1.note the time of application

Application time early can waste pesticides or reduce efficacy; late will cause a lot of pathogens to invade the host, even spraying treatment, also has little effect.

2.note the use of concentration 

High concentrations can cause phytotoxicity and waste, lower concentration has no efficacy. For some non-wettable powder or difficult to wet, you should add a little water, the liquid will be transferred into a paste, then add water to use.

3.note the number of pesticide 

Fungicides generally should be sprayed every 10 to 15 days in one time, a total of 2 to 3 times spraying, Fungicides shall be sprayed after raining. Application of fungicides, attention should be paid to considering cost and saving medicine. 

4.note the quality of application 

The spray volume should be appropriate, if spray volume is too small to carefully protect various parts of the plant; too large to easily result in injury and waste. Spraying needs a fine mist to uniformity, both front and the opposite should be sprayed. 

5.note the phytotoxicity problem 

There are many causes of phytotoxicity and strong water-soluble pesticide is prone to injury. The sensitivity of various crops are different, such as Bordeaux mixture usually does not cause injury, but beans, potatoes, cotton (13365,105.00,0.79%) are sensitive to lime sulfur, likely to cause injury. Different developing stages of crop response to pesticide are also different, generally seedling and booting stages are prone to injury and should be used with caution. In addition, phytotoxicity and weather, meteorological conditions are also related.