Some are white, others tan, gray, black, brown and even red. But no matter what color, the small cowpea is the lifeblood to millions of people in West Africa.
“When cowpeas come in from the field, the weevil infestation is very small. It’s not a problem at harvest. But each female weevil produces 40 or 50 offspring in a matter of four weeks. In a month you have more than 1,600 weevils, and within a few months the crop is completely lost. The people who grow cowpeas are often poor and don’t get much from harvest anyway, so losing the crop is completely devastating,” says Larry Murdock, a Purdue entomologist.
Jim Murren, the international Extension coordinator for International Programs in Agriculture at Purdue, says: “Cowpeas are a major part of the diet in West Africa. It is often called ‘poor man’s meat’ because it is such a vital source of protein for those families who can’t afford other protein sources.”
Diet isn’t the only place where cowpeas are important, however. West and Central Africa produce 3.7 million tons of cowpeas each year — 66 percent of which comes from Nigeria alone. “Nigeria is a world leader in cowpea production, growing as much as 2.6 million tons annually. So in addition to being a major food source, this crop is big business,” Murren says.Extension hits the road
That’s why five Purdue Extension professionals traveled to Nigeria recently to train the people to use a new storage technology: hermetically sealed, or airtight, plastic bags. Often referred to as triple bags, this technology consists of two clear plastic bags inside one another and an outer bag of woven polyethylene. Farmers fill the innermost bag with cowpeas and seal each layer individually by expelling the air in the bag, twisting the top closed and tying it shut. The idea is to make sure the crop is stored in as airtight an environment as possible so weevils suffocate. The bags come in both 50- and 100-kilogram sizes, and can save an individual farmer nearly $150 in crop losses each year. In a place where most families live on less than $2 a day, that money can mean the difference between life and death.
The project, titled Purdue Improved Cowpea Storage, or PICS, began more than 20 years ago, when Murdock and other Purdue Agriculture researchers began looking at ways to curb the devastation caused by the cowpea weevils. Now, thanks to an $11.4 million grant from the Bill and Melinda Gates Foundation, teams of Purdue Extension professionals have been traveling around West African countries to train farmers to use the bags. The PICS initiative is a five-year project that will encompass 28,000 villages in 10 West African nations, and when it’s all said and done, the PICS team hopes to have 50 percent of the privately stored cowpeas in triple bags.Educators go village to village
The most recent PICS team of Murren; Bill Horan, BS ’83, MS ’89, Wells County; Maria Restrepo, Pike County; Adrienne Held, Warrick County; and Jeremy Weber, BS ’99, MS ’06, Franklin County, spent 11 days in August traveling thousands of miles around Nigeria to host “train the trainer” sessions. They taught villagers how to use the bags in hopes the villagers would share their knowledge with farmers in the countryside.
Since weevil populations are low at harvest, it might seem obvious for farmers to sell the crops immediately. But much like the commodity markets in the U.S., the price of cowpeas hits rock bottom when the market is flooded and demand is low. Farmers also need to be able to store some of the crop for their families’ nutritional needs. In a desperate attempt to keep their families fed and money in their pockets, farmers often use ineffective storage methods.
“The people try to store cowpeas using methods like barrels, woven bags, kerosene, ash and even some chemicals to keep the weevils out. Unfortunately, these methods either don’t prevent infestation or the chemicals are poison. We hear stories about people getting sick, or even dying, after they’ve consumed stored cowpeas,” Murren says.
When these storage methods don’t work and crops are lost, families are forced to go to the market to purchase more. “Not only is it a problem that farmers are having to sell their cowpeas for very little profit at harvest, but most of them will run out of their own personal supply before the next harvest, and when they do, they have to buy more. Since supply is low at that time and demand is high, families are forced to pay significantly higher prices for potentially toxic cowpeas,” Murren says.
Murdock, who had been studying cowpea varieties genetically altered to be weevil resistant, was very familiar with the storage issues and decided he wanted to help. So, in 1986, he and a team of researchers traveled to the West African nation of Cameroon to see what types of cowpea storage technologies they could devise. “There’s no magic bullet, so we needed to create a series of technologies for people to choose from,” Murdock says. “We went to the villages to survey how the crop was grown and treated, and over the next two years we devised a series of technologies, including the hermetically sealed bags.”