Water and Soil Release Kinetics of Cartap hydrochloride from Controlled Release Formulations

Controlled release formulations of insecticide cartap hydrochloride (2-dimethylaminopropane-1,3-diol) have been prepared using commercially available polyvinyl chloride (emulsion and suspension), carboxy methyl cellulose and carboxy methyl cellulose with clay (bentonite, kaolinite and Fullers’ earth). Kinetics of cartap hydrochloride release in soil and water from the different formulations was studied in comparison with the commercially available granules (4G). Release from the commercial formulation was faster than the new CR formulations. Addition of clay in the carboxy methylcellulose matrix reduced the rate of release. The diffusion exponent (n value) of carrap hydrochloride in water and soil ranged from 0.53–0.74 and 0.46–0.74, respecttvely. The release was diffusion controlled with a hall release time (T½) of 4.8–36.3 days in water and 7.5–44.8 days in soil from different matrices. The maximum release of cartap hydrochloride in water and soil from controlled released formulations ooccured between 11.3–37.5 and 20.3–43.4 days, respectively. The results suggest that depending upon the polymer matrix used, the application rate of cartap hydrochloride can be optimized to achieve insect control at the desired level and period.