The Interspecific Hybrid Elaeis oleifera x E. guineensis :
A Solution for the Surinamese Oil Palm Industry.
Palm Industry in
disease 'Fatal Yellowing' (Speerrot, Pudrici¢n fatal
relecimiento Fatal). The causing agent of this condition remains unknown
and chances of finding a feasible cure any time soon appear extremely slim.
No trace of tolerance has been found in E. guineensis germplasm, but inter-
specific hybrids with E. oleifera invariably proved highly tolerant, if not
resistant. The most promising way out of the present impasse therefore
lies in replanting devastated areas with such hybrids.
Interspecific hybrids until present do not seem competitive with commercial
E. guineensis in terms of Crude Palm Oil production. However, indications
are that they could well compete if output of Refined Palm Oil is conside-
is to supply the local market with Refined Palm Olein, this conclusion is
of utmost importance.
This article compiles the actual state of knowledge on yield potential of
interspecific hybrids and advocates a systematic inventarization and col-
effort in wild populations of E. oleifera in
identify parent palms for a commercial scale replanting programme, to be
initiated as soon as possible.
Speerrot is bezig de Surinaamse oliepalmindustrie van de kaart te vegen.
Tot op heden is de oorzaak van deze aandoening onbekend en het ziet er niet
naar uit dat er binnen afzienbare tijd een in de practijk toepasbare oplos-
sing voor gevonden zal worden. Binnen het genus Elaeis guineensis werd
geen enkele vorm van tolerantie aangetroffen, doch interspecifieke kruisin-
gen met Elaeis oleifera bleken steevast bijzonder tolerant, zoalniet resis-
tent. Herbeplanting met dergelijke hybriden lijkt dus de meest belofte-
volle uitweg uit de huidige patstelling.
Gepubliceerde resultaten geven in het algemeen aan dat interspecifieke
hybriden niet kunnen concurreren met commerci‰le E. guineensis inzake
productie van Ruwe Palm Olie per Ha. Nader onderzoek van deze resultaten
leert echter dat zij de vergelijking waarschijnlijk w‚l aankunnen indien
men de productiviteit beschouwt in termen van Geraffineerde Palm Olie.
Deze conclusie is van het grootste belang voor Suriname, waar de ‚‚rste
opdracht van de oliepalmindustrie bestaat in de spijsoliebevoorrading van
5de locale markt.
Dit artikel vat de huidige stand van kennis inzake het productiepotentieel
van deze hybriden samen en verdedigt een systematische inventarizatie van
het genetisch potentieel in wilde opstanden van E. oleifera in Suriname.
De hierbij te identificeren elitepalmen zullen dienen als ouders voor de
dringende grootschalige herbeplantingscampagne.
The American Oil Palm, Elaeis oleifera (formerly also called E. melanococca
and Corozo m.) has aroused scientific interest ever since the discovery of
its crossability with E. guineensis back in the forties. In spite of pro-
mising initial results, only in very few occasions the interspecific hybrid
has been planted on a commercial scale. In all of these cases, the inten-
tion was not to genetically improve the Oil Palm, but to preserve the cul-
ture, mostly after extinction of the original E.g. plantations by diseases
unknown in its African regions of origin and against which no resistance
could be found in pure bred progenies. Published reports on the production
of these plantings do not arouse enthousiasm but one cannot omit to mention
that they invariably have been implemented with virtually unselected E.o.
parents, often from the immediate surroundings of the plantations. The
worst results were obtained with germplasm of Central American origin,
which is known to have serious fertility problems.
As a result, hopes of exploiting the desirable characters of the American
palm in the culture crop shifted away from the straightforward F1 cross
toward stabilization of individual characters into E.g.. No need to em-
phasize that this won't give practical results in any near future.
Furthermore, it remains to be proven that resistance against Fatal Yellow-
ing can be genetically stabilized in anything beyond a F1. Several
searchers therefore proposed the vegetative multiplication of individual
elite hybrids. This method however will remain unavailable to most
developing countries for quite some time to come and does not take away the
need of breeding efforts to create such elite palms in the first place.
