Investigations on determination of the decomposition variation of some pesticides mixtured with plant growth regulators, foliar fertilizers and spreader-sticker in vineyard

Currently, it is still possible to encounter pesticide residues on plant crops which exceed maximum residue limits. This project was performed to investigate if this residual problem is caused by not only the fact that the growers use the plant protection products without utilizing any recommendation and they dont rely on the waiting period but also the use of a number of pesticides, plant growth regulators, foliar fertilizers and spreader-sticker as mixture. This study, carried out in 2015-2016, investigated the effects of degradation period of some pesticides commonly used as mixture with plant growth regulators, foliar fertilizers and spreader-sticker just before grapevine leaf collection and grape harvest period. There has been no significant interaction in the mixtures formed by pesticides and mixtures formed by both pesticides and other preparations in the physical and chromatographic analyzes carried out in the laboratory in order to determine whether the pesticides used as a mixture in vineyard are degradated in the tank. Two different trials (grapevine leaves and grapes stage) were carried out in Kemalpaşa/Izmir in the year of 2016, in order to determine whether there is a change in the period of degradation of the pesticides used in the mixture in the field conditions. degradation A mixture of azoxystrobin, imidacloprid and metalaxyl were applied in triplicate with plant growth regulator, foliar fertilizer and spreader- sticker in single, double and triple mixes in an 8-character trial in the grapevine leaf period and the degradation period of the active ingredients was determined from the leaf samples collected at appropriate intervals. The degradation of azoxystrobin and imidacloprid in the leaves applied with spreader-sticker +plant growth regulator; plant growth regulator+ foliar fertilizer; spreader-sticker+foliar fertilizer+plant growth regulator slowed down and moreover, even at the end of the waiting period the amount of residues did not fall below the maximum residue limit. In the leaves, the rate of degradation of imidacloprid is slowed down by plant growth regulators and foliar fertilizer, which are added individually to mixtures of these pesticides. All other mixtures slowed down the degradation period of metalaxyl except the mixture which was applied with a single foliar fertilizer. In the grape period, triple mixtures of boscalid, chlorpyrifos ethyl and hexythiazox preparations were applied just like the way it was applied in the grapevine leaf period. While all mixtures used in this application increase the degradation period of boscalid, chlorpyrifos ethyl and hexythiazox do not have any effect on the degradation period.