Environmental Engineering Reference
In-Depth Information
of 25% of the label-recommended amount is usually sufficient to control
young seedlings. Glyphosate can be applied as little as several hours
before planting. If a strong monsoon is expected, final soil preparation
should be postponed until the weather stabilizes.
Seeding
Most of the warm-season turf-grasses are propagated vegetatively, but
centipede grass, common cynodon, some types of zoysia grass and sev-
eral other less commonly used species can be seeded as well. In cool
climates, seeding is an essential method of turf establishment, but in
warm climates seeding is optional. As a consequence, seed selection is
much more limited. Selection of high-quality seed that is adapted to the
site conditions and the intended use of the turf is very important. The
purchaser of turf-grass seed must study the label to determine the kind,
amount and quality of seed in the container as well as to determine how
much seed will be needed to establish a particular area of turf. Species
differ substantially in seeding rates. For example, common cynodon or
zoysia grass may require 1000 g of seed per 100 m
2
, whereas centipede
grass may require only 200 g.
In the tropics the most important characteristic of seeds is their
germination rate. Desired germination rates of selected turf species are
presented in Table 4.1. The numbers serve as a guide and may differ for
different varieties, producers and countries. Accurate rates for particular
varieties can be found on the seed label, the purchaser must remember
that the germination tests performed by the seed producers took place
under controlled conditions, usually more favourable than actual field
conditions. In addition, the rates on the seed label take no account of
conditions during shipping and storage, which can damage the seed.
Seed purity is less important in the tropics than in cooler climates because
Table 4.1. Seeding rate and desired minimum germination rate of selected
warm-season turf-grasses.
Seeding rate
(kg/100 m
2
)
Desired minimum
germination rate (%)
Species
Centipede grass
0.1-0.25
70
Cynodon
0.5-1
85
Zoysia
0.5-1.5
50
Carpet grass
2-3
85
Bahia grass
2-5
70
