. Fry, J. Pan, X. Rajashekar, C. Bremer, D. Engelke, M. Wang, X. 2009 Cold acclimation of Zoysia japonica and Z. matrella and changes in rhizome abscisic acid levels Intl. Turfgrass Soc. Res. J. 11 883 889 Zhang, X. Ervin, E.H. 2004 Cytokinin
Lixin Xu, Mili Zhang, Xunzhong Zhang, and Lie-Bao Han
Xi Xiong, Ken Diesburg, and Daniel T. Lloyd
Zoysiagrass ( Zoysia japonica Steud.) is a popular turfgrass species used in golf course fairways in Missouri and surrounding states ( Lyman et al., 2007 ). Throughout this region, zoysiagrass enters dormancy typically in November and resumes
M.D. Richardson and J.W. Boyd
Establishment of zoysiagrass (Zoysia japonica Steud.) from sprigs is often impractical for golf courses and sports fields because of the slow growth rate of the species and subsequent long establishment period. A study was conducted at two different sites in Arkansas to evaluate the effects of soil topdressing and post-plant fertility rates on establishment of zoysiagrass from vegetative sprigs. Each site was planted according to standard methods using freshly-harvested sprigs (18 m3/ha) and either top dressed with 1.0 cm of native soil or maintained without topdressing. Beginning immediately after establishment, N was applied monthly at rates of 0, 1.25, 2.50, 3.75, or 5.0 g·m-2 as urea. Rate of cover was monitored throughout the growing season and elemental analysis of plant tissues was determined 120 days after planting. Topdressing the sprigs with native soil significantly improved establishment compared to traditional sprigging at both sites, presumably because of enhanced sprig survival. Applications of N during the establishment period had little or no overall effect on establishment, although the 0 g·m-2 rate was slightly inferior to all other rates. This study indicates that methods that enhance sprig survival are more important than added fertility for the rapid establishment of zoysiagrass sprigs.
Michele R. Warmund, Rusty Fuller, and John H. Dunn
Rhizomes of `Meyer' zoysiagrass (Zoysia japonica Steud.) were subjected to temperatures below 0 °C and were subsequently placed in a growth chamber with air at 34 °C day/28 °C night to determine the rate of shoot growth from nodes. Rhizomes exposed to subzero temperatures produced shoots steadily up to 16 days after freezing (DAF), but subsequent shoot growth from rhizomes was minimal. At 32 DAF, shoots were present on 68% and 44% of the nodes of unfrozen control (2 °C) rhizomes and those frozen to -7 °C, respectively. In another study, samples were frozen to a sublethal temperature (-7 °C) to examine the distribution of extracellular ice voids near the apical meristems of rhizomes and to characterize tissue recovery. Extracellular voids were present within the leaf tissue and between the leaves in samples prepared for scanning electron microscopy (SEM) immediately after freezing to -7 °C. By 12 DAF, most of the remaining voids were observed in older leaves. Nearly all extracellular voids in the leaves were absent by 20 DAF. However, by 28 DAF, some rhizomes still had small voids between leaves. Although the structure of zoysiagrass rhizomes subjected to -7 °C was temporarily disrupted, tissues recovered from extracellular freezing and new shoot growth was produced following exposure to warm temperatures.
Y.L. Qian and J.D. Fry
`Meyer' zoysiagrass (Zoysia japonica Steud.) was established on a silt loam soil in 27-cm-diameter × 92-cm-deep containers in a greenhouse to investigate the influence of irrigation frequency on turfgrass rooting and drought tolerance. Turf was irrigated daily or at the onset of leaf rolling with a water volume equal to the cumulative evapotranspiration of well-watered turf in small weighing lysimeters. After >90 days of irrigation treatments, a dry-down was imposed during which no additional water was applied for 55 days. A recovery period followed during which time turf was watered to maintain soil matric potential at greater than –30 kPa. Compared to turf irrigated daily, that watered at the onset of leaf rolling exhibited 1) 32% to 36% lower leaf water potential and 14% to 22% lower osmotic potential before the onset of drought; 2) 13% higher leaf water potential ≈40 days into dry-down; 3) more extensive rooting at 55- and 75-cm soil depths as indicated by 11% to 19% lower volumetric soil moisture content at the end of dry-down; 4) 25% to 40% lower shoot growth rate during irrigation and 13% to 33% higher shoot growth rate during dry-down; and 5) higher quality ratings during dry-down and recovery. Thus, deep, infrequent irrigation better prepares zoysiagrass for an oncoming drought than light, frequent irrigation.
