Sweet potato protection! CTAHR team joins nationwide effort

University of Hawaiʻi at Mānoa

CTAHR will use a new grant to study ‘Okinawan’ sweet potato

When a virus or virus-like agent infects a vegetatively propagated crop, the negative consequences can go far beyond a disappointing yield, appearance, taste and plant longevity. If the difficult-to-find disease goes undetected inside the propagation material, the problem could be passed on to a new farm, establish itself, and spread even further.

With a new grant from the U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service, a group of University of Hawaiʻi at Mānoa College of Tropical Agriculture and Human Resources (CTAHR) extension agents and researchers on Oʻahu, Kauaʻi, Maui and the Big Island have joined a national network’s sweet potato research group.

Since 2008, the National Clean Plant Network has brought together growers, scientists and government agencies with the shared goal of safeguarding clean plants and ensuring a sustainable source of disease-free, vegetative propagation materials (such as cuttings, slips, scionwood, etc.).

For their first project, Amjad Ahmad, Rosemary Gutierrez, Roshan Manandhar, Susan Miyasaka, Sharon Motomura-Wages and Jensen Uyeda, along with Jon Suzuki from the USDA’s Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center in Hilo, will focus on ‘Okinawan’ sweet potato, the purple-fleshed variety that is a primary commercial cultivar in Hawaiʻi.

“During the first year, we hope to produce a total of 100 virus-tested ‘Okinawan’ plantlets in the tissue-culture laboratory of the Komohana Research and Extension Center, then distribute to extension agents across the state,” Miyasaka says.

The plan calls for the extension agents to multiply the clean material to produce 500 cuttings, and distribute them to growers. The agents will use either pot or hydroponic cultures under conditions that will minimize any re-introduction of disease, while Suzuki will test for major sweet potato viruses in order to ensure that the propagating materials are clean. If all goes well, by the second year of funding, the agents will be able to ramp up production to distribute 2,500 clean cuttings to growers.

Sweetpotato Varietal Trial Field Day Enormous Success

For this trial 12 varieties of Sweetpotato were measured for the Marketable Yield and Weevil damaged per variety.

The participants of the Field Day provided information on each varieties appearance, taste, and texture - yes, each participant was provided with cooked samples of each variety!

This Trial was to help growers make decisions to determine which variety of sweetpotato to invest their efforts in for the various markets.

The sweeter varieties were more marketable for various reasons but were prone to insect damage.

Dr. Rosemary Gutierrez-Coarite Ph.D. surveys the rows of sweetpotato grown for the Varietal Trial.
Ernest Rezents, Professor Emeritus Maui College and former head of the MCC Agriculture Department, looks for Rough Weevil damage as the typical damage done by Sweetpotato Weevil is displayed by Dr. Gutierrez-Coarite.

Sweetpotato Varietal Trial Field Day

This field day is open to all growers in Maui and will cover:
Yield and pest damage of twelve sweetpotato varieties.

When: Wednesday, July 14th, 2021, from 3:00 to 4:00 PM
Where: Kula Agricultural Park, lot # 16. 757-797 Pulehu Rd, Kula
(Face masks and social distancing during the event are required)
Registration is required: RSVP to Rosemary by emailing to gr6@hawaii.edu

DOWNLOAD the Field Day Flyer

Open to everyone without regard to race, age, sex, color, or disability. Educational activities are accessible for individuals with disabilities. For more information or to request an auxiliary aid or service (e.g., sign language interpreter, designated parking, or material in alternative format), contact Rosemary Gutierrez-Coarite at (808) 244-3242 or via email at gr6@hawaii.edu seven days before the activity/event.

Rosemary Gutierrez-Coarite Ph.D.
Assistant Extension Agent, Edible Crops
Department of Tropical Plant and Soil Science
UH CTAHR Maui Cooperative Extension Service
310 Kaahumanu Ave., Bldg. 214 Kahului, HI 96732
808-244-3242 ext. 232
" No task is too big when done together by all"

Hawaiian ‘Uala Varieties – Online Research Presentation

Date:July 10, 2021
To register:
email info@mnbg.org or call 808-249-2798
Suggested Donation:$10

Hawaiian ‘Uala (Sweet Potato) varieties have not been extensively characterized since E.S. Handy’s archipelago-wide collections from Hawaiian farmers in the early 20th century, and the conservation status of what was likely well over 100 Hawaiian cultivars remains unclear today.

A recent study titled Characterizing the Diversity of Hawai‘i Sweet Potatoes published in the Journal of Economic Botany attempts to understand, through molecular tools, the relatedness and genetic diversity of old Hawaiian cultivars of ‘uala relative to other varieties in local cultivation.

In this live online presentation, Aurora K. Kagawa-Viviani will share the findings of her research to better understand Hawaiian ‘uala varieties using information on plant genetics and characteristics. Following the presentation, we invite audience members to join an open discussion to reflect on what this tells us about Hawaiian agricultural and cultural history and to suggest ideas to support future increased local cultivation of a diversity of ‘uala for home and commercial production.

