Cacao varieties explainedReferences:
This page will be used as a gathering point for information about cacao
varieties that are mentioned elsewhere on my blog. There are many
hundreds of recognised cacao varieties, nominal groupings, and clones,
so I have no expectation that the information on this page will ever be
Cacao naming conventions: the Hopelessly Vague, the Informative, and the Unique
nominal groupings of cacao are so vague as to be nearly meaningless,
such as the problematically imprecise Porcelana, and the stubbornly
entrenched triumvirate: Criollo, Trinitario, and Forastero.
contrast, some of the most informative, genetic-based groupings or
“clusters” are named after the place in South America where
that genetic material (in the form of seeds and/or cuttings) was first
collected – such as Curaray, Nanay, and Marañon.
there are the cacao clones, which have been tracked, studied, and, in
many cases, bred by agronomists over several decades. (Generally
speaking, a “clone” is an organism produced asexually from
one ancestor. A clone is genetically identical to its ancestor. Cacao
trees can easily be cloned by growing vegetative cuttings taken either
from the original ancestor, or from any of its clones.)
cacao clone is identified by a unique code name consisting of letters
and numbers. The letters are often an acronym (e.g. ICS, for Imperial
College Selection) indicating a scientific organisation where the
clones were first propagated or bred, or an abbreviation (e.g. Mo, for
Morona) indicating the general location where the original (often wild)
plant material was collected from.
It is worth noting that
subjective terms like “superior”,
“outstanding”, and “desirable” tend to mean
very different things to cacao agronomists and chocolate connoisseurs.
In the world of cacao breeding and cloning, yield is king, so traits
like disease resistance and exceptional vigour are considered highly
desirable. But, in the connoisseurs’ world, flavour reigns
supreme, and there is a very common misconception that healthy traits
such as hybrid vigour inevitably equate to inferior flavour. That idea
is, at best, overly simplistic.
Listed below is some historical,
scientific, and/or geograpical information about the cacao clones
mentioned elsehwere in my blog. The clone groups are listed
alphabetically. You can use Ctrl+F to find a specific clone: all are
presented here with a dash (-) and no additional space between the
letters and numbers in the clone ID, for example: ICS-95.
Cacao Clones Explained:
– the Estación Experimental Tropical clones. Amores et al
provide a brief history of the EET clones in their 2010 report, titled
“Cocoa productivity and quality improvement, a participative
approach”, commissioned by INIAP (Instituto Nacional
Autónomo de Investigaciones Agropecuarias):
In the late 70′s a group of superior cacao clones were released
by INIAP for commercial planting. These were the output of a process
that started in the late 40′s and early 50′s. After
visiting hundreds of farms in distinct cacao growing zones a number of
trees were selected based on visual observations. The high yielders
with some disease resistance were identified and selected for further
cloning. The clones were used to set up observation plots in
Estación Pichilingue [at Quevedo, Ecuador]. Several years of
careful evaluation led to the selection of the clones EET-103, EET-96,
EET-95, EET-64, EET-48 and EET-19 to be released as a clonal variety of
the Nacional type.
– the Imperial College Selection. There are 100 ICS clones. They
were selected by F.J. Pound from 1933 to 1935 on behalf of the (then)
Imperial College of Tropical Agriculture in Trinidad (which is now the
St Augustine Campus of the University of the West Indies). According to
Johnson et al’s “Field Guide to the ICS Clones of
Trinidad”, Pound made this selection from 15-30 year-old trees
already growing in Trinidad (in other words, the ICS clones were
selected prior to Pound’s expeditions to the Amazon in search of
witches’ broom-resistant cacao). Pound made his selection of ICS
clone material by surveying literally tens of thousands of trees. He
did this by observing trees in farmers’ fields for two years, and
by referring to observations made by growers, and by researchers within
Trinidad’s Department of Agriculture. Pound wanted to select a
representative sample of Trinidad’s entire cacao population
(estimated to be 50 million trees, resulting from centuries of cacao
cultivation, hybridisation, and farmer selection) “while not
overlooking outstanding combinations of desirable characters”
including high yield, exceptional vigour, and large pod and bean size.
– Described in the “Field Guide to the ICS Clones of
Trinidad” (p.7) as a “remarkable individual”: high
yielding and very vigorous in Trinidad; yielding well on most soils;
resistant to Monilia (frosty pod rot) in Latin America.
ICS-95 was singled out by Wood and Lass (1985, p.82) as one of the
“most valuable” ICS clones due to its reliably high yields
and disease resistance. They note that ICS-95 is among the small number
of ICS clones which has been introduced to various countries for use as
parent stock in breeding programmes.
- Iquitos Mixed Calabacillo. According to Wood and Lass (1985, p.83)
the original IMC genetic material was collected by F.J. Pound on an
island in the Amazon opposite Iquitos. (Iquitos is the largest city in
the Peruvian Amazon.) The original IMC material was collected (in the
form of seeds) during Pound’s 1937-38 expedition to the Amazon in
search of cacao populations with resistance to witches’ broom
disease. The seeds were sent to Barbados where they were grown; then
budwood was taken from these seedlings and used to establish 2,500
clones at Marper Farm in Trinidad.
“Calabacillo” comes from the unusual shape of these cacao
pods (smooth and round) which is reminiscent of the fruit of the
calabash tree (Crescentia cujete). Hart (1911, pp.2-4) lists
Calabacillo as one of just three “classes” of cacao –
the other two being Criollo and Forastero. Hart regarded Calabacillo as
“inferior” to both Criollo and Forastero, but noted that
Calabacillo trees “flourish where better varieties refuse to
thrive” and hence are “strongly recommended as a stock for
grafting selected varieties”.
– Resistant to Ceratocystis wilt; produces flattish, dark purple
beans. IMC-67 was one of the parent clones used in the TSH breeding
programme (Wood and Lass, p.84).
– the Trinidad Select Hybrids are a series of clones developed in
Trinidad by English-born botanist William Freeman. According to
Caribbean Icons, Freeman worked as a research officer for
Trinidad’s Cocoa Board, where he bred improved cocoa clones and
hybrid seedlings during the period from 1956 to 1978. The TSH clones
are “highly regarded for their superior yield, excellent flavour
and resistance to diseases” (ibid.).
The parent clones which
were crossed over three or four generations to produce the TSH clones
include: ICS-1, SCA-6, IMC-67, and P-18 (Wood and Lass, 1985, p.84).
– According to a study by Ram et al (2006), TSH-565 is a
descendant of the famously witches’ broom-resistant clone SCA-6.
In their evaluation of several SCA-6 descendants, Ram et al found that
TSH-565 was the second most productive clone (after TSH-516) following
exposure to Crinipellis perniciosa (witches’ broom) and
Phytophthora (black pod) in field trials in Bahia.
et al (2010) “Cocoa productivity and quality improvement, a
participative approach”, Final report, accessed online via
http://www.procitropicos.org.br/ Jan.2012, Hart, J. Hinchley (1911)
A Manual on the Cultivation and Curing of Cacao, Duckworth & Co., London
Johnson, Bekele, and Schnell, “Field Guide to the ICS Clones of Trinidad”
Accessed online at http://www.catie.ac.cr/CatieSE4/BancoMedios/Imagenes/cacao.pdf Jan. 2012, Ram et al (2006)
evaluation of cocoa witches’ broom incidence in SCA-6 descendants
in three agrosystems of South Bahia, Brazil”, 15th International
Cocoa Research Conference, Costa Rica, p.145, Wood and Lass (1985)
Cocoa – 4th edition, Longman, London