Can Vegetables Be More Productive Under Tree Based Systems? TMPEGS – Presentation at the third annual SANREM III Meeting, Los Baños, Laguna, Philippines May 26, 2008 AVRDC North Carolina Agricultural and Technical State University AVRDC

Overall hypothesis In intensive vegetable production system in the uplands, monoculture systems are not sustainable, but integrating trees is feasible and offers better prospects.

TMPEGS T echnology : –Develop economically viable and ecologically-sound vegetable- agroforestry (VAF) systems

Evolution of the AF system in Southern Philippines (Mindanao) (hedgerow intercropping) : Pruned hedgerow : NVS present: c ommercial trees Positive Control soil erosion Provide organic fertilizer Fodder for animal Negative Labor intensive Competes with crops: spaces, growth resources, labour, etc Positive Very cheap to establish Control soil erosion effectively Negative No economic benefits ? Potentials: Productivity/Profitability Sustainability Diversity Environmental services

Environmental services Reduction of soil loss..

Relative yield of maize over six cropping periods as influenced by different timber tree species as hedgerows spaced at 8m x 3m Yield of control

TMPEGS T echnology : –Develop economically viable and ecologically-sound vegetable- agroforestry (VAF) systems

Net benefit = 2T+(Y 2 - 2Y 1 )-2D Competition zone Complementarity zone

Vegetable Agroforestry System Research Goal: Tree-vegetable integration on farm with minimal negative interaction but optimal positive interaction, thus increasing productivity, economic profitability, nutrient use efficiency and environmental services

Tree integration on intensive vegetable based systems with minimal negative interaction Approaches: Tree-vegetable matching Tree management Crop management

Methodology 1.Assessment of existing VAF systems covering 21 farms, 2 AF systems, 6 tree species, 8 vegetables, 4 aspects. Data collected were tree parameters (stem diameter, tree height, canopy height and width), spatial performance of vegetables (height, stem diameter, crown width, biomass), spatial light transmission (fish eye photography/quantum light meter) 2.Focus group discussion with 15 VAF farmers on various ways of integrating trees on vegetable farms and their practices and experiences on tree and vegetable management addressing tree-vegetable competition and complementarity 3.Evaluation of 5 commercial, 20 indigenous, and 5 tree vegetables under tree based system.

D Eucalyptus- tomato interaction under boundary planting system Average height at nuetral zone

Three zones of tree-crop interaction in vegetable agroforestry systems Average yield

Net complementarity as a simple tool in assessing appropriate tree-vegetable integration Net complementarity = degree of complementarity-degree of competitiveness Degree of complementarity = relative yield (at complementary zone) -1 x distance of influence (0= no complementarity) Degree of competitiveness = 1- relative yield (at competition zone) x distance of influence (0= no competition) Relative yield at complementarity zone = yield at complementarity zone divided by neutral zone Relative yield at competition zone = yield at competition zone divided by /neutral zone

Influence of timber tree species on VAF net complementarity under farmer management (tree-vegetable matching) Acacia mangium Eucalyptus robusta Eucalyptus torillana Gmelina arborea Maesopsis emini Net complementarityTree species

Evaluation of 12 tropical fruit trees at vegetables based system at AVRDC, Taiwan Artocarpus heterophyllus Chrysopyllum caimito Tamarindus indicus Anona reticulata Promising fruit tree species Adapted from Palada et al Establishing vegetable agroforesty system research at AVRDC

Influence of vegetable crops on net complementarity under farmers management (tree-vegetable matching) Vegetables Net complementarity index Bell pepper Brocolli Cabbage Cauliflower Chinese cabbage Tomato White beans Maize

Influence of aspects on VAF net complementarity North (vegetable on south side) South (vegetable on north side) East (vegetable on west side) West (vegetable on east side) North

Influence of aspects on net complementarity under farmers management (crop management) AspectsNet complementarity East (vegetable on west side) West (vegetable on east side) North (vegetable on south side) South (vegetable on north side)

Vegetable-tree matching Evaluation of 5 commercial, 20 indigenous (from AVRDC GRU), and 5 tree vegetables under tree based system consist of leafy, fruits and root vegetables Vegetables were planted 2 rows perpendicular to the 6 year old Eucalytus torillana tree row 25 cm from tree trunk Vegetable entries were arranged in RCB design replicated 3 times Vegetables were harvested spatially row by row Zones of interaction were calculated in each plot

Promising vegetables at competition zone (4.5 (±1.2) m from tree hedge) Adaptability index = Yield at competition zone (Y1) / yield at neutral zone (Y0) Where: 1= adapted

Promising vegetables at complementarity zone (from 5 – 15 (±2) m from tree hedge) Complementarity index = Yield at complementarity (Y2) / yield at neutral zone (Y0) Where: 1= no complementarity effect

Net complementarity indices of selected vegetables planted perpendicular to the tree line (researcher-managed) Net complementarity index = Y2-Y1 Where: 1= no benefit

Adaptation of vegetables under different shading regimes in multi-storey agroforestry system in Indonesia. Increase in yield over no shade VegetablesMedium light (%) Amaranth spp180 Kangkong90 Eggplant71 Chili9 Tomato5 Note: Under heavy shade (Low light: *1000 lux), the growth and yield of 10 vegetables evaluated were negatively affected. Adapted from Manurong et al Can vegetables be productive under tree shade management in West Java?

Summary and Recommendations 1.Reduce competition between trees and vegetables (Y1) by: Using vegetables that have high adaptability indices, adapted to low light environment, at competition zone (up to 4.5m from tree line) Using trees which are less competitive Employing tree root pruning and root barrier (chili yield was significantly higher in with root barrier treatment) Can Vegetables Be More Productive Under Tree Based Systems? 3 ways of improving economic viability of vegetable agroforestry systems Yes!

2. Increase tree-vegetable complementarity (Y2) Using vegetables with high complementarity response indices at complementarity zone (4.6 – 15 m away from the tree line) Employing appropriate pruning regime, leaving % of the tree canopy- favorable for both trees and crops Using optimum tree lines/hedges spacing, meters apart and 3 meters between trees, having approximately trees per hectare 3. Use valuable trees (T) Premium timber trees (indigenous species) Adapted fruit trees (Taiwan) Rubber trees 3 ways of improving economic viability of vegetable agroforestry systems

Thank you very much! Questions Acknowledgement and Contact This study was funded and supported by the Sustainable Agriculture and Natural Resources Management – Collaborative Research Support Program (SANREM-CRSP) and by the World Agroforestry Centre (ICRAF). Agustin R. Mercado, Jr. World Agroforestry Centre Claveria Research Site, MOSCAT Campus, Claveria, Misamis Oriental, 9004 Philippines

TEMPEGS VAF Collaborators Agustin Mercado, Jr. - World Agroforestry Centre Caroline Duque World Agroforestry Centre Manuel Reyes – World Vegetable Centre Liwayway Engle - World Vegetable Centre Flordeliza Faustino - World Vegetable Centre Gregory Luther - World Vegetable Centre Gerhard Manurong - World Agroforestry Centre James Roshetko - World Agroforestry Centre Bambang Purwoko - Bogor Agricultural University Anas Susila - Bogor Agricultural University Try Van My - Nong Lam University, Vietnam Manuel Reyes - North Carolina A&T State University