E.H. Ervin, C.H. Ok, B.S. Fresenburg, and J.H. Dunn
'Meyer' zoysiagrass (Zoysia japonica Steud.) is a popular turfgrass species for transition zone golf course fairways and tees because it is generally winter hardy while providing an excellent playing surface with minimal chemical and irrigation inputs. However, its functionality declines readily on many of the shaded areas on these courses. Reduced irradiance causes excessive shoot elongation, reduced tillering, and weak plants that are poorly suited to tolerate or recover from traffic and divoting. Trinexapac-ethyl (TE) effectively reduces gibberellic acid (GA) biosynthesis and subsequent shoot cell elongation. The objective of this study was to determine if monthly applications of TE would reduce shoot elongation of 'Meyer' zoysiagrass and improve stand persistence under two levels of shade. Shade structures were constructed in the field that continuously restricted 77% and 89% irradiance. A mature stand of 'Meyer' was treated with all combinations of three levels of shade (0%, 77%, and 89%) and three levels of monthly TE application [0, 48 g·ha-1 a.i. (0.5×), and 96 g·ha-1 a.i. (1×)] in 1998 and 1999. In full sun, the 0.5×-rate reduced clipping production by 17% to 20% over a four-week period and the 1×-rate by 30% to 37%. Monthly application of TE at the 1×-rate increased 'Meyer' tiller density in full sun and under 77% shade. Both rates of TE consistently reduced shoot growth under shade relative to the shaded control. Only the monthly applications at the 1×-rate consistently delayed loss of quality under 77% shade. The zoysiagrass persisted very poorly under 89% shade whether treated or not with TE and plots were mostly dead at the end of the experiment. Our results indicate TE can be an effective management practice to increase 'Meyer' zoysiagrass persistence in shaded environments. Chemical name used: 4-cyclopropyl-α-hydroxy-methylene-3,5-dioxocyclohexanecarboxylic acid ethyl ester (trinexapac-ethyl)
Jinmin Fu, Jack Fry, and Bingru Huang
Water requirements for `Meyer' zoysiagrass (Zoysia japonica Steud., hereafter referred to as zoysia), `Midlawn' bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy, hereafter referred to as bermuda], `Falcon II' tall fescue (Festuca arundinacea Schreb.) and `Brilliant' kentucky bluegrass (Poa pratensis L., hereafter referred to as bluegrass) were evaluated under a mobile rainout shelter at deficit irrigation levels of 20% to 100% of actual evapotranspiration (ETa), applied twice weekly, between June and September 2001 and 2002. Soil was a river-deposited silt loam (fine, montmorillonitic, mesic Aquic Arquidolls). Minimum annual irrigation amounts required to maintain quality ranged from 244 mm for bermuda to 552 mm for bluegrass. Turfgrass species and respective irrigation levels (% of ETa) at which season-long acceptable turf quality was maintained in each year were bluegrass, 100% (evaluated 2001 only); tall fescue, 60% in 2001 and 80% in 2002; bermuda, 60% in both years; and zoysia, 80% in both years. A landscape manager who could tolerate one week of less-than-acceptable quality could have irrigated tall fescue at 40% ETa (224 mm) in 2001 and 60% ETa (359 mm) in 2002. Likewise, bermuda exhibited unacceptable quality on only one September rating date when irrigated at 40% ETa (163 mm) in 2001. Bermuda was able to tolerate a lower leaf relative water content (LRWC) and higher level of leaf electrolyte leakage (EL) compared to other grasses before quality declined to an unacceptable level.
