INFLUENCE OF AIR VELOCITY, AIR-TEMPERATURE, AND AIR HUMIDITY ON THE VOLATILIZATION OF TRIFLURALIN FROM SOIL

The volatilisation of the formulated herbicide trifluralin from soil s urfaces was tested under defined conditions in a wind tunnel system. S even experiments with different sets of climatic parameters were perfo rmed. The following air parameters were varied: velocity 0.4 m/s, 1.0 - 1.2 m/s, 1.8 m/s; temperature 15-degrees-C, 20 - 21-degrees-C, 30-de grees-C; relative humidity 31 %, 48 - 51 %, 78 %. The amount volatilis ed was quantified by analysing the trifluralin concentration in the ai r during four time intervals between 0 and 24 hours. The volatilisatio n rate for trifluralin ranged from 64 to 96 % (initial dose 100 %). Th e highest volatilisation was found for the experiment applying high ai r humidity conditions (20 C; 1.2 m/s; 78 % relative humidity). The low est volatilisation was observed during the standard experiment with in termediate climatic conditions (21-degrees-C, 1.0 m/s, 49 % relative h umidity).