Agriculture Reference
In-Depth Information
hobby gardeners. This remains an active part of what has become the global plant
media industry developed on the back of an initial desire by research workers for
repeatable and regular growth patterns in their experimental material. The problem
with John Innes mixtures is that the loam component is very difficult to standardise
across large volumes of compost. Consequently, researchers in the University of
California devised alternative formulations of media where loam is replaced by peat
which became known quite simply as “UC mixes” (Baker et al.
1957
). Mixtures of
peat and sand are more easily standardised and formulated on a factory scale. They
provide composts with better properties of air fill porosity and resultant reproduc-
ibility of crop growth. This Californian research initiative has resulted, over the last
50 years, in an entire revolution in the ornamental and nursery industries, whereby
plant selling has changed from almost exclusively bare-root material which could
only be sold in the period of plant dormancy, to almost year-round provision of
container-grown and containerised shrubs, trees, perennials and annual plants. As
a result, it is probably fair to claim that the entire shift from small local nurseries
to massive garden centres has come about because of the characteristics of plants
which the retail consumer can conveniently carry home and plant at any time of
the year. This revolution, fired initially from the availability of convenient rooting
media, has spawned a massive worldwide garden centre industry. The result is that
this industry is now worth billions of dollars and has become part of the tourist in-
dustry in many countries, since retail customers use garden centres as part of their
rest and relaxation during holidays and weekends. The revolution of continuously
available plants permitted garden designers the freedom they needed for producing
ever changing scenery in their urbanised clients' regard as “garden rooms”.
Genetic Uniformity in Vegetable Crops
Genetic uniformity has become the hallmark of field and protected vegetable crops
and underpins growers' abilities for supplying supermarkets with high quality pro-
duce on a year-round basis. This has been achieved by an almost universal change
to the use of F
1
hybrid cultivars. These provide uniformity of growth and maturity
allowing the application of precision management techniques delivering controlled
ripening and harvesting. Compared with open pollinated cultivars, where individual
plants grew at differing rates and maturities and which were very unpredictable, F
1
hybrid crops have resulted in substantial financial gains across the industry world-
wide and down the supply chain to retailers. From the plant breeders' perspective
they also offer much greater security for their intellectual property rights (IPR) be-
cause they are far less accessible for duplication and copying. The seed of F
1
culti-
vars must be produced annually by crossing the inbred parental lines and self-saved
seed from a commercial crop cannot easily reproduce the specified hybrid. Much
of the development of F
1
hybrid vegetables can be traced back to genetic studies in
Japan in the 1930s which resulted in the production of the Brussels sprout (
Brassica
oleracea
var
gemifera
) cv Green Jade. This could not have come about without an