Abstract This study describes the distribution patterns of S. hermonthica infestation present in 117 farmers’ fields located in 61 villages in the three major cereal growing areas of Benue and Nasarawa states. A total of 1098 respondents were randomly selected proportionate to the number of households in all the zones. Striga count was taken using a quadrat and farmers’ fields were visually assessed using a five-category ranking (very high density,high density, medium, low, very low density) and recording the geo referenced data. On average, 67.3 and 3.2% of the surveyed area were infested with high and low density of Striga, respectively. The mean number of Striga plants per m2 was greater at Nassarawa State (one to eighteen plants m-2) than Benue State (one to twelve plants m -2). In Benue, the largest percentage of Striga infestation was recorded in Buruku (49.7%) and the lowest was obtained in Guma (38.3%). In Nassarawa, under sorghum cultivation, higher Strigadensties were recorded in Karu and Awe LGA; while Doma, Keana and Obi LGA recorded moderate Striga infestation. In both locations, Striga infestation was highest in sorghum fields; while millet fields recorded the least. About 40% and 35.4% of the farmers reported that new modern farming methods and Striga control copping strategies, respectively are received from Extension agents , during Monthly Technology Review Meeting (MTRM). The study has provided baseline information on the spread of S. hermonthica in the Southern Guinea Savanna of Nigeria and therefore, copping strategies for its control should be intensified.
J. Bio. & Env. Sci. 2014 However, there were some differences within the sampled population in each village. Indeed, while in some areas farmers grew a cereal monoculture; in the other areas they generally rotated cereal with other crops such as sesame, legume or tuber crops. The most important crop mixtures found during the survey were maize/sorghum, sorghum/groundnut, yam/maize, upland rice/maize, sorghum maize/cowpea, and groundnut/ millet. Sorghum, maize, and millet are the most important food crops attacked by S. hermonthica. Among the constraints to agriculture, weed infestation by Striga was highly ranked (data not shown).The level of Striga infestation in the farmers’ fields ranged from mild to severe. The study revealed that most farmers became aware of modern farming methods and Striga from their extension agents, radio and television programme, IO/NGOs, neighbours, and research institutions/ Universities (Table 6). Most of the farmers (35.4%) indicated that they got technical advice on Striga control from extension services. However, the technical information was made available to farmers during the Monthly Technology Review Meetings (MTRM) and farm visit. Information on new farming practices are disseminated by the international organizations and non-government organizations through their technical officers. Even though the research institution/ universities were available, there is no much input in terms of technology dissemination, as they were poorly scored by the farmers. This may be attributed to poor linkages between the research institutions/universities and the farmers because the attitude of farmers had not changed to conform to the current practice, where farmers are supposed to demand services, rather than wait for the services to be provided on a top-down basis. Table 6. Source of information on farming and control tecnologies for Striga. Agricultural Tecnologies IO/ NGO Extension Service Radio/TV programme Cooperative Neigbour Research Institute Others Percentage (%) Improved crop variety 20.3 40 20.2 4 15.5 - - Control of Striga 10.2 35.4 22.1 - 12.1 18.2 2.0 Soil fertility management - 37.4 26.4 16.2 20 - - Improved grain storage 17.2 41.7 26.1 10 - 2.0 3.0 Livestock management technologies 6.0 31.7 28.0 4.3 18.8 1.0 10.2 The observed spatial distribution of Striga in the surveyed fields may have several important implications for the management of this parasitic weed. Due to the presence of areas with a high risk of infestation close to less infested areas that is amenable to flooding and movement of animals for pasture making the dispersal of seed easily, it would be recommended to focus monitoring and controlefforts in those zones with high infestation. Although a satisfactory control could beobtained by focusing on low income and sustainable strategies such as the use of the cover crop,Mucunaspp., as an intercrop to reduce Striga infections to appreciable levels through suicidal germination (Akal et al., 2012) Crop rotation and intercropping technologies also requireseveral years of repeated and continued application before realizing a significant rise in annual grain yield. Acknowledgments This research was supported by the Tertiary Education Fund (TETFUND) of the Federal Government of Nigeria and Nasarawa State University, Keffi who facilitated this survey work as part of my P.hDProgramme. 426 | Ibrahim et al.
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