Although F1 hybrids in some cases slightly outyielded the E.g. standard in
terms of Crude Palm Oil per hectare (Tan, 1987), IRHO (1989), reporting on
one of the broadest trials ever set up, found them to produce between 9 and
90 % of commercial E.g., eliminating the prospect of hybrid plantings as
a feasible proposition. Such results however need careful interpretation:
1. Germplasm collection, selection and breeding in E.g. were initiated
in the 1920's and continue to give spectacular results (a.o. Rajanaidu
e.a., 1989). E.o. was first systematically collected in
rica, up from the late sixties. One can therefore state that the
oleifera parents used underwent next to no selection or breeding. If
E.g. were to be collected the same way (i.e. at random), an analogous
trial, but within the species, would probably give similar results.
2. The oil of hybrid palms is richer in unsaturated fatty acids and
therefore more fluid than classical palm oil. In most cases it is
fluid at room temperature, and for use as a cooking oil under tropical
conditions it will need no or next to no fractioning. Refining of
E.g. oil under these conditions takes out over 20 % of the Crude Palm
Oil as stearin. Therefore, in terms of cooking oil for tropical con-
ditions, IRHO's best hybrids actually outyielded the E.g. standard.
3. Height increment of a hybrid plantation is much lower than a classical
one and its economic lifespan could be up to 3 times as long, depen-
ding on the type of combination used. This character should be appro-
priately taken into consideration when evaluating the8 economical
feasibility of a commercial venture.
Generally, literature mentions low natural fruitset and high bunch failure
in hybrids and according to IRHO (1980), artificial pollination would be
inevitable. However, the extent of these problems proved extremely
variable between progenies (Arnaud, 1980; Schwendiman e.a.,1982 and 1983)
and strikingly high natural fertility was observed in hybrids of Surinamese
descent (Cloesen, 1987; Rao e.a., 1989).
Above mentioned findings permit to conclude that the general prejudice
against commercial feasibility of F1 hybrid plantings is not justified.
in the case of
planting with E.g. impossible and where the primary objective of Oil Palm
culture is not the export of CPO but the production of refined cooking oil
for the local market, hybrids may prove an attractive alternative for areas
and infrastructure otherwise obsolete.
1. Identifying elite Elaeis oleifera
literature mentions three types of E.o., commonly
can, Brazilian and Surinamese. These types give very different hybrids
with E.g., although remarkable differences have also been observed between
progenies from the same origin (Meunier e.a., 1976).
the ones encountered in
network. Those from the North, along the
resembling Surinamese, the others leaning towards the Central American type
(GhesquiŠre e.a., 1987, Barcelos e.a., 1985). Nevertheless, some phenoty-
pic characters, such as the strikingly bigger fruitsize, clearly distin-
guish the Brazilians from both other types. Oleiferas from the Peruvian
Amazon are similar to the ones found in the
The dwarf type palm endemic in
French Guyana, which made Meunier (1975) distinguish it as the subtype
1.1. Selection parameters
Parents in hybridization efforts preferably should show high productivity
as well as good oil extraction.
Oleifera germplasm was first systematically collected in
revealed the elite palms. In
only in the eighties and field planting of collected palms began in earnest
in 1985. Therefore only very preliminary production results could have
been obtained up till now. A systematic prospection for the Surinamese
type of E.o. has never been carried out and selection of parent palms for
high Fresh Fruit Bunch (FFB) production is thus impossible, except for
the Central American type.
This however should not be considered a serious handicap. Nine to ten year
Surinamese oleiferas, planted 10 m apart in
maximum of 15.5 kg of FFB per palm and per annum (Rao e.a., 1989), as com-
pared to a mean of over 200 kg for commercial E.g. in that country. Their
hybrids however, like the ones from other oleiferas, can outyield E.
guineensis in terms of FFB. This indicates that the contribution of E.
guineensis and the heterosis effect play a far more important role in the
determination of the hybrid's FFB yield potential than does the oleifera
parent. Therefore, selection efforts should concentrate on the parameters
determining the oil extraction rate. These characters, being less influen-
ced by the environment, can also reliably be measured in wild populations.
