INCREASING OFF-SEASON TOMATO PRODUCTION USING GRAFTING TECHNOLOGY FOR PERI-URBAN AGRICULTURE IN SOUTHEAST ASIA

Tomato (Lycopersicon esculentum Mill.) production during the hot-wet season in most Southeast Asian countries is constrained by biotic and abiotic factors including flooding, impact of heavy rains, high temperature and high incidence of soil-borne diseases such as bacterial wilt (Ralstonia solanacearum) and nematodes. Due to low yields and supplies, market prices of tomato during the wet season are usually high. For almost 10 years, AVRDC-The World Vegetable Center developed the grafting technology for tomato to increase yield and production during the wet season in peri-urban vegetable growing areas of Southeast Asia. Studies conducted over several years in Taiwan have shown that grafting tomato onto eggplant (Solanum melongena) rootstocks increased tomato tolerance to flooding and bacterial wilt disease resulting in higher yield and economic returns than non-grafted plants. Under adverse conditions, grafted tomato plants produced yields that are 20-100% higher than non-grafted plants. On-farm trials in peri-urban areas of the Philippines and Vietnam also confirmed the results of on-station trials where grafting tomato onto eggplant rootstocks increased yields up to 100% since all non-grafted plants did not survive after heavy rainfall and flooding.