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Florida Agricultural Experiment Stations
Center for Tropical Agriculture
Institute of Food and Agricultural Sciences
University of Florida, Gainesville
Origin and Development ...---..............-------- ------ ...... 3
Description ---... .... ------- ............~~... ...... 4
Performance ..-----........---------... --..----...~~.....- 5
Adaptation ------.--.------------------....-...--- 5
Production Pointers ----------..-......-...------ 7
Seed Supplies --....----------.... --... ---.........--..-.............-....... 12
Acknowledgments ----.........--------.........-- ...--- 12
Cover.-Mrs. Noel Holder, wife of the Livestock Officer at the Ebini Re-
search Station (Guyana), in a plot of Jupiter soybeans. Plants grown near
6 latitude were 30 inches (76-cm) tall, stood erect, produced a closed canopy
in 30-inch (76-cm) rows, and yielded 35 bushels per acre (2350 kg/ha).
Jupiter A New Soybean Variety for Tropical Latitudes'
Varieties of soybeans (Glycine max (L) Merr.) adapted to
temperate regions seldom perform well at tropical latitudes.
Their response to tropical photoperiods (short days and long
nights) causes them to flower and mature too soon after plant-
ing. Acceptable plant height is seldom achieved and yields are
low because plants do not have sufficient time or leaf surface to
produce large quantities of food material and store it in seeds.
The Jupiter variety, released in May 1971 by the Florida Agri-
cultural Experiment Station and the Plant Science Research
Division, U. S. Department of Agriculture, has a photoperiod
response that causes it to flower and mature in tropical latitudes
on a time schedule similar to that for adapted varieties in tem-
Origin and Development
Jupiter originated from a cross between D49-2491 and
Bilomi No. 3, made at Gainesville, Florida in 1956. D49-2491
is closely related and nearly identical to the determinate Lee
variety which has been grown extensively in Southeastern
U.S.A. since its release in 1954. Bilomi No. 3 has an inde-
terminate growth habit and is a late flowering, late maturing
variety introduced from the Philippines. It is maintained as
PI 240,664 in the USDA soybean germplasm collection.
An Fi plant from the cross was grown in the greenhouse at
Stoneville, Mississippi by Dr. Edgar E. Hartwig during the
winter of 1956-57. It produced about 500 seeds which were
planted at Gainesville in 1957. All subsequent generations were
grown at Gainesville.
Approximately 200 plant-progeny hills were grown in 1958,
and late maturing determinate types were selected for growing
SJoint contribution from the Florida Agricultural Experiment Station and
the Plant Science Research Division, Agricultural Research Service, U. S.
Department of Agriculture.
SResearch Agronomist, Plant Science Research Division, Agricultural
Research Service, U. S. Department of Agriculture and Professor of
Agronomy, University of Florida, Gainesville, Florida.
F4 progenies in 1959. Selections tested in 1960 were very vari-
able for F4 lines in height, maturity, and podding habit. Many
plants had no pods on the lower half of their stems and branches.
Therefore, individual plant selection was continued, and pref-
erence was given to plants with more uniformly podded stems.
Breeding lines were established from F7 rows in 1962, and F62-
3977, which became Jupiter, was the latest flowering and latest
maturing line grown.
Seeds have both yellow and green coats and both brown and
black hila. The green color is not apparent in many commercial
seed lots because it fades to yellow soon after plants mature
(Figure 1). For seed produced at Gainesville, average seed
weight is about 16 grams per 100.
Jupiter has purple flowers, brown pod walls, brown pu-
bescence, purple hypocotyls, a determinate growth habit, and
moderately good seed holding qualities. It is resistant to bac-
terial pustule, wildfire, and one race of frogeye leaf spot, and
Figure 1. Seeds and pods of Jupiter. Seeds harvested about two weeks after
plants matured do not show the green coat color that is evident
at maturity. Pods show characteristic brown podwall color and
reddish brown (tawny) pubescence.
is moderately resistant to targetspot. It appears to have good
resistance to several nematode species that occur in Florida
and in the tropics, but it is susceptible to the rootknot species
Meloidogyne javanica (Treub). Plant height and other growth
characteristics depend on day length.
More plant to plant variability is evident in Jupiter than is
evident in most varieties advanced from single F, plants. At
Gainesville, first flowers open on some plants 10 to 14 days
before they open on the latest flowering plants. As the length
of time from planting to flowering is shortened by the photo-
period of the environment, flowering date variability is greatly
reduced. However, it probably is associated with the differences
in plant height that have been observed at 6 latitude. The
variability contained in Jupiter may be advantageous, because
it may permit the selection of biotypes that are better adapted
to specific environments.
Jupiter averaged 85 % the yield of Hardee in tests at Gaines-
ville and Live Oak in 1963-66. It is not adapted as far north as
Gainesville, because of its late flowering, late maturity, rank
growth, and lower yield.