1.2. In search of genetic variability
(1980), reporting on E.o. collected from
bia, found the whole of the studied population to be very homogenous,
leaving little scope for selection on oil content. This is reflected in
very low Standard Deviations, as illustrated in Table 1. Far more diver-
sity was found in
e.a. (1985). No systematic survey has been done on Surinamese oleifera but
comparing mentioned figures with the ones found by V.D.Woude & Schut
(1975), it may be clear that this subtype, except for Bunch Weight (BW),
Individual Fruit weight (IF) and Oil to Mesocarp (O/M), compares very well
to both others. It is clear also that spread, and thus selection poten-
tial, is very high, especially if one takes into account that the latter
study refers to only 100 palms in a single population.
Few authors reported on Oil to Bunch (O/B) in pure E.o.. The best values
found were 7.5 % for Central American material (Escobar, 1980) and 10.2 %
for the Kuala Lumpur Melanococca (KLM), which is considered of Brazilian
origin (Rao e.a., 1989). In both these results, a significant portion of
total O/B comes from parthenocarpic fruit, which is virtually absent in
Surinamese oleifera. Combining data from V.D. Woude and Schut (1975) and
Martin (1970), it can be calculated that the best individual Surinamese
oleifera found probably had an extraction rate over 9 %, parthenocarpic
fruitset NOT taken into account. Parthenocarpy increases mean Oil to
Fruit and hence O/B. It is however also an indication of an innate defi-
cient fertility and a predisposition for bunch failure. One should there-
fore select AGAINST parthenocarpy, as will be discussed later.
It may be clear from the above that a thorough collection effort in wild
Brazilian germplasm. The main handicap of this type is its low O/M.
However, variability with respect to this character is considerable,
opening great prospects for selection.
2. Selecting a desirable type of hybrid
2.1. Problems associated with hybrids
Perhaps the most effective way to define a desirable hybrid begins with an
analysis of reported shortcomings. The main problems mentioned in the
literature are deficient fertility and natural pollinization, low oil
content, excessive vegetative vigour and small fruitsize.
2.1.1. Bunch development and fruitset
High bunch failure and bad fruitset, which have been attributed to a
combination of reduced capacity to develop normal embryon sacs, reduced
pollen viability, problems in the release of pollen and low activity of
insects on both male and female flowers, are mainly observed in hybrids
based on Central American material (Arnaud, 1980; Schwendiman e.a., 1982
and 1983; Baudoin e.a., 1984). None of these studies included Surinamese
progenies, but indications are that fertility is not a problem. Cloesen
(1987) observed neither parthenocarpy or bunch failure in four Surinamese
F1 palms nor in backcrosses to E.o. and Rao e.a. (1989) also drew attention
to their unusual fertility. The pure Surinamese oleifera is also reputed
to have high F/B and remarkably low parthenocarpy, even in rather isolated
Sterling e.a. (1988 B) suggested to take advantage of the outspoken
parthenocarpy observed in Central American hybrids for the development of
'parthenocarpic lines'. This pathway however seems rather risky. It is
true of course that parthenocarpic fruits contain more mesocarp and hence
more oil to fruit, but parthenocarpy also indicates an underlying deficient
fertility. Although this kind of palms may produce well in small plots
surrounded by E.g., it is very doubtful that they would continue to do so
in pure stands, where natural fruitset could well be insufficient to
prevent massive bunch failure. Artificial pollination during the whole
lifespan of a plantation can hardly be considered. Furthermore, it would
annihilate the benefit of reduced trunk height increment, since flowers
above eye level would easily go undetected.
e.a. (1990), in
- its hybrid and backcross to E.g. to be less attractive to the pollinating
insects Elaeidobius kamerunicus and Mystrops costarricensis. Tan (1987),
however, recorded a dramatic improvement of fruitset in Brazilian hybrids
introduction of E. kamerunicus in
the weevil to be able to breed in hybrid male inflorescences. The apparent
contradiction between both findings may be attributed to the different
odour of male inflorescences of the parental oleifera. The first author
most probably worked with Central American progenies, whose male inflores-
cences, contrary to E.g., lack the characteristic strong anis odour at
anthesis (L¢pez, 1980) or even spread a distasteful smell. The male
inflorescence of the pure Surinamese oleifera having the same colour and
fragrance as E.g., there is no reason to believe that pollinating insects
would be less active on its hybrid than on E.g.. The lack of persistent
spathes around anthesizing female flowers in Surinamese E.o. and hybrids,
contrary to both other types, is likely to facilitate insect pollination
further. Apparent good fruitset in hybrid palms on
confirm this hypothesis.
