Abstract

MOISES-CAPENDA DA ROSA, Jesus J.; MIRANDA-CABRERA, Ileana  and  MARTINEZ-ZUBIAUR, Yamila. Epidemiology of african cassava mosaic diseases in Huíla province, Angola. Rev. Protección Veg. [online]. 2018, vol.33, n.3 ISSN 2224-4697.

The epidemiological factors influencing on the incidence and severity of the African Cassava Mosaic Disease (CMD) were evaluated in two localities of the province of Huila, Angola. Twenty production fields were monitored, and a survey was applied to the farmers. One percent of the plants growing in each field was sampled in June, 2016; February and June, 2017; and February, 2018. Severity and whitefly density were compared by an analysis of variance. CMD symptoms were observed in 100 % of the fields, and the severity showed significant differences for both locations in each period. In Caluquembe, the density of whiteflies (Bemisia tabaci) was greater in June 2016 than in the rest of the periods analyzed, while, in the same period, it was significantly lower in Kuvango. Severity was determined not only by the density of the insect. The climatic variables analyzed showed that temperature and humidity had the greatest influence in both locations, although rainfall and altitude also influenced. The analysis of the fraction attributable to the risk permitted the estimation of the risk on CMD severity by factors like field size, cutting origins, host crops (cabbage and tomato crops) in the field or nearby, and no use of physical protection measures. It was detected that more than 66 % of the fields surveyed were exposed to these risk factors. The results confirmed the need for making changes in the tactics of CMD management in order to reduce its incidence and severity.

Keywords : Begomovirus; CMD; whiteflies; cassava; Huila; Bemisia tabaci.

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