Table of Contents
Fike, W.T. 1990. The rise and fall of kenaf as a fiber crop in North
Carolina. p. 297-299. In: J. Janick and J.E. Simon (eds.), Advances in new
crops. Timber Press, Portland, OR.
The Rise and Fall of Kenaf as a Fiber Crop in North Carolina
William T. Fike
- ADAPTING KENAF TO NORTH CAROLINA
- Cultivar Evaluation
- Date of Planting and Soil Preparation
- COMMERCIAL PRODUCTION OF KENAF
- KENAFA NEW CROP?
Kenaf (Hibiscus cannabinus L., Malvaceae) is presently grown in India
and Thailand, where it is an important source of bast or cordage fibers used in
the manufacture of rope, bagging and other coarse fiber products. Plants grown
as annuals in North Carolina reach heights of 2.5 to 3.0 m, have stem diameters
of 7 to 18 mm, and usually flower by the first of November. These flowers
rarely produce seed under our environmental conditions. In Florida, plants
will reach heights of 5.5 m. and have increased stem diameters. Kenaf is
usually planted in 97 cm rows in Florida, but in North Carolina, kenaf is
planted in 1&-36 cm rows with higher densities ranging from 803 to 927
thousand plants per ha. Yields of dry matter (about 13 to 18 tonnes/ha) are
equal between the two locations.
Kenaf has been evaluated in North Carolina and the Southeastern United States
since 1957 as an annual source of fiber for pulping (Wolff and Jones 1958,
White et al. 1970, Taylor and Whitely 1981). Two types of fibers occur in the
kenaf plant: bast fibers in the outer bark and short woody fibers in the thick
core of pith. Both fibers can be used in making paper pulp. The kenaf would
not substitute directly for wood in paper pulps but combinations of fibers from
both sources could meet future demands for paper pulps in many areas of the
United States. Greater yields of fiber per unit area can be obtained from
kenaf than from our southern pine forests (Wolff 1964). Due to the vast
forested areas in North Carolina, numerous tree farms, and the increased costs
of pulping differing crops, we concluded that kenaf would never be grown by
North Carolina farmers as a substitute fiber source for wood fiber. The kenaf
bast fibers can, alternatively, be used alone or in combination with other
fibers in the production of a fine quality paper product such as cigarette
paper. Present sources of fibers for this product (i.e., seed flax straw) have
been diminishing in recent years and a substitute fiber source could be
beneficial to this industry.
Kenaf has been evaluated in most areas of North Carolina. Highest yields (13
to 18 tonnes/ha) have consistently been obtained in Eastern North Carolina, the
Tidewater region of the state, because of adequate moisture retention by its
fertile soils. In addition, highly organic soils of this area have little, if
any problems with rootknot nematode and hardpans, which are probably the most
serious pests of kenaf.
'Tainung l' and `Everglades 71' had been the leading cultivars in North
Carolina production trials. Other cultivars grown in the Tropics for cordage
('Cuba 108', 'Cuba 2032', 'Guatamala 45' and 'Guatemala 51') had also been
evaluated for North Carolina conditions. Quality seed of all kenaf cultivars
were difficult to obtain. Most seed was obtained from El Salvador and
performed adequately. A continued source of high quality seed of known purity
was lacking. Initial seed increase fields were planted in Weslaco, Texas, but
an early freeze destroyed the crop. An experimental planting was also made in
Haiti and high quality seed was produced, but the long distance and poor
communication were a problem. Experimental plantings for seed production were
also successfully made in Burkina Faso by a local seedsman.
