Table of Contents
Baldwin, B.S. 1996. Adaptation of kenaf to temperate
climatic zones. p. 402-404. In: J. Janick (ed.), Progress in new crops. ASHS
Press, Arlington, VA.
Adaptation of Kenaf to Temperate Climatic Zones
Brian S. Baldwin
- MISSISSIPPI KENAF PROJECT
- DEVELOPMENT OF ADAPTED CULTIVARS
Kenaf (Hibiscus cannabinus L., Malvaceae) is related to okra
(Abelmoschus esculentus L.), cotton (Gossypium spp.) and
Rose-of-Sharon (Hibiscus syriacus L.). Kenaf plants tend to grow as a
single unbranched stem when planted at production densities (170-220,000
plants/ha). Stem color varies from pure green to deep burgundy. Flowers are
borne singly, with five yellow petals and a red "blood spot" in the center of
the flower. Leaves generally take two forms: deeply lobed and entire more or
less resembling cotton leaves. The fiber is derived from the stem. Bast, or
bark fibers are composed of phloem bundles and used extensively in cordage.
The core, or woody fibers can be utilized in the production of paper,
absorbants, animal bedding, and soilless potting media (Goforth and Fuller
Between the 1940s and 1960s, the feasibility of utilizing kenaf as a source of
cellulose fiber for use in pulp and cordage was investigated by the USDA-ARS
(White et al. 1970). It has been reported that whole stalk kenaf could be
utilized in the production of paper (Nieschlag et al. 1960). However, pulping
processes in the 1950s and 1960s as well as the availability of cheap wood
caused interest in kenaf to wane. White and his group (1970) made an extensive
investigation of the potential of growing kenaf in the southeastern United
States as well as three mid-western states as far north as Nebraska. Of the 12
locations tested, only southern Florida was free of frost late enough in the
year to provide viable seed for almost all of the varieties tested. Cultivars
from Cuban (Cubano, C108, C2032), Floridian (E41 and E71), and Guatemalan (G4)
ancestry were utilized because each showed some degree of resistance to
anthracnose (Colletotrichum hibisci Polacci) (Wilson et al. 1965). Most
kenaf cultivars are short-day plants. Dempsey (1975) reports that most
improved kenaf cultivars remain vegetative until the daylight period falls
below 12.5 h. Plantings of these cultivars north of 20deg. latitude results in
strong vegetative growth, but induction of flowering occurs too close to the
frost date for the production of viable seed. As a result, much of the seed
planted in the United States is produced in Florida, south Texas, the
Caribbean, and Latin America. Like its relatives, okra and cotton, kenaf
attracts a number of pollinators to its flowers. Because of the moderate level
of cross-pollination, seed obtained from tropical sources is frequently not
true-to-type. This means that seed labelled as a single cultivar may contain
plants with differing characteristics. Selections from these mixed seed lots
and other germplasm has allowed researchers to develop lines that flower and
set seed in Mississippi.
The kenaf project was initiated in 1989 with the purchase and contract growth
of several cultivars of seed for planting in the delta region of Mississippi.
Survey of the literature indicated that the Cuban, Floridian, Guatemalan, and
Taiwanese cultivars were probably best suited to Mississippi. Initial
selections were made from several of these cultivars in 1993. Initial
selection criteria was based solely on flowering date. Seven single plant
selections were made from E71. In 1994, 0.20 ha plots were planted of G4, G45,
G48, E41, E71, Cubano, C108, and C2032. Flowering date as well as
Cristulariella pyramidalis Waterman & Marshall (a defoliating leaf
spot) resistance were the selection criteria. Initial selections were
crossed and selfed in the greenhouse and subsequent seed planted to the field
the following spring. Germplasm was obtained from Charles Cook (USDA-ARS,
Weslaco, TX) that were believed to be determinant. Somaclonal variants from
Nancy Reichert's research (MSU/MAFES, Starkville, MS) were incorporated into
the field nursery and observed for deviation from their parental lines.
