- Taro Production Guidelines for Kauai
Crop Production Guidelines |
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By: Hector Valenzuela and Dwight Sato
University of Hawaii, Assistant Extension Vegetable Specialist
and Extension Agent, respectively.
INTRODUCTION
Now that many commercial growers and homegardeners are starting
to make plans to re-establish and fix up their gardens and taro
patches, it may be a good time to go over some of the recommended
cultural practices for taro production developed by researchers
at the University of Hawaii. Taro is a very hardy and resilient
vegetable which when unwanted in vegetable fields may turn into a
bothersome weed. In fact cocoyam, which is a close relative of
taro, and consumed by the Latin and Caribbean population, was
about the only vegetable that survived the devastating freeze
that hit South Florida on the early morning of December 26, 1989.
Losses for 1990 in Dade County accountable to the vegetable
freeze was in the hundreds of millions of dollars. The undamaged
cocoyam corms (the underground storage organ, which is actually
stem tissue is called a corm) lying below the soil level,
however, re-sprouted once the temperatures rose and plants which
were ready for harvest were dug a few months later. Similarly in
the Pacific Islands, taro, and other relatives of the aroid
family are often the first crops grown in islands and atolls
which have been hit by hurricanes or flooding tidal waves. The
fast recovery of aroids in areas affected by hurricanes or high
tides is a sign of their adaptability to flooding, and also to
salty irrigation water. This resiliency despite the recurrence of
natural disasters, may explain in part the spiritual symbolic
value that taro represents to the Hawaiian heritage.
TARO VARIETIES
Taro can be cultivated under both wetland (paddy-taro) and
dryland (upland) conditions. Some varieties do well under both
types of culture. Important local varieties include Bun Long or
table taro mostly grown in the Big Island for fresh market and
making chips; Lehua Maoli for poi taro with most of the state's
production concentrated in Kauai; Niue or Samoan Taro; and
dasheen or araimo for Japanese taro. Dasheen varieties include
Tsurunoko, Miyako, and Akado. The wetland or lo'i system, which
takes advantage of taro's flood tolerance, was apparently
developed early on by Hawaiians to eliminate weed competition and
to lower the growing temperature of the corms (the underground
storage organ which is actually an underground stem tissue).
PROPAGATION
For propagation, taro cuttings or hulis are used. The hulis are a
part of the stem about 12-18 inches long attached to a 2-3 inch
section of the corm. The cuttings are planted vertically with
soil covering about one-third to half of the standing huli. Since
hulis are difficult to obtain, commercial growers or avid
gardeners need to establish their own nurseries with their
favorite variety. Initial hulis can be obtained from fellow
growers, and also from the Cooperative Extension Service. Several
community organizations throughout the state, such as the
Ho'okahe Wai, Ho'oulu 'Aina, a charitable organization in
Honolulu, are also making efforts to collect old taro varieties
to maintain them in cultural gardens throughout the state. Make
sure that you start with disease-free propagating material by
closely inspecting each cutting, washing with potable water,
soaking hulis in a 10% bleach solution for 30 seconds, and by
storing the hulis in a dry, cool, and well-ventilated area for 3
to 5 days before planting to allow for old wounds to heal.
In the dryland system of production hulis can be planted by hand
or with a modified vegetable transplanter. Plants are spaced 18
inches apart, and rows are spaced 3-4 feet apart. Research in
Hilo indicates that liming to a soil pH above 6, may result in
lower incidence of corm rots, and improved plant vigor. Lime
preferably after field plowing and for best results, at least a
month before planting. The early liming treatment will allow for
the proper soil reaction and rise in pH by the time the taro is
ready to be planted. Commercial taro fields in Hawaii, are
heavily fertilized compared to traditional practices in other
Pacific Islands or in Africa. In high rainfall areas apply a
total of 2000 lbs of 23-0-36 fertilizer per acre divided in six
equal doses beginning at planting, and the rest at five monthly
intervals. In addition, at pre-plant apply 2500 pounds per acre
of a 0-45-0 fertilizer. Costly soil amendments such as dolomite,
and hydrated lime are normally not recommended considering the
economics of commercial taro production in Hawaii. Gardeners may
broadcast before planting 3 pounds of a 10-20-20 fertilizer, and
then sidedress 1 pound of a 16-16-16 fertilizer at two, four, and
again at 6 months after planting on a 100 square foot area.
