Intercropping maize with grain legumes for Striga control in Zimbabwe

摘要

On-farm experiments were conducted in Chinyika Resettlement Area during the 1994/95 and 1995/96 rainy seasons at four sites to test the effectiveness of intercropping maize with cowpea, groundnut, field bean and bambara nut in suppressing Striga asiatica (L.) Kuntze. During the 1994/95 rainy season maize/cowpea intercrop supported less S. asiatica plant m~(-2) than sole maize, while other intercrops supported similar numbers of emerged S. asiatica plants m~(-2) as sole maize. Combined analysis oversites showed that the numbers of emerged S. asiatica plants in the intercrops were similar to those in sole maize during the 1995/96 season. However, during the same season the number of emerged S. asiatica plants was significantly (P<0.05) lower in themaize/groundnut intercrop at 8 weeks after crop emergence (WACE) at one site but similar at the remaining sites. Due to moisture stress and severe competition from the parasitic weed, no maize grain was harvested during the 1994/95 season. The maize/cowpea intercrop had the lowest maize stover yield, while the maize/field bean intercrop had the highest stover yield. Maize grain yields were not significantly different for all treatments during the 1995/96 season but the partial land equivalent ratios (PLERs) ranged from 0.8 to 1.70 indicating that intercropping maize with legumes had an advantage over planting sole maize in S. asiatica infested fields.