水稻田几种常用喷雾法的药液沉积率测定

对稻区常用的几种喷雾方法所产生雾滴的沉积率进行了测定。手动喷雾器的大容量喷雾法的药液沉积率虽高,但药剂有效成份之沉积率较低。低容量喷雾法的药液沉积率较低,而药剂有效成份沉积率较高。对稻区流行的喷雨法和水唧简法的沉积率不稳定和偏低,进行了评价。湿润展布剂对于药液的沉积能力有显著影响,在有湿润展布剂时,药液沉积率显著提高。不合湿展剂时,增加喷雾量对于药液沉积率的提高作用较小。大容量喷撒法有大量农药散落到田水中,而在株冠层内的穿透和分布能力并不好。

DEPOSIT RATES OF SPRAY DROPLETS EMMITTED FROM CURRENT SPRAYERS ADOPTED IN PADDY AREA

Deposit rates of droplets emmitted from current sprayers generally adopted by paddy farmers were determined and compared with those emmitted from some improved spray systems. Hand-operated high volume sprayer, the knapsack sprayer, offered relatively high deposit rate (ml/cm²)but low recovery rate,while low volume spray system produced lower deposit rate but higher recovery rate. The socalled raining spray (i.e., sprayer operated with,its nozzle taken off) and a simple handoperated giant (liquid sprayed out with a simple pisto directly through a slit extensively adopted by farmers in eastern and southern China showed much less recovery rate due to rough and big droplets. It has been proved that about 30-40% of deposit rate increase could be achieved with conventional spray systems if wetting and spreading agent was used. Increase of application rate could not increase deposit rate if wetting agent was absent.