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

The decline of the two fungicides vinclozolin (formulation Ronilan FL) and triadimefon (formulation Bayleton Special) was studied in greenho uses. The decline of vinclozolin was also studied in climate chambers. In greenhouse experiments the fungicides were applied with either a l ow-volume sprayer or a high-volume sprayer, while in the climate chamb er experiments the fungicide was applied with a pipet. Concentrations on leaves 1 day after spraying in the greenhouses with Ronilan FL were 0.87 mu g of vinclozolin/cm(2) and after spraying with Bayleton Speci al close to the detection limit (0.002 mu g of triadimefon/cm(2)). Con centrations were higher on floors than on leaves. Air concentrations w ere higher immediately after low-volume spraying than after high-volum e spraying but decreased rapidly. Air concentrations of vinclozolin du ring the first harvest, the third day after application, were below th e detection limit (0.4 mu g/m(3)). Climate chamber experiments showed no, significant differences in residue decline rate between different climate conditions, with temperatures in the range of 18-26 degrees C and a vapor pressure deficit between 0.26 and 0.79 kPa.