Demand-Driven Technologies for Sustainable Maize ... - IITA

271Assessment of Striga infestation in crop fieldsin the savanna zones of northeast NigeriaI.Y. Dugje 1 , A.Y. Kamara 2 , and L.O. Omoigui 21Department of Crop Production, University of Maiduguri2IITA, Ibadan, Nigeria.AbstractStriga is a major constraint to crop productivity in the savanna zonesof northeast Nigeria. In a community livelihood survey, farmers inthe region ranked Striga infestation as the topmost priority constraint.A fi eld survey was, therefore, conducted to assess the level of fi eldinfestation by Striga species in crop and fallow fi elds in the threeecological zones of the region. The survey, which was conducted in2004, covered 935 fi elds comprising 459 compound and 476 bushfi elds from 30 communities, which were selected from four LocalGovernment Areas (LGA) in the southern part of Borno State. Fourmajor Striga species were found to be associated with specifi c hosts:Striga hermonthica (Del.) Benth in sorghum and maize; Striga aspera(Willd.) Benth in rice; Striga densifl ora Benth in pearl millet and fallowand Striga gesnerioides (Willd.) Vatke in cowpea. Across ecologies andfi elds (compound or bush), 68% of the 935 fi elds were infested byStriga. Similarly, 75% of compound fi elds and 62% of bush fi eldswere infested with the four Striga species. The order of prevalenceof the Striga species was S. hermonthica>S. gesnerioides>S. aspera>S.densifl ora. For S. hermonthica, the level of infestation in the ecologieswas in the order: Sudan savanna>northern Guinea savanna>southernGuinea savanna while infestation by S. gesnerioides was in the order ofnorthern Guinea savanna>Sudan savanna>southern Guinea savanna.Across the three ecologies, 86% of the maize and sorghum fi eldswere infested with S. hermonthica, while 83% of cowpea fi elds wereinfested with S. gesnerioides. About 44% of the rice fi elds in the zoneswere infested with S. aspera, while 36% of fallows were infested withS. densifl ora. In all ecologies, the number of emerged Striga plants insorghum fi elds was higher than in maize fi elds, suggesting that Strigais more adapted to sorghum. Generally, Striga infestation was higherin compound fi elds than bush fi elds across the three ecologies. Theresults of this study showed that Striga is a major factor in environmentaldegradation and a signifi cant constraint to crop production in allthe ecologies. Therefore to improve crop production and increaseincome of farmers, efforts should be made to combat Striga throughmultidimensional or integrated approach in these areas.