Title : Management practices for Callosobruchus maculatus (Fab.) for the preservation of cowpea (Vigna unguiculata (L.) Walp) and Bambara groundnut (Vigna subterranea (L.) Verdcourt) in the regions of Dosso, Maradi, and Tillabéri, Niger
Abstract:
In Niger, considerable damage is recorded on grain legumes during storage. For this, diversified means and methods are often used for the management of Callosobruchus maculatus (Fab.). The objective of this study is to contribute to the reduction of post-harvest losses by understanding pest management practices. Thus, surveys were carried out in 16 villages: 10 villages in the Dosso region (Badiffa, Goubawa, Goubaye, Issakitchi, Kaiwa, Kamreye, Mallé, Matankari, Sabarou, Tchito), two (2) villages in the Tillabéri region. (Windé Beri, Barbousayé) and four (4) villages belonging to the Maradi region (Doramaoua, Gazobi, Ido Bissa, Naki Karfi). The methodology thus adopted made it possible to survey 404 heads of households chosen in Dosso (255), Maradi (95) and Tillabéri (54) on their management practices for C. maculatus. A study also focused on wholesale traders (12) from Niébé to Tessaoua, Gazaoua, Boureimi (Doutchi) to understand bruchid management practices. The samples collected made it possible to conduct the analysis of pesticide residues at the Laboratory (LANSPEX). This study showed that certain chemicals encountered are unapproved and of dubious origin, varying depending on the region. Indeed 16.5% of households use unapproved chemical products (Executor (5.20%) and Superdelvap (10.89%)), Rambo/Permethrin 0.60% (0.5%) for the management of C. maculatus from Cowpea. Also, around 43% of chemical products are unapproved and 57% have a very dangerous status according to the WHO. For the management of C. maculatus in Voandzou, producers are increasingly using very toxic chemicals (Phostoxin, Superdelvap) to the detriment of local products. The majority of technologies used seem effective and vary depending on the region. The containers (PICS bags, and polyethylene plastic containers (5L and 25L)) of Cowpea seem effective. Simple polyethylene drums are more used for storing voandzou in Tillabéri (70.4%). PICS bags are used more in Maradi (35.8%) and Dosso (35.3%). On the other hand, the mud attic is found mainly in the Dosso region (37.3%).The average storage duration of Voandzou seeds is higher in Dosso (4.81 months). Analysis of variance (ANOVA) indicates a significant difference at the 5% threshold (P<0.001) between the three regions. The study made it possible to better classify the management methods of C. maculatus according to 4 social categories (Happy, Middle, Poor and Very Poor) using the HEA (Household Economy Approach) initiated by Save the Children in 1990. Some peasant methods (simple woven polypropylene bags), simple bags (woven polypropylene bags) + Superdelvap, can + Phostoxin) appear unsatisfactory for the social categories in Niger. The analysis of pesticide residues revealed the presence of Phostoxin degradation debris supposedly non-toxic in 16.66% of the samples, particularly those coming from the Dosso region. However, no traces of organochlorine, carbamate, organophosphorus and pyrethroid pesticide residues were noted on all the samples analyzed.
Keywords: Cowpea, Voandzou, Storage, Chemicals, Seeds, Technologies, Residues, Social Categories, C. Maculatus