Aaron J. Patton, David W. Williams, and Zachary J. Reicher
Zoysiagrass (Zoysia japonica Steud.) requires few inputs and provides high-quality turf in the transition zone, but is expensive to sprig or sod. Establishment by seed is less expensive than vegetative establishment, but little is known about renovation of existing turf to zoysiagrass using seed. Two experiments were performed to determine effects of herbicides and seeding rates on establishment of zoysiagrass in Indiana and Kentucky. In the first experiment, interseeding zoysiagrass into existing perennial ryegrass (Lolium perenne L.) without the use of glyphosate before seeding resulted in 2% zoysiagrass coverage 120 days after seeding (DAS). In plots receiving glyphosate before seeding, zoysiagrass coverage reached 100% by 120 DAS. In the second experiment, MSMA + dithiopyr applied 14 days after emergence (DAE) or MSMA applied at 14+28+42 DAE provided the best control of annual grassy weeds and the greatest amount of zoysiagrass establishment. Applying MSMA + dithiopyr 14 DAE provided 7% less zoysiagrass coverage compared to MSMA applied 14 DAE at one of the four locations. Increasing the seeding rate from 49 kg·ha-1 to 98 kg·ha-1 provided 3% to 11% more zoysiagrass coverage by the end of the growing season at 3 of 4 locations. Successful zoysiagrass establishment in the transition zone is most dependent on adequate control of existing turf using glyphosate before seeding and applications of MSMA at 14+28+42 DAE, but establishment is only marginally dependent on seeding rates greater than 49 kg·ha-1. Chemical names used: N-(phosphonomethyl) glycine (glyphosate); monosodium methanearsenate (MSMA); S,S-dimethyl 2-(difluoromethyl)-4-(2-methylpropyl)-6-(triflurormethyl)-3,5-pyridinedicarbothioate (dithiopyr).
Y.L. Qian and M.C. Engelke
Determining the appropriate level of irrigation for turfgrasses is vital to the health of the turfgrass and the conservation of water. The linear gradient irrigation system (LGIS) allows long-term assessment of turf performance under continuous irrigation gradients from excess to no irrigation. The objectives of this study were to: 1) evaluate the minimum irrigation requirements and relative drought resistance of `Rebel II' tall fescue (Festuca arundinacea Schreb.), `Meyer' zoysiagrass (Zoysia japonica Steud.), `Tifway' bermudagrass [Cynodon dactylon (L.) Pers.], `Prairie' buffalograss [Buchloe dactyloides (Nutt.) Engelm], and `Nortam' St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze]; and 2) evaluate the long-term effects of irrigation levels on turf persistence, weed invasion, and disease incidence for the five selected turfgrasses under field conditions. Turf was sodded under LGIS with an irrigation gradient ranging from 120% Class A pan evaporation (Ep) to natural precipitation, along a 20-m turf area. Evaluation during the summers of 1993–96 indicated that grasses differed in drought resistance and persistence under variable irrigation regimes. Irrigation (Ep) required to maintain acceptable turf quality for respective grasses was `Rebel II' (67%), `Meyer' (68%), `Nortam' (44%), `Tifway' (35%), and `Prairie' (26%). Higher dollar spot (Sclerotinia homoeocarpa Bennett) infection was observed at 115% Ep irrigation regime in `Tifway' bermudagrass, whereas gray leaf spot [Pyricularia grisea (Hebert) Barr] was observed only at 10% Ep irrigation regime in St. Augustinegrass plots. An outbreak of brown patch (Rhizoctonia solani Kuehn.) occurred in Sept. 1996 in St. Augustinegrass plots receiving irrigation at >80% Ep.
Aaron J. Patton, Jon M. Trappe, and Michael D. Richardson
promoters on the rate of seedling establishment of japanese lawn grass ( Zoysia japonica Steud.) Intl. Turfgrass Soc. Res. J. 6 269 271 McGinnies, W.J. 1960 Effects of moisture stress and temperature on germination of six range grasses Agron. J. 52 159 162