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Abstract

Cassava Mosaic disease (CMD) is transmitted either through infected cuttings or by whiteflies. We investigated how phytosanitation methods could affect cassava varieties responses to CMD infection and its vectorand the relationship between vector abundance and CMD incidence. The experiment was set in a completely randomized design with three phytosanitation methods applied on four cassava varieties. CMD severity and whitefly population were assessed at 1, 3, 6 and 9 months after planting. Yield data was recorded at harvest, 12 months after planting. Phytosanitation had effect on CMD incidence on all varieties except the local check which had more than 90% of its plants infected. There was no difference in whitefly population abundance between treatments. We found a negative correlation between vector abundance and CMD incidence with variety 92/0326 having lowest CMD incidence and more whitefly counts. At harvest, main difference in the fresh root yield was observed between the removal treatment and the others. Large difference in yield were observed between varieties, with the local variety producing less than the other varieties. The combination of phytosanitation and cassava varieties with initial level of CMD resistance can reduce the transmission of CMD in cassava fields in the humid tropical forest.

Parasitism of the whitefly Bemisia tabaci by aphelinid parasitoids on cassava across five agro-ecological zones of Cameroon

“…Management of B. tabaci often requires an integrated approach that considers one or more management options (Van den Elsen-van den et al, 2016). Pesticides are frequently used in temperate regions to control B. tabaci populations, but they are not widely used in SSA, except on susceptible high-value vegetable crops (Wilson and Tisdell, 2001;Aktar et al, 2009;Maitah et al, 2015;Mahmood et al, 2015;Fotso et al, 2017). Factors such as temperature, precipitation, relative humidity, altitude, host-plant resistance, and natural enemies are considered key factors in natural whitefly mortality and can, under certain conditions, limit the size of whitefly populations (Kedar et al, 2014;Swati and Rolania, 2017).…”