Articles
THE SELECTION AND BREEDING OF WOODY PLANTS FOR FUNCTIONAL USE IN THE LANDSCAPE*
At least three points support the necessity of such a research effort:
- the first corresponds to an evolution of the needs of man himself, resulting from the changes in our life style (urbanisation), and our population growth;
- the second is a change in the environment in which vegetation must live, particularly in the phytosanitary aspect;
- the third point relates to the difficulty of maintaining the present situation.
Clonal selections lose their qualities (or degenerate) for diverse reasons while the wild populations of some ecologically well adapted plants disappear and can therefore no longer supply seeds.
Until nowadays the origin of the woody ornamental cultivars arises most often (if we exclude the few native genera) from the introduction of small seed samples coming from foreign countries.
These first introductions are relatively recent (middle of the 18th century) and come from explorers, botanists but rarely from geneticists.
To-day’s amateurs, thanks to great facilities to travel, continue these introductions as do, after more serious experiments, most of the botanic gardens in the world.
The American nurseryman of May 1985 discusses the recommendations by the great arboreta of the USA for introducing plants not often used before to-day.
Though such introductions may satisfy amateurs, it is rare that their wide use will be effective without some selection, capable of correcting a few defects or of enlarging the possibilities of utilization.
The qualities that D. Percy (1985) finds necessary for a groundcover plant are:
- good availability at a reasonable price
- rapid establishment and initial growth
- low maintenance requirements and long life once established
- tolerance of drought and waterlogging
- ability to withstand severe winters, wind funneling and sand blasting.
These may be seen as qualities required of every ornamental species.
They represent a great challenge.
Passionate amateurs, a few nurserymen, universities and some research stations try -each for a small number of genera- to improve the actual cultivars for one or another of these characteristics.