ABSTRACT

Plant diseases are mostly controlled by chemical pesticides and in some cases by cultural practices. However, the widespread use of chemicals in agriculture has been a subject of public concern and scrutiny due to the potential harmful effects on the environment, their undesirable effects on nontarget organisms, and possible carcinogenicity of some chemicals [1]. Other problems include development of resistant races of pathogens, a gradual elimination and phasing out of some available pesticides, and the reluctance of some chemical companies to develop and test new chemicals due

to the problems with registration process and cost [1]. The need for the development of nonchemical alternative methods to control plant diseases is therefore clear [1].