A branch of a cacao
tree in western Ecuador killed by witches broom disease. Click the
image for more information about it.
Tackling Tough Problems in the World of
Chocolate By Alfredo Flores
February 10, 2004
Here's some sobering news for Valentine's Day gift-seekers: All
is not well in the world of chocolate. That's because several fungi, most
significantly Crinipellis perniciosa, are attacking Theobroma cacao
trees, source of the seeds that are the chief ingredient for cocoa and
chocolate. C. perniciosa penetrates the stem and fruit tissue of cacao
trees, inhibiting their formation of seed pods and destroying mature pods.
But scientists with the Agricultural Research Service have been
tackling the problem. Raymond J. Schnell and colleagues at ARS'
Horticultural Research Unit in Miami, Fla., have studied cacao's genome and
have found genetic markers for resistance to witches' broom, the disease caused
by C. perniciosa.
Schnell and other ARS scientists are participating this week in
a first-of-its-kind symposium on T. cacao, hosted by the National
Academy of Sciences in Washington, D.C. Schnell will discuss research on
cacao's genome, its historic origins, and current and future challenges in
tropical tree crop breeding. The meeting is expected to draw scientists from
Germany, France, Switzerland and Austria, as well as the United States, to
discuss recent advances in cacao research.
Latin America was a traditional hub of cocoa production until
witches' broom began to devastate production a little more than a decade ago.
Since then, Brazil, which used to export $100 million worth of cocoa beans to
the United States annually, has gone from being the world's third-largest
exporter to a net importer. Western Africa is now the world's premier
cacao-growing region, with the Ivory Coast supplying about half of the world's
Schnell is currently in the third year of a five-year
cooperative agreement with Masterfoods,
Inc., of Hackettstown, N.J.--makers of M&Ms, Dove Chocolate and
Snickers candy bars--to breed cacao that resists serious diseases. Breeding
populations established in Costa Rica and Ecuador have shown tolerance to
witches' broom and to frosty pod and black pod, both of which rot cacao pods,
as well as to Ceratocystis, a fungus that causes cankers on branches and
ARS is the chief scientific research agency of the
U.S. Department of Agriculture.