Galls Gone Wild!

Galls Gone Wild!

Cue steel drums. Now get ready for a wild picture:


Cue grumbling. OK, cheap move, but really, would you have clicked on a blog post titled “Pongamia’s potential in Okinawa”?

PresentingI recently had the honor and privilege of being invited to speak at a conference on the Island of Kumejima, in Okinawa prefecture. It was a delight to be able to explore such a beautiful part of the world, especially an area with a strange dichotomy wherein some aspects of the landscape appeared analogous to my home state – Hawaii – while other aspects were utterly divergent and completely foreign.

One of the people I struck up a conversation with an emeritus professor from the University of Tokyo, and current President of the Deep Ocean Water Applications Society. As interested in pongamia as he was, I was equally intrigued by his Ocean Thermal Energy Conversion (OTEC) field, though that’s enough fodder for a whole separate blog post. After hearing my presentation on TerViva’s work to commercialize pongamia, this professor did a bit of research on his own and determined that in the Japanese language, pongamia is called “Kuroyona,” and that there are many Kuroyona trees to be found in Okinawa prefecture.

While the picture at the beginning of this blog post may have tipped you off, I can confirm that pongamia most certainly do exist on Okinawa Island. After a bit of exploring, I was able to locate several dozen Kuroyona trees, and observed them to be robust, with some displaying dense examples of early stage flowering, which could lead to a plentiful crop of oilseeds. In addition to these observations, I also recorded the presence of many leaf galls, which are structures built on the host pongamia’s leaf tissue by mites. In this context, there was no indication that the presence of leaf galls was having a negative impact on the trees in which I saw them; I determined there was no indication of ill effect due to the lack of superficially observable differences between trees with heavy gall outbreaks relative to trees with no visible galls. It should be mentioned here that the pongamia trees TerViva is growing in the United States have been verified to be gall-free by the USDA, and TerViva has not observed any galls on trees growing in the wild in the United States. Pongamia sign

The presence of pongamia in Okinawa is significant for a couple of reasons in particular:

  • Presents further indication of just how hardy Kuroyona is, given that Okinawa is impacted by typhoons an average of 7-8 times every year
  • As vividly depicted in the picture of galls going wild at the beginning of this post, the pongamia trees I observed appeared to be thriving in spite of what in some instances was high-density gall colonization
  • In spite of these environmental insults, and indication of minimal maintenance, the Kuroyona I observed were vigorous, and many trees displayed early indications of high density inflorescence, meaning the trees could be highly productive

flowersAs a result of my exploration and observations, I naturally wondered: what is the potential for pongamia cultivation in Okinawa Prefecture?

Looking for statistics on oil/diesel use in Okinawa Prefecture was difficult, and ultimately I was unsuccessful, which probably had something to do with the fact that I don’t speak Japanese, and so cannot search Japanese-language websites. Luckily, some friends from Kumejima Island (a larger island in Okinawa Prefecture) stepped in and graciously helped by providing me with the following information: As of 2004, ~300,000 gallons of oil per year were used for transport (both gas and diesel) on Kumejima Island.

Anyone who read my previous blog post will remember that I am prone to spontaneous bouts of case study formulation. Here’s a quick one: how much land would be required for a pongamia orchard large enough to supply all of the diesel needed for transportation on Kumejima Island? First, some assumptions:

  • Half of the transportation fuel used on Kumejima Island in 2004 was diesel, which can be replaced by biodiesel produced from pongamia oil
  • Kuroyona orchards on Kumejima Island still yield the 400 gallons of oil per acre that we expect them to yield in the United States

Given these assumptions, TerViva would need to plant an orchard ~375 acres in size to supply all the diesel used for transportation on Kumejima Island, ~150,000 gallons as of 2004. Since it is almost 2015, let’s assume diesel use has grown by 33% since 2004, to annual consumption of ~200,000 gallons. To produce 200,000 gallons of pongamia biodiesel, TerViva would need to plant a 500-acre orchard. As a point of reference, 500 acres represents less than 3.5% of the entire landmass of the island of Kumejima. Because I was not overly diligent in the research for this blog post, let’s say I was off, that it’ll take double the land I calculated would be needed; that is still less than 7% of the entire island’s land mass.

Allow me to summarize the above babble: using less than 7% of the land on Kumejima Island, TerViva could supply all of the diesel needed for transportation on the entire island. All of your diesel needs for less than 7% of your land? That’s a pretty good deal.

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