2.1.2. Extraction rate
Although hybrids with O/B as high as 30 % were mentioned to exist (Tam
e.a., 1976), laboratory extraction rates in the range of 10 to 25 % are
more commonly found in the literature, with the better results invariably
corresponding to Brazilian material (Hardon, 1969, Obasola, 1969, Meunier
e.a., 1976, Tam e.a., 1976, Escobar, 1980, Tan, 1987, Lubis e.a., 1987,
Sterling e.a., 1988 B, Mukesh & Tan, 1989 etc.). Figures for Surinamese
hybrids are given in Table 2.
and high parthenocarpy found by Lubis
attributed to deficient pollination. M/F on the other hand was far
oleifera germplasm in Cloesen's observations.
(1969) Tam e.a. (1976) and
confirm that bunch quality parameters in hybrids are intermediate between
parental types. Therefore, hybrids based on selected Surinamese mother
palms should have O/B comparable to what is commonly obtained with other
2.1.3. Crown dimensions
Both Brazilian and Central American hybrids are reputed to develop longer
and more rigid fronds than E.g.. Therefore, Obasola (1969), Lubis e.a.
planted further apart, reducing yield per ha (at least in the first years
after planting). Although high yields have been obtained in hybrids
planted as dense as 148 palms per ha up till the 13th year of age (Tan,
1987), it is very doubtful they would continue to do so much longer. The
Surinamese hybrid, to the contrary, has a vegetative development inter-
mediate between both parental species and can be planted in densities of
160 or even 180 palms per hectare. Applying such corrections to published
results, Surinamese progenies outyield other origins in terms of FFB/ha.
In addition, their leaves, contrary to the stiff and flat habit in other
hybrids, gently bend in a parabolic curve, assuring a better light distri-
bution in the canopy and less mutual overshading.
It would be of interest to study crown dimensions in hybrid progenies of
dwarf oleiferas found in
these palms is very similar to Surinamese E.o., but on average they seem
to have better F/B, considerably higher O/DM, less saturated oil and fruits
more than double the size. On the other hand however, they also seem less
fertile, as reflected in a far higher percentage parthenocarpy (Barcelos
e.a., 1985, V.D. Woude and Schut, 1975).
2.1.4. Size of bunch stalks and leaf petioles
Heavy frond petioles in Brazilian and Central American hybrids reportedly
slow down pruning and thick bunch stalks complicate harvesting operations
even further (Tan, 1987). These characters most certainly reduce the
benefit of the lower height increment, since problems are likely to grow
with the length of the palms. In Surinamese hybrids, bunch stalks are
comparable to those of E.g. and leaf petiole cross section is smaller.
Individual (fertile) fruits in pure E.o. are small, averaging slightly
above 3 grams in Central American types. Surinamese fruits are even
most populations average over 7 g.
Fruitsize in hybrids is scarcely documented in the literature. Generally,
figures hover around 7 to 8 g (Obasola, 1969, Sterling e.a., 1988 B),
unless Dura (or Tenera) were used as guineensis parent (Escobar, 1980,
Mukesh and Tan, 1989). In the latter case, extremes up to 18 g have been
reported. Curiously however, Brazilian hybrids do not seem to give bigger
fruits than others and Surinamese fruits do not seem smaller (Meunier,
1976, Cloesen, 1987). It is thus not obvious where to search in order to
optimize this character and the influence of the guineensis parent may well
be decisive. It should also be noted that not all commercial lines of E.g.
have significantly bigger fruits.
2.2. Take advantage of desirable properties
Desirable characteristics, shared by all types of hybrids include reduced
trunk height increment; an oil richer in insaturated fatty acids, carotenes
and tocopherols; a brighter colour of mature fruit and a high degree of
tolerance, or even resistance to next to all economically important pests
diseases of E.g. in
discussed in this article.