Kenaf grows well in soils that produce good yields of maize and soybean. Once
the soils have been adequately limed and the phosphorus and potassium levels
are in the medium to medium high range (soil-test index ranges are 0 to 25 =
low, 26 to 50 = medium, and greater than 50 = high), an application of 135 kg
of nitrogen, 29 kg of phosphorus and 56 kg of potassium per ha should be
adequate for top yields of kenaf. The fertilizer should be applied broadcast
at planting. The nitrogen rate can be reduced by 22 kg/ha if the soil tests
over 4% organic matter, or if the kenaf follows soybeans. In one nitrogen test
comparing 45, 67, 90,112,135 and 160 kg/ha of nitrogen, increasing increments
of nitrogen fertilizer enhanced individual plant height, stem diameter, and
plant yield (Sirichandhra 1981). In some trials yield per hectare was not
improved with increasing increments of added nitrogen because of a decrease in
plant stand due to increased competition between plants.
Kenaf plantings did best when seeded into a warm soil, about May 20. However,
plantings delayed after this date resulted in loss of yield. Seedbeds for
kenaf should be smooth and firm before planting. Seed will germinate and
plants emerge in just two days. Herbicides must be applied at planting to
insure that emerging seedlings will not be sprayed and therefore killed or
Highest kenaf yields in North Carolina were obtained when two 36 cm rows were
planted on 97 cm beds. This row spacing was selected for ease of cultivation
and for harvesting the crop with a forage chopper. In many cases, planting 3
rows per bed further increased yields because higher seeding rates could be
used at planting. Dry matter yields increased proportionately with plant
populations at all row spacings tested, (Zublena 1979). Another advantage of
higher populations was that stalk diameter was minimized and yield of bast
fiber increased from 36% bast fiber in a 1.52 cm stem to 44% bast fiber in a
0.66 cm stem (Sirichandhra 1981). Because of this increase in the percent of
bast fibers at high populations, plus the added advantage of better weed
control, commercial plantings in North Carolina were made in 18-cm drilled
rows. Kenaf was seeded with a grain drill for a final plant stand of 700 to
900 thousand plants per ha in 18 cm rows. This requires a seeding rate of 16
to 20 seed per meter of row. Seeding rates varied with cultivar; 'Cuba 2032'
required 27 kg per ha, while 'Tainung 1; because of larger seed, required 35 kg
Although kenaf grows rapidly and under ideal conditions could provide good weed
control as it matures, control of early spring weeds is important. Trifluralin
is not phytotoxic to kenaf and provided good weed control of grassy weeds and
small seeded broadleafs (White et al. 1970). However, adequate weed control
was not obtained when the organic matter content of the soil was greater than
4%. In those soils, propachlor (at 6.7 kg/ha) is recommended.
Plants defoliate following a frost and were harvested with a mower conditioner
and windrowed. The windrows were flailed with a decorticator to separate the
woody fiber from the bast fiber. The crop was then baled and stored in 12 x 30
x 9 m stacks until used. Date of harvest had a tremendous effect on dry matter
yield per hectare. Most of our tests were harvested late and yields appeared
low. The average yield for kenaf from an October 28 harvest was about 7 tonnes
while the yield from the December 16 harvest was only about 5 tonnes. Dry
matter yields of kenaf plants decreased with time. The soluble portions of the
dry matter are leached from the plant while the fiber content decreases very
little (Bagby et al. 1975). Lower yields from the later harvest would
therefore provide equal amounts of bast fibers for pulping.
Plants remained green until December in two of the three years of commercial
production. When harvest was delayed until January or later, wet soils made
harvesting difficult. As farms were spread throughout three counties and
harvesting was conducted by only one crew, many problems occurred. Additional
mower-conditioners, balers, and pick-up equipment would be needed in the future
for efficient timely harvest.
A North Carolina paper company was interested in contracting kenaf production
in Eastern North Carolina, the Tidewater area of the state. In conjunction
with the North Carolina Agricultural Extension Service, discussions were
initiated with the Blackland Farm Managers Association and the Washington
County Farmers Cooperative in October and December of 1976 and March of 1977.
A total of 505 ha were contracted by 15 farmers for planting during the 1977
growing season. Plantings were also made on 404 ha in 1978 and 324 ha in 1979.
