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

310Table 2: Grain yield and Striga count for IR-OPV compared to a localhybrid check (H513) from 15 farmers’ fields in Western Kenyaduring the 2004B season.SiteGrain yield (t ha -1 ) Striga count (plants m -2 )Check (H513) IR-OPV Check (H513) IR-OPV1 2.2 1.9 7.7 0.02 2.6 1.9 0.0 0.03 3.4 1.9 2.2 0.24 0.8 0.9 48.6 5.55 2.5 2.3 2.2 0.86 3.1 2.6 3.1 0.87 0.6 2.2 4.0 0.08 0.3 1.8 0.2 0.09 0.7 1.6 0.3 0.010 0.5 2.7 2.0 0.011 0.3 3.7 3.4 0.012 1.2 5.4 2.1 0.413 0.7 3.6 16.9 0.114 1.1 1.5 2.3 0.115 1.4 1.1 6.3 0.0Means 1.4 2.3 6.9 0.5price in 2004 was 1.6 US$/kg or 40 US$/ha (at a seed rate of 25 kg/ha).Considering this, the total extra cost of herbicide resistant maize would be44 US$/ha when compared to a local or a recycled OPV, but only 4 US$/ha if compared to a hybrid. The herbicide can be mixed with the regularseed treatment chemicals; therefore, there are no additional costs of seedpreparation, and there are no application costs for the farmer. Whencompared to recycled OPVs, therefore, the extra benefi t would range from84 US$/ha to 388 US$/ha, for an extra cost of 44 US$/ha, or a MRR of21 to 97. For hybrids, the MRRs are from 31 to 107. These ratios suggestvery high returns to the investment; therefore, the technology stands avery good chance of being adopted, if these yield increases arerealized in farmers’ fi elds.Impact assessmentThe results of the different surveys conducted in this study indicatedthat 40-70% of the maize area in the Striga-prone zone (Fig. 1) wasinfested with Striga and that grain yield of infested fi elds, on average,was about 50% lower than yield from Striga-free areas. SuppressingStriga infestation could, therefore, increase current average yields by25-54%. In other words, yields could increase by 0.34-1.2 t/ha which,when averaged over 210,000 ha, translates to about 70,000-256,000