Theobroma cacao means food of the gods. It is also the botanical
name for the cocoa tree, a much-revered crop for thousands of years. Satisfying
the world's growing appetite for chocolate is an interesting case study in the
development of sustainable agriculture.
Nowadays over 20 million people world-wide depend directly on
cocoa cultivation for their livelihood. Almost 90% of
cocoa production comes from smallholdings of under 5 hectares. Use of
fertilisers is limited but that of insecticides and fungicides is required due
to the prevalence of pests and diseases. It is estimated that around
30% of the cocoa crop world-wide is lost to pest and disease attack. Chemical
treatment is however not always possible, due either to the nature of the pests
or because the chemicals are too expensive for most farmers. The use of
chemicals should in any case be minimised to reduce environmental pollution and
health risks to farmers.
Another challenge for cocoa cultivation is the increasing scarcity
of suitable growing areas. Increased global cocoa production from 1.5 million
tons in 1984 to 2.7 million tons in 1998 was almost entirely due to an increase
in production area, whereas productivity remained low. New production zones
were mostly set up on cleared forestland, which is becoming increasingly
scarce. Meanwhile, many of the traditional production areas have old poor
yielding trees that it would be wise to replace.
In-built resistance
Research organisations and the cocoa using industry are seeking
solutions to these problems. With the predicted continuing predominance of
small cocoa farmers, it is impractical to introduce technological changes that
depend on significant increases in financial inputs, certainly so in
times of depressed cocoa prices. The introduction and use of more productive
varieties resistant to pests and diseases is therefore one of the most
cost-effective and environmentally friendly innovations that can be proposed to
overcome cocoa production constraints. Cocoa trees with effective built-in
resistance to most diseases and pests are not yet available, although
significant genetic potential for resistance is generally found in
cultivated plants.
Teaming up
There are several international programmes aimed at the
development of these improved and sustainable methods of cocoa production.
Research organisations in France, Britain and the US have a common overall
objective but specialise each in specific aspects.
In recent years new techniques have been developed which may
eventually make significant contributions to the creation of improved varieties
resulting in higher yields. Collections of cocoa plant material, such as in
Trinidad, have been established and since the late 1970's, there have been
systematic efforts to analyse the plant material, mainly by observing
morphological traits.
The development of DNA marker technology revolutionises
this practice, allowing the genetic diversity in these collections to be better
understood. In addition to understanding biodiversity, these techniques can
also be used to identify characteristics in individual trees that have
increased resistance to diseases. As an example, a collaborative project
between research institutes in France and producing countries is identifying
trees that have increased resistance to black pod, a major fungal disease of
cocoa. These trees can then be used in conventional breeding programmes, or
clonally propagated, getting higher yielding trees to the farmers, to give them
a more sustainable future.
Integrating all these new developments into a modern
cocoa-breeding programme will be a major contribution to improving cocoa
production.