The 24(c) registration labels for Ramrod 65W and Treflan EC were obtained by
the Company for use as preemergence herbicides on kenaf. The Company took the
soil test and fertilizer recommendations were made by the Soil Testing Division
of the North Carolina Department of Agriculture. The following contract was
"Specifically, you agree to furnish ____ acres of land capable of producing
good corn and soybean yields for the purpose of growing kenaf. In addition,
you will agree to furnish and apply fertilizer as recommended by the North
Carolina Agricultural Extension Service, based on soil tests that we will take
on your fields. Such fertilizer is to be applied preplant or at the time of
You further agree to seed the aforementioned acreage with kenaf seed that we
will furnish. Such seeding shall be done with a grain drill at a rate of 25
pounds per acre (approximately 6-7 seeds per row foot). In addition, you will
furnish and apply a recommended herbicide on the same day of planting. Such
herbicides shall be applied in accordance with instructions from the North
Carolina Agricultural Extension Service, including instructions as to the type
of herbicide to be applied. You also agree to furnish and supply insecticides
at such times and in such manner as may be recommended by the North Carolina
Agricultural Extension Service.
It is further agreed that you will use all diligence and care possible in
growing the kenaf in accordance with the provisions of this contract.
In return for the above services, we will pay you $225 per acre for all land
which is actually used for the production of kenaf as above described, $125 per
acre of such compensation to be paid at the time of planting, and the remaining
$100 per acre to be paid when the kenaf is cut and harvested by us or by
December 1, whichever is the earliest. We will also furnish necessary kenaf
seed, will make a soil test of each field, will cut and bale the kenaf, and
remove the baled kenaf from the field. We and the North Carolina Agricultural
Extension Service will also instruct and recommend from time to time certain
procedures, modifications, or applications which will assist in the growing of
a crop which is suitable for the purposes intended"
Through the cooperation of industry, the USDA/ARS, NCSU Agricultural Research
plus Extension Programs, it was predicted that kenaf production in future years
could increase to as many as 4000 ha (10000 acres), and a new crop would be
provided to North Carolina farmers. Unfortunately, the Company producing
cigarette paper decided to eliminate their research efforts on kenaf and
continued to use flax straw as its raw material for pulping. Although the
venture failed, production information was obtained that may be used in the
future. Farmers liked kenaf and appreciated the company's efforts in promoting
the crop. They were treated fairly by the company and still hope that one day
they will again grow kenaf.
- Bagby, M.O., W.C. Adamson, T.E. Clark, and G.A. White. 1975. Kenaf stem yield
and composition: Influence of maturity and field storage. Atlanta, GA: TAPPI
NPFP Progress Report 6, p. 69-72.
- Sirichandhra, A. 1981. The effects of nitrogen fertilizer, crop row width and
plant population on the yield and the components of yield of kenaf. MS Thesis,
North Carolina State Univ., Raleigh.
- Taylor, C.S. and E.L. Whiteley. 1981. Kenaf, Hibiscus cannabinus L. p.
22-72. In: E.C. Knox and A.A. Theisens (Eds.), Feasibility of introducing new
crops: Production-marketing-consumption (PMC) systems. Rodale Press, Emmaus,
- White, G.A., D.G. Cummins, E.L. Whiteley, W.T. Fike, J.K. Greig, J.A. Martin,
G.B. Killinger, J.J. Higgins and T.F. Clark. 1970. Cultural and harvesting
methods for kenaf: An annual crop source of pulp in the southeast. ARS, USDA
Production Res. Rpt. 113.
- Wolff, I.A. and Q. Jones. 1958. Cooperative new crops research: What the
program has to involve. Chemurgic Dig. 17(9):4-8.
- Wolff, I.A. 1964. New crop prospects: paper from annual plant sources.
Chemurgic Dig. 22(3):3-4.
- Zublena, J.P. 1979. Kenaf (Hibiscus cannabinus L.) adaptation and
management for fiber production in New, Jersey. Ph.D. Diss. Rutgers Univ., New
Last update March 10, 1997