Poly-ε-caprolactone-based granules with allylisothiocyanate for controlling of golden cyst potato nematode

Abstract

In this study, the characteristics of extruded granules based on biodegradable poly-ε-caprolactone and montmorillonite deposited with allylisothiocyanate and their effect on Globodera rostochiensis RoI were investigated. The prepared granules were characterized using Fourier-transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. It was shown that encapsulation efficiency of allylisothiocyanate in montmorillonite depends on the conditions of complex preparation and ranges from 0.76 to 29.83%, and in poly-ε-caprolactone/montmorillonite/allylisothiocyanate granules after thermal processing it decreases down to 1.06 %. According to the results of Fourier-transform infrared spectroscopy it was found that allylisothiocyanate inclusion did not result in formation of new chemical bonds, but significantly affected the temperature of poly-ε-caprolactone degradation that decreased from 537 to 472 °С. In comparison with the thermogram of montmorillonite, the weight loss corresponding to dehydration at 100 °С decreased by 2.9 %, which probably means that part of the intramolecular water was replaced by allylisothiocyanate molecules encapsulated in montmorillonite. In the experiment with two potato varieties infested with nematode cysts it was shown that soil treatment with allylisothiocyanate solutions allows to decrease number of cysts of Globodera rostochiensis RoI compared to positive control (non-treated infested potato) in 1.5–3.0 times depending on the variety. Moreover, in contrast to allylisothiocyanate solutions, poly-ε-caprolactone/montmorillonite/allylisothiocyanate granules are more effective that makes them promising for applications in Globodera rostochiensis RoI control.