African Cassava Whitefly, Bemisia tabaci, Resistance in African and South American Cassava Genotypes

Biochemical factors associated with cassava resistance to whitefly infestation

“…The high whitefly feeding was also shown by the sooty mold increase in susceptible genotypes (NASE 13, UG 120170 and UG 130068) from 90 to 180 DAP ( Table 7), indicating that there were increased defense responses such as peroxidase and tannin and supported the report of War et al (2012). Similar results were reported by Omongo et al (2012), who showed increased feeding damage observed on various cassava land races at 83 days after planting. Howeler (2012) reported that most indirect damage including foliage feeding on cassava was observed between 90 to 180 DAP.…”

“…A similar association was reported in several studies (Omongo et al, 2012;Shah et al, 2015;Sing'ombe et al, 2015), indicating that increased plant whitefly population results in increased feeding and increased in defense response reactions in resistant genotypes (Gerling, 1990;War et al, 2012).…”

Sources of pest resistance in cassava

“…Of these, landrace M Ecu 72 has received the most attention from research (e.g., Bellotti and Arias, 2001;Carabalí et al, 2010a, b), being used in crosses with M Bra 12, which resulted in the resistant hybrid Nataima-31 (Arias et al, 2004). In a recent study, M Ecu 72 also showed promising levels of resistance to African populations of B. tabaci, which are becoming increasingly serious cassava pests on that continent (Omongo et al, 2012). However, the extent to which resistance to A. socialis is associated with resistance to B. tabaci is not known, and should be examined.…”

“…Less known, but thought to be similarly destructive, is a complex of monophagous cassava whiteflies largely dominated in the Americas by Aleurotrachelus socialis Bondar (Bellotti et al, 1999). In Africa, the polyphagous species Bemisia tabaci (Gennadius) is the most important whitefly pest (Omongo et al, 2012). Several thrips species, notably Corynothrips stenopterus Williams and Frankliniella williamsi Hood, are also considered major cassava pests (Bellotti and Schoonhoven, 1978;Bellotti et al, 1987), but their impact is less serious than that of the other arthropods mentioned above (Schoonhoven and Peña, 1976;Bellotti et al, 1999).…”

Status of cassava mosaic disease and whitefly population in Zambia

“…The presence of sooty mould was indicative of high whitefly populations particularly in Western, NorthWestern and some parts of Eastern Province. Sooty mould is not common in Zambia unlike in East Africa (Omongo et al, 2012). The large whitefly populations has effects on cassava plants; direct feeding damage by whiteflies and the production of honey dew, which falls onto the lower leaves.…”