Leistra Minze, Wolters André, van den Berg Frederik
Alterra, Wageningen University and Research Centre, PO Box 47, 6700 AA Wageningen, The Netherlands.
Pest Manag Sci. 2008 Jun;64(6):669-75. doi: 10.1002/ps.1542.
Volatilisation of pesticides from crop canopies can be an important emission pathway. In addition to pesticide properties, competing processes in the canopy and environmental conditions play a part. A computation model is being developed to simulate the processes, but only some of the input data can be obtained directly from the literature.
Three well-defined experiments on the volatilisation of radiolabelled parathion-methyl (as example compound) from plants in a wind tunnel system were simulated with the computation model. Missing parameter values were estimated by calibration against the experimental results. The resulting thickness of the air boundary layer, rate of plant penetation and rate of phototransformation were compared with a diversity of literature data. The sequence of importance of the canopy processes was: volatilisation > plant penetration > phototransformation.
Computer simulation of wind tunnel experiments, with radiolabelled pesticide sprayed on plants, yields values for the rate coefficients of processes at the plant surface. As some input data for simulations are not required in the framework of registration procedures, attempts to estimate missing parameter values on the basis of divergent experimental results have to be continued.
农药从作物冠层挥发可能是一条重要的排放途径。除农药特性外，冠层中的竞争过程和环境条件也起作用。正在开发一个计算模型来模拟这些过程，但只有部分输入数据可直接从文献中获得。
用计算模型模拟了在风洞系统中对植物上放射性标记甲基对硫磷（作为示例化合物）挥发进行的三个明确实验。通过对照实验结果进行校准来估计缺失的参数值。将所得的空气边界层厚度、植物渗透速率和光转化速率与大量文献数据进行了比较。冠层过程的重要性顺序为：挥发＞植物渗透＞光转化。
对喷洒有放射性标记农药的植物进行风洞实验的计算机模拟，得出了植物表面过程速率系数的值。由于在注册程序框架内不需要一些模拟输入数据，因此必须继续尝试根据不同的实验结果估计缺失的参数值。
