Environmental Engineering Reference
In-Depth Information
very tough turf-grass. The only stress it does not tolerate well is low light
intensity. In the humid tropics, especially during rainy periods lasting for
several months, the light intensity is frequently reduced by heavy cloud
coverage. Under these conditions cynodon thins out and to some extent
loses its competitive advantage over weeds and other grasses. It also
performs quite poorly under tree shade.
The genus
Cynodon
includes eight species besides
C. dactylon.
Several
of them and their hybrids are used as turf-grasses and range in import-
ance from major to marginal.
The
Cynodon dactylon
Cynodon transvaalensis
hybrid originated in
the USA and since the 1970s has become the most important cynodon
hybrid around the world. It is found predominantly on golf courses and
on other recreational and sport turfs. It is continuously improved as new
cultivars are released. Some well-known cultivars of this hybrid are
available around the world and the most widely used are Tiflawn,
Tifway, Tifgreen, Tifdwarf and TifEagle.
C. transvaalensis
Burtt Davey, a very fine-textured turf species, also
called African cynodon, has the softest leaf blades of all cynodon species.
It is the parent, with
C. dactylon
, of many new fine-textured hybrids.
Cynodon magennisii
Hurcombe, a natural hybrid of
C. dactylon
and
C. transvaalensis,
is very fine textured and is used for golf course
greens in many parts of the world, especially Africa and Central and
South America.
Cynodon bradleyi
Stent, a fine-leaf turf species, is used in eastern and
central Africa for golf course greens.
The genus Zoysia (Eragrostoideae)
The genus
Zoysia,
which originated in Asia, includes 10 species, but only
three are considered important turf-grasses:
Zoysia japonica
Steud.,
known also as Korean lawn grass or Japanese lawn grass;
Zoysia matrella
(L.) Merr., known as Manila grass; and
Zoysia tenuifolia
Willd. ex Thiele,
also called Mascarene grass or Korean velvet grass.
Z. japonica
is a creeping turf-grass that produces both stolons and
rhizomes (Fig. 2.2). It grows well in a wide range of soils, in the full sun
and under moderate shade. It tolerates heat and drought and is also the
most cold tolerant of the zoysias. In the tropics, it grows well but much
more slowly than cynodon. A smooth cynodon lawn can be established in
2-3 months, but a lawn of zoysia grass may take 8-10 months. The most
obvious characteristic of this species is the stiffness of the leaf blades,
which is caused by their high silica content. This morphological charac-
teristic, easily recognizable to the touch, makes zoysia resistant to phys-
ical injury like that originating from foot or vehicular traffic. Zoysia's
