Description

Abstract: Intensive commercial vegetable production under monoculture systems is not sustainable. However, integration of trees compatible with vegetable crops offers potential for enhanced sustainability. Our objectives is to integrate trees on intensive vegetable systems or incorporate vegetables into tree-based systems. Specifically, our objectives is to evaluate and improve production of commercial and indigenous vegetables under tree-based systems. Assessments and experiments with vegetable agro-forestry systems (VAF) were conducted in the Philippines, Taiwan, Indonesia, and Vietnam using cashew, timber, and fruit trees in combination with commercial and indigenous vegetable species. Farmer perceptions and experiences, light transmission, tree growth, crop growth and yield were collected to determine productivity, adaptability, competition, complementarity, and profitability.

In the Philippines, suitable trees were Eucalyptus robusta, Eucalyptus torillana, and Acacia mangium with tree line spacing of 25 to 30 meters. Commercial vegetables were cabbage, cauliflower, carrot and bell pepper; indigenous vegetables were amaranth, jute, and Malabar spinach; fruit vegetables were yardlong bean and eggplant, with Moringa oleifera as a tree vegetable. Positive complementarity was observed between tree height and amount of canopy after tree pruning, but negative on canopy width. In Taiwan, outstanding species were Anona reticulata, Artocarpus heterophyllus, Chrysophyllum caimito, and Tamarindus indica. All vegetable crops produced average yields with minimum competition from tree crops, suggesting that integration of high-value vegetable crops provides quick economic returns at early establishment in agro-forestry systems. In Indonesia, vegetables (amaranth, kangkong, eggplant, chili, and tomato) grown under trees with medium shade resulted in yield increases of 5 percent to 180 percent over full sunlight. Heavy shade reduced yields of fruit vegetables (eggplant, chili, and tomato) but had no negative effect on leafy vegetables (amaranth and kangkong).