How many times does aluminum phosphide fumigate Chinese medicine a year? What month?

There are no hard and fast rules about how many times a year. Isn't it obvious that the insects in the granary crawled all over the floor without fumigation? However, if fumigation is done properly, once a year is enough. The best month for aluminum phosphide fumigation is July-September. Generally speaking, it is useless not to fumigate with aluminum phosphide when the grain temperature is relatively low. As long as it meets the fumigation conditions, it can be fumigated. It is very helpful to check GB and phosphine fumigation technical specifications.