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

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

Summary

University of Maine Cooperative Extension agriculture research faculty collaborated with a local organic grower and the USDA-ARS Reasearch Center in Wyndmoor, PA to evaluate the potential of mycorrhizal fungi, to boost yields in field grown leeks using both a commercially available mycorhhizal innocula and a “farm raised” mycorrhizal innocula. The farm raised innoculum was produced using a technique developed at the Wyndmoor, PA research facility, and both the farm raised and the commercial mychorrhizal fungi innocula treatments were compared to a control treatment using no mycorrhizal innocula. The study was conducted at both the Highmoor Farm Experimental Horticultural Research Station in Monmouth, Maine and at Wolf Pine Farm, an organic CSA Farm located in Alfred, Maine. Leeks were chosen for this study in 2010 for their low pest profile, market value, and ease of harvest and data collection.

Data collected in the 2010 leek study at both farm sites indicated that the leeks treated with the “farm raised” mycorhizal innocula yielded more than 20 percent higher by weight than the control, uninoculated leeks (see table). Yields from the leeks treated with the commercial innocula did not yield significantly different from the control. Results will be shared at the coming vegetable growers and organic farming meetings in Maine, New Hampshire and Massachusetts.

• Mean Wt. in grams of leeks at harvest from each of the three treatments, data from both farm sites combined.

Objectives/Performance Targets

Evaluate whether innoculating leeks with mycorrhizal fungi at the time of seeding in flats would lead to an increase in yield, using two sources of innocula, farm raised, commercially produced, and comparing them to a control (uninoculated) at two farm sites, Wolf Pine Farm in Alfred, ME and Highmoor Farm Experimental Station in Monmouth, Maine. These objectives were completed during a successful 2010 field studies at both farms.

Performance Targets Aceived:
• On Farm Production of Mycorrhizal Fungi Innocula using technique developed by USDA-ARS Reasearch Station in Wyndmoor, PA
• Leeks grown in seedling flats with three treatments: 1. Farm Raised Innocula; 2. Commercially Produced Innocula: 3. Control (no innocula)
• Field Planting in Randomized Complete Blocks experimental using standard agricultural practices for each farm (conventional at Highmoor Farm and organic at Wolf Pine).
• Data collected at harvest included weight of rinsed leeks, length, diameter, and evaluation of disease.
• Data analyzed

Accomplishments/Milestones

In 2008 with a related SARE Partnership grant, tomatoes innoculated with farm raised mycorrhizae produced 7% higher yield at Wolf Pine Farm, however, there was a lot of variance in the study (perhaps due to septoria leaf spot) and results were not statistically significant. In 2009 in the first year of this SARE partnership grant we expanded our study to also include a second farm site, Highmoor Farm, but lost our tomato crops at both farms to the large outbreak of Late Blight that hit the entire Northeast, yielding no results. We applied and were granted a one year extension on the project. Leeks were chosen for this study in 2010 for their low pest profile, market value, and ease of harvest and data collection. 2010 was a much better growing season and we were able to harvest and record data at both farm sites. Preliminary results of this study were shared with growers at a seminar during the Common Ground Fair in Unity, ME in September of 2010. Results will be shared at upcoming grower meetings during the 2011 season.

Impacts and Contributions/Outcomes

Mycorrhizal fungi have long been demonstrated to enhance crops’ ability to mobilize and take up soil nutrients, particularly phosphorus, aid in water uptake and reduce disease pressures. However they have not been used extensively in vegetable crop production. In recent years commercially raised innocula has started to become more widely avaiable and some farmers are beginning to adopt their use, though potential benefits are not well documentd.

In this study study, leeks innoculated with the farm raised mycorrhizal innocula using a method developed at the USDA-ARS Research Station in Wyndmoor, PA yeilded a higher mean weight of 21%, combined for both farms, compared to the control treaament (see table 1). The leeks from the commercially produced innocula did not produce a higher mean weight as compared to the control treatment. It was interesting to note that before planting in the field we had plants from all three treatments at both farms analyzed for presence of mycorrhizal colonization on the roots at the USDA-ARS Research Center in Wyndmoor, PA. The leeks treated with the commercially produced innocula had 0 colonization by mycorrhizal fungi, where the farm raised innocula treatment had abundant colonization by mycorrhize. It would be interesting in a subsequent study to evaluate a wider variety of commercially available innocula and compare them to the farm raised method and to a control (no innocula) using a variety of vegetable crops.

Collaborators: