Project Number: 8072-12000-013-01-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 16, 2016
End Date: Aug 15, 2019
The objectives of this agreement are to: 1) Improve and enhance the reliability of the method for the on-farm production of inoculum of isolates of arbuscular mycorrhizal [AM] fungi that are indigenous to the farm and, 2) Compare techniques for the detection of AM fungus colonization of roots to determine which could be conducted by farmers on-the-farm. Added: To quantify the impact of mycorrhizal and non-mycorrhizal over wintering cover crops upon the indigenous population of arbuscular mycorrhizal fungi/ To examine the use of an alternate host plant, corn, instead of Bahiagrass in the on-farm production of inoculum of arbuscular mycorrhizal fungi.
Arbuscular mycorrhizal [AM] fungi are naturally-occurring soil fungi that form a mutualistic symbiosis with the majority of crop plants. Among the benefits imparted to the plant are increased nutrient uptake, disease resistance, and drought tolerance. These benefits indicate that optimal utilization of the symbiosis should be an important tool for the sustainability of agriculture. Inocula of AM fungi are available commercially, however, on-farm production of inoculum has been shown to be an inexpensive and reliable alternative to purchased inocula. On-farm production of inoculum of AM fungi requires compost, vermiculite, nurse host plant seedlings (bahiagrass (Paspalum notatum Flugge)), and a starter inoculum. Use of soil from the farm is the simplest form of starter inoculum, and has the advantage of enabling the production of isolates of AM fungi indigenous to the farm. The current version of the method uses Bahiagrass seedlings, grown previously in a greenhouse for 2-3 months, as host plants for the AM fungi. We propose to examine the use of corn as a host plant. The advantage here would be the rapid germination and growth of corn would allow for sowing the seeds at the time the on-farm system is set up, representing another step in making the do-it-yourself inoculum production system more user friendly for the farmers. Inoculum of AM fungi is most efficiently used in vegetable production as an amendment to horticultural growth media for the production of seedlings later out planted to the field. Other growers can take advantage of the indigenous population of AM fungi through management practices, one of which is over wintering cover crops. We will test the impact of two sets of over wintering cover crops, one a non-host to AM fungi (expected to have a negative impact upon the population) and the other host to AM fungi (expected to have a positive impact upon the population) upon propagule levels of AM fungi and subsequent colonization of onion seedlings transplanted into these soils as part of a larger effort to study the impact of the cover crops upon managing Allium leafminer damage.