Page 151 - PC2019 Program & Proceedings

PLANT CANADA 2019

S87. Mycorrhizal fungi in the roots of onion and carrot in relation to mycorrhizal fungal inoculant
and soil phosphorus
1
2
*1
Ilyas, U. ; M. Raizada ; L. du Toit ; M.R. McDonald
1
1 University of Guelph
2 Washington State University
The use of arbuscular mycorrhizal fungal (AMF) inoculants is becoming popular for the commercial
production of onions and carrots in Ontario. This study evaluated the effect of these inoculants on the
diversity of native AMF communities in roots of onion and carrot, and how these AMF communities
varied with soil phosphorus (P) concentration. Field trials were conducted on high organic matter soils
(56% organic matter) with two levels of soil P concentrations: low P ~46ppm without application of P
fertilizer and high P ~68 ppm with P application, at a site in the Holland Marsh. Treatments were seed
pre-coated with AMF (3–5 propagules of Rhizophagus intraradices Walker and Schüßler per seed) and
untreated seeds, grown on low and high P soil. The AMF communities in roots were identified by
Illumina sequencing. Five genera of AMF were identified in roots of onion and four in carrot. The AMF
community in onions from inoculated seed was richer and more diverse compared to the no AMF check,
but there were no differences in carrots. The diversity of AMF in carrots was lower on high P soil, but
there was no effect of soil P on richness or diversity of AMF in onions. Overall, both AMF inoculant and
soil P concentrations affected the diversity of AMF communities in roots, but these effects varied with
crop type.

Umbrin Ilyas (uilyas@uoguelph.ca)

S88. Evidence for a recent re-expansion of market gardening in Ontario through organic field fruit
and vegetable production
Chappell, E; E. Deboer; B.J. Micallef
University of Guelph

Market gardening can be defined as the production of fruits and vegetables for the fresh-market by small-
to medium-sized family operations that each grow multiple commodities close to urban centers. A brief
history of the fruit and vegetable industry in Ontario over the last 100+ years will be presented, including
field and greenhouse production in the Golden Horseshoe, Holland Marsh, Norfolk County and SW
Ontario. The impact of both urbanization and the profitability of farming on market gardening are
analyzed, including their role in the significant contraction of market gardening that occurred in Ontario
starting in the late 1960’s. Some myths or misconceptions regarding the fresh fruit and vegetable industry
are examined, including myths related to greenhouse production, the impact of ‘yield’, operation size, and
the role of corporate farming. This historical analysis will be used to put into context and to access the
future of market gardening in Ontario, including evidence for a recent re-expansion of market gardening
through organic fruit and vegetable production. Results from a survey of organic growers in Ontario will
be presented in terms of challenges to expansion of organic fruit and vegetable production and their
marketing channels. As a backdrop to these analyses, B. Micallef will share some experiences of his
family, who have been market gardening in Ontario for 84 years.

Barry Micallef (bmicalle@uoguelph.ca)

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