| Busey, P. and B. J. Center.
1979. Growth rates of turfgrasses propagated vegetatively.
Agron. J. 71:817-821.
Abstract
Vegetative propagation is valuable as a cultural method in
commercial sod production and as a tool in turfgrass research.
Experiments were performed in the greenhouse and in the field
in order to describe and compare growth rates in vegetative
propagation of seven warm season turfgrasses. Daily
growth rates were calculated as the logarithm of the quotient
final/initial fresh weights, divided by the number of days
between planting and harvest. By means of this criterion
an elemental concept was demonstrated as a measure of rapidity
of vegetative propagation and as a predictor of sod production
time. The soil medium for most experiments was a Hallandale
fine sand, a siliceous, hyperthermic, Typic Psammaquent.
Maximum growth rates of turfgrass species ranged from 1.8%
per day for centipedegrass [Eremochloa ophiuroides
(Munro) Hack.] to 9.2% for common bermudagrass [Cynodon
dactylon (L.) Pers.]. These rates were larger
than growth rates in commercial sod production, that were
estimated t be no more than 2.6% per day. Duration of
growth periods may explain the disparity between theoretical
and observed growth rates. Growth periods of as long
as two years are used in commercial sod production; much shorter
intervals were used in our studies. A comparison of
growth rates for various durations of growth periods suggested
that for zoysiagrass (Zoysia japonica Steud.)
and St. Augustinegrass (Stenotaphrum secundatum
[Walt.] Kuntze) growth was not strictly exponential, but was
sigmoidal. The leveling off of growth rates as turfgrasses
become larger, or more densely sodded, may be explained by
self-inhibition through crowding. It appears possible
to use frequent divisions to rapidly propagate warm season
turfgrasses for initial increase of foundation blocks and
experimental plantings. This and other cultural practices
may be applied to improving the efficiency of commercial sod
production. We propose the use of growth rate analysis
as a method for describing and comparing cultural practices.
Dry weight is preferred as the growth criterion, in contrast
to fresh weight, coverage, or possibly other parameters. This
simple model may be a powerful tool, as well, for testing
genotypic response to pests and environmental stresses.
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