2019 ASHS Annual Conference

A new sector of protected horticulture involves a combination of sole-source electric lighting and soilless cultivation within insulated, environmentally controlled warehouses. For low-profile microgreens, baby greens, leafy greens, and culinary herbs, it is possible to mount hydroponic culture trays and overhead lighting fixtures on racks in multiple vertical tiers within high-bay buildings. Such indoor-agriculture (IA) / vertical-farm (VF) operations can produce greens crops year-round locally in otherwise seasonal climates with crop-yield potential two orders of magnitude higher than for field production on an annualized, land-area-footprint basis. When effective pest-exclusion and stringent sanitation measures are practiced, produce can be grown pesticide-free. Emission spectra from light-emitting diodes (LEDs) can be selected or manipulated to not only promote crop yield, but also crop-quality parameters such as texture, flavor, pigmentation, and phytonutrient content. Under such high environmental control, lighting and growth prescriptions can be developed for individual species and cultivars. Vertical farming requires up-front investment in costly technology as well as expensive costs of operation, especially electricity for lighting as well as associated heating-ventilating-air- conditioning (HVAC) needs. Thus, the availability, freshness, and quality of year-round VF produce must command premium pricing in the local marketplace. Issues of consumer willingness to pay, business profitability, carbon footprint, seasonal competition from field-grown produce, local regulations, investor return on investment, and consumer acceptance of indoor growth technology are just some of the issues that the nascent VF industry is dealing with in struggling to become viable. Research addressing all of these factors is badly needed!