Environmental Engineering Reference
In-Depth Information
others (Table 2.1), but the more establishment time can be shortened the
better. Establishment vigour is also discussed in Chapter 4 (this volume).
Leaf texture
Relative blade width is called texture. Turf scientists use the three basic
terms, coarse (wide), medium and fine (narrow), to describe texture,
sometimes combining them to subdivide the continuum, as in 'med-
ium-fine', 'fine-medium', 'coarse-medium' and 'medium-coarse'. Most
often, texture is chosen simply by visual preference. Sometimes, espe-
cially for sport turfs, the necessity for a certain texture is dictated by the
sport itself. Golf, tennis, cricket, hockey and numerous other games can
only be played on turfs having particular texture. Table 2.1 shows com-
mon species ranked by texture.
Mowing height
Each turf-grass species yields the best-quality turf at a particular mowing
height (see Chapter 6, this volume). Some, such as hybrid cynodon, are
mowed at 4-5 mm, whereas others, such as St Augustine grass, are
mowed at 80-100 mm. Mowing too high usually reduces visual quality,
but mowing too low may damage the turf. Mowing the turf below the
recommended height reduces photosynthesis and therefore production
of carbohydrates, which makes the turf weak and subject to invasion by
weeds, insects and diseases. On the other hand, a moderate increase over
the recommended mowing height is not harmful. For most turf areas it
will somewhat reduce the optimal visual quality, but will result in an
increased leaf surface that will promote more photosynthesis, a deeper
root system, better drought tolerance and better overall turf health. On
sports fields, mowing height is often imposed by the requirements of a
game and cannot be increased.
Within the mowing-height ranking (Table 2.1) substantial differences
may occur within a single species.
Fertility requirements
Some turf-grasses have high fertility requirements, whereas others will
perform satisfactorily with little or no fertilizer (Table 2.2). In fact, fre-
quent fertilization of some of the less demanding species, such as Bahia
grass or carpet grass, may result in serious weed, disease and insect
problems.
In contrast,
the quite demanding cynodon may show
