Selection and Breeding of Kenaf for Mississippi
Brian S. Baldwin
Most kenaf varieties grown in the United States have been
developed in tropical regions of the world. Selection and
improvement for varieties adapted to the unique growing
conditions found in Mississippi have been minimal. Generally,
tropical varieties are shortday types (bloom very late in
summer). While these varieties tend to remain vegetative over a
long period at nontropical latitudes (and therefore give maximum
yield), they seldom produce seed before frost. Because of
variable spring conditions, early spring planting cannot be
guaranteed, therefore dayneutral (blooming after a given number
of days) or longer shortday (blooming earlier in the summer)
cultivars would be desirable for Mississippi.
Like its relatives cotton and okra, kenaf's large showy flowers
and nectars attract a number of insects, which pollinate (and
crosspollinate) the flowers. Because of a moderate level of
crosspollination, seed obtained is frequently not true to type.
This means that seed labelled as a single variety may contain
plants with different leaf shapes, flower color, fiber quality,
and date of maturity.
While this variation within a particular variety has caused
problems, especially in testing for fiber quality, such variation
is a plant breeder's dream. The variation allows plant breeders
to pick and choose individual plants that will resist diseases,
have stronger fiber, and bloom earlier than the rest of the
population. Selection of individual plants from tropical
cultivars has enabled Mississippi researchers at Poplarville and
Starkville to generate plant lines that will bloom and produce
seed in Mississippi. Once these plants are selected, a number of
techniques can be used to keep insects from mixing pollen
different plant types. Controlled crosspollination can then be
used to incorporate two or more desirable characteristics into
the same plant.
Kenaf seed takes roughly 45 days to ripen in northern
Mississippi, making a flowering date of the first week in
September necessary to obtain enough viable seed before the frost.
One characteristic that is important, but has little to do with
adaptation, is leaf shape. Many cultivars currently used in the
United States are of a leaf type that resembles marijuana
(Cannabus sativa). While kenaf is not related to marijuana, the
fact that some cultivars have leaves that look similar has led to
occasional problems with local law enforcement officials.
The Mississippi kenaf project is currently selecting and
increasing seed of plants that are best adapted to Mississippi's
climate and harvesting techniques to maximize yield as well as
fiber quality.
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Brian S. Baldwin is an Assistant Professor of Agronomy,
Department of Plant and Soil Sciences, Mississippi State
University.