Cotton breeding progress stagnation, changing production conditions, and continued high fiber quality demands are challenging the cotton industry in Burkina Faso. The F₁ populations developed by half diallel crosses between germplasm from Texas A&M AgriLife Research and Burkina Faso were evaluated for several agronomic traits. The aim was to identify the most promising parents and hybrids for further varietal improvement. Three AgriLife parents helped improve the most important targeted traits. Parent 15-3-416 reduced days to 50% flowering (−3.14 days) and shortened plant height (−22.25 cm) in hybrids while 16-2-216FQ improved their fiber percentage (+2.68%). Hybrids with Burkina Faso elite cultivar E32 as male parent and the three best AgriLife parents as the females showed good specific combining ability (SCA). FK37 × 15-10-610-7 and FK64 × 15-10-610-7 showed heterosis for earliness by reducing, respectively, days to 50% flowering (−4.27 days) or days to 50% boll opening (−3.95 days) below parent means. E32 × 16-2-216FQ and FK64 × 16-2-216FQ increased fiber percentage by +1.75% and +2.06%, respectively. FK64 × 15-3-416 increased seed index (SI) (+0.62 g) and fiber percentage (+1.19%), while maintaining other traits at the parents’ average levels. E32 × 15-3-416 showed the most heterosis for desired improvements, reducing days to 50% flowering (−4) and increasing the number of bolls/vegetative branch (+3.05), number of bolls/fruiting branch (+6.38), number of bolls/plant (+13.49), boll weight (+1.53 g), SI (+0.40 g), and fiber percentage (+1.18%). Inter-program crosses show the potential to enhance genetic diversity in Burkina Faso’s breeding program. Subsequent selection methods must be carefully applied considering the Burkina Faso breeding objectives for future cultivars.

Genetically modified cotton (GMC) was compared with two conventional cultivars, using data from trials and commercial farms. Objectives were to highlight disparate agronomic and technological performance parameters and identify perspectives to Burkina Faso comeback to GMC. Results showed that compared materials are similar for most agronomic characteristics, except fiber percent. As this important parameter is concerned, GMC outperformed conventional cultivars in trials (+1.2 to +2.2%) and some commercial fields by +0.3, +0.5, +0.6 and +1% at Banfora, Koudougou, Houndé and Dédougou, respectively. For fiber quality, they did not show significant difference in maturity, micronaire, uniformity index, elongation, short fiber index, reflectance and yellowness. For two important parameters in cotton fiber marketing, Upper Half Mean Length and Strength, GMC was highly handicapped by -1.43 to -2.09 mm and -19.70 to -40.67 kN m Kg-1 compared to conventional cultivars, in commercial production. In trials, differences averaged -1.75 mm and -32.34 kN m Kg-1. Differences between compared materials are genetic, due to failure in recovering important characteristics after the transgenic conversion. Local GMC cultivars could be an asset if more perfectly achieved, on site selected and pre-release evaluated, to take into account local production particularities. Key words: Genetic conversion, Bt cotton, agronomic characteritics, fiber properties, Burkina Faso.

The market value of cotton in exporting countries, such as Burkina Faso, depends on the quality of major fiber properties. A lack of variation among the genetic resources available in Burkina Faso hinders breeding progress to meet fiber quality demands in future cultivars. F₁ populations from a half diallel crossing scheme between lines developed at Texas A&M AgriLife cotton breeding program at Lubbock and germplasm accessed from Burkina Faso were evaluated for fiber property enhancement. Crosses exclusively within common origin materials did not result in highly enhanced hybrids. Hybrids within American materials expressed significant SCA effects undesirable for future cultivars in Burkina Faso. Five hybrids within the Burkina Faso material expressed significant SCA effects: two of them implicating FK37 as the better parent in transmitting superior targeted fiber traits to its progenies. Hybrid FK37xE9 significantly enhanced UHML, Str, UI and SFI but not Mic and Rd. Inter-program hybrids with at least one significant SCA effect were crosses with female American lines and male Burkina Faso parents. Hybrids E53x16-2-216FQ, E53x15-10-610-7 and E32x15-10-610-7 showed significantly improved Str and UI for the most economically important traits, which also include Mic, UHML, SFI, Rd and +b. Together, the GCA and SCA effects, heritability and correlations showed more additive than non-additive gene actions. Therefore, knowledge of the best combiners and hybrids could be used in the cultivar development process to enhance value with improved fiber characteristics.

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 pesticides. This has led to experiment on Bt cotton from 2003 to 2007. The inevitable coexistence between transgenic and conventional cottons requires the assessment of transgene outflow. The study was carried out from 2004 to 2006, at Farako-Bâ, Boni and Kouaré. The presence/absence of transgenes was assessed using Bollgard II detection kits. The experimental design consisted of a Bt plot surrounded by a non-transgenic field. Different distances between the Bt and the non-transgenic field were considered. Application and non application of pest control measure was also taken into account. 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. Key words: Transgenic cotton, Bollgard II cotton, Transgenes, transgene outflow, immunological test, Burkina Faso.