Assessment of Tolerance Potential of Cassava (Manihot esculenta Crantz) Genotypes to Whiteflies (Bemisia tabaci) in East Cameroon
A. Mogo *
Ministry of Scientific Research and Innovation, P.O.Box 1457, Yaoundé, Cameroon.
M. W. C. Tagong
University of Yaoundé I, P.O.Box 812, Yaoundé, Cameroon.
E. L. Ngonkeu Mangaptche
University of Yaoundé I, P.O.Box 812, Yaoundé, Cameroon and Institute of Agricultural Research for Development (IRAD), P.O.Box 2067, Yaoundé, Cameroon.
J. N. Fomekong
University of Yaoundé I, P.O.Box 812, Yaoundé, Cameroon.
Fotso .
University of Bamenda, P.O.Box 39, Bambili, Cameroon.
N. Woin
Ministry of Scientific Research and Innovation, P.O.Box 1457, Yaoundé, Cameroon.
*Author to whom correspondence should be addressed.
Abstract
Cassava is a basic staple in Cameroon whose industrialization faces major constraints especially those related to the management of whiteflies (Bemisia tabaci), a vector of the African cassava mosaic virus (ACMV). This work has as main objective to identify the tolerance of some cassava genotypes to whiteflies and to undertake an agro-morphological characterization of infected cultivars to the ACMV. Data were collected from September to November 2015 on six cultivars: Five improved (TMS92/0057, TMS92/0067, TMS92/0326, TMS96/1414 and TME419) and one local (NTOLO), on a young plot (three months old) and mature plot (six months age). Adult whiteflies were counted on the underside of the last leaves of one apex and for nymphs; they were counted randomly between the ninth and fourteenth leaves. Three cultivars (TMS96/1414; TMS92/0057 and TMS92/0067) ramified early with a large number of apices. For the younger plants (three months old), three cultivars (NTOLO, TMS96/1414 and TMS92/0326) harbored the largest number of adult whiteflies, whereas two others (TMS92/0326 and TME 419) were the most attacked by the ACMD. Younger plants (3 Months old) were most vulnerable to ACMV attack (r = 0,307** with whiteflies population), while the older ones (at 6 Months), represent early senescence period for short-cycle genotypes.
Keywords: Cassava, tolerant cultivars, whiteflies, African cassava mosaic disease, severity, incidence, East-Cameroon