On-farm Colonization of tomatoes by Mycorrhizal Fungi, phase 2

Project Overview

Project Type: Partnership
Funds awarded in 2009: $8,307.00
Projected End Date: 12/31/2010
Region: Northeast
State: Maine
Project Leader:
Frank Wertheim
UMaine Cooperative Extension

Annual Reports


  • Vegetables: tomatoes


  • Crop Production: biological inoculants, organic fertilizers
  • Education and Training: on-farm/ranch research
  • Production Systems: organic agriculture
  • Soil Management: soil microbiology

    Proposal abstract:

    Current Issue

    On-farm production of AM fungi has the potential to enhance some vegetable crops’ ability to mobilize and take up soil nutrients, particularly phosphorus, aid in water uptake, and reduce disease pressures and the need for off-farm inputs. The purpose of this study is to explore on-farm production of AM fungi, and their use as an inoculum to boost production in field grown tomatoes at Wolf Pine Farm, an organic CSA located in Alfred Maine and on a Maine Experiment Research Station, Highmoor Farm located in Monmouth Maine. A field research project will be conducted at these locations in collaboration with the USDA-ARS Eastern Regional Research Center in Wyndmoor, PA. Results of this study will be shared with vegetable producers in Maine and New England.

    Project objectives from proposal:

    David Douds at the USDA-ARS Eastern Regional Research Center in Wyndmoor, PA has been working on developing an on-farm economical means of producing AM fungal inoculum for use in vegetable production. To date field studies on-farm have been limited. The purpose of this study is to evaluate this method in field grown tomatoes at a small organic Maine farm and at a Maine Experiment Station research facility to determine if on-farm production of AM fungi has the potential to reduce fertilizer inputs and/or boost yields. An organic farm was chosen for this study as they often face challenges to adequate soil phosphorus fertility due to the high cost of acquiring off-farm organic sources. The Experiment Station site was chosen to strengthen the study by having a replication at a second farm site and to also evaluate the method on a farm which uses conventional fertilizer practices. Tomatoes were chosen as a crop as they are known to have positive association with mycorrhizae (Mohandas, 1987) and because they are an important crop in small diversified vegetable and berry farms throughout New England.

    An on-farm research project will be designed at Wolf Pine Farm, a well established certified organic CSA located in Alfred Maine, in collaboration with farm owner/operator Amy Sprague, and at Highmoor Farm, a Maine Experiment Station located in Monmouth Maine, collaborating with Vegetable and Small Fruit Specialist David Handley. David Douds will also serve as collaborator/advisor in this study. By doing this on-farm research project under field conditions we will be able to assess the practicality of this method as a sustainable farming practice that other growers could adopt. We will share the results of this research with farmers, researchers and Extension professionals via print and online publications, trade shows and conference presentations in Maine and the Northeast.

    Note: This is the second year this study will be performed at the Wolf Pine Farm Organic CSA. A SARE partnership grant supported this research in 2008 and no significant differences between treatments were found – which may have been due to the long period of cool rainy weather in June, July and August and the high incidence of foliar diseases which occurred in the field on the tomatoes which were part of the study. This is another reason why a second farm site (Highmoor Farm Experiment Station) is being proposed for this Partnership Grant. By having two farm field trials in different parts of the state, one an organic farm and one which uses conventional practices are used – we will have some “insurance” against disease or another environmental factor contributing to variability in the study. In addition we will be able to assess the results of this study from two farms, one organic and one conventional farm practices.

    The project has two phases. Phase 1 – On-Farm Mycorrhizal Production: Conducted during the 2007 growing season to produce an on-farm source of AM fungi to be used in the field study the following year. Phase 2: Tomato Mycorrhizae Field Study: Use the AM fungi produced on-farm to pre-inoculate tomato seedlings in the greenhouse and grow them in the field under regular farm culture during the 2008 growing season.

    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.