Jupiter has been included in variety trials in several tropical
and subtropical countries. Data received from these tests usually
have been incomplete. However, by 1970 enough fragmentary
data were accumulated to indicate that Jupiter was potentially
well adapted to several tropical and subtropical countries.
In 1970 and 1971 more complete data were obtained from
replicated variety trials near 6 north latitude in Guyana (Table
1). Plant height was adequate, and plants produced a closed
canopy in 30-inch (76-cm) rows (Cover).
The photoperiod response of a soybean variety determines
its area of best adaptation. Soybean varieties grown in the
U.S.A. are classed into numerical maturity groups. Groups 0
and I are adapted to the northern tier of states, and higher
numbered groups are adapted progressively further south.
Groups VII and VIII are adapted to states bordering the Gulf
of Mexico. On this basis Jupiter is classed in maturity group IX.
Table 1. Performance of Jupiter and other varieties on two soil types near 6 north latitude in Guyana.
Tabela sand (Series 800) Kassarama loam (Series 810) Plant height
Variety 1970 1971 1970 1971 1970 1971
bu/a kg/ha bu/a kg/ha bu/a kg/ha bu/a kg/ha in. cm. in. cm.
Bilomi No. 3
35 2325 34 2251
26 1767 -
27 1800 20 1310
- 18 1210
- 27 1814
- 24 1579
- 25 1646
- 25 1646
35 2359 19 48 31 79
29 1969 46 116
25 1700 19 48 27 69
- 20 51 -
- 8 20 -
- 23 58 -
- 9 23 -
- 8 20 -
LSD.05 8 531 6 370 9 591 7 477
LSD.01 11 712 7 491 12 800 9 625
The influence of environment (primarily photoperiod) on
the growth and development of Jupiter is shown in Table 2.
The major effect is on days to early bloom. Determinate vari-
eties stop vegetative growth about the time first flowers open;
therefore, days to early bloom is a major factor determining
mature plant height. The range in days to early bloom, and in
mature plant height, between 6 and 18' latitude (Table 2) is
near the optimum range for these two traits in a well-adapted
As distance from the equator increases, however, differences
in day length also increase. Jupiter planted in April or May on
fertile soil at 18 north latitude may make excessive vegetative
growth. Conversely, if planted at 180 when days are near their
minimum length, vegetative growth will likely be below optimum.
For locations with alternating wet and dry seasons, the time
wet seasons occur (with respect to day length) and their dura-
tion may determine if Jupiter is well-adapted to that location.
For maximum seed yield, ample soil moisture is needed until
leaves begin to yellow in normal maturity. Ideally, dryer con-
ditions should prevail at and just after maturity to facilitate
efficient harvesting and to prevent seed deterioration.
Soybeans usually perform best when soil pH is between 5.7
and 6.2. When lime is needed, finely ground dolomitic limestone
usually is best, because it contains both calcium and magnesium.
It should be thoroughly mixed with the soil at least two months
before soybeans are planted.
Apply fertilizer to satisfy requirements for all other nutri-
ents except nitrogen. Table 3 gives fertilizers and rates of
nutrients that were used to produce the yields reported in Table
1. These rates were chosen to meet expected plant needs on soils
very low in available nutrients and where no data were avail-
able on soybean responses to added nutrients. Because these
rates increased seed yields from essentially zero to 35 bushels
per acre (2350 kg/ha), they are given as a guide for selecting
variables in fertilizer experiments. Soil tests will provide addi-
tional information. However, the best rate of each nutrient,
for each production area, must be determined by fertilizer ex-
periments in that area.
Fertilizer applied in direct contact with seeds often reduces
germination. It should be applied broadcast, or banded 2 or
Table 2. Growth and development of Jupiter soybeans at three latitudes.
day length* Planting Days to Days to plant ht.
Location Latitude (June 22) date early bloom maturity (in) (cm)
Floridat 30 15:00 June 1 90 150 60 152
Puerto Rico 18 14:00 June 4 62 -48 122
Guyanat 6 13:15 May 5 42 105 25 64
*Includes both morning and evening twilight (sun 6* below horizon).
tData are averages for two or more years.
Figure 2. Jupiter plants from a short-day planting at Gainesville show about
the degree of plant development that was observed at 6" north
latitude (Strings are 8 inches (20 cm) apart). These plants re-
mained in the field about one month after they matured, and seed
did not shatter.
more inches (5 or more cm) to the side and below the seed.
Profitable soybean production on nearly all soils depends
on nitrogen that is fixed symbiotically. In some soils a small
amount of "starter" nitrogen appears to be beneficial, but in
other soils no beneficial effects can be demonstrated. Large
Table 3. Fertilizers used to produce the yields reported in Table 1. Except
for dolomitic limestone and trace elements, rates are for nutrients
rather than sources.
