Plants respond to a wide range of several synthetic chemicals that can stimulate the production of plant defense compounds that help prevent pest infestation.In this study, we examined the effect of exogenous field application of jojoba oil and methomyl on biochemical constituents of broad bean plant cv “Giza 3", grown in reclaimed agricultural soil, and evaluated its ability to capacity to induce a defense response against Spodoptera littoralis. In a plant measurements selection assay, jojoba oil and methomyl had significant increases in mineral elements, carbohydrates and amino acids content of broad bean leaves. Results from bioassays jojoba oil and methomyl showed a significant (p < 0.05) decrease in feeding activity and growth rate larvae of cotton leafworm. However, foliar spraying of jojoba oil showed a more significant effect on the treated plant than methomyl. Results revealed that exogenous field application of jojoba oil can play an important role in the protection of broad beans from cotton leafworm.