept. 55-8. 1955.
Figure 9. Yellow
sugar cane aphid, Sipha
flava (Forbes).
Figure 10.-Striped grass looper, Mocis sp.
Figure 11.-Two-Lined Spittlebug, Prosapia bicincta (Say), adult males,
showing variation in Florida specimens. Photographs by: E. M. Collins, Div. of
Plant Industry.
S-----------I M OW--N ------- -
^-.I--y-r------^
q%14
Worms
Several types of army worms attack pangolagrass, including
Spodoptera frugiperda (J. E. Smith) and others. They can be
recognized by their length of 1 to 11/2 inches at maturity and
brown color with variable yellowish gray and dark stripes.
Grassworms (Mocis spp.) or Striped Grass Loopers are "mea-
suring worms" and may reach 21/2 inches in length when full-
grown (Figure 10) (18). Their color is variable, with stripes
and spots making a pattern which blends with the vegetation.
These insects drop to the ground when disturbed. Damage to
grass may be first seen as irregular notching of the edges of the
upper leaves. Stripping of leaves and tender stems becomes
severe as the worms get larger. Large flights of blackbirds in a
pasture often indicate the presence of worms, and many
moderate infestations are thus controlled.
Two-Lined Spittlebug
The nymph (immature) form of spittlebug [Prosapia bicincta
(Say.)] attacks pangolagrass at the base of the stem, and is
found within a slimy, spittle-like mass. The adult spittlebug is
/8 inch in length, dark gray to black in color, usually with two
fine reddish lines across the wings (Figure 11) (26). Both
nymph and adult cause grass damage which may appear in July
or August, sometimes earlier, and continue until cold weather.
41"..
,.Itp.
Figure 12.-Spittlebug attack has given the top growth in this pasture the
appeorancee of being frosted. Photographed October 20, 1965.
25
Attacks are most common in grass 12 inches or more in height
with dense growth and an accumulation of dead plant litter on
the soil surface. Early identification of spittlebug requires look-
ing deep into the crown of affected grass. Damage appears as
areas of dead grass which develop rapidly in the normally green
forage. Light infestations produce scattered tufts of dying stems
that often go unnoticed or for which casual inspection reveals no
cause. A heavily infested pasture has a brown and dry aspect
such as that of an area following a killing frost (Figure 12).
Extensive spittlebug damage lowers the palatability and nutri-
tional value for grazing or harvesting and may reduce or almost
destroy the stand of pangolagrass.
Other Insects
Leafhoppers (several species) are commonly found on pango-
lagrass during the summer, but damage is not drastic and occurs
when forage is plentiful. No control measures are recommended.
Rhodes grass scale [Antonina graminis (Mask.) ] has been found
damaging pangolagrass to a limited extent. Mole crickets
(Scapteriscus spp.) may attack but are not of general im-
portance on pangolagrass.
Insect Control
There are three approaches to controlling or reducing the
insect problems associated with pangolagrass.
Grazing
Heavy grazing of insect-infested grass by cattle is recom-
mended whenever animal numbers and size of area permit.
Rapid removal of herbage is essential. It opens the stand and
allows access to birds and promotes drying of the grass crowns.
This is most useful with worms and spittlebugs and helpful with
aphids.
Harvesting
A second possibility is removal of top growth for hay or silage.
This prevents further quality decline and usually brings insect
activity to a halt although aphids and spittlebugs may continue
to be a problem in close-clipped grass.
Insecticides
The third and most direct method is use of insecticides. These
should be employed when grazing or harvesting methods cannot
be used. Chemical controls have definite limitations as to insects
killed, human and animal toxicity, and Federal Food and Drug
Administration regulations. These control programs should use
only the latest Agricultural Extension Service and label informa-
tion for maximum effectiveness and safety.
No insecticides are recommended for use against spittlebugs
on pangolagrass in Florida. Toxaphene and other chemicals have
been effective against this insect in many places, but not when
the nymph is surrounded by a spittle mass buried deep in vege-
tative material.
