Tropicultura (Jan 2009)
Analyse de l'influence du fonds génétique, des conditions climatiques et du mode de protection phytosanitaire sur l'expression de la bactériose chez différentes variétés de cotonnier au Burkina Faso
Abstract
Analysis of the Influence of Gene Pool, Climatic Conditions and Plant Protection Program on the Effect of Bacterial Blight on Different Cotton Varieties of Burkina Faso. In september 2004 and 2005, the incidence and severity of bacterial blight caused by Xanthomonas campestris pv. malvacearum were evaluated on different American cotton varieties (Bollgard II and DP50) and local varieties (FK 37 and Stam 59A), tested at Farako-ba station (Bobo Dioulasso) and at Kouare station (Fada Gourma), which are respectively in the western and eastern region of the country. The design of the experiment was a completely randomized Fisher bloc with four replicates. The incidence was appreciated according to the presence or absence of the disease while a six class scale was used to evaluate the severity of the attacks. The results show that the incidence of the disease was 100%. No immune variety was detected. The mean severity varied from 0.62 to 1.72 for local varieties and from 0.54 to 3.75 for American varieties. The foreign cultivars, with or without transgene, were more sensitive to bacterial blight than the local varieties. At Kouare station, the disease was more aggressive than Farako-ba station in 2004. The disease severity depends on (i) environmental conditions which vary according to years and (ii) plant protection, by insecticide direct treatments or by introduction of Bt gene, which seems to rend them more resistant to the bacterial disease.
