Like metal drum silos used for grain storage, the PICS bag is sealed tightly and pests in the grains cannot survive for long as they are deprived of oxygen.
After every harvest, farmers usually have problems storing maize, beans, rice, sorghum, millet and other cereals. The problem is worsened by the fact that most of the pests have developed resistance to the common chemical pesticides in the market. Research has shown that in Africa, farmers lose more than 40 per cent of their crop harvest every year due to pests and lack of proper and efficient storage.
A new storage bag developed by Purdue University, which is being tested by icipe may be a solution to storage problems faced by thousands of farmers. The Purdue Improved Crop Storage (PICS) bag has been used by millions of farmers and consumers to protect the harvested grains in West and Central Africa. The bag has also been effective for storage of grains like maize and beans in East Africa.
The PICS bag is made of three layers of plastic material that deprive pests in stored grain of oxygen. It consists of two inner bags made of high density polyethylene material and an outer sack composed woven bag. The inner liners have walls of 80 microns thickness, which prevents air from moving across the wall of the bag. The outer woven bag enables easy handling.
The bag works in the same way as metal silos that are used for grain storage- insects cannot survive without oxygen since they use it to digest food to get energy for growth, development and reproduction. When the bag is sealed, the insects in the grains use up all the oxygen in the container while raising the carbon dioxide level. When the oxygen level in the container goes down, the insects cannot feed, their growth, development and reproduction is stopped. They eventually stop growing and die. Insects at larvae and pupae stage are the first to die, leaving the stored grain free of any pests. PICS bags also help preserve the quality of grains. Even after several months of storage, the quality of grain is as good as when it was put in the bag. A PICS bag costs Ksh 200.
Interested farmers can purchase them through Bell Industries Ltd, P.O. Box 18603 -00500, Nairobi Tel 020 6535 828/9 23688 703, 0733 764 562.