The monograph contains general information about the occurrence of allelopathic soil sickness under cultivated flowers, crops and fruits. It also discusses (a) the ancient (b) methods to control soil sickness, (c) chemical Nature of substances exerting the toxic effects, (d) the role of micro-organisms, (e) physiological and biochemical processes of individual organisms of soil sickness. It also described the methods and possible ways to overcome this phenomenon. ...