The parasitic weed species Striga asiatica (L.) Kuntze is one of the major constraints in maize production in Malawi. Studies were conducted in 1999/2000 season to evaluate use of herbicide, resistant varieties and fertilizer application as components for integrated management for S. asiatica in Malawi. Two promising open-pollinated varieties from the International institute of Tropical Agriculture (IITA) were evaluated under S. asiatica infection at Chitedze Research Station and 5 farmers' fields at 0 and 59:21 :0+4S kgha-1 fertilizer rates. Another trial investigated the effects of seed dressing with Imazapyr (an acetolactate synthase IALSI -inhibiting herbicide) at 0 and 45 gha-1 and two fertilizer rates (0 and 59:21 :0+4S kgha-l) on maize with ALS target site resistance on Striga suppression and grain yield also at Chitedze Research Station and 5 farmers' fields. In the variety trial genotypes did not significantly suppress Striga at al\ sites (P>0.05), while fertilizer use was important at one site only, where it increased emergence from 17 to 36 plants m-2 (PSO.05). Fertilizer increased yields at al\ sites (PSO.05). The local OPV (Masika) gave significant yield advantages at most sites. In the herbicide trial, Imazapyr suppressed Striga emergence at al\ sites, but increased yield at only one site. In contrast, fertilizer application had no effect on Striga emergence (P>0.05, but significantly increased yield at al\ sites (PSO.05). Fertilizer use is found to be the single most important factor in increasing maize yield under S. asiatica infection, while herbicide use is important for reducing emergence.

Conservation Agriculture Program

Text in English

0410|AGRIS 0401|AL-Maize Program

INT2340

CIMMYT Staff Publications Collection