Benefit cost analysis of innovation packages to reduce the use of synthetic pesticides: the cases of combined insect-proof nets with Neem and Carapa oil for tomato protection

The agricultural sector in Cote d'Ivoire faces the continuous rise of urban and peri-urban agriculture and the excessive use of synthetic pesticides. This study estimates the effects of combined insect-proof nets with Neem and Carapa oil on the yield and the profitability of tomato cropping systems. An experimental trial was composed of three types of pest management strategies: an untreated control, a treatment with Neen and Carapa oil, and two treatments which combined plants extracts and insects-proof nets. The double difference and cost-benefit analysis methods were used for the economic assessment. Our results revealed a significant difference in average yields between cropping systems. The yield with combined insect-proof nets with Neem and Carapa oil is almost three times greater than the control (16.1 vs. 6.6 t ha(-1)) in the dry season. There is no significant difference during the rainy season. The benefit:cost ratio is 1.90:1 for Neem and Carapa oil only and 2.98:1 for Neem and Carapa oil with insect-proof nets. The cost of the insect-proof nets cause the difference in the benefit:cost ratio. The sensitivity analysis reveals that the tomato cropping systems remain profitable even when farm-gate prices and production decrease by 20 and 30%, respectively, and production costs increase by 30%. Iron frames and insect-proof nets are not yet considered as agricultural investments. A tax policy considering iron frames and insect-proof nets as agriculture investments would lower the tax rate from 20 to 5%, and therefore improve the benefit:cost ratio. A supply chain policy aiming at producing insect-proof net locally, would generate economies of scale and therefore lower the unit price of insect-proof nets. Other policies could consist in technology support and training. There is a need to perform a sustainability assessment of the Neem and Carapa oil supply chains.