Show FA FARM it m TOPICS TEAR GAS USED IN SOIL BATTLE harmful organisms killed by injecting cy by F L STARK use of old world war tear gas in another type of warfare in the soil is being used today reports of the plant pathology department at cornell university indicate this gas is used to partially sterilize soils and kill harmful organisms gani sms known as a heavy oily colorless liquid that readily vaporizes vaporizer orizes into a pung pungent tear gash gas it quickly changes to a gas arid diffuses throughout the soil after in ejection jec tion for many years it has been realized that the soils in which plants grow harbor injurious organisms several means have been used to destroy them namely cultural practices heat and chemicals the possible use of was revealed during the world war when large quantities were used as tear gas since then the use of this wartime material has been developed far enough so it can be used successfully cess fully to partially sterilize soils the gas is toxic to all forms of life and it is completely volatile therefore no residue remains in the soil upon aeration the material is applied into the soil by an applicator which works on the principle of the hypodermic needle small amounts are injected into the soil to a depth of about six inches injections are usually made about 12 inches apart with the apparatus pa ratus one man can treat from 1000 to 1500 square feet of soil in an hour is being used to sterilize soil to eliminate disease causing fungi insects nematodes and weeds and their seeds its most efficient use to date has been in compost piles but it has also been effectively used to sterilize seed beds and in benches or ground beds in greenhouses its extensive field use is said to be limited only because of the rather high cost of the material soil conditions at the time the tear gas is applied are important in fumigating fumi gating soils the gas must penetrate through all parts of the soil to destroy the organisms and a lethal concentration of the gas must be kept in contact with the organisms long enough to kill them after the pests are killed the vapor should escape as rapidly as possible the horticulturists were told the speaker stated that a light sandy soil with a medium amount of moisture and at a fairly high temperature above 65 agrees fahrenheit is ideal for fumigation |