2.2.1. Reduced trunk height increment
Length increment is a major factor determining the cost of harvesting and
the economic lifespan of a plantation. Lubis e.a. (1987) reported annual
height increments of 18 cm for Surinamese hybrids, as compared to 32 and
34 cm for Brazilian and Central American ones, and 46 cm for commercial
E.g.. Cloesen (1987) found height increment of Surinamese hybrids (about
17 cm/yr) to be comparable to pure Colombian oleiferas and estimated their
economic lifespan nearly 3 times as long as E.g. and at least 1.5 times as
long as Colombian hybrids in the same experiment.
It should be mentioned, however, that the smaller habit of the Surinamese
hybrid also reflects in a smaller trunk volume. Sterling e.a. (1987 and
1988 A), studying 'compact' material, attributed their strong tendency
for alternate periods of high and low production to reduced carbohydrate
storage capacity in their smaller trunks. The same problem could occur in
Surinamese hybrids when planted in areas with a pronounced dry season.
2.2.2. Higher unsaturation of oil
The mesocarp oil of pure E.o. melts at 13-14øC, as compared to some 24øC
for classical CPO. The former therefore would not need fractionation for
use as a salad oil, even in temperate climates. Producing vegetable oil
for use in tropical conditions, Palm Oil would be cristalized at 22øC and
refining efficiency (olein/CPO) after double fractionation would be about
72 %, under conditions at
results on hybrid oils were found in the literature, but indications are
that the latter are fluid at room temperature and that their melting point
is 22øC or lower. As a result, fractionation would be obsolete and overall
refining efficiency would most certainly exceed 90 %.
Oil unsaturation tends to be higher in Central American oleiferas and
hybrids than in both other origins, although figures by Tam e.a. (1976)
suggest that promising palms are to be found also in the progenies of the
"Kuala Lumpur Melanococca", which is considered Brazilian. The few
reported values for Surinamese material are within the range found in
unsaturation is very close to the average between parent palms, suggesting
that selection of the guineensis parent may be equally important.
2.2.3. Bright colour of ripe fruit
The clear colour at ripeness of the hybrid fruit, as compared to E.g.
(nigrescens type) must result in less "omitted" bunches and less unripe
harvesting. The Surinamese hybrid is particularly interesting in this
respect : like its oleifera parent, ripe fruits are bright orange, com-
parable to the E. guineensis 'virescens' type, even though immature fruits
may be black.
2.2.4. Carotenes and tocopherols
The hybrid's oil is also richer in carotenes (provitamin A) and tocopherols
(vitamin E). However, untill refining methods will be developed that do
not completely eliminate these nutritionally important components, these
properties can hardly be used as an argument in favor of hybrid oils.
material for the first Oil Palm plantings in
country itself. As superior seeds from
cially available in the eighties, local breeding efforts were discontinued,
corresponding know-how still exists. Although
only country affected by Fatal Yellowing, no commercial seed house has a
breeding programme for interspecific hybrids and a seed garden with
selected Surinamese E.o. does not exist. It is therefore considered more
than worthwile that a renewed selection and breeding capacity be set up in
the country. The Ministry of Agriculture's Palm Research Centre (POC)
would herein collaborate with the Common Vegetable Oils amd Fats Companies
known wild populations of E.o. in
that selection of parent palms, as well as hybrid seed production could be
done right on the spot. Only later on, E.o. seed gardens would be laid
out, using elite material identified in the first phase. However, even
preliminary selection results are expected no sooner than within two years.
In the mean time, hybrid seed from elite oleifera of other origins should
be imported so that replanting can be initiated without delay. A project
proposal has been formulated in order to obtain international financing for
the import component of such an effort.
The Surinamese Oil Palm Industry will be wiped out, unless areas devastated
by Fatal Yellowing are replanted as soon as possible. F1 interspecific
hybrids with E. oleifera are the only planting material proven to survive
and produce in such areas. These hybrids can be produced readily, and the
best progenies will outyield the former E.g. plantings, at least in terms
of Refined Palm Oil per Hectare.
Elite oleifera parents, to the best of our present knowledge, should be
cantly longer economic life as well as improved natural fertility and
would be easier to harvest than any other type. A project proposal has
been worked out, aimed at such a genuine genetic improvement effort based
on national resources.
