Document Type : Full Paper
Authors
1
MSc., College of Agriculture, Isfahan University of Technology, Isfahan, Iran
2
Associate Professors, College of Agriculture, Isfahan University of Technology, Isfahan, Iran
3
Assistant Professors, College of Agriculture, Isfahan University of Technology, Isfahan, Iran
Abstract
Turf is one of the most important ground covers and it is one of the main elements of
urban landscape design. Plant growth regulators, such as growth inhibitors, are widely
used in turfgrass management to suppress shoot growth and inflorescences production.
This experiment was conducted to determine the interactive effects of trinexapac-ethyl
(TE) and salinity on the growth, visual quality, and chemical constituents of perennial
ryegrass (Lolium perenne L.). Plants were grown hydroponically under four levels of
salinity (1.5 (control), 2.5, 5.0 and 7.5 dS/m) and three levels of trinexapac-ethyl (0,
0.02, and 0.04 g/m2). The results showed that growth rate of perennial ryegrass
decreased significantly with both trinexapac-ethyl and salinity treatments, although the
differences in growth rate were not significant between trinexapac-ethyl treatments at
0.02 and 0.04 g a.i./m2 application rates. Root penetration depth, fresh and dry weights
increased by trinexapac-ethyl, while salinity decreased them. The results showed that
total chlorophyll, chlorophyll a, chlorophyll b, and proline concentrations increased by
application of trinexapac-ethyl, while TE had no significant effect on the carotenoid
content. Salinity treatment decreased total chlorophyll, chlorophyll a, chlorophyll b, and
carotenoid content, but increased proline concentration. Overall, it can be suggested that
for improving the tolerance of perennial ryegrass to salinity up to 2.5 dS/m and reduced
mowing frequency, the turf should be sprayed monthly with TE at 0.02 g/m2.
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