Ian Smith HortiCulture
Plant Integrity and quality
Often nurseries propagate new plants from sales stock. The problem with this is that there
may be subtle changes over time in the plants appearance and performance. If these plants are
used for propagation, the integrity of the plant selection may be degraded. Similarly, diseases,
particularly virus are not always obvious and so new plants propagated from this stock will be
infected. Continual propagation from diseased and "off-type" stock will lead to deterioration in
the quality and performance of the product.
Plant quality and health
Nurseries continuously monitors plant integrity and the presence of pests and diseases and
where necessary, implement spray programs. This provides immediate benefit by maintaining
quality and health standards however, it has limited long-term value as there is always the
opportunity for plants to escape detection and reach the consumer. This is particularly true of
virus diseases, the symptoms may not be expressed in good growing conditions in the nursery
or when the plant is growing actively in favourable spring and summer growth periods. These
plants may continue to decline in health and performance in gardens over subsequent years.
Where possible, when new plants are selected or developed, healthy, true-to-type
representatives are selected and grown on as a reference collection of the original genetic
material. As the quality and integrity of the production plants declines, propagation from the
reference plants can be used to re-establish the production stock ensuring quality and
integrity of future plants.
Some plants are known to be infected by virus that may not cause obvious symptoms,
however, over time this can multiply and lead to a decline in performance and appearance.
Testing has revealed that some plants e.g. Canna are all likely to be infected by virus and so it
is essential to not only protect plant integrity, but to remove the virus to maximise
performance and longevity.
True-to-type plants from reference collections are introduced into tissue culture and subjected
to various techniques to remove virus and other pathogens and pests. These Elite high health
plants are then subsequently multiplied in the laboratory environment before being distributed
to commercial tissue culture laboratories, where they are multiplied as a source of healthy
true-to-type production stock. This process is repeated on a regular basis to ensure only
quality, healthy stock is available to consumers.