Economic assessment of leafminer invasion and control strategies in Kenya's snowpea industry: the case of Nyeri North and South Imenti Districts

Abstract

Kenya's horticultural industry is confronted with an emergmg challenge of quarantined mvasrve leafminer, which has recently become a pest of economic importance in Kenya. Quarantine pests are a leading cause of Kenya's fresh produce rejection in Europe, accounting for 70 percent of the total interceptions (KEPHIS, 2006). This study examines the farmers' awareness of leaf miner, the loss the pest causes, strategies used by farmers to control it and factors influencing this choice. The study was conducted in purposively selected snow peas growing areas of eastern and central provinces in Kenya. A random sample of 220 respondents, stratified by close monitoring for compliance with GLOBALGAP was interviewed during the survey. The quantitative data from these interviews was supplemented with secondary data from KEPHIS on the Kenya's fresh produce interception and rejection at international market. The study finds high awareness of leafminer pest among farmers and that majority of surveyed farmers target the protected life stages (larval and pupae) during which the larvae are sandwiched between leaf tissues and are therefore less likely to directly get into contact with the applied pesticide. Poor targeting of the pest results in substantial losses with some farmers reporting yield losses of up to 100 percent during periods of heavy leafminer infestation. Both qualitative and quantitative analyses estimate average reduction in snowpea yields of 60 percent due to leaf miner attack. Results further show that farmers whose production practices are monitored for compliance with GLOBALGAP use fewer control strategies and incur higher losses ostensibly because their usage of pesticides is controlled by buyers. Non-monitored farmers, on the other hand, apply control strategies that may be damaging to the environment. This study concludes that lack of coordinated effort in dealing with leafminer problem will pose a threat to fresh export trade. The current control strategies by farmers are incompatible with various IPM programmes and Good Agricultural Practices (GAP) of international market standards requirements. The implication of this study is that leafminer is likely to become a serious challenge to contract farming and smallholder market access unless an integrated management strategy is developed and farmers educated on methods of identifying it in its early stages. Since control of invasive species like leafminer has a public good characteristic, the study recommends a collaborative approach between various stakeholders in Agriculture.