This insect has been controlled in Coastal bermudagrass by
early spring burning, but the method has little promise for use
with pangolagrass. Harvest of forage or close grazing to prevent
heavy growth of grass in midsummer is the best approach to this
problem. New plantings and recently renovated areas are less
affected than old sods.
Control recommendations for aphids and worms are given in
Table 4 (32). It is observed that insect infestations in pastures
usually start in small isolated areas. Therefore it is advisable to
make frequent inspections and spot treat before infestations be-
come general. This not only saves on insecticides, but may pre-
vent excessive injury and reduce the residue problem.
Stunt Disease
Research workers in Surinam, South America, have reported
a virus-type stunt disease attacking pangolagrass with great
severity (6). It has been observed that affected plants lose
vigor and develop dwarfed stems with densely tufted leaves that
frequently exhibit red to yellow coloration. This condition is
distributed in various parts of the world where pangolagrass is
grown but has not been observed in Florida. Resistant grasses
that resemble pangolagrass have been introduced and tested.
Their performance is variable, but they represent a possible re-
placement in the event of invasion by stunt disease.
SUMMARY AND CONCLUSIONS
Pangolagrass was brought to the United States from South
Africa in 1935 and has since become widely used in tropical and
subtropical pasture areas of the world. It produces almost no
Table 4.-Recommendations on control of aphids and grass worms by insecticides (32).
Insect Material Amount/Acre Restrictions and Remarks
Aphids 15% parathion WP or 1-2 lbs. The amount of insecticide per acre varies with the height
Several species 1% parathion dust or 20-30 lbs. and density of the grass. DO NOT apply parathion within
40% TEPP (liquid) or %1 pint 7 days, or TEPP within 2 days, or phosdrin within 1 day
5% malathion dust or 20-30 lbs. of grazing by dairy or beef animals. No waiting period
25% malathion WP or 2-4 lbs. for malathion.
25% phosdrin EC or 1-2 pts.
2% phosdrin dust 15-25 lbs.
Armyworms 10% toxaphene dust or 15-20 lbs. DO NOT graze dairy cattle on toxaphene treated pastures.
Grass loopers 40% toxaphene WP or 3-4 lbs. Allow at least 7 days between applications of toxaphene
Other 5% Sevin dust or 20-30 lbs. and grazing by beef animals. DO NOT apply parathion
Caterpillars 80% Sevin sprayable or 114-2 lbs. within 7 days or phosdrin within 1 day of grazing by dairy
2% phosdrin dust or 20-25 lbs. or beef animals. There is no time limitation for grass
25% phosdrin EC or 1 quart treated with Sevin or malathion for dairy or beef animals.
2% parathion dust or 15-20 Ibs.
15% parathion WP 2 lbs.
WP = wettable powder; EC = emulsifiable concentrate.
RESIDUES AND PRECAUTIONS
The use of insecticides not recommended or in dosages greater than recommended may result in insecticide residues in excess of legal
tolerances. If the dosages recommended in the chart are exceeded, the minimum days between last application and harvest or
grazing are not applicable and a longer interval should be allowed.
All insecticides are poisonous to man and animals and should be handled with the precautions given on the insecticide label.
TEPP, parathion, phosdrin, and demeton (Systox) are especially toxic.
The use of trade names in this insecticide recommendation is solely for the purpose of providing specific information. It is not a guarantee or warranty of
the products named and does not signify that they are approved to the exclusion of others of suitable composition.
seed and must be planted by use of stems and crowns. Pangola-
grass responds strongly to fertilizer application and is sensitive
to copper deficiency. Its forage has outstanding palatability both
for grazing and use in harvested form. Selective grazing causes
pangolagrass to decrease in a mixed pasture. Orderly utilization
and maintenance practices are essential to realize the potentially
high yield and quality.
Pangolagrass often is severely damaged by cold and insects.
