Atrazine residues in Irish potatoe ( Solanum tuberosum L.) varieties from three selected areas in Plateau State, Nigeria

Atrazine is a pre-emergent herbicide used for the control of broad-leaf weeds that has residual activity in the environment. Extensive use of atrazine (strength of 800 g/kg Atrazine 50% WP) in Irish potato production in Plateau State, Nigeria has prompted this study to evaluate the atrazine residue levels in Irish potato varieties in three selected (Mangu, Jos South and Bokkos) areas of Plateau State. A questionnaire-based survey was conducted to determine the types and extent of herbicides used by farmers cultivating Irish potatoes. Samples of four Irish potato varieties: Diamant, Marabel, Christian Lady and Yellow and soils at 0-15cm depth were collected from each of the three Local Government Areas (LGAs). All the samples were subjected to chemical extractions using standard procedures and the extracts were analyzed for atrazine residues using spectrophotometer. Data were analysed using descriptive statistics and ANOVA at p=0.05. Results showed 63.6% of farmers using synthetic herbicides on their farms, while 76.27% used atrazine as their preferred herbicide over paraquat 23.73%. Soil samples from Mangu had significantly highest value of 9.98 mg/kg of atrazine residues and from the Diamant variety with no detection of atrazine in soil samples from other selected LGAs and their respective varieties. The Yellow variety from both Jos South and Bokkos had the highest values of 3.32 mg/kg and 3.13 mg/kg atrazine herbicide residues, while the least value of 1.51 mg/kg was from Diamant variety in Bokkos. However, trazine residue was not detected in Yellow, Marabel and Christian lady varieties from Mangu, Jos South and Bokkos, respectively. This study showed high atrazine residues with concentrations above 0.05 mg/kg and 0.1 mg/kg (US EPA acceptable maximum residue level) in the soil and Irish potato samples, respectively. This atrazine pesticide over time could lead to bioaccumulation in living organisms, food chain and ecosystem.