Nutrient Source Ibs/a .kg/ha
P205 Triple superphosphate 110 123
K20 Muriate of potash 240 269
N Ammonium sulfate 15 17
MgO Kieserite 16 18
Trace elements FN 503 15 17
CaO + MgO Dolomitic limestone 1500 1680
amounts of nitrogen fertilizer may be detrimental, because they
inhibit nodule formation and reduce the amount of nitrogen that
is fixed symbiotically.
Symbiotic nitrogen fixation in soybeans depends on the for-
mation of nodules on roots by a particular species of bacteria,
Rhizobium japonicum. This species is seldom found in soils
where nodulated soybeans have not been grown; therefore, the
proper bacteria must be supplied by inoculum cultures. Com-
mercial inoculum cultures prepared in the U.S.A. have billions
of live bacteria mixed in packages of finely ground peat. Infor-
mation printed on the packages includes crop plants that are
effectively nodulated, the expiration date of the inoculum, sug-
gested inoculation procedures, and precautions that should be
Take all precautions printed on the package and add others
that will help maintain viability of the bacteria. Because good
nodulation is difficult to achieve in many soils where soybeans
are grown for the first time, and because it is so essential to
profitable production, several important precautions and pro-
cedures are listed below.
1. Be sure inoculum is for soybeans. Cultures prepared for
other legumes do not nodulate soybeans.
2. Use inoculum before the expiration date and store inoc-
ulum in a cool place until it is used.
3. Use two to three times the rate recommended on the
4. Use procedures that maintain uniformly coated inoculum
on seeds until they are planted. Even though one recom-
mended procedure on many labels is to use dry inoculum
on dry seeds, this procedure usually results in non-uni-
form and inadequate nodulation in soils that contain no
Rhizobium japonicum. Apply inoculum to moistened seeds
or apply it as a slurry. Some sticking agent (molasses,
milk, or a commercial product) may be needed to hold
inoculum on seeds until they are planted.
5. Inoculate seeds in the shade and plant as soon as seeds
flow freely, but before seed coats have completely dried.
Protect inoculated seeds from sunlight and drying winds.
Seeds absorb excess moisture if too much liquid is used
in the inoculation process.
6. Plant seeds about 11, inches (4 cm) deep in contact with
moist soil. High soil temperatures, sunlight, and drying
kill the bacteria. Therefore, planted seed must be covered
immediately, and the soil around the seed should remain
moist until bacteria infect roots.
These procedures assume that seed inoculation will be used.
However, any method that will provide adequate numbers of
live bacteria to infect roots of very young seedlings is satis-
Plant in a weed-free seedbed that contains enough soil mois-
ture for rapid and uniform emergence. In sandy soils, planting
less than one inch (2.5 cm) deep may result in reduced germina-
tion in addition to reduced survival of inoculum bacteria. How-
ever, emergence is often reduced when seeds are planted more
than two inches (5 cm) deep. The 11/2-inch (4-cm) planting
depth is near optimum.
Keep fields free from weeds to prevent competition for plant
nutrients and to reduce harvest losses.
Control insects. Damage from foliage feeding insects is
easily detected. Damage from pod feeding insects, especially
stinkbugs, may not be obvious to untrained observers. Stinkbugs
introduce a yeast fungus when they puncture pods and feed on
developing seeds. If this occurs when seeds are small, the dam-
aged pod will drop. If it occurs at a later stage of seed develop-
ment, damaged pods will be empty or will contain damaged
seeds. In choosing and using insecticides, take adequate pre-
cautions to prevent harmful residues in the harvested crop.
Harvest as soon as possible after the moisture content of
beans reaches 14%. Adjust combine according to manufac-
turer's instructions, and make changes as necessary. If cracking
occurs, reduce cylinder speed or increase space between cylinder
and rasp bar.
Stored soybeans should not contain more than 12% moisture.
Where frequent rains occur during and after harvest, artificial
drying may be necessary.
Although soybean yields usually increase with consecutive
well-fertilized crops, continuous soybeans increases the possi-
bility that soil-borne pathogens will build up to levels that will
reduce yields. Rotating soybeans with unrelated crops reduces
Small quantities of seed for experimental purposes may be
obtained from Dr. D. E. McCloud, Agronomy Department,
University of Florida, Gainesville, Florida, 32601.
The author expresses appreciation to the Ministry of Agri-
culture, Government of Guyana, for cooperation in conducting
variety trials and for permission to use the data presented in
Table 1. Also, beginning in 1967 Guyanese personnel tested
F62-3977 (Jupiter) and recognized its potential for tropical
latitudes. Personnel instrumental in the original testing and
evaluation of Jupiter in Guyana include Mr. N. Sawh (Technical
Assistant), Dr. R. S. Chetram (Agricultural Officer, Crops),
Mr. H. A. D. Chesney (now Deputy Chief Agricultural Officer)
and Mr. B. W. Carter (Chief Agricultural Officer).
Appreciation is also expressed to USAID/Guyana and the
University of Florida Center for Tropical Agriculture for their
assistance in conducting tropical tests and printing this circular.