Triple bagging for cowpea storage in rural Niger: Questions farmers ask

Abstract

From 2007 through 2011 experiments were conducted and observations made in the West African country of Niger to address questions or concerns raised by farmers and extension workers about the Purdue Improved Cowpea Storage (PICS) triple bagging technology being widely disseminated in the country. When 518 triple bags stored by farmers in different villages across southern Niger were studied, the airspaces within the bags typically contained reduced levels of O2 while CO2 was increased. Bagged stored cowpea grain was much less damaged and had higher market value compared to grain for sale in the local markets. Two HDPE plastic liners rendered the system substantially airtight and improved preservation of the grain compared to a single HDPE liner. The concentrations of O2 and CO2 were similar along the length of the triple bag, in top, bottom and middle sections. Cowpea grain stored for 18 months in PICS bags retained high rates of germination. Briefly opening bags that had been closed for long periods did not affect the preservation of the grain. Treating the contents of the triple bag with phostoxin did not enhance preservation. Leaving the triple bag containing infested cowpea open for several days prior to closure increased the risk of blemishes or holes in the HDPE liners caused by cowpea bruchid, Callosobruchus maculatus (F.) adults.