Inducing systemic acquired resistance (SAR) against root-knot nematode Meloidogyne javanica and evaluation of biochemical changes in cucumber root

For inducing systemic acquired resistance (SAR), Salicylic acid (SA), Ascorbic acid (AA), and silicon (Si) were applied on shoots, roots, and both of them simultaneously. Results showed that all treatments reduced the number of galls, root gall index, number of egg mass/root system, number of nematodes/root system, number of eggs/root system, number of nematodes/pot soil, the final population density of nematodes, and rate of reproduction. Treatments also increased growth criteria, including chlorophyll, shoot fresh weight, root fresh weight, shoots dry weight, root dry weight, shoots length, and root length. SA foliar and root application decreased infection criteria and increased total phenol, peroxidase, and phenol oxidase activities. Ascorbic acid and silicon increased total phenol, peroxidase, and phenol oxidase activities.