author(s)
Iman Sharifian, Saeed Farahani, Seyed Ebrahim Shafiei, Masood Sanchooli

abstract
Application of controlled release formulations in agricultural pest control has sharpened recently. Evaluation of controlled release time and its permeation is one of the most important factors of pellet formulation efficiency against stored products pests. The aim of present study was evaluation of controlled release time and efficiency of 1 g insecticide pellets, made based on Eucalyptol, botanic constituent, and Poly(vinyl alcohol), the biodegradable polymer, in laboratory condition. Pellets containing active ingredient (250 µl of 1,8-Cineole) was located in n-hexane medium (120 ml) for slow release, and sampling was carried out in 12 h intervals for 72 h with three replications. Spectrometry of samples was performed by UV-visible spectrometer. Obtained data were used for concentrationmaximum absorption counting, and for drawing of concentration-time graphs. Obtained results were indicated that release rate was highest in first 12 h (33% of total release) and reduced by time gradually, and release in 60-72 h interval was inappreciable (0.65% of total release). Overall, pellets release efficiency (released amount of total 1,8-Cineole from pellets) was estimated about 83%.