A Bio-Economic On-Farm Evaluation of the Use of Sweet Potato for Complementary Weed Control in a Yam/Maize/Egusi/Cassava Intercrop in Pigeon Pea Hedgerows in the Rain Forest Belt of Nigeria

ABSTRACT

The bio-economic on-farm evaluation was conducted on resource-poor farmers' farms in the Orlu and Owerri Agricultural Zones in the rain forest belt of Nigeria in 1996 and 1997. It estimated the difference in profit or loss expected from the introduction of sweet potato at 6, 8 and 10 weeks after planting (WAP) as a complementary weed control measure to egusi in a yam/maize/egusi/cassava intercrop against the practice of two hand weedings (4 and 12 WAP). A randomized complete block design with five replications and forty farmers was used. Analysis of variance was used to assess the biological yields and partial budgeting used for the economic analysis while farmers' potential acceptability or rejection of the intervention was assessed by means of simple direct survey.

The prevalent grass weeds were suppressed by the egusi and sweet potato although they later reappeared sparsely. The egusi acted as the early weed suppressant during the initial growth of the component crops. The sweet potato continued the ground cover provided by the egusi at different degrees. The yields of all the component crops except cassava were statistically similar. The yield of yam and cassava was higher where sweet potato was introduced at 10 WAP (9.4% and 7.6%, respectively) than with two hand weedings. It has both the highest combined monetary value of all the component crops (N234,752) and net benefit (N228,702). There were savings in labour in the use of the intervention and it offers an opportunity that can reduce production cost and drudgery.