|
WITCHES' BROOM, COCOA - BRAZIL
******************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>
Date: Fri 27 Mar 2009
Source: FlexNews, Reuters report [edited]
<http://www.flex-news-food.com/pages/22866/Brazil/Cocoa/drought-disease-dent-brazils-next-cocoa-crop.html>
Drought, disease to dent Brazil's next cocoa crop
-------------------------------------------------
Dry weather late last year [2008] and a resurgence of witches' broom
disease will cut yields during Brazil's 2009/10 midcrop, which starts
officially in May [2009], cocoa specialist Thomas Hartmann said.
Witches' broom disease, caused by a fungus, halved Brazil's crop
output in the 1990s. The disease can be contained by pruning infected
branches and spraying fungicides containing copper.
"The outlook isn't too good regrettably. It has been moist and warm
and fungus likes this," Hartmann said. He said the 1st forecasts for
the midcrop season ranged between 900 000 and 1 million [60 kg] bags,
with the higher probability at the low end of the range, compared to
1.28 million bags reached in the 2007/08 midcrop.
Brazil's ranking for cocoa output has fallen to 6th globally. Its
output was roughly halved during the 1990s by witches' broom disease
and the sector has shown few signs of recovery since.
--
Communicated by:
ProMED-mail
<promed@promedmail.org>
[Witches' broom (WB) of cocoa (_Theobroma cacao_) is caused by the
fungus _Moniliophthora_ (previously _Crinipellis_) _perniciosa_,
which is specific to this host genus. It is a serious disease of the
crop with yield losses of up to 90 percent or more. The pathogen is
native to the Amazon and is now present in most of the cocoa growing
regions in the Americas and the Caribbean.
Symptoms include the formation of multiple small shoots from flower
clusters and branches (called "witches' brooms"), which later become
necrotic. Pods can become infected up to about 12 weeks of age and
are often destroyed, or they ripen prematurely resulting in smaller
or no beans. The number of pods affected depends on the inoculum
pressure during the susceptible early phase of fruit formation.
Spore production occurs in small fruiting bodies developing on
branches and pods during rainy periods. Spores are spread by wind,
mechanical means, and with infected plant and other materials. There
is currently no effective control of WB, but cultural techniques and
grafting of established trees with budwood from varieties with
reduced WB sensitivity are being used to reduce disease impact.
WB was detected for the 1st time in Brazil in 1989 in the state of
Bahia. It ravaged production and yields in Bahia decreased from over
400 000 metric tons in the 1980s to less than 100 000 metric tons
within 10 years. Further losses in many areas are due to abandonment
of cocoa cultivation.
A related fungus, _Moniliophthora roreri_, causes frosty pod rot of
cocoa. Both diseases are spreading in the Americas and the Caribbean.
Collaborative programmes have been established for resistance
breeding and to attempt to stop the spread. Both diseases pose a
potential threat to cocoa growing areas in Africa and Asia if the
pathogens are introduced there.
Cocoa trees produce 2 harvests per year, the main crop in
October-April and the (usually smaller) midcrop in May-September. In
Brazil, however, production of the midcrop is higher than that of the
main crop.
Maps
Brazil
<http://en.18dao.net/images/9/96/Map-Brazil.jpg> and
<http://healthmap.org/promed/en?v=-10.8,-53.1,4>
Pictures
WB leaf and crown symptoms:
<http://www.worldwatch.org/brain/images/press/news/lg_WitchesBroom.jpg>,
<http://www.dropdata.org/cocoa/cocoa_pics/witch_broom_s.JPG>, and
<http://www.ars.usda.gov/is/espanol/kids/farm/story3/k8634-1i.jpg>
WB pod symptoms:
<http://www.fadiba.dk/Cocoa%20harvest%202.JPG> and
<http://www.mars.com/NR/rdonlyres/CE929BCC-741C-450F-B521-0DB986BE4F74/0/big_community.jpg>
Double infection with frosty pod (left) and WB (right):
<http://blog.worldcocoafoundation.org/FrostyPod_and_WitchesBroom.JPG>
_M. perniciosa_ fruiting bodies:
<http://www.bspp.org.uk/publications/new-disease-reports/018/2008-59-2.jpg>
and
<http://www.apsnet.org/education/K-12PlantPathways/NewsViews/Images/2004_04_views.jpg>
Links
Information on cocoa WB:
<http://www.apsnet.org/education/K-12PlantPathways/NewsViews/views/2004_04_views.htm>,
<http://www.oardc.ohio-state.edu/cocoa/witchbrm.htm>, and via
<http://www.worldcocoafoundation.org/About/newsletters/newsletter_Jan-Mar2008.asp>
WB and frosty pod information:
<http://www.dropdata.org/cocoa/cocoa_prob.htm#Crinipellis>
WB in Brazil:
<http://www.oardc.ohio-state.edu/cocoa/aitken.htm> and
<http://web.clas.ufl.edu/jur/200207/papers/paper_evans.html>
Review of cocoa diseases, including WB:
<http://discovermagazine.com/2002/aug/featchocolate>
_M. perniciosa_ taxonomy:
<http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=500896>
Cocoa pests and diseases -- references and resources:
<http://www.worldcocoafoundation.org/info-center/document-research-center/Cacao_DiseasesandPests.asp>
Economic impact of cocoa diseases:
<http://www.apsnet.org/online/feature/cacao/top.html>. - Mod.DHA]
[see also:
2005
----
Frosty pod rot, cacao - Belize: 1st report 20051113.3327
2001
-----
Cacao diseases 20010222.0341]
........................................dha/mj/jw
*##########################################################*
************************************************************
ProMED-mail makes every effort to verify the reports that
are posted, but the accuracy and completeness of the
information, and of any statements or opinions based
thereon, are not guaranteed. The reader assumes all risks in
using information posted or archived by ProMED-mail. ISID
and its associated service providers shall not be held
responsible for errors or omissions or held liable for any
damages incurred as a result of use or reliance upon posted
or archived material.
************************************************************
Become a ProMED-mail Premium Subscriber at
<http://www.isid.org/ProMEDMail_Premium.shtml>
************************************************************
Visit ProMED-mail's web site at <http://www.promedmail.org>.
Send all items for posting to: promed@promedmail.org
(NOT to an individual moderator). If you do not give your
full name and affiliation, it may not be posted. Send
commands to subscribe/unsubscribe, get archives, help,
etc. to: majordomo@promedmail.org. For assistance from a
human being send mail to: owner-promed@promedmail.org.
############################################################
############################################################
|