Winterkilling reduces use in the northern section of Florida, and
damage may extend into the Everglades. Pastures planted or
cultivated within the previous 12 months are more resistant to
winterkill. The long-established grass survives better when heavy
growth has been removed. Insect attack on pangolagrass has
intensified with increased acreage and more years of use. Aphids
and worms can be controlled by modern insecticides and by graz-
ing or harvesting. The Two-Lined spittlebug, attacking stems
and crowns from June through September, kills top growth and
reduces forage value and, in some instances, kills the plant.
Insecticides have not provided effective control, but recently
planted or renovated areas are virtually immune to spittlebug.
Harvested or heavily grazed sods are less susceptible than those
with dense grass growth.
Pangolagrass is most suitable for use in comparatively inten-
sive forage systems where some forage is harvested as hay or
silage. Its productivity and feeding value make this versatile
grass an important forage variety in its area of adaptation.
LITERATURE CITED
1. Blaser, R. E., W. E. Stokes, J. D. Warner, G. E. Ritchey, and G. B.
Killinger. 1945. Pastures for Florida. Fla. Agr. Exp. Sta. Bul. 409.
2. Blue, William G., and Nathan Gammon, Jr. 1955. Rates and ratios
of nitrogen, phosphorus, and potassium for whiteclover and pangola-
grass on Rex fine sand. Proc. Soil Sci. Soc. of Fla. 15:208-218.
3. Butterworth, M. H. 1961. Studies on pangolagrass at I.C.T.A. Trini-
dad II. Tropical Agriculture, 38, 3.
4. Chapman, H. L., Jr., and A. E. Kretschmer, Jr. 1964. Effects of late
nitrogen fertilization on digestibility and feeding value of pangolagrass
hay. Proc. Fla. Soil and Crop Sci. Soc. 24:176-183.
5. Davis, George K., W. G. Kirk, E. M. Hodges, and D. W. Jones. 1949.
Fla. Agr. Exp. Sta. Ann. Rept. p. 240-243.
6. Dirven, J. G. P., and H. A. van Hoof. 1960. A destructive virus disease
of pangolagrass. T. P. Ziekten 66:344-349.
7. Forster, R. H., P. N. Wilson, and M. N. Butterworth. 1960. Pasture
grass investigations in Trinidad with special reference to pangolagrass.
Proc. 8th Int. Grassland Cong. p. 390-393.
8. Gammon, Nathan, Jr., and William G. Blue. 1952. Potassium require-
ments for pastures. Proc. Soil Sci. Soc. of Fla. 12:154-156.
9. Haines, C. E., H. L. Chapman, Jr., R. J. Allen, Jr., and R. W. Kidder.
1960. Fla. Agr. Exp. Sta. Ann. Rept. p. 259.
10. Hayslip, N. C., and A. E. Kretschmer, Jr. 1963. Fla. Agr. Exp. Sta.
Ann. Rept. p. 272-273.
11. Hodges, E. M. 1950. Pangola from South Africa. Fla. Cattleman and
Livestock Jour. 14(4) :30-31.
12. ..... L. E. Ensminger, and G. B. Killinger. 1944. Fla.
Agr. Exp. Sta. Ann. Rept. p. 157-159.
13. ..... and D. W. Jones. 1958. Winterkilling of pangola-
grass pastures. Fla. Cattleman and Livestock Jour. 22(9) :24.
14. .. D. W. Jones, and W. G. Kirk. 1958. Grass pastures
in central Florida. Fla. Agr. Exp. Sta. Bul. 484A.
15. W. G. Kirk, F. M. Peacock, and J. E. McCaleb.
1956, 1957, 1958, and 1960. Fla. Agr. Exp. Sta. Ann. Rept.
16. .... W. G. Kirk, F. M. Peacock, D. W. Jones, G. K.
Davis, and J. R. Neller. 1964. Forage and animal response to different
phosphatic fertilizers on pangolagrass pastures. Fla. Agr. Exp. Sta.
Bul. 686.
