Action Thresholds for Desert Produce Crops

Abstract

This publication provides an overview of action threshold (AT) guidelines for managing insect pests in leafy vegetables and cole crops in the desert Southwest. Developed from over 30 years of applied field research at the Yuma Agricultural Center, these thresholds help pest control advisors (PCAs) determine when insecticide applications are justified based on pest density or damage levels. The guide distinguishes between prevention strategies, nominal action thresholds, and zero-tolerance thresholds for market contamination, with specific thresholds for pests such as beet armyworm, whiteflies, aphids, thrips, and flea beetles. Emphasis is placed on integrating cultural, physical, and biological control methods before resorting to chemical control, reinforcing the core principles of Integrated Pest Management (IPM).