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随着果树科学技术的发展,各种生长调节剂、微量元素、高效杀虫剂等,在生产中得以广泛推广应用。在果树生产上,这类药剂一般使用剂量很小,浓度极低;有时需要稀释几万倍、几十万倍乃至几百万倍。人们在使用这类农药时,为应用和计算方便起见,一般采用百万分浓度来表示。这个百万分浓度的符号,就是ppm。1ppm等于百万分之一,同理50ppm等于百万分之五十,1000ppm等于百万分之一千(即0.1％)。在配制这类农药时,计算工作是十分重要的,要做好精确计算,必须掌握计算公式。下面就计算和换算方法各举一例说明。例一,计算方法: 某专业户在甜橙果实采后贮藏保鲜时选用2,4—D处理果实,需要配制20公斤250ppm的
With the development of science and technology of fruit trees, various growth regulators, trace elements, high-efficiency insecticides, etc., are widely used in production. In the production of fruit trees, such agents generally use a very small dose, the concentration is very low; sometimes need to dilute tens of thousands, hundreds of thousands of times or even millions of times. When people use this type of pesticide, for the convenience of application and calculation, it is generally expressed in parts per million. The symbol of the millionth percentile is ppm. 1ppm equals one part per million, and similarly 50ppm equals 50ppm and 1000ppm equals one thousandth of a million (ie 0.1%). In the preparation of such pesticides, calculation work is very important, accurate calculation to be done, we must master the formula. The following calculation and conversion methods give an example of each. Example 1, calculation method: a professional households in the post-harvest storage of fresh orange fruit selection of 2,4-D fruit processing, preparation of 20 kg of 250ppm