17. Johnson, W. O. April 1958. Winter minimum temperatures in penin-
sular Florida. Federal Frost Warning Service, Lakeland, Florida.
18. Kelsheimer, E. G., D. W. Jones, and E. M. Hodges. 1953. Control of
some insect pests of improved pastures. Fla. Agr. Exp. Sta. Cir. S-64.
19. Koger, M., W. G. Blue, G. B. Killinger, R. E. L. Greene, H. C. Harris,
J. M. Meyers, A. C. Warnick, and N. Gammon, Jr. 1961. Beef produc-
tion, soil and forage analyses, and economic returns from eight pasture
programs in north-central Florida. Fla. Agr. Exp. Sta. Tech. Bul. 631.
20. McCaleb, J. E., C. L. Dantzman, and E. M. Hodges. 1966. Response of
pangolagrass and Pensacola bahiagrass to different amounts of phos-
phorus and potassium. Proc. Soil and Crop Sci. Soc. of Fla.
21. ........ ....... E. M. Hodges, and C. L. Dantzman. 1962. Fla. Agr.
Exp. Sta. Ann. Rept. p. 315.
22. .... E. M. Hodges, C. L. Dantzman, D. W. Jones, R. J.
Bullock, and W. G. Kirk. 1965. Response of pangolagrass (Digitaria de-
cumbens Stent.) to different ratios of nitrogen and potassium. Proc.
Soil and Crop Sci. Soc. of Fla. 25:69-75.
23. .. .. F. M. Peacock, and E. M. Hodges. 1965. Effect of
feed additives on preservation and feeding value of pangolagrass silage.
Fla. Agr. Exp. Sta. Bul. 697.
24. McCloud, D. E. 1956. Immigrant makes good in Florida. Chilean Ni-
trate Farm Forum. 57:17-18.
25. McCloud, D. E., and John M. Creel, Jr. 1957. Nitrogen in relation to
winterkill, Bermuda vs. Pangola. Plant Food Rev. 3(1) :18-19.
26. Mead, F. W. 1962.. A spittlebug, Prosapia bicincta. Fla. Dept. of
Agr., Entomol. Cir. 7.
27. Nestel, B. L., and M. J. Creek. 1962. Pangolagrass. Herb. Abs. 32, 4.
28. Orsenigo, J. R., and A. E. Kretschmer. 1963. Herbicides for pangola-
grass establishment. Proc. Soil and Crop Sci. Soc. of Fla. 23:182-187.
29. Ruelke, O. C. 1961. The role of growth inhibitors in reducing winter
injury of Florida's pastures. Proc. Soil and Crop Sci. Soc. of Fla.
21:136-139.
30. 1963. Winter injury of Florida's pastures. Proc.
Soil and Crop Sci. Soc. of Fla. 23:194-198.
31. Schank, S. C., H. F. Decker, G. B. Killinger, and R. J. Allen, Jr. 1966.
Agronomic and cytotaxonomic comparisons between Digitaria decum-
bens and D. pentzii. Crop Science 6:82-83.
32. Strayer, John R. 1966. Pasture insect control. Fla. Agr. Ext. Ser.
Cir. 292.
33. Tapia, Carlos, Candelario Carrera, and Mario Ferrer F. Pangola exce-
lente zacate tropical para pastoreo. Institute Nacional de Investiga-
ciones Agricoles, Mexico 8, D.F.
34. Wakeman, Donald L., and James F. Hentges, Jr. 1958. Self-feeding
pangolagrass silage to wintering beef cows. Fla. Agr. Exp. Sta. Cir.
S-108.
35. Wallace, A. T., G. B. Killinger, R. W. Bledsoe, and D. B. Duncan. 1957.
Design, analysis, and results of an experiment on response of pango-
lagrass and Pensacola bahiagrass to time, rate, and source of nitrogen.
Fla. Agr. Exp. Sta. Tech. Bul. 581.
a.
t
i.
c-
t
P'
a
k
|