Long-Term Studies of Fungicide Concentrations in Greenhouses. 2. Fungicide Concentrations in Air and on Leaves after Different Exposure Times and under Different Climate Conditions

Abstract

The decline of the two fungicides vinclozolin (formulation Ronilan FL) and triadimefon (formulation Bayleton Special) was studied in greenhouses. The decline of vinclozolin was also studied in climate chambers. In greenhouse experiments the fungicides were applied with either a low-volume sprayer or a high-volume sprayer, while in the climate chamber experiments the fungicide was applied with a pipet. Concentrations on leaves 1 day after spraying in the greenhouses with Ronilan FL were 0.87 μg of vinclozolin/cm2 and after spraying with Bayleton Special close to the detection limit (0.002 μg of triadimefon/cm2). Concentrations were higher on floors than on leaves. Air concentrations were higher immediately after low-volume spraying than after high-volume spraying but decreased rapidly. Air concentrations of vinclozolin during the first harvest, the third day after application, were below the detection limit (0.4 μg/m3). Climate chamber experiments showed no significant differences in residue decline rate between different climate conditions, with temperatures in the range of 18−26 °C and a vapor pressure deficit between 0.26 and 0.79 kPa. Keywords: Spraying; greenhouse; fungicide; pesticide; residues; decline; vinclozolin