Incidence and Severity of Striga spp. in the Coastal Savanna Zone of Ghana

Abstract

A survey was conducted in the coastal savanna zone of Ghana to determine the incidence and severity of Striga. The aim was to use the results to sensitize stakeholders in agricultural research and development to the current status of the problem so as to help them address it. Of the respondents to the survey, 67.1% had seen Striga before, whilst 32.9% had not. Of the farmers who had seen Striga before, 2.5% indicated that they had known or seen Striga as far back as 1966. However, between 1970 and 1989, 21% of the farmers had seen Striga, whilst between 1989 and the time of the survey in 2001, 40.7% had seen Striga, indicating that its incidence had increased with time. Maize is the single most important crop attacked by Striga in the area: 65.8% of the respondents recognized it in maize, with 5.3% each for cowpeas and millet. Infestation in crops such as sorghum, bambarra groundnut, soybean and rice were indicated by about 3% of the respondents for each crop. Twelve respondents, representing 14.8% of the sample, said they knew of crop varieties that were not attacked by Striga. Of these 12, one (8.3%) mentioned sugar cane, one pepper and one cowpea; four (33.3%) said cassava; two (16.6%) mentioned okra, and the same percentage mentioned aubergines. About 18.5% of the respondents said they had seen Striga attack other weeds as well as crops. Of these, 66.7% specified grass, 20% speargrass, and Andropogon, Cyperus and Sporobulus each received 6.7% of mentions. Of those farmers who had Striga in their fields, 82.4% adopted one of two forms of control. Of the farmers who controlled Striga, 53% did it through mechanical weeding and 47% through hand pulling.