Dicamba (2-methoxy-3,6-dichlorobenzoic acid) has been shown to be effective in controlling
Striga asiatica in maize in the USA. Experiments were therefore conducted from 1990 to 1992 to evaluate its effectiveness against S. hermonthica in Western Kenya. Dicamba was more effective when applied at the rate of 0.75 kg a.i. ha
-1 compared to 0.50 kg a.i. ha
-1. Applying dicamba over the top of maize plants or post-directing it to the lower plant part did not significantly affect its effectiveness. Application at 30 days after planting was not as effective as delaying the application to 45 days after planting. Crop injury was observed early in a few cases, though the affected plants later recovered and yield was not affected. Dicamba was not persistent as
Striga emerged later in the season. Although dicamba can provide some control early in the season, its low persistence implies that other control measures need to be integrated with it to avoid subsequent seed production by the
Striga plants that germinate later in the season.
Keywords: Dicamba, maize, Striga hermonthica