Chemicals are applied to crops mainly as liquid (water based) solutions using a crop sprayer.
The liquid is applied as fine droplets to give an even cover to the crops.
A problem farmers often encounter when spraying is spray drift.
It is important to make sure that the weather conditions are right for spraying.
There should be very little wind or no wind movement in order to reduce the problem of drift.
Very hot weather will also increase spray drift because the water evaporates more quickly.
Farmers often spray their crops either early morning or later in the day when the weather conditions are more suitable.
When spraying insecticides, farmers often spray at dusk when the bees have returned to their hives so that the bees are not harmed.