HARVEST AND POST HARVEST PRACTICES
Most taros will mature in 6 to 10 months. Corms in the
garden can be dug with a shovel. Modified potato harvesters are
available to dig taro under commercial conditions. Such a machine
has been employed for demonstration purposes by the Cooperative
Extension Service in Molokai. In commercial packing sheds of
South Florida the corms are conveyed to a machine with circular
brushes which removes the soil, washes the corms, selects by size
and the corms are then packed with the help of hand labor. A
typically-sized machine packs eighty 50-pound boxes per hour with
the help of seven laborers. At this point the product may be
shipped to a buyer for placement in a cold room. The recommended
temperature for prolonged storage is 45-50 F with a relative
humidity of 85. Luau leaves can be harvested at any time during
the growth of taro. Only young taro leaves are used for luau.
Corms yields will be reduced if more than 3 leaves are picked per
plant.
PESTS AND DISEASES
Despite its hardiness, taro is susceptible to attack by some
important pests and diseases. Slugs may damage corms creating
wounds which provide entry of secondary disease organisms.
Weed-free fields and hilling may help reduce slug infestations.
The golden mystery snail has become a threat to taro production
in Hawaii. Yield reductions caused by the golden mystery snail
can reach in excess of 60% from feeding in both the foliage and
the corm. Hand-picking, irrigation with saline water, and copper
based pesticides are among the practices currently being tested
for control of this pest Cultural practices to avoid incidence of
diseases in taro include the use of disease-free propagating
material, avoiding contaminated fields, eliminating diseased
plants growing in the field, and increased spacing at planting to
improve ventilation. Weeds may also reduce taro yields by
competing for space and nutrients. To prevent yield losses from
weed competition maintain taro free of weeds during the first
three months after planting.
VALUE OF TARO
The value of taro production in Hawaii has increased over the
past few years from a farm-gate value of $1.7 million in 1987 to
$3 million in 1991. Hawaii taro farmers have an opportunity to
capitalize on this trend of increased popularity of taro products
by closely working with their present customers, and by
establishing new markets with currently unknown buyers.
Commercial growers should make careful marketing plans, and
identify potential buyers even before the first huli is planted.
Costs of production for taro in 1989 were estimated at $6,175 per
acre with labor accounting for 49% of total costs, and machinery
and equipment for about 23% of the total. Homegardeners, growing
taro for family reunions, and for self-consumption can plant taro
any time of the year. For homegardeners and part-time farmers
taro is a low-maintenance crop that will maintain a ground cover
in the field to reduce soil erosion, and will provide a bountiful
harvest at 8 to 10 months after planting. Nutritionally the root
crop is rich in fibre, calcium, potassium, iron, vitamin A,
vitamin B1, vitamin B2, and vitamin C. The quality of the diet of
indigenous people living in the Pacific Islands has generally
decreased when the consumption of taro has been replaced by other
sources of carbohydrates such as white bread. In Hawaii and in
other regions taro also has a rich cultural and spiritual value.
Traditionally it was prohibited to argue when a bowl of poi was
placed on the dinner table, and the kupunas would uncover the poi
bowl to end family disputes. Today, that cultural heritage is
kept alive by teaching the younger generations about the old
spiritual ways, and keeping a taro patch in the field or in the
garden is still an easy way to stay in touch with nature.
Notice: Reference to a firm or trade does not imply endorsement
over firms or products not mentioned.