Striga management and the African farmer

Abstract

Striga asiatica and S. hermonthica are widespread plant parasites of cereals in Sub-Saharan Africa. In maize cropland alone, Striga has infested about 2.4 million ha, resulting in yield loss of 1.6 million tons per year, valued at US$383 million. Because the parasite attacks below ground, conventional weeding is largely ineffective. Researchers have been slow to develop other Striga control practices useful to small-scale African farmers. Two recent technical breakthroughs, however, offer opportunities for better Striga management. First, herbicide-resistant maize lines provide several weeks' chemical protection from infection, resulting in over one ton per ha yield improvement and reducing Striga expression by 80%. Second, many legumes induce Striga seed to germinate and die in the absence of susceptible host roots, a characteristic usefully employed in cereal–legume intercropping and rotation. The challenge is to translate these technical achievements into products and technologies available to and adopted by Africa's poor farmers.