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III. Results and Discussion
a. Visual Turfgrass Quality and ET Rate
The major objective of this study was to evaluate well-grown tall fescues for ET rates and associated above-ground morphological characteristics. The turfs that
were evaluated in this study were established from seed for seven months. The relatively high visual turfgrass quality ratings shown in Table 7 reflect the fact that high quality cultivars were assessed and a good management
program was employed.
The differences among the seven cultivars for ET rate when evaluated under well-watered conditions was not significant (Table 8). However, it should be noted that a total of 22 cultivars were evaluated for ET rates, while
only seven cultivars were evaluated for clipping yield and other morphological characteristics. The differences among the 22 cultivars in ET rates was significant, and the percent difference between cultivars with the highest
and lowest ET rate was similar to previous research findings (Table 9).
b. Clipping Yield, Leaf Extension Rates, and Other Morphological Characteristics
Unlike the ET rate, there were significant differences among the seven cultivars for clipping yield (Table 10), leaf extension rate (Table 11), and leaf density,
length, and width (Table 12). The percent difference between the cultivars was: clipping yield (46%); leaf extension rate (34%); leaf density (52%); leaf length (23%) and leaf width (31%).
c. ET Rate and Clipping Yield Correlated to Morphological Characteristics
ET rates were not correlated significantly to clipping yield, leaf extension rate, or any of the above-ground morphological characteristics (Table 13). Conversely,
clipping yield was significantly (+) correlated to leaf extension rate, leaf length, and leaf width, and significantly (-) correlated to leaf density. (Note, a (+) correlation indicates that as one variable increases, the
second variable increases also, or as one variable decreases, the second variable decreases also. A (-) correlation indicates that as one variable increases, the second variable decreases, or as one variable decreases, the
second variable increases.)
-SUMMARY-
These data show that there are minimal differences among the seven tall fescue cultivars
assessed in this study for ET rate when grown in 10-inch diameter x 12-inch deep lysimeters and maintained under well-watered, field conditions.
However, there were significant differences
among the same cultivars for important agronomic characteristics, such as clipping yield (46% difference between the highest and lowest cultivar)and leaf density (52% difference between the highest and lowest cultivar).
ET rate, when evaluated under well-watered conditions, was not associated to clipping yield, leaf density, or any other morphological characteristics that were measured. However, there was a significant
(+) association between clipping yield and leaf extension rate and a significant (-) association between clipping yield and leaf density.
From an applied field perspective, it is interesting that
tall fescue cultivars with slow leaf extension rates and high leaf densities produced the lowest amount of clippings. Cultivars with a combined slow leaf extension rate and high leaf density included RF 1, Shortcut (Marathon III), and Tomahawk. It should be noted that high visual turfgrass quality is normally associated with higher leaf densities and smaller leaves.
Some caution
should be exercised when interpreting this report because data represent only one season, and turfs were grown in pots under well-watered conditions. This study represents an initial first step in studying tall fescue, water
savings and morphological characteristics. |
