Nelly Bassily | September 15, 2008
Used cooking oil containers lined with watered-down molasses may be the key to managing a pest that plagues cotton growers. The colour yellow and the sweet scent of molasses are irresistible to bollworm moths. But when they dive in for a snack, they get snagged by the sticky molasses, ensuring that they can’t lay eggs in the cotton field.
This simple but effective device was developed by Ugandan scientist Dr. Ben Ssekamatte. He first tested it on organic cotton fields in Zambia. Recently, he trialed the device at experimental gardens in the Lira and Pader districts of Uganda’s Northern Region.
Bollworms can destroy up to 40 per cent of a cotton crop. The moths lay their eggs on the cotton plant and the larvae attack the plant’s bolls, chewing holes and leaving them open to bacteria and rot. The squares, or fruit buds, of the cotton plant are also affected.
Bollworms are such a concern that, earlier this year, the Ugandan government approved confined field trials of a genetically modified cotton variety that resists bollworms. But Dr. Ssekamatte believes that farmers can fight bollworm and increase their yields with organic techniques. He says the bollworm trap is particularly suited to small-scale cotton farmers.
The materials for the trap are inexpensive and readily available. Three-litre yellow cooking oil containers are usually discarded after use, but they are well-suited to form the base of the trap. A mixture of 20 per cent molasses and water is poured inside. Holes in the sides of the container help bollworm moths find their way to the molasses. Dr. Ssekamatte explains that the trap should be placed three centimetres above the tops of the cotton plants, ready to lure moths away from the crop.
Uganda’s level of cotton production has fluctuated tremendously in past decades. During the colonial period, Uganda was a world leader in cotton production. Now, it produces less than one per cent of the world’s cotton. Many cotton growers have become interested in organic production because of the promise of premium prices.