In 2008, the commercial cultivation of Genetically Modified (GM) cotton (Bollgard II) started in Burkina Faso. The adoption rate increased rapidly in subsequent years to reach around 70% in 2014. Although some criticisms were raised concerning the suitability of the technology for the farming system in Burkina Faso, the introduction of transgenic cotton in the country was generally regarded as a great success. Despite this, during the 2016-2017 agricultural campaign, the government of Burkina Faso decided to suspend the cultivation of Bollgard II. In this context, this paper investigates farmers' knowledge, perceptions, opinions and attitudes towards Bollgard II as well as their views on the recent decision to suspend its cultivation. Data was collected from 324 cotton farmers, both growers of conventional and Bollgard II. The results showed that the farmers surveyed had a poor knowledge concerning the core concepts of biotechnology and Bollgard II in particular. Moreover, the regulatory oversight of the implementation of the technology was found insufficient, as illustrated by the lack of compliance with prescriptions concerning refuge areas and pesticide treatments. Nevertheless, overall, the farmers interviewed had a slightly positive opinion about the effects on yield, income and their wellbeing. In particular the reduction in pesticide treatments was perceived very positively by all respondents. Although the study finds that the majority of farmers disagreed with the recent suspension of Bt cotton cultivation by the government, it also makes clear that a thorough debate on the technology and its implementation is necessary.

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.

In cotton and cereals production systems, the most important cause of soil fertility degradation is the inappropriate crop residues management. In a long-term experiment carried out from 1982 to 2012, the effects of crop residues management (CRM) during 30 years on soil chemical properties and crops yields were evaluated in a cotton-cereals rotation. The experimental design was nonrandomized blocks having 3 treatments. Extensive CRM with exportation of residues was compared to semi-intensive CRM and intensive CRM and recycling the residues into compost and farmyard manure, respectively. The results showed that continuous cropping of soil during 30 years affects significantly (p <0.05), the main chemical characteristics of soil for comparing crop residues management practices. From 25 th to 30 th years, the decrease of carbon, Nitrogen and total P contents was very high as well as those of exchangeable bases, particularly, Ca 2+ and Mg 2+ contents. The cation exchange capacity (CEC) decrease was 63, 31 and 26%, respectively in extensive, semi-intensive and intensive CRM. Recycling crop residues into compost or farmyard manure does not prevent soil chemical degradation and crops yields decrease but allowed to reduce them significantly. Moreover, integrated management of crop residues, a reduction of soil tillage frequency and preventing soil erosion are suggested for a sustainable maintenance of soil chemical properties.

While a fierce debate about the advantages and disadvantages of genetically modified crops is ongoing, it is surprising that farmers are often not consulted. In Burkina Faso, where insect resistant Bollgard II® cotton (further termed Bt cotton) was commercially released in 2008, studies highlight that cotton producers are in general satisfied with the reduction in insecticide use while the economic benefits are a source of controversy. To gain insight into farmers’ preferences towards attributes in cotton cultivation, a discrete choice experiment (DCE) was developed. Five key attributes were identified to describe improved cotton varieties: seed development and provenance, seed costs, yield, required number of insecticide sprays, and preservation of agricultural practices. Farm-gate surveys were conducted among 324 cotton farmers in Western Burkina Faso. The results show that overall, farmers have a positive preference towards yield improvements and a negative preference towards pure private seed development and towards an increase in the requested number of insecticide applications or in the seed costs. According to their varieties at the time of the surveys (Bt and non-Bt), a difference was observed regarding their preferences for a status quo situation, indicating that those growing Bt had a stronger preference to keep the status quo than non-Bt farmers. When dividing the sample in segments based on the farm size, it was shown that there were different preferences with respect to the development of the variety and the required number of insecticide applications. Overall, it can be concluded from this study that economic benefits (linked to higher yields, lower seed costs, or reduced pesticide use) shape farmer’s preferences.