John Spafford

Graduate Student
M.S. Research: Increasing productivity of asparagus through sustainable disease management tacticsA man wearing a straw hat standing in a field with trees in the background.

Email John:
164 Plant Biology Lab
(517) 355-4576

  • B.S., Biology, Hobart and William Smith Colleges

The asparagus industry in Michigan is worth $23 million. The nutrient-rich, perennial vegetables are grown and sold for processing and fresh market sale. The production of asparagus is complicated, seeds are planted in crown nurseries and grown for a year. Crowns, the root system of the seedlings, are harvested and then replanted in production fields. Asparagus production is expensive and it takes several years before the spears can be harvested at a profit. When asparagus is healthy it can produce spears for 13 years. During this time it is exposed to a variety of diseases. In the soil Fusarium oxysporum f.sp. asparagi and Phytophthora asparagi can cause crown and root rot. Damage to the spears and fern are caused by the diseases Purple Spot (Stemphylium vesicarium) and Rust (Puccinia asparagi). Management practices for these diseases are typically costly, limited, and low impact. Asparagus production is declining nationwide, and growers are reporting high yield loss and shorter asparagus lifespans. The focus of my project will be developing sustainable and effective management practices. In crown nurseries, new products and approaches will be evaluated for soil-borne pathogen control. In production fields, new fungicides will be evaluated for control of Rust and Purple Spot. Different cultivars will also be assessed for resistance to foliar pathogens. The outcome of this project will be to inform and cooperate with Michigan asparagus growers to develop effective management programs.