Additional selections were made from Indian and Russian germplasm. Crosses
were made by utilizing the rooted meristems of the improved short-day types
(that initiated flowering in the field) and germinated plants of the
determinant types, or crossing rooted cuttings of a shorter short-day plant
with a longer short-day plant. Agronomic potential of each selection and cross
was evaluated when sufficient seed was generated. Evaluations were made based
on plant height, plot yield, date of flowering and Cristulariella
Currently, kenaf lines developed in Mississippi initiate flowers from the last
week in June (May planting date) until frost. A study by Baldwin (1994)
indicated that kenaf seed developing in north Mississippi needs 43-45 day after
pollination to mature. With an average frost date of Nov. 7 (Starkville, MS),
that study determined a target of Sept. 21-25 as the date of first open
Our goal is not to be a major seed production center, but to have the ability
to manipulate the genetics of the crop should the need arise.
Cristulariella is a disease that strikes kenaf during humid summers. It
defoliates the entire plant from 0.3 m below the apical meristem and remaining
leaves are damaged by necrotic spotting. Cristulariella has been
reported in North Carolina, Maryland, Alabama, (Pollack and Waterworth 1969),
and Mississippi (Lawrence, MSU Plant Pathologist pers. commun.). The disease
can be severe in the southeastern U.S., but typically is not a problem in the
less humid western states. Southeastern growers cannot expect western breeders
to select resistance for this disease. We must work with our own germplasm in
Special interest is being paid to lines descended from determinant germplasm.
The weather patterns of the Southeast and much of the Midwest result in heavy
rains during the winter months. Frost-killed kenaf takes roughly 3-4 weeks to
dry to 30% moisture (safe for harvest and storage). Therefore, the dependence
on a killing frost to desiccate kenaf has meant that commercial production has
had to stand in the fields until Mar. or Apr. Several selections from the
determinant stock senesce and die as early as the last week in Sept., however,
yield is severely compromised. Evaluations are now being made to find lines
that senesce closer to the frost date, so that dry-down time will be decreased
and fall harvest may be possible. Indeed, cultivars show differential rate of
dry-down after kill. Investigations are under way to determine which cultivars
reliably desiccate rapidly. Mississippi State University experimental lines
MOP6 and MOP6E show the greatest promise for this, drying to 30% moisture 2-3
weeks before most other cultivars.
Variation existing in seedlots from kenaf production fields has allowed plant
breeders to make selections for lines that are best adapted to each production
region. Efforts in Mississippi have focused on successful seed set, disease
resistance, and dry-down time to avoid winter rains and late harvest.
Currently there are nearly 300 lines in the Mississippi program that flower and
set seed at 33deg.N latitude. The best of these lines are being evaluated for
yield and disease resistance at three locations in Mississippi. Release of
germplasm and cultivars are expected in Spring 1997.
- Baldwin, B.S. 1994. Physiological maturity determination and germinability of
kenaf seed. Sixth Annu. Internat. Kenaf Conf. New Orleans, LA.
- Dempsey, J.M. 1975. Kenaf. p. 203-304. In: Fiber crops. Rose Printing
Co., Tallahassee, FL.
- Goforth, C., and M.J. Fuller 1994. A summary of kenaf production and product
development research, 1989-1993. Mississippi Agr. & For. Expt. Sta.,
Mississippi State. Bul. 1011.
- Nieschag, H.J., G.H. Nelson, I.A. Wolf, and R.E. Perdue. 1960. A search for new
fiber crops. TAPPI 43(3):193-201
- Pollock, F.G. and H.E. Waterworth. 1969. A leafspot disease of kenaf in
Maryland associated with Cristulariella pyramidalis. Plant Dis. Rep.
- 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. USDA-ARS
Production Research Rep. 113. Washington, DC.
- Wilson, R.D., T.E. Summers, J.G. Joyner, D.W. Fishler, and C.C. Sealer. 1965.
'Everglades 41' and 'Everglades 71' two new varieties of kenaf (Hibiscus
cannabinus L.) for fiber and seed. Fla. Agr. Expt. Sta. Circ. S-168.
Last update June 17, 1997