Biochar is a solid byproduct of biomass thermal decomposition. It boosts agricultural production and develops systemic plant resistance when added to the soil. Biochar is frequently used as a soil additive to increase crop yield and soil fertility. However, the combined effect of biochar and oil cakes on plant’s (Tomato), nematodes, and biochemical parameters has not been well investigated. The objective of this study was to investigate the ability of biochar in combination with various oil cakes to develop resistance to the root-knot nematode (RKN), Meloidogyne incognita in tomato (Solanum lycopersicum L.) plant and to investigate its biochemical parameters. The current study was carried out in pot condition to evaluate the effect of biochar alone and in conjunction with different oil cakes viz. castor, coconut, mustard, linseed, and sesame on tomato cv. Pusa-Ruby. Our findings indicate that biochar with oil cakes enhanced plant growth, fresh weight to dry weight, total chlorophyll, carotenoid levels, nitrate reductase activity, and reduced the eggmass/root, the number of galls and nematode population compared to the control. Biochar + castor oil cake showed a higher effect in the declining nematode population, followed by biochar + mustard cake, biochar + sesame cake, biochar + linseed cake, and biochar + coconut cake. When biochar was used alone, the effect was minimal. Among all treatments, the amendment of biochar and castor oil cake has the highest ability to manage the root-knot nematode infestation in tomatoes.
