On-Farm Colonization of Tomatoes by AM Fungi

2008 Annual Report for ONE08-091

Project Type: Partnership
Funds awarded in 2008: $4,055.00
Projected End Date: 12/31/2010
Region: Northeast
State: Maine
Project Leader:
Frank Wertheim
UMaine Cooperative Extension

On-Farm Colonization of Tomatoes by AM Fungi

Summary

On Farm use of mycorrhizal fungi has the potential to enhance host susceptible vegetable crops’ ability to mobilize and take up soil nutrients, particularly phosphorus, aid in water uptake, and reduce some soil borne disease pressures. This past year saw rapidly fluctuating costs of fertilizers – at one point in the 2008 growing season farmers were reporting a tripling in prices. Therefore, the potential for crops inoculated with mycorrhizal fungi to increase uptake of soil phosphorus could boost yields, and save farmers money by decreasing the need for off-farm inputs.

The purpose of this study was to explore on-farm production of mycorrhizal fungi, and their use as an inoculum to boost production in field grown tomatoes on a small organic Maine farm. An on-farm research project carried out at Wolf Pine Farm, a well established certified organic CSA located in Alfred Maine, working together with farm owner/operator Amy Sprague and in collaboration with the USDA-ARS Eastern Regional Research Center in Wyndmoor, PA.

Objectives/Performance Targets

• One objective of this research is to assess the feasibility of on-farm production of mycorrhizal fungi as inexpensive source of inoculum for use in vegetable production.

• A second objective is to assess whether use of on-farm produced inoculum can boost yields in field grown tomatoes on a small organic Maine farm.

Accomplishments/Milestones

We were successful in producing a viable and inexpensive on-farm source of mycorrhizal fungi inoculum to be used to inoculate tomato seedlings. We grew pre-inoculated bahiagrass seedlings provided to us by the USDA-ARS Eastern Regional Research Center in Wyndmoor, PA in a compost vermiculite growing medium during the summer of 2007. The USDA-ARS Lab confirmed we had high levels of viable spores in our growing medium, which was then used in the spring of 2008 to inoculate tomato seedlings at the cotyledon stage as they were transplanted into plug trays for growth in the greenhouse before transplanting seedlings to the field. We transplanted the inoculated seedlings into the field in June of 2008.

We grew the mycorrhizal infected tomatoes in the field in a Latin square experimental design and compared them to a control, non inoculated seedlings. Fruit from inoculated and control plants were weighed as they ripened data was logged and the fruit then went back into the farm Community Supported Agriculture market.

Impacts and Contributions/Outcomes

The mean weight of the fruit, from each treatment replication per harvest date, from the mycorrhizal inoculated plants was higher 14.44 lbs compared to the non inoculated control 13.44 lbs. However, the results were not statistically significant with an LSD value of 3.99 indicating there was significant variation within the trial. The summer of 2008 was unusually cold and wet with long rainy periods extending from June through early August. We noted a significant amount of septoria leaf spot which appeared to stunt the overall growth of the crop and resulting yields, and probably contributed to the amount of variation in the trial.

Even though the results were not statistically significant we were encouraged that the inoculated seedlings out performed the control by approximately 7 % higher yields. This result is typical of a first year field study. Our research team plans to repeat the field study in 2009 and will also add an additional farm site which will be Highmoor Farm, the Maine Experiment Station Farm located in Monmouth, ME. It is our hope that a repeat study with a second farm site added will give us more and potentially significant data in 2009 which we will with agricultural professionals and farmers in the region.

Frank Wertheim will be sharing the results to date of this research with both the Maine Organic Farmers and Gardeners Association and the Maine Vegetable and Small Fruit Growers Association during the January, 2009 Maine Agriculture Trade Show. Mr. Wertheim is also scheduled to speak to the Northeast Organic Farmers Association at their annual meeting in Concord, NH on March 7, 2009.

Collaborators:

Dr. David Handley

david.handley@maine.edu
Vegetable and Small Fruit Specialist
University of Maine Cooperative Extension
P.O. Box 179
Monmouth, ME 04259
Office Phone: 2079332100
Dr. Mark Hutton

mark.hutton@maine.edu
Vegetable and Small Fruit Specialist
University of Maine Cooperative Extension
P.O. Box 179
Monmouth, ME 04259
Office Phone: 2079332100
Amy Sprague

amy.sprague@wolfpinefarm.com
Farmer
259 Mouse Lane
Alfred, ME 04002
Office Phone: 2073242357
Website: http://www.wolfpinefarm.com
Dr. David Douds

ddouds@errc.ars.usda.gov
Research Scientist
USDA-ARS Eastern Regional Research Center
600 E. Mermaid Lane
Wyndmoor, PA 19038
Office Phone: 2152336421