This document summarizes research on using agrobiodiversity to manage pests and diseases. The research involved working with over 1500 smallholder farmers across multiple crops and locations. It found that higher crop diversity on farms reduced vulnerability to pests and diseases by disrupting pest and pathogen transmission. Analyzing over 2000 farmer interviews and field trials, it also showed that traditional crop varieties maintained genetic resistance relevant to local conditions and pests. The research concluded that supporting on-farm agrobiodiversity benefits smallholder food security and livelihoods by reducing crop losses from biotic stresses.