This research shows that spent mushroom growing material from oyster mushrooms can help protect banana plants from a devastating fungal disease called Fusarium wilt. The spent substrate contains beneficial compounds and microorganisms that suppress the harmful fungus both in laboratory tests and in potted plants. This provides an environmentally-friendly way to recycle mushroom waste while helping farmers manage crop diseases. Impacts on everyday life: • Provides organic farmers with a sustainable disease management tool • Enables beneficial reuse of mushroom cultivation waste • Helps protect banana crops that are important for food security • Reduces need for chemical fungicides in agriculture • Creates additional value from mushroom production