Effects of witchtweed (Striga species) control methods on growth and yield of maize (Zea mays L.) in Swaziland

Abstract

Striga hermonthica and S. asiatica arc parasitic weeds that reduce yield in cereal crops. Information is scarce on the response of Striga to weed control methods in Swaziland. Therefore, a held experiment was conducted in 2006/2007 cropping season, to assess Striga control methods in maize. The experimental design was a randomized complete block, using a 4 x 3-factorial arrangement, to assess four maize varieties and three weed control methods. Results showed that Imidazolinone-resistant (IR) maize variety. KB 04 OA10). had a significantly better Striga control than other maize varieties. The pre- and post-emergence herbicide mixture of Bladex plus and Bullet was more effective in Striga control, and effected sustainable weed control over the selective hand-weeding method. Grain yields were significantly higher with SC 403 + Bladex plus (2236.9 kg ha-1) and using selective hand­ weeding than SC 403 + Bladex plus + Bullet (3591.9 kg ha-1); the lowest yield (1279.8 kg ha ’) was from CML-181 combined with hand weeding. Nevertheless, the local maize variety, SC 403, was the highest yielding (3034 kg ha-1), which was 47.4% higher than the best 1R- maize variety. 1R maize varieties have a potential for reducing Striga growth and development, and combined with the use of herbicides, maize yield in Striga-infested fields in Swaziland could be improved. Fanners who can afford lR-maize and herbicide technology are encouraged to use Bladex plus in combination with Bullet, for pre-emergence weed control.