Agro-ecological risk of pesticides application for protecting apple plantations in the conditions of Pre-Carpathian Province of the Carpathian mountains in Ukraine

Abstract

It was found that the rate of detoxification of pesticides depends on their physicochemical properties and correlates with the polarity of the compounds. According to the magnitude of dipole moments, the studied pesticides are divided into three groups: nonpolar with µ from 0 to 2 Debye (D), low-polar with µ from 2 to 6 Debye and polar with µ more than 6 Debye. Non-polar pesticides are practically insoluble in water and their decay period in the ecosystem is longer than that of low-polar and polar pesticides. Peculiarities, speed and dynamics of pesticide detoxification in the apple orchard ecosystem have been studied. It was found that non-polar pesticides decompose at a rate of 0.07–0.12±0.05 parts per day, and low-polar pesticides — at a rate of 0.15–0.22±0.05 parts per day. On the tenth day after spraying, 0.05 to 1.24 mg/kg of the studied pesticides were detected in apple fruits and from 0.15 to 4.41 mg/kg in apple leaves. The classification of pesticides according to the degree of danger was carried out and it was found that the studied drugs have a degree of danger from 3 to 6. Pesticides with 3 degrees of danger are more dangerous to humans and biota and require more detailed regulation, regulation and control. The seasonal load of pesticides (H) for the intensive chemical system was 29.5 kg/ha, for the advanced system — 10.5 kg/ha and for the system of biological and chemical protection — 0.45 kg/ha. The weighted average hazard (Q) in the intensive chemical protection system was 5.0, for the advanced system — 4.9, and for the biological and chemical protection system — 6.8. It was found that the agroecotoxicological index for all protection systems was less than 1, all protection systems are not very dangerous and do not lead to ecosystem pollution. For the intensive system of chemical protection, this figure ranged from 0.24 to 0.49, for the advanced — from 0.014 to 0.025, and for the system of biological and chemical protection — from 6·10–5 to 8·10–5.