To address increasing concerns for improved food safety, quality, and appropriate environmental
practices of on-farm operations, governments and private sector are increasingly promoting
standards for good agricultural practices. In Thailand, voluntary and free of charge Good Agricultural
Practices (GAP) certification program was implemented by the government. It aims at mobilising
farmers to improve on-farmoperations to produce safe products and preserve the environmentwhile
reducing the costs of production. This study is a three-stage investigation into the factors and patterns
of GAP adoption and continued adoption by rice farmers using successively probit for first adoption
patterns, probit with selection models for continued participation, and comparison of practices
among non-adopters, one-time only adopters, and continued adopters. The analyses are based on a
survey of 250 farmers from Ayutthaya Province in the Central Plains of Thailand. Results demonstrate
that adoption and dis-adoption are highly related to household labour constraints, land ownership,
and initial high expectations regarding the market opportunities of the GAP produced rice. We found
several encouraging differences between non-adopters and first-time adopters, indicating better pest
and nutrient management. Although we observed an important rate of dis-adoption, we also
determined that farmers are maintaining those better practices even after abandoning the program