Analysis of Rainfed Sorghum bicolor (L.) Moench Variabilities (Njigaari and Mbayeeri) Ecotypes for their Improvement and Striga hermonthica (Del.) Benth Controls in the Sudano-sahelian Zone of Cameroun

The agromorphological and genetic parameters of sorghum are important keys in rainfed sorghum production processes. To know the genetic diversity and agromorphological characteristics under striga infestation of this cereal in the Sudano-Sahelian zone of Cameroon, a survey near to 230 farmers were done. Survey was followed by a collection of rainfed sorghum accessions in 2015 and 2016 in 16 villages of the 4 Divisions namely Mayo-Danay, Mayo-Kani, Mayo-Louti and Mayo-Rey of North. The field trials were conducted in Touboro from 2016 to 2017 with a split plot design and composed of 24 factors (accessions) in a naturally striga-infested plot. Results showed that sorghum ecotypes varied significantly (P < .05) according to sorghum height, stem diameter, number of leaves, panicle weight and seed yield. Eight (8) genetic and agro-morphological diversity groups were defined from Principal Component Analysis (PCA) and Hierarchical Ascendant Classification (HAC). These groups are distinguished by the r=0.988 value of the similarity coefficient. Surveys resulted in 14 endogenous striga control techniques divided into three categories, namely cultural control, chemical control and biological control. The agro-morphological parameters that determine the choice of ecotype by the farmers were among others edaphic constraints, climatic constraints, pest pressure, taste quality, culinary uses, glume and grain color, duration of the ripening cycle which can be very early, early and late. Mbayeeri accessions such as LMO-LT18; LMO-LT19; LMO-LT20; LMO-LT21; LMO-LT22; LMO-LT23 and GD-LT03 were more solicited by farmers because of their resistance to striga and their adaptation in flooded soil despite the late development cycle. While the accessions TO-MPP15; KW-CP09; GD-CP14; GDO-MP07; GD-MP04 and LMO-CP17 were appreciated by farmers because of their earliness and resistance to striga. Some ecotypes namely GD-MP04, LMO-LT18, TO-MPP15, SD-CPP11, ZD-CPP12, LMO-LT19 and LMO-LT23 were more solicited and well appreciated by women to prepare local beer according to taste quality and striga tolerance. While, accessions like KW-MPP08, GDO-MP07, LMO-LT20, LMO-LT21 and LMO-LT22 were very well appreciated for couscous and porridge food prepared by women. So, in the local market these accessions are very expensive. A genetic improvement program readjusting the late development cycle of appreciated, solicited and tolerant sorghum ecotypes to striga should be an important asset to striga control and for the improvement of socio-economic conditions of farmers in northern Cameroon.