Analysis of factors influencing the adoption of good agricultural practices (gaps) among smallholder avocado farmers in Muranga County, Kenya

Abstract

Kenya's avocado sector is one of the fastest-growing in Africa, yet a persistent gap exists between production volumes and export performance, with less than 20% of output consistently reaching international markets. Compliance with Good Agricultural Practices (GAPs) is a critical precondition for export market access, particularly given the stringent sanitary and phytosanitary (SPS) requirements imposed by markets such as the European Union and China. Despite widespread promotion of GAPs frameworks, adoption among smallholder farmers in Murang'a County, Kenya's leading avocado-producing region, remains uneven and inadequately understood. This study examined the influence of farm size, training, and contract farming with exporter companies on the adoption of GAPs across pre-harvest, harvest, and post-harvest production stages. The study used secondary data from a cross-sectional survey, with structured questionnaires administered digitally via KoboToolbox to 698 smallholder avocado farmers in Murang'a County, Kenya. Multi-stage purposive and random sampling were used to select respondents across key sub-counties. GAPs adoption was disaggregated into three binary outcomes: pre-harvest, harvest, and post-harvest practices. A Multivariate Probit (MVP) model was applied to jointly estimate adoption decisions across the three stages while accounting for inter-practice correlations and cluster-robust standard errors. Farm size exerted a positive effect only on pre-harvest GAPs adoption (β = 0.186, p < 0.10), with pre-harvest adopters operating on significantly smaller avocado areas than non-adopters (1.18 vs. 1.48 acres, p = 0.011). Training was a significant predictor of pre-harvest adoption (β = 0.514, p < 0.05) but had no significant effect on harvest or post-harvest adoption. Contract farming strongly influenced both pre-harvest (β = 1.505, p < 0.01) and post-harvest adoption (β = 0.777, p < 0.05). High GAPs adopters exported a significantly greater proportion of their harvest and achieved higher shares of Grade 1 produce than low GAPs adopters. The findings challenge the conventional assumption that larger farms are more likely to adopt GAPs, demonstrating instead that institutional factors, particularly contract farming and targeted training, are more powerful determinants of compliance. Policy should prioritize expanding contract farming arrangements, broadening training content to cover downstream practices, and strengthening public extension services across the avocado value chain in Kenya.