The parasitic weed Striga causes yield losses of 30-80% on 2.5 million hectares of crops in Africa. Striga seeds germinate and attach themselves to the roots of crop plants below ground. Striga sucks nutrients and water from the crop plant. The purple Striga flower appears above ground attached to the crop plant. A promising herbicide technology has been developed. The crop seed is coated with a herbicide. Striga seeds germinate, attach to the crop root and are killed by the herbicide. The herbicide technology is known as “IR-maize.”
“Striga hermonthica (L.) Benth. or witchweed is a parasitic weed that attacks maize, sorghum, and pearl millet. It has become an increasing problem to small-scale subsistence farmers in sub-Saharan Africa and represents today the largest single biological barrier to food production in the region…. Striga infestations can become so severe in all major cereal producing regions of Africa that farmers will abandon their fields to cereal production and therefore large swathes of Africa will be precluded from becoming major cereal producing areas.
With this seed coating technology, Striga seeds after germination and before attachment and Striga seedlings that attach are controlled when the herbicide concentration in the soil or plant is adequate, thereby protecting the maize plant when it is most sensitive to parasitism.
New technologies being developed should be tested on-farm, under researcher- as well as under farmer-managed conditions before general dissemination…. Therefore, a set of trials, surveys, and farmer evaluations were conducted in western Kenya, parallel to the development of IR-maize.
IR-maize showed good Striga control and a dramatic yield increase of 2,400 kg ha−1 (from 1,300 to 3,700 kg ha−1).”
Authors: Ransom, J., et al.
Affiliations: North Dakota State University.
Title: Herbicide applied to imidazolinone resistant-maize seed as a Striga control option for small-scale African farmers.
Source: Weed Science. 2012. 60:283-289.