Definition - What does Fumigant mean?
Fumigants are poisonous, gaseous substances that are used to exterminate insects, nematodes and other pests (plant or insect) that damage crops, stored produce, seeds and plant stock. The fumigants can be sprayed or spread over the targeted area, on the crops/produce and in the soil. Fumigants use a mixture of chemicals to control unwanted organisms and high vapor pressure during application.
WineFrog explains Fumigant
Fumigants should only be applied to crops or produce by experienced professionals with proper equipment, as they can be extremely hazardous to human skin and warm blooded animals. The most common fumigants used are hydrogen phosphate or hydrogen cyanide (HCN), methyl bromide and ethylene compounds. In grapevines, soil fumigants are the most effective against nematodes, plant pathogens, root disease and weeds when applied before planting. It is also important to have some form of air control when using fumigants as they can travel to unwanted areas quickly.