Fruits and vegetables provide food and increase incomes for small-scale farmers in the tropics. These high-value crops are also important components of home garden agroforestry systems; they contribute to biological stability, enhance crop diversity, conserve soil properties and increase total productivity. Although the benefits of integrating high-value crops into agroforestry systems have been recognized, few studies have been done to quantify and describe tree-crop interactions. A vegetable agroforestry system (VAF) research was initiated at the World Vegetable Center to study the relationships between fruit trees and vegetable crops in terms of competition and complimentation.