Evaluation of the efficacy of some organic substances to induce resistance in cucumber against root knot nematode, Meloidogyne spp.

The study aimed to evaluate the impact of certain biofertilizers on some growth parameters, total chlorophyll content and the concentrations of enzymes phenylalanine ammonia-lyase ( PAL) and peroxidase (POX) pre and post infestation of cucumber with root-knot nematodes ( Meloidogyne spp.). The results demonstrate that supplementing substances before or after nematode infection resulted in enhanced growth parameters of cucumbers, including shoot growth, fresh and dry weight of root, total chlorophyll content and the concentrations of the enzymes PAL and POX, with significant differences compared to non-infected plants. Among those that showed a positive effect were ascorbic acid, K2HPO4, 2 HPO 4 , liquid earthworms, crushed fertilizer and compost. Among the test biofertilizers evaluated, the liquid vermicompost proved to be the standout performer compared to the other treatments, demonstrating the most substantial growth improvements such as the highest increase in both shoot fresh weight (44.67 g per plant) and dry weight (5.93 g per plant). Additionally, this treatment resulted in a remarkable 83 % increase in total chlorophyll content and a significant increase in PAL and POX enzyme activity (18.25 and 25.29 IU g(-1) respectively).