ABSTRACT
Metabolites of a Bacillus subtilis isolate excreted into the nutrient solution during fermentation can be used as resistance-inducing substances as well. The yield efficiency of the induced resistant barley plants was independent of the fertilization level with nitrogen. According to J. Kuc, one major problem encountered with the use of induced resistance for the control of plant disease in the field is not its effectiveness, but rather the economics of the application technology and the delivery of the immunizing agent. In plant protection, the use of induced resistance appears to be realistic as a supplement to conventional methods of pest control. Abiotic inducer metabolites of a Bacillus subtilis strain have been tested with different cultures in horticulture and agriculture under practical conditions by Schonbeck and co-workers. According to J. S. Boyer, up to 70% of yield losses in crops are due to these abiotic factors.
