Dusting sulphur is widely used for controlling insects pests and diseases on various crops plants such as melons, grapes, tomatoes, roses etc. It's powder made by specific formulation. It is used as spray on flowers, vegetables and fruits. Very useful in preventing the powdery mildew, black spot and rusts on plants.
Dusting sulphur must be applied on the tree/plants before the occurrence of disease. It makes a layer over the plant and hence protect it from mildews. In the case of insect, dusting sulphur can kill only a few pests like thirps and mites. IT's not poisonous and hence can be used.
It's a ground form of elemental sulphur and also applied as a spray with wetting agents.