About Aurora
Aurora K. Kagawa-Viviani is an ecohydrology researcher on a joint project of the UH-Hilo Hawai‘i Cooperative Studies Unit, USGS- Pacific Island Ecosystems Research Center, and the UH Mānoa Water Resources Research Center.

He ʻuala ka ʻai hoʻōla koke i ka wī

Ka Wai Ola
By Claire Kuʻuleilani Hughes, Dr. PH., R.D.

He ʻuala ka ʻai hoʻōla koke i ka wī

He kilo ʻāina noʻeau ka mahiʻai Hawaiʻi. Ua kilo ka mahiʻai i ka lā a me ka ua, ka maikaʻi o ka lepo a me ka momona e hoʻoulu ai i nā mea kanu. Ua kilo ka mahiʻai i ka ulu ʻana a me ka hua ʻana o nā mea kanu ma nā ʻano wahi like ʻole, a me nā lepo a me ka ua hoʻi o kēlā ʻano kēia ʻano. Ua kilo ka mahiʻai i ka oʻo a me ka hua ʻana o ka lāʻau, a ua aʻo mai i ka hoʻoulu ʻana i nā ʻano kalo hou. Ma 1940, he 350 paha ka nui o nā ʻano kalo i ʻike ʻia ma Hawaiʻi. Ua hoʻoulu ʻia he 300 a ʻoi ʻano kalo hou mai iwakāluakūmāhā paha kalo i lawe mua ʻia i Hawaiʻi e nā Hawaiʻi mua loa.

Ulu maikaʻi ke kalo ma nā ʻano lepo like ʻole a pono ke kalo i ka lā a me ka wai. Ua ʻike maila nā malihini mua i kipa mai i Hawaiʻi ma 1778 i ka nui o ka ʻāina e hoʻohana maiau a maʻemaʻe ʻia nei ma ke ʻano he loʻi kalo a puni ka pae ʻāina. He hōʻike ka nui o nā loʻi kalo a me nā ʻano kalo like ʻole i ke ʻano o ka mea ʻai i makemake ʻia ka Hawaiʻi.

Hoʻoulu pū ʻia ka ʻuala e nā mahiʻai. Ulu ka ʻuala ma nā ʻano lepo like ʻole, ma nā ʻāina wela, a me nā ʻāina ua liʻiliʻi i a māloʻo hoʻi, kahi e ulu ʻole ai ke kalo. Ma kekahi palapala o ka makahiki 1940 ua hōʻike ʻia nā wahi a me ke ʻano o ka lepo e ulu ai ka ʻuala, ua palapala ʻia, ulu ka ʻuala ma ka nāhelehele, ma ka pōhaku pele a me ka lepo popopo, ma ke ʻākoʻakoʻa, ka lepo ʻula, a me ke ʻākeke. Māhuahua ka mahi ʻuala ʻana ma ka huli Kona o nā mokupuni a pau a ulu hoʻi ma nā ʻano lepo a pau, koe naʻe ka pālolo.

Ua hoʻoulu ka poʻe Hawaiʻi kahiko i 240 ʻano ʻuala. Ua kūpono ka hoʻoulu ʻia ʻana o ka ʻuala a me ke kalo ma nā māla ʻai. No ka mahiʻai, he mea nui ka maʻalahi o ka mahi ʻuala. Oʻo koke ka ʻuala. Nui aʻe ka hana o ka mahi kalo. He mea nui ke kahe mau o ka wai huʻihuʻi, a he makahiki paha ka lōʻihi o ka wā ma mua o ke oʻo ʻana. No laila, he kōkua nui ka ʻuala i nā ʻohana ma ka wā wī.

Nui ka ikehuʻā kōpia, ka hāʻaʻa ʻai a me nā wikamina A me B ma ka ʻuala, me ka nui aʻe o ka wikamina A ma nā ʻano ʻuala polū a ʻalani. He wikamina C, potasiuma, pokepola, a hao ko ka ʻuala, a liʻiliʻi ka paʻakai a me ka ʻaila. ʻO ke kalo, nui ke ikehuʻa kōpia, ka hāʻaʻa ʻai, wikamina B, a me nā minerala ʻē ʻaʻe. He ʻono nā ka lau kalo a me ka lau ʻuala i hākui ʻia me nā lāʻauʻē ʻaʻe a me ka iʻa a i ʻole ka moa paha. Nui ka wikamina A, B, a me C ma ia mau lau.

Mau nō ka pohihihi e pili ana i ka hiki ʻana mai o ka ʻuala i Hawaiʻi nei. Hōʻike mai ʻo Sir Peter Buck, ua lawe ʻia mai ka ʻuala i Hawaiʻi e nā hoʻokele Polinekia ma ka waʻa. Ua hoʻomana ka mahiʻai i ko lākou ʻaumakua. He kinolau ke kalo no Kāne me Lono. He kinolau ka ʻuala no Kānepuaʻa, Kamapuaʻa, me Kūkeaolewa.