2023 & 2024 Taro Trials at USP Farm
Introduction
There are hundreds, if not thousands, of taro varieties. The University of Hawaii alone has a list of 84 well-documented and described varieties. Given that we are growing taro outside of its ideal tropical environment, with a shorter season than it expects, some of our work is simple variety exploration to find which varieties grow well in our region. We are growing in standard row cropping systems, with no flooding, and are primarily looking at yield and average corm size.
Note: Yanna Fishman, from a purely observational perspective, has noticed that the varieties of taro (and other clonally propagated tropical root crops) that she has worked with over consecutive years generally tend to increase in productivity and plant vigor. Many factors could be at play, including a trend toward warmer temperatures and increased competency and knowledge in growing. However, we are also open to the possibility of inheritable epigenetic adaptation.
2023 trial planting at the Southern Appalachian Highland Conservancy Community Farm, Alexander, North Carolina.
2023 Taro Trial
At our farm site on the Southern Appalachian Highland Conservancy Community Farm, Alexander, North Carolina, we set up a block design with 2 replications of 6 taro varieties. We aimed to plant out 18 plants in each block, but were slightly light on planting material for several varieties. The ground was newly opened, without irrigation, and not of the best quality. We planted an edge row using additional taro varieties that we had in lower quantities. The layout of the field is represented below, along with the number of plants in parentheses.
We transplanted sprouted cormels into the field on May 25, 2023. Spacing was 12” between plants, with Zinnias used as a break between varieties within the row. We planted through landscaping fabric for weed control.
2023 was a dry growing year, and the taro plants stayed smaller than usual. We allowed a frost to kill the top growth before harvesting the plants in mid-November. The total yield per variety should not be seen as representative of taro’s yield potential (see farmer interviews below), but rather a comparative assessment between varieties.
Total yield is calculated post-harvest, after the corms and cormels have been washed and dried with the stem removed.
Yield per plant is calculated by taking the total yield per variety and dividing by the total number of plants harvested.
Harvested corms/cormels are calculated by counting all separate pieces of corm or cormels, regardless of size.
Yield per corm/cormel is calculated by taking the counted total number of corms/cormels per variety and dividing by the total yield per variety.
| Variety Name | Surviving Plants | Harvested Corms / Cormels | Total Yield (g) | Yield per Plant (g) | Average Weight per Corm / Cormel (g) |
|---|---|---|---|---|---|
| Big Taro | 6 | 39 | 2,478.00 | 413 | 64 |
| Puerto Rico | 33 | 177 | 13,312.00 | 403 | 75 |
| Lee | 30 | 471 | 8,827.00 | 294 | 19 |
| Korean | 34 | 594 | 9,772.00 | 287 | 16 |
| Filipino | 17 | 100 | 4,110.00 | 242 | 41 |
| Kai Kea (HI) | 26 | 125 | 6,248.00 | 240 | 50 |
| Pilialoha | 5 | 52 | 1,187.00 | 237 | 23 |
| Thai | 8 | 44 | 1,454.00 | 182 | 33 |
| Bun Long | 29 | 148 | 4,696.00 | 162 | 32 |
| Lehua Maoli | 9 | 38 | 1,150.00 | 128 | 30 |
| Manini Owali | 5 | 7 | 607 | 121 | 87 |
| Paakala | 5 | 7 | 304 | 61 | 43 |
Taro growing through landscaping fabric. Other tropical perennials growing alongside (arrowroot to the left, and yacon to the right).
2024 Taro Trial
In 2024, we planted another round of varieties at the same farm location. This time, we did not replicate any of the plantings, but planted into uniform rows with drip irrigation. We followed 12” spacing between plants and broke varieties with a zinnia planting. Our transplant date was May 15, 2024.
Our harvest protocol was the same as in 2023, waiting for a frost to kill the greens before digging and weighing the yield. In 2024, we counted the total corms and cormels separately.
Below you can see the data for the 2024 harvest; overall yields were better across the board, almost certainly because of better soil quality and irrigation.
| Variety Name | Surviving Plants | Harvested Corms | Harvested Cormels | Total Yield (g) | Yield per Plant (g) | Average Weight per Corm / Cormel (g) |
|---|---|---|---|---|---|---|
| Korean | 32 | 32 | 1,012.00 | 24,411.00 | 763 | 24 |
| Kai Kea (HI) | 5 | 5 | 44 | 3,531.00 | 706 | 80 |
| Big Taro | 9 | 9 | 86 | 6,074.00 | 675 | 71 |
| Paakala | 1 | 1 | 12 | 512 | 512 | 43 |
| Filipino | 8 | 8 | 65 | 3,967.00 | 496 | 61 |
| Lehua Maoli | 19 | 19 | 119 | 8,098.00 | 426 | 68 |
| Araimo | 3 | 3 | 32 | 1,128.00 | 376 | 35 |
| Thai | 20 | 20 | 137 | 6,158.00 | 308 | 45 |
| Akado | 12 | 12 | 92 | 3,464.00 | 289 | 38 |
| Miyako | 18 | 18 | 104 | 3,919.00 | 218 | 38 |
| Puerto Rico | 3 | 3 | 11 | 590 | 197 | 54 |
| Bun Long | 2 | 2 | 9 | 290 | 145 | 32 |
Results & Discussion
The two years of variety trials have shown us that yield and corm count are highly variable across varieties, and have helped provide guidance in selected varieties most suitable for taro growing in our region.
Total yield is important, but as noted in the farmer interviews (below), there is a market preference for large cormels and corms, so the average weight per corm is also important in terms of marketability.
A challenge of the variety trial is that it is hard to standardize the propagation material size. As was noted in the on-farm trials (see below), propagation material size can have a serious impact on yield. Producing enough nursery stock of consistent size to do a large variety trial was challenging. Further work to assess yield based on more standardized planting material size would be beneficial.
Given that limitation, results over the two years help paint a picture of suitable higher-yielding varieties. Korean and Lee varieties of taro (very similar, possibly the same) produce high quantities of smaller eddoes.
Big Taro and Kai Kea produced consistently high yields and a much larger average corm size, making them good contenders for the market demand for larger corm size.
Puerto Rico was extremely promising in 2023, but less so in 2024. We are doing further grow outs with this variety to get a better sense of its performance.
A final note is that culinary qualities and winter storage qualities are also very important. For example, Lehua Maoli has lower yields but stores incredibly well, and Bun Long has purple fibers throughout its corm flesh, which is sought after by some chefs.
Graphical representation of the yield per plant and average corm/cormel weight over the 2023 and 2024 variety trials
