Thatch and Quality of Meyer Zoysia in Relation to Management1
- J. H. Dunn,
- K. M. Sheffer and
- P. M. Halisky2
Thatch control is a serious management problem in ‘Meyer’ zoysia (Zoysia japonica Steud.), one of the best adapted turfgrass varieties in the upper South. Improved cultural methods would greatly enhance the use and adaptability of Meyer zoysia in this region. The purpose of this study was to evaluate the effectiveness of annual, mechanical thatch removal, two mowing heights, and three N carriers, each applied at two rates of N, in reducing thatch accumulation and improving quality of Meyer zoysia.
Vertical slicing reduced the thatch depth by 12 to 18% each year over a period of 5 years. Mowing at 1.9 cm compared with 3.8 cm decreased thatch by 13 to 25% annually over the same period. Thatch was not significantly affected by applications of 0.98 or 2.93/kg N/100 m2 annually with IBDU, (isobutylidene diurea), UF (ureaformaldehyde), or urea.
Mowing at 1.9 cm plus mechanical thatch removal almost eliminated “winter injury” in 1976, while zoysia turf with no thatch removal and 3.8 cm mowing was 81% injured. Nematode (Helicotylenchus spp., Tylenchorynchus spp., and Xiphinema spp.) populations were sometimes large in turf showing winter injury but there was no significant correlation of nematode genus or population size with injury. Zoysia mowed at 3.8 cm recovered more slowly following thatch removal than that mowed at 1.9 cm and was infested with Kentucky bluegrass (Poa pratensis L.) which comprised 16% of the turf after S years.
Thatch depth was not affected by applications of 0.98 or 2.93 kg N/100 m2 IBDU, UF, or urea. Differences in quality and fall color were small in response to N carriers and rate of application. However, UF and IBDU, particularly at the higher rate of N, stimulated henbit (Lamium amplexicaule L.) in winter and early spring when zoysia was dormant.
Mowing at 1.9 cm plus annual thatch removal, irrigation, and a moderate rate of N reduces “sponginess” and can produce good quality summer zoysia turf over a period of several years, irrespective of N carrier.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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