Rubber dandelions: Still a critical need

By Katrina Cornish

Rubber dandelions, Taraxacum kok-saghyz, the Kazakhstani cousin of our common dandelion, are still a focus of research and development at Ohio State University because they make high quality natural rubber in their roots. In the modern age, natural rubber continues to play a vital role in advanced economies, such as ours, making activities like driving, flying, and warfare possible. Yet, its remarkable significance often goes unnoticed due to its widespread use in our daily lives. In 2019, around 14 million metric tons of rubber were collected from rubber trees (Hevea brasiliensis), native to the Amazon rainforest in Brazil, through hand-tapping latex.  When our supply chains were severely disrupted due to the COVID-19 pandemic, supplies of many materials upon which we depend were restricted. Some U.S. rubber companies resorted to flying in their supplies — I think no longer commodity priced! The need for U.S. self-sustainability is now in the public and political eye, and rubber dandelions can be farmed in Ohio both in conventional and controlled environment agriculture.

Despite their Amazonian origin, rubber trees are mostly cultivated in tropical southeast Asian plantations and small holdings because of the fatal tree disease South American Leaf Blight (SALB) endemic in Brazil. Collected latex is about one-third emulsified rubber particles, resulting in an astonishing 42 billion liters gathered in small bowls the size of teacups. To put this into perspective, it is equivalent to 3.7 billion U.S. gallons, capable of filling over 5,600 Olympic-sized swimming pools. Roughly 11% of the latex is centrifuged to remove half of the water, using equipment like cold milk separators, while the remaining portion is transformed into solid rubber. Manufacturers receive concentrated latex for producing items like gloves and condoms, made by dipping formers into latex emulsions. Solidified rubber is molded into various products such as tires, bushings, and gaskets.

Rubber tree are grown as clonal scions grafted onto seedling roots stocks. Thus, miles upon miles of trees are genetically identical making them highly prone to disease and our rubber supply chains very vulnerable. In 2019, two leaf pathogens (Pestalotiopsis and Neofusicoccus), jumped over from Oil Palm, and in the next six months spread rapidly to over one million acres of trees across seven countries. 2020 saw a 10% drop in natural rubber production — 1.4 million metric tons — more than the U.S. imports. Although, rubber supplies have now largely recovered, they remain at risk of collapse. In October of 2022, direct flights were opened for the first time between Brazil and China connecting the southeast Asian rubber tree plantations to endemic SALB regions. It remains to be seen if, and when, SALB makes the crossing now that the quarantine has been broken.

OSU researchers have developed partially effected herbicide protocols and are nine generations into population development selected for large root size in the field. Significant grant funded commercial efforts are ongoing at various start-up companies which can use the OSU pilot plants in Wooster for processing. We are currently talking with Ohio farmers who may be interested in trialing rubber dandelions as a new industrial crop.

Katrina Cornish, Ph.D., FNAI, FAIMBE, FAAAS, Research Director, Program of Excellence in Natural Rubber Alternatives, cornish.19@osu.edu, 760-622-4330. Department of Horticulture and Crop Science and Food, Agricultural and Biological Engineering, Ohio Agricultural Research and Development Center, College of Food Agricultural and Environmental Sciences, The Ohio State University, Wooster, OH 44691.