Evaluation of hydroponic systems for Taraxacum kok-saghyz and comparisons with greenhouse and field production methods

Rubber dandelion ( Taraxacum kok-saghyz , TK) produces latex and rubber in its roots and is an option for alternative natural rubber (NR) production. The predominant commercial source of NR is the tropical rubber tree, Hevea brasiliensis . However, NR use is increasing globally and Hevea will be unable to supply enough NR to meet this demand due to acreage restrictions. TK can grow as a field crop in temperate regions and can also be produced hydroponically, circumventing issues this plant faces in the field and post-harvest such as weed pressure, short growing seasons, and soil contamination of the harvested roots. Hydroponic production of TK was explored with a focus on maximizing NR-containing root biomass. TK roots were grown in a custom-built ebb and flood research system as well as a commercial aeroponic Tower Garden hydroponic system. Nutrient solution, aeration, repeated harvests and seeding quantity in grow plugs were tested in hydroponics. Root weight was consistently greater in the medium designed to support growth of roots rather than leaves and significantly greater in several harvests. Root NR concentration was unaffected by growth medium and seeding rate. Providing aeration directly to plant roots produced significantly larger roots with greater amounts of NR. The system may produce 10 harvests/year of roots, yielding much more root biomass annually than a single field crop grown in Wooster, Ohio soil and has potential to produce much more NR than one field harvest per year. Preliminary calculations comparing hydroponics with conventional soil-based field and greenhouse production are included. • Hevea brasiliensis cannot continue to meet global natural rubber demands. • Taraxacum kok-saghyz (TK) has high potential as an alternative rubber crop. • Hydroponic production parameters were tested and optimized for TK. • Roots were repeatedly harvested from same plants showing large production potential. • Comparison of hydroponics with field and greenhouse production are included.