Field inoculation with arbuscular mycorrhizal fungi reduces Striga hermonthica performance on cereal crops and has the potential to contribute to integrated Striga management

Maize and sorghum were grown in the field in north Cameroon, Africa, during the cropping seasons (June-October) of 2000 for maize, and 2001 and 2002 for sorghum. Both cereals were grown in fields infested with or free of seeds of the root hemiparasite Striga hermonthica, and with or without inoculation with arbuscular mycorrhizal (AM) fungi (Glomus clarum and Gigaspora margarita). Infection of maize by S. hermonthica resulted in a significant reduction in cob yield of 20%. The effects of S. hermonthica on sorghum were not significant. With AM fungal inoculation, a significant reduction (30% and more than 50% on maize and sorghum, respectively) in the number of S. hermonthica shoots was noted. Dry weight of Striga followed the same pattern (40% reduction on maize, and 46 and 63% reduction on sorghum in 2001 and 2002, respectively) after AM fungal inoculation. There was a significant interaction effect between S. hermonthica and AM fungi on yield parameters of sorghum in the cropping season of 2002. No significant yield increase due to AM fungal inoculation was noted for maize or sorghum in 2001. The results are discussed in the context of managing mycorrhizas as a component of integrated management of S. hermonthica on cereals aimed at sustainability. (C) 2004 Elsevier B.V. All rights reserved.