Airtight plastic bags can help farmers protect their harvests without the use of harmful chemicals. These bags are designed to keep air out of crops in storage. They are a simple way to fight insects and keep food fresh. Ten countries in West and Central Africa are involved in a project to improve the storage of cowpeas, also known as black-eyed peas. Farmers can lose much of the harvest to insects called bruchids. These grow from egg to adult in a few weeks and then lay forty to sixty more eggs. They can destroy the whole harvest within months. Farmers can sell their crop immediately. But selling at harvest time means more competition and lower prices. Or they can use pesticides to kill the bugs. But crop scientist Dieudonne Baributsa says that is also risky. He said farmers may misuse or overuse the pesticide. Mr. Baributsa is a researcher at Purdue University in the American state of Indiana. The project is called PICS, for Purdue Improved Cowpea Storage. Mr. Baributsa says the storage bags are thick enough that any insects already in the cowpeas will die from a lack of oxygen. The lack of air will also help prevent the growth of bacteria and fungi that can ruin the harvest.The bags cost about two dollars each. Mr. Baributsa says that is not much, especially if it means farmers can wait long enough to get a better price for their crop. The bags are produced locally. Donors currently support the project, but the groups involved are working to build a lasting market for the bags. The bags are being advertised by radio and mobile phone videos in local languages. The project includes Nigeria, Niger, Burkina Faso, Ghana and Mali. The other countries are Senegal, Cameroon, Benin, Togo and Chad.A company based in the United States called GrainPro makes another kind of airtight bag. These are called SuperGrainbags. Phil Villers, the company president, says safely storing a harvest not only earns more money for farmers. It also reduces the amount of food lost to insects, spoilage and mishandling. For VOA Special English I’m Alex Villarreal.