|Lee, Joseph - Joe|
|ZIEGLER-ULSH, CHRISTINE - Rodale Institute|
|GANSER, STEVE - Eagle Point Farm|
Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/25/2016
Publication Date: 6/7/2016
Publication URL: http://handle.nal.usda.gov/10113/62921
Citation: Douds, D.D., Lee, J., McKeever, L., Ziegler-Ulsh, C., Ganser, S. 2016. Utilization of inoculum of AM fungi produced on-farm for the production of Solanum lycopersicum: a summary of 7 years of field trials on a conventional vegetable farm with high soil phosphorus. Scientia Horticulturae. 207:89-96.
Interpretive Summary: Arbuscular mycorrhizal [AM] fungi are soil fungi that form a beneficial symbiosis with the roots of most crop plants. The benefits to the plant include increased uptake of mineral nutrients from the soil, enhanced drought resistance, and increased disease resistance. These characteristics cause most agricultural scientists to recommend increased utilization of the symbiosis to enhance agricultural sustainability. We have developed an inexpensive method for the production of inoculum of AM fungi on-the-farm. Inoculum was produced on a cooperating farm and utilized to grow tomato seedlings for transplant to the field. Experiments were conducted for seven consecutive years, with 3-7 varieties of tomato each year. Fruit was harvested throughout the production season, as would happen under normal farm practice, and yields for inoculated were compared to uninoculated plants. The average yield increase due to inoculation with AM fungi over the seven years was statistically significant at 6%. On-farm production and utilization of AM fungus inoculum for the growth of vegetable crops increases yield of tomato with minimal changes to routine farm practice.
Technical Abstract: Adding arbuscular mycorrhizal [AM] fungus inoculum to potting media enables vegetable farmers to better take advantage of the AM symbiosis. On-farm production of AM fungus inoculum is a viable alternative to commercially-available inocula. We conducted a seven year experiment at a conventional vegetable farm in southeastern Pennsylvania with high soil available P typical of the Mid-Atlantic region of the USA (210 mg kg-1 soil). Seedlings of three to seven cultivars of Solanum lycopersicum L were inoculated in the greenhouse phase of production with a mixed species inoculum of AM fungi produced on-farm. Performance of the inoculation treatment was evaluated based on growth response in the greenhouse and fruit production in the field compared to uninoculated controls. Colonization levels were typically only 1-10% of root length at the time of outplanting. The mean mycorrhizal growth dependency based upon shoot growth at the time of outplanting was significant at 12.5 plus or minus 3.55% (a= 0.05). In addition, the mean mycorrhizal yield response over the seven year experiment was significant at 6.02 plus or minus 1.92% (a= 0.05).