| Abstrakt: |
Late‐season application of N to bermudagrass (Cynodon dactylon× transvaalensisBurtt‐Davey) putting greens are often made in an attempt to extend turfgrass growth and color. Research was conducted to evaluate the physiological and morphological responses of bermudagrass to late‐season application of N and K. Application of 0, 4.9, and 9.8 g N m−2in factorial combination with 0, 4.1, 8.2 g K m−2were made in October of 1989, 1990, and 1991. Following fertilizer application, measurements of fall and spring turfgrass color, total nonstructural carbohydrate (TNC) concentrations, and leaf tissue concentrations of N, P, and K were made. No changes in turfgrass color or TNC levels were observed for any level of K fertilization. Application of 4.9 or 9.8 g N m−2, alone or in combination with K, improved fall turfgrass color through October for each trial, and gave significantly higher spring turfgrass color ratings. Rhizome TNC levels declined linearly in December 1989 as N levels increased from 0 to 9.8 g m−2. There was a quadratic response in TNC levels across N fertility levels in March 1990. No significant differences in TNC levels were measured for any N level for 1990 and 1991 in December or March, although N at 9.8 g m−2tended to give lower rhizome TNC levels as compared with 0 or 4.9 g m−2of N. Nitrogen applications provided a linear increase in N, P, and K concentrations in the leaves. Late‐season application of N improved fall and spring bermudagrass color, and generally had little effect on rhizome TNC levels when measured in December or March. |
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