Cotton in Benin: governance and pest management

Key words: cotton, synthetic pesticides, neem oil (Azadirachta indica), Beauveria bassiana,

Bacillus thuringiensis, field experiment, farmers’ participation

 

Pests are one of the main factors limiting cotton production worldwide. Most of the pest

control strategies in cotton production rely heavily on the application of synthetic pesticides.

The recurrent use of synthetic pesticides has large consequences for the environment (air,

water, fauna, and flora) and human health. In cotton growing areas in Benin, targeted pests

develop resistance, and this resistance is extended to malaria mosquitos. Other negative

impacts are pest resurgence and secondary pest outbreaks due to the effects on the beneficial

insect fauna. This dissertation addresses the technical and institutional constraints hindering

the wide-scale use of staggered targeted control, ‘Lutte étagée ciblée’ (LEC, in French) for

cotton production.

Wider adoption of LEC can only be achieved if some institutional changes were to

occur, such as in the role of input suppliers in order to improve the procurement of LEC

pesticides. This can only happen if farmers would be empowered and better organised.

Locally available phytochemicals and biopesticides can be used to address problems related to

the difficulty in obtaining synthetic pesticides, as well as their negative environmental impact.

Neem oil (Azadirachta indica) and Beauveria bassiana are good candidates to be used in an

integrated pest management approach, as their impact on the beneficial fauna is minimal. We

tested whether the efficacy could be enhanced by using mixed formulations of neem oil and

bio-insecticides, but yields obtained with neem oil used alone and mixed with biopesticides

were not different. This suggests an absence of a synergistic effect between neem oil and B.

bassiana (Bb11) and between neem oil and B. thuringiensis. The combination of biopesticides

increased the cost of production more than that of the conventional treatments, compromising

the profitability of such formulations. Participation in the research process increased farmers’

knowledge on pest and natural enemy recognition. The increase in knowledge did not lead to

any modification in farmer practices with respect to the use of neem oil and Beauveria, but it

led to a significant change towards threshold-based pesticide applications. Policy implications

for successfully changing farming practices are discussed.