Investigation of pesticide resicide in maize gutation drops

The corn plant is one of the plants that has been cultivated worldwide for years. It has an important place in our country's grain production share and can generally be grown in every region. After the seed of the corn plant is planted in the soil, it is affected by fungal agents and pests. Since it is aimed to obtain high yields, every corn seed is sprayed with seed pesticides to protect it from diseases and pests. It is an unexpected situation that pesticides that are systemic and used to protect the seed are found in the plant roots and leaves, then in the guttation fluid, nectar, pollen and even in the new seed, and pose a fatal risk to bees. In cases where humidity is high and the soil moisture rate is high, if the plant does not sweat, guttation fluid occurs by expelling water from the hydathodes with xylem tissues. It has been reported in many studies that beneficial and non-target organisms use guttation fluid as a water source and that the pesticide residues in the guttation fluid pose a risk to these organisms. In this study, guttation emergence times in corn plants were determined, changes in pesticide residue rates were observed over time, and it was determined whether the residue amounts in guttation fluid had a toxic effect on bees. In this thesis, the first guttation fluid of seed-treated grain and silage corn plants was observed 8 days after planting, and it was followed for 28 days, collected, and the pesticide residues in it were examined. Extractions were made using the QuEChERS method in the samples and LC/MS/MS device was used for analysis. It was observed that guttation fluid carried pesticides and the highest residue amount was found to be the active substance clothianidin with 8012 ppb in guttation fluids in Aydın region. In addition, residues of azoxystrabin and metalaxyl-M active substances were found in samples in Aydın region and the highest values were 1.6 ppb and 33.40 ppb, respectively. According to the results, it was observed that the active substance clothianidin was found more in guttation fluid than azoxystrobin, fludioxonil and metalaxyl-M active substances. Clothianidin active substance in guttation fluids taken from Aydın region was detected 170 times more than metalaxyl-M substance. As a result of bee toxicological tests conducted in the laboratory, it was determined that the residue amount of clothianidin active substance in guttation fluid on the first day was lethal for bees and caused death in a short time, and even small amounts in guttation fluid were very dangerous for bees. In the tests conducted, it was observed that clothianidin active substance was more toxic than metalaxyl-M active substance, and it was also determined that the mortality rates increased in the first doses as the exposure to metalaxyl-M active substance continued. Keywords: Azoxystrobin, Clothianidin, Corn, Fludioxonil, Gutation, Honey Bees, Metalaxyl-M, Neonicotinoid, Seed Coated Pesticides.