Assessment of Glyphosate Residue Awareness and Herbicide Management Practices among Organic and Chemical Maize Farmers: Implications for Food Safety in Adamawa State, Nigeria

Abstract

This study assessed awareness of glyphosate residues and herbicide management practices among farmers using organic and chemical maize production methods in Adamawa State, Nigeria. A cross-sectional survey of 200 respondents in nine local government areas was conducted using structured questionnaires. Responses were analysed using descriptive statistics and chi-square tests. Herbicide application was reported by 79% of respondents, and glyphosate was the most commonly used herbicide (65%). Overall, 79% reported applying herbicides at least twice per season. Pre-harvest intervals were not observed by 61% of respondents, while 65% did not consistently follow recommended herbicide dosages. In addition, 16% reported applying glyphosate immediately before harvest. Although 69% believed that glyphosate residues could adversely affect health, only 46% reported awareness of glyphosate residues. Farming type was significantly associated with glyphosate use (p < 0.001). Education was associated with residue awareness (χ² = 26.41, p < 0.001), and residue awareness was associated with dosage compliance (χ² = 39.83, p < 0.001). These findings indicate differences in reported knowledge and herbicide-management practices across the surveyed farmers. They support the need for targeted extension activities addressing application timing, dosage compliance and residue awareness. As residue concentrations were not measured, the results describe reported practices and potential food-safety concerns rather than confirmed glyphosate contamination of maize grain.