3 research outputs found
Incidence and severity of cassava mosaic disease in the Republic of Congo
Diagnostic surveys were conducted in 2002 and 2003 in order to provide a comprehensive and detailed assessment of the status of cassava mosaic disease (CMD) in the Republic of Congo (ROC) and to determine if the disease was spreading. In 2002, 105 farmers’ fields were assessed in the four major cassava-producing regions ofthe country. In 2003, 163 fields were sampled in nine regions and Brazzaville Commune. Incidence of cassava mosaic disease was generally high, averaging 80 and 86 % for 2002 and 2003, respectively; while damage was moderate to severe. In 2002, disease incidence was moderate in Pool (73%) but high in Brazzaville (81%),Cuvette Centrale (82%) and in Plateaux Region (84%). Pool region still had the lowest incidence (78%) in 2003, while Sangha (95%) had the highest incidence. The greatest disease severity was recorded in Niari region in the south and Cuvette Ouest region in the north in 2003. East African cassava mosaic virus Uganda variant (EACMVUG) occurred virtually throughout the country, commonly in dual infections with African cassava mosaic virus. The high incidence of disease in plants considered to be the results of cutting infection (74% in 2002 and 82% in 2003), relatively low incidence of disease in plants considered to be infected by whiteflies and wide distribution of EACMV-UG points to the fact that the CMD pandemic is a chronic in the country and the areas sampled are currently in a stable post-epidemic phase. This situation is comparable to that in areas of East Africa affected by a pandemic during the 1990s, including Uganda, parts of western Kenya and north-western Tanzania. These findings clearly verify the assertion that the CMD pendemic has expanded across Central Africa and provide abasis for designing interventions and control strategies for the entire region
Incidence and severity of cassava mosaic disease in the Republic of Congo
Diagnostic surveys were conducted in 2002 and 2003 in order to provide a comprehensive and detailed assessment of the status of cassava mosaic disease (CMD) in the Republic of Congo (ROC) and to determine if the disease was spreading. In 2002, 105 farmers’ fields were assessed in the four major cassava-producing regions of
the country. In 2003, 163 fields were sampled in nine regions and Brazzaville Commune. Incidence of cassava mosaic disease was generally high, averaging 80 and 86 % for 2002 and 2003, respectively; while damage was moderate to severe. In 2002, disease incidence was moderate in Pool (73%) but high in Brazzaville (81%),
Cuvette Centrale (82%) and in Plateaux Region (84%). Pool region still had the lowest incidence (78%) in 2003, while Sangha (95%) had the highest incidence. The greatest disease severity was recorded in Niari region in the south and Cuvette Ouest region in the north in 2003. East African cassava mosaic virus Uganda variant (EACMVUG) occurred virtually throughout the country, commonly in dual infections with African cassava mosaic virus. The high incidence of disease in plants considered to be the results of cutting infection (74% in 2002 and 82% in 2003), relatively low incidence of disease in plants considered to be infected by whiteflies and wide distribution of EACMV-UG points to the fact that the CMD pandemic is a chronic in the country and the areas sampled are currently in a stable post-epidemic phase. This situation is comparable to that in areas of East Africa affected by a pandemic during the 1990s, including Uganda, parts of western Kenya and north-western Tanzania. These findings clearly verify the assertion that the CMD pendemic has expanded across Central Africa and provide a
basis for designing interventions and control strategies for the entire region
Incidence and Severity of Cassava Mosaic Disease in the Republic of Congo
Diagnostic surveys were conducted in 2002 and 2003 in order to provide
a comprehensive and detailed assessment of the status of cassava mosaic
disease (CMD) in the Republic of Congo (ROC) and to determine if the
disease was spreading. In 2002, 105 farmers' fields were assessed in
the four major cassava-producing regions of the country. In 2003, 163
fields were sampled in nine regions and Brazzaville Commune. Incidence
of cassava mosaic disease was generally high, averaging 80 and 86 % for
2002 and 2003, respectively; while damage was moderate to severe. In
2002, disease incidence was moderate in Pool (73%) but high in
Brazzaville (81%), Cuvette Centrale (82%) and in Plateaux Region (84%).
Pool region still had the lowest incidence (78%) in 2003, while Sangha
(95%) had the highest incidence. The greatest disease severity was
recorded in Niari region in the south and Cuvette Ouest region in the
north in 2003. East African cassava mosaic virus Uganda variant
(EACMV-UG) occurred virtually throughout the country, commonly in dual
infections with African cassava mosaic virus. The high incidence of
disease in plants considered to be the results of cutting infection
(74% in 2002 and 82% in 2003), relatively low incidence of disease in
plants considered to be infected by whiteflies and wide distribution of
EACMV-UG points to the fact that the CMD pandemic is a chronic in the
country and the areas sampled are currently in a stable post-epidemic
phase. This situation is comparable to that in areas of East Africa
affected by a pandemic during the 1990s, including Uganda, parts of
western Kenya and north-western Tanzania. These findings clearly verify
the assertion that the CMD pendemic has expanded across Central Africa
and provide a basis for designing interventions and control strategies
for the entire region.Les enquêtes diagnostiques étaient faites en Janvier 2002 et
en Février 2003 en vue d'une évaluation compréhensive et
détaillée et mettre à la portée de tous les statuts
de la maladie mosaïque du manioc (MMM) en République du Congo
(RC) et de déterminer si la maladie pouvait se répandre.
Pendant la première année, 105 champs de cultivateurs
étaient examinés dans les quatre régions produisant le
manioc dans le pays. En 2003, un échantillon de 163 champs
étaient sélectionnés dans neuf régions y compris la
commune de Brazzaville. L'incidence de la MMM était
généralement élevée moyennant respectivement 80 et
86% pour l'année 2002 et 2003, pendant que le dommage s'aggraver
de plus en plus. En 2002, l'incidence de la maladie était
modérée dans la région du Pool (73%) mais
élevée en Brazzaville (81%), dans la cuvette centrale (82%)
et la région des plateaux (84%). L'incidence dans la région
du Pool demeurait encore plus faible (78%) en 2003 pendant que Sangha
avait l'incidence plus élevée (95%). En 2003 la plus grande
gravité de la maladie était enregistrée dans la
région de Niari au Sud et dans la région Ouest de la cuvette
au Nord. La variante du virus de la mosaïque du manioc de
l'Afrique de l'Est en Ouganda (VVMMAEO) s'était virtuellement
manifestée à travers le pays; les infections s'étaient
couplées avec le virus de la mosaïque du manioc africain. La
grande incidence de la maladie des plantes considérée
être les résultats de la contagion des boutures était de
74% en 2002. Relativement, la basse incidence dans les plantes
considérées être contaminées par les mouches
blanches et la grande part du VVMMAEO était de 82% en 2003. Ceci a
abouti à la conclusion selon laquelle la pandémie de la MMM
avait contaminé le pays quelques années auparavant et que les
régions ayant fait l'objet de l'échantillon sont actuellement
dans une phase post-endémique. Cette situation est comparable
à celle des régions de l'Afrique de l'Est qui étaient
contaminées par une pandémie les années 1990 y compris
l'Ouganda, les parties Ouest du Kenya et le Nord- Ouest de la Tanzanie