No abstract

African cotton cultivars produce consistent fiber quality. However, they are far from perfect as they are old, with fiber quality lagging compared to modern cotton cultivars produced in competing countries. This study compared cotton accessions collected across Burkina Faso belonging to the four cultivated species to cultivars from West African countries (Benin, Burkina Faso, Mali, and Togo) plus Chad. The objectives were to quantify the fiber quality components within the collection and to identify accessions with the potential to enhance the fiber quality of African cultivars to address evolving markets and environments. In terms of lint percent, accession E32 (G. hirsutum) outperformed all cultivars by 2.5 to 4.6%. Accessions E25, E1, and E12 (all G. barbadense), and E53 (G. hirsutum) produced fibers 1.7 to 4.6 mm longer than the control cultivars, except for cultivar FK37. All G. hirsutum, G. barbadense, and G. herbaceum accessions had longer fibers than all control cultivars. Some G. hirsutum accessions with perennial tendency, averged 3.5 to 5.5% greater elongation. For fiber strength, all G. barbadense accessions appeared better than comparision cultivars and E13, E38 (G. arboreum), and E43 (G. herbaceum) produced fibers with bundle strength values from 7.3 to 10.2 kN m Kg-1 greater than any comparision cultivar. Further enhancement of certain African cotton fiber properties could be possible through a research-based breeding program to identify and use current variability found in Africian accessions as well as other accessions.

Le coton du Burkina Faso est presqu’entièrement exporté ; les variétés cultivées doivent régulièrement répondre aux exigences du marché. Une fratrie de lignées de cotonnier a été comparée à deux variétés, FK37 et Stam 59A, respectivement dans les zones cotonnières humides et sèches de 2006 à 2009, pour mettre en exergue celle qui améliore les performances agronomiques et technologiques de fibre de ces témoins. A l’issue d’évaluations multilocales, FK64 et FK69 ont été identifiées comme de potentielles nouvelles variétés et testées en milieu paysan. Dans les zones humides, FK64 et FK69 n’ont pas apporté d’amélioration significative ; il est inopportun de les y vulgariser. Dans les zones sèches, FK64 a le mieux performé et a été retenue pour y être vulgarisée. Elle apporte un surplus en pourcentage fibre (+ 0,41%) et en seed index (+ 0,35 g). Aussi, elle apparait meilleure que Stam 59A pour la longueur (+ 1,44 mm) et la ténacité (+ 1,90 g/tex), deux caractéristiques déterminantes du marketing de la fibre. Avec la suspension du coton Bt et le retour à la culture conventionnelle, FK64 lancée en culture commerciale a convaincu. Elle pourrait être candidate à la transformation en cas de retour dans la technologie Bt.Mots clés: Evaluations multilocales, tests variétaux, caractéristiques agronomiques, caractéristiques technologiques, Burkina Faso.   English Title: Assessment and selection of a cultivar of cotton (FK64, Gossypium hirsutum L.) in Burkina Faso Cotton produced in Burkina Faso is almost entirely exported; so cultivars must be developed following the market demand. A sibling of cotton lines was compared to two varieties, FK37 and Stam 59A, respectively in humid and dry cotton production areas between 2006 and 2009 to highlight which one enhances agronomic and fiber quality performances compared to the local control. After multilocation trials, FK64 and FK69 were highlighted as promising news varieties then evaluated under farmer’s conditions of production. In the humid areas, FK64 as well as FK69 did not bring any significant improvement; it was not recommended to release any of them there. In the dry production areas, FK64 performed better, then it was retained to be possibly popularized. It brings a surplus in terms of ginning out turn (+ 0,41%) and seed index (+ 0,35 g). Moreover, it outperformed Stam 59A in fiber length (+ 1,44 mm) and strength (+ 1,90 g/tex), two major cotton fiber marketing properties. At the morrow of the suspension of the Bt cotton and back to conventional production, FK64 was launched in commercial production and it convinced. It could be aspirant to Bt introgression in case country resumes back to the technology.Keywords: multilocation trials, varietal trials, agronomical characteristics, fiber properties, Burkina Faso.

Cotton is the main cash crop in Burkina Faso. However, production is highly affected by bollworms and leafworms in the last years due to the spread out of the resistance of bollworms to most used The results show that without insecticide application, the flow of transgene near the source at 2 m (4.63 %) was different and higher than those of more distant rates. With insecticide application, no transgene flow was detected at ≥ 25 m from the transgenic field. Study must be continued after commercial adoption to draw concrete conclusions and to suggest some strategies to prevent Bt cotton transgene outflow in Burkina Faso.