The author, Henri-Paul Cloesen, was Head of the Agronomical Service (LD)
at Victoria Oil Palm Estate (Suriname) between 1985 and 1987. The present
article is a literature study.
Table 1. SPREAD IN BUNCH AND FRUIT QUALITY PARAMETERS in E. oleifera of
8MIN 0.7 - 33.5 32.9 - 19.5 7.9 25.9 1.1
MAX 3.4 - 74.3 64.4 - 42.1 23.3 51.5 4.3
MEAN 1.9 - 61.7 45.1 - 31.9 15.3 39.6 2.8
SD EST. 0.68 - 10.20 7.88 - 5.65 3.85 6.40 0.80
CV EST. 35.53 - 16.53 17.46 - 17.71 25.16 16.16 28.57
MIN 0.9 1.8 11.2 14.6 - 16.1 - 10.8 3.45
MAX 18.0 28.8 90.5 62.3 - 57.2 - 56.9 14.66
MEAN 6.7 10.6 68.94 46.0 - 42.84 - 41.1 7.87
SD 3.67 - 15.74 6.51 - 6.52 - - 2.30
CV 54.78 - 26.50 14.15 - 15.23 - - 29.22
BW (**) St/B F/B M/F O/M O/DM K/F Sh/F IF
MIN - 15.2 - - 12.7 - - - -
MAX - 21.8 - - 24.8 - - - -
MEAN 11.6 18.7 60.8 36.5 18.8 - 15.9 47.6 3.31
CV - 9.4 4.7 5.5 15.4 - 8.5 3.9 11.65
SD CALC. - 1.76 2.86 2.01 2.90 - 1.35 1.86 0.39
MIN CALC. - 15.2 55.1 32.5 13.0 - 13.2 43.9 2.53
MAX CALC. - 22.2 66.5 40.5 24.6 - 18.6 51.3 4.09
** REFERS ONLY TO COLOMBIAN OLEIFERAS, 6TH-10TH YEAR AFTER PLANTING
Table 2. BUNCH CHARACTERISTICS in Surinamese hybrids
Source F/B M/F M/B O/M O/B N Observations
Lubis (1987)F 33.4 67.5 22.5 35.8 8.1 ? E.g.= Pisifera
P 16.2 89.9 14.6 17.9 2.6
T 49.6 37.1 10.7
Cloesen (1987) 73.9 59.0 43.6 15.6 4 E.g. = Pisifera
O/M estimated as 35 %
No parth. fruitset.
Lubis (1975)F 41.5 46.7 19.4 38.6 7.5 42 E.g. = Deli Dura
(in Meunier P 14.3 88.5 12.7 24.7 3.1
e.a., 1976) T 55.8 32.0 10.6
F : Fertile fruits P : Parthenocarpic fruits T : Total
Table 3 : UNSATURATED FATTY ACIDS IN OIL (%)
ORIGIN E.o. Hybrid E.g. OBSERVATIONS/SOURCE
unspecif. 68.9 9
Lelydorp 68.2 - 73.7 Means 2 populations3
69.8 - 74.2 7 analyses2
unspecif. 60.0 - 77.7 All known populations6
KLM (*) 62.3 44.2 1
77.9 - 82.6 57.0 - 69.0 49.8 Mother = E.g. Dura5
PERU (**) 63.6 1 Population8
unspecif. 78.7 63.9 49.9 Hyb. prob. Colombian9
Monter¡a Up to 82 Up to 75 4
78.7 67.0 54.9 E.g. = La M‚4
78.7 62.7 47.0 E.g. = Yangambi4
Turbo 71.7 (**) 65.15 44.2 1
(*) The Kuala Lumpur Melanococca is considered Brazilian
Palms found in
(***)Sample heavily oxidized. This may have lowered % unsaturated acids.
(1) Hardon (1969) (4) Meunier e.a. (1976) (7) Lubis e.a. (1987)
(2) Martin (1970) (5) Tam e.a. (1976) (8) Kahn & M. (19..)
(3) V.D. Woude & S.(1975)(6) Barcelos e.a. (1985) (9) Rao e.a. (1989)
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