ABSTRACT
The impact of crop diseases on quantitative and qualitative yields may vary, depending on the pathogen characteristics and responses of the host plant species to the pathogen(s) prevailing environment. The chemicals used against soilborne microbial plant pathogens include fungicides, antibiotics, bactericides, nematicides and herbicides. During occurrence of a disease in epidemic proportions, large scale application of chemicals is recommended to minimize further spread to new locations. Development of diseases caused by soilborne microbial pathogens may be restricted by applying chemicals as seed treatment, root-dip of transplants/propagules treatment, soil application and foliage treatment. Although chemicals have provided more effective protection to the crops against several microbial plant pathogens, the adverse effects on the environment and nontarget microorganisms cannot be ignored. Crop diseases caused by soilborne bacterial pathogens are less numerous, compared with those caused by fungal pathogens.
