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By Pat Malcolm
Many agricultural plants that are reproduced by vegetative
division face a mysterious problem that results in a decline
in
the clone vigor, and most farmers and nurserymen claim that
the
plant crop has “run out.” A number of factors adversely affect
the plant clone to the point that it becomes unproductive and
uneconomical to continue growing.
A technique has been discovered that has revitalized the
agricultural crops such as strawberry, raspberry, blackberry,
sweet potato, banana, and a newcomer: the canna lily. This
flower bulb or rhizome is facing present and future disastrous
consequences unless governmental regulatory steps are taken to
correct the dilemma facing the canna lily industry. Since the
1940s, canna lily rhizomes have been continuously commercially
grown from the original stock that could easily be harvested
in
the fall, packaged and resold by Dutch mailorder companies
(few
exist today, most went bankrupt) as named varieties. Commerce
developed so extensively around the success of selling
millions
of these rhizomes that some farmers began to cultivate canna
lilies in fields, planted in rows like corn, exclusively for
the Dutch mailorder companies. For some canna growers in the
states of Arkansas, Oklahoma, and Texas, the financial rewards
were so excessive, that they began to plant hundreds of acres
as an exclusive agricultural crop. Because of a shift in
business retailers a decade ago, when the canna lily sales
were
shifted away from packaged rhizomes of mailorder companies to
the potted, growing, blooming canna lilies for spring and
summer sales by boxstores such as Walmart, Lowes, and Home
Depot. The boxstores bought their potted products mainly from
contracted nursery growers, purchased as dormant, canna lily
rhizomes from the exclusive field grown canna farmers who
originally supplied the mailorder companies just a decade ago.
This dramatic change from selling dormant canna lily bulbs to
trusting mailorder customers to the customers at box stores,
who observed the plant flowers and leaves before purchasing,
has made it necessary for box stores to reject many of the
inferior potted canna lilies, that had over the years declined
(run out) to a state of unpredictability. This rejection had
not occurred to mailorder customers who were buying an unseen,
untested rhizome with a “wish” that it grow into that
beautifully-pictured dormant plant that was packaged for sale
in the mailorder catalog.
Growing canna lilies for retail sale has now become a crisis
much like the one that threatened the growers of strawberry
plants, raspberry bushes, blackberry bushes, and banana trees
years ago.
The canna commercial growers proceeded each year to set aside
part of the current canna rhizome crop to use as seed for
renewal planting the following season. As growing continued
each year, certain genetic defects and susceptibilities began
to appear and accumulate and grow more seriously each year.
The
canna farms continued regrowing and selling more and more
diseased and mutated canna rhizomes each year, until they can
be viewed with horror in full bloom and the distorted flowers
and ratty leaves by the contrast the buyers at the stores and
the retail customers. Many of these canna varieties were
originally grown and sold as true to name varieties. After
many
decades of vegetative reproduction, the canna crop has become
a
mixture of harmful and inferior mutations susceptible to many
diseases, insects, nematodes, and flower abnormalities.
Commercial growers of cannas practiced a technique that they
called “roguing” that involved searching through rows of
cannas
in full bloom and discarding those that appeared to vary
visually from the desired variety intended to be grown. This
technique only worked partially, because many of the
weaknesses
and inferior qualities could not be visually determined, such
as
canna rhizomes that failed to bloom at the time the farmer
decided to “rogue” the canna fields. Additionally, the genetic
factors that were mutated into the rhizomes that made the
plant
susceptible to diseases and other impediments would not be
seen,
since the commercial fields were normally sprayed effectively
to
remove pests; however, the normal home gardener does not
expect
to buy a plant that must be continuously sprayed with
fungicides, nematode treatments, or for insects, and as soon
as
their potted plants are placed in the home garden, the leaves
are exposed to the assaults of the leaf rollers, and the
webworms, and the rhizomes become infested with the ravages of
the nematodes. This disenchantment of retail buyers and
admirers of cannas is expected to drastically curb the future
purchases of canna lilies.
Plant decline in such agricultural products as strawberry
plants, raspberry plants, blackberry plants, sweet potato
vines, and banana trees has been approached and largely
overcome by the process of tissue culture. Plant scientists
have discovered that the rapidly growing tip of a plant called
the “apical meristem,” can be removed and placed into a tissue
growing medium. The plants from which the apical meristems are
removed are carefully selected to reproduce and must conform
to
the original desirable characteristics of the parent cultivar.
The apical meristem grows so rapidly that by carefully
selecting the few cells at the tip, virus and other mutation
problems are left behind to result in a new plant that is
vigorous, disease-free, and fast growing.
This group of cells grows into a complete plant with a shoot
and root system intact, that are collectively called “nuclear
stock mother plants.” These “mother plants” are used to divide
vegetatively from which commercial, private sector nurseries
are permitted to sell certified plants to farmers that are
free
of virus, bacteria, and other diseases.
As of August 1, 2006, no suggestion has been made to restore
the canna growing industry from its present chaotic
disposition
by the use of tissue culture technique. Tissue culture could
restore the reputation of marketing and production of canna
lily rhizomes to a satisfactory acceptance level of approval
by
both wholesale and retail customers.
About The Author: Patrick A. Malcolm, owner of TyTy Nursery,
has an M.S. degree in Biochemistry and has cultivated berry
plants for over three decades. www.tytyga.com
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