• Paraquat Behavior in Costa Rican Soils and Residues in Coffee 

      Constenla Umaña, Manuel Arturo; Riley, Dave; Kennedy, Steve H.; Rojas Sánchez, Carlos Enrique; Mora Alfaro, Luis Enrique; Stevens, John E. B. (1990)
      The paraquat deactivation capacities of soils, from 20 coffee plantations, generally ranged from 100 to 500 mg of paraquat/kg of soil. Even when paraquat had been applied up to twice per year (1.2 kg ha-1 year) for 20 ...