Weed management alternatives for organic coffee agroforestry systems of Puerto Rico

Project Overview

Project Type: Research and Education
Funds awarded in 2010: $150,000.00
Projected End Date: 12/31/2014
Region: Southern
State: Puerto Rico
Principal Investigator:
Mariangie Ramos
University of Puerto Rico at Utuado

Annual Reports


  • Additional Plants: coffee


  • Crop Production: agroforestry, cover crops
  • Education and Training: demonstration, on-farm/ranch research, participatory research, workshop, technical assistance
  • Farm Business Management: budgets/cost and returns
  • Natural Resources/Environment: biodiversity, habitat enhancement, indicators, soil stabilization, wildlife
  • Pest Management: biological control, botanical pesticides, cultural control, field monitoring/scouting, mulches - living, physical control, row covers (for pests), weather monitoring, weed ecology
  • Production Systems: agroecosystems, holistic management, organic agriculture, transitioning to organic
  • Soil Management: organic matter, soil analysis, nutrient mineralization, soil microbiology, soil chemistry, soil physics, soil quality/health
  • Sustainable Communities: partnerships, social psychological indicators, sustainability measures

    Proposal abstract:

    Several farmer and exporter groups are interested in producing organic coffee in Puerto Rico, as an alternative for limited-income farmers to cope with current production constraints. However, the conversion process could be challenging for farmers, since they (or the local extension personnel) are not familiar with USDA-NOP regulations and suitable organic management practices. Based on preliminary work with coffee farmers of the region, we have observed that one of the main constraints to organic coffee production will be weed management, as farmers rely heavily on herbicides and sometimes do not have shade trees. The purpose of this interdisciplinary project is to investigate and develop sustainable weed management strategies for coffee farmers that currently follow organic methods or for those interested in transitioning to organic coffee production. In order to develop sustainable weed management strategies, research efforts will consider the effectiveness of organic weed management practices at both suppressing weeds and conserving the natural resource base. Specifically, the proposed project will evaluate the effect of weed management practices in the following relevant ecosystem services: soil conservation, natural pest control and nematode diversity conservation. An experiment evaluating the effectiveness of different organic weed management practices will be conducted independently in two sites (one private established organic coffee agroforestry system and one in transition). Twenty 12 m2 plots will be established in both study sites, and one of the five treatments will be assigned randomly to each. The organic weed management treatments are: a) mechanical control with a trimmer, b) selective application of an OMRI-listed herbicide, c) cover cropping with Arachis pintoi, d) cover cropping with Heterotis rotundifolia, and a control, where weeds will not be managed. Weed suppression, coffee production, labor time and provision of ecosystem services will be evaluated in each experimental plot. The experiment will be conducted twice and will last eight months each time. After experiment results are analyzed, a workshop will be held at UPR-Utuado, in collaboration with farmers and coffee exporter groups. The purpose of the workshop is to evaluate farmers' perceptions of different organic weed management practices. Individual surveys and group SWOT analyses of each weed management practice will be used to gather this information. Experiment and workshop results will be used to develop an illustrative organic weed management manual for coffee agroforestry systems. Printed copies of manuals will be distributed to organic farmers, to those interested in transitioning to organic agricultural practices and to related government agencies (including agencies in the US Virgin Islands) and extension personnel. . An electronic copy of the manual will be available online on the UPR-Utuado webpage and a link to the manual will be available at eOrganic. Ten months after the manual is distributed, farmers will be visited to observe potential changes in their weed management practices or attitude towards ecosystem services and organic agriculture. We expect that the proposed project will have a strong impact in the organic coffee industry of Puerto Rico, and in the attitudes toward organic weed management practices by farmers, government officials and scientists.

    Project objectives from proposal:

    1) Evaluate the effectiveness of different organic weed management practices in established organic CAFS and coffee farms transitioning to organic CAFS (PD).
    2) Determine the effect of different organic weed management practices on labor time and coffee production (PD).
    3) Determine the effect of different organic weed management practices on the ecosystem service of soil conservation (Dr. Yaniria Sánchez).
    4) Determine the effect of different organic weed management practices on the ecosystem service of natural pest control (PD).
    5) Determine the effect of different organic weed management practices on the ecosystem service of soil nematode diversity conservation (Dr. Marisol Dávila)
    6) Evaluate farmers' perceptions of different organic weed management practices (PD and Co-PD's).
    7) Develop guidelines for weed management in organic coffee farms (PD and Co-PD's).

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.