Abulegasim Elzein, Beeden Fen, Adolphe Avocanh, Jürgen Kroschel, Paul Marley, Georg Cadisch:
Compatibility of Striga-Mycoherbicides with Fungicides Delivered Using Seed Treatment Technology and its Implication for Striga and Cereal Fungal Diseases Control


1University of Hohenheim, Institute of Plant Production and Agroecology in the Tropics and Subtropics, Germany
2International Institute of Tropical Agriculture (IITA), Biological Control Station, Benin
3International Potato Center (CIP), Integrated Crop Management Division, Peru
4Ahmadu Bello University, Institute for Agricultural Research, Nigeria

Root parasitic weeds of the genus Striga and fungal diseases constitute a major biotic constraint to staple food production in Africa, and consequently aggravate hunger and poverty. With the aim of improving sorghum and maize performance and yield, an investigation on the possibility of delivering Striga-mycoherbicides (Fusarium oxysporum Foxy 2 & PSM197) and selected fungicides using seed treatment technology to control simultaneously Striga hermonthica and sorghum and maize fungal diseases was made for the first time. Film"=coated seeds of sorghum with different application rates (dosages) of Apron XL and Ridomil Gold in combination with the mycohericides Foxy 2 and PSM197 and different coating adhesives were used. The effects of Apron XL and Ridomil Gold fungicides on growth and sporulation of the two isolates was examined by growing the film"=coated sorghum seeds on PDA media. Delivering of the fungicides Apron XL and Ridomil with Striga"=mycoherbicides Foxy 2 and PSM197 using seed treatment technology did not interfere with the seed coating process nor with the initial survival of fungal isolates on coated sorghum seeds. Apron XL clearly enhanced the growth, sporulation and viability of both isolates, indicating strong compatibility with Striga"=mycoherbicides. However, Ridomil Gold was not compatible on PDA medium. Under field conditions of West Africa, the integration of fungicide Apron XL (at a rate of 0.5ml kg-1 of seeds) with Striga"=mycoherbicides (Foxy2 & PSM197) and resistant maize cultivars using seed treatment technology and Arabic gum as adhesive showed significant reduction in Striga emergence by 81% and 90% compared to the respective resistant and susceptible controls. Improved performance of maize treated with Striga"=mycoherbicides and fungicide by 300% was further recorded. The compatibility between Striga"=mycoherbicides and Apron XL fungicide has significant implication for controlling simultaneously Striga and sorghum and maize fungal diseases and improving crop performance and yield.

Keywords: Fungal diseases, fungicides, Fusarium oxysporum, integrated control, biological control, mycoherbicide, seed coating, Sorghum bicolor, Striga hermonthica, Striga-resistant cultivar, Zea mays


Contact Address: Abulegasim Elzein, University of Hohenheim, Institute of Plant Production and Agroecology in the Tropics and SubtropicsGarbenstr. 13, D-70599 Stuttgart, Germany, e-mail: gasim@uni-hohenheim.de
Andreas Deininger, November 2007