, S, and S:OMC H substrates had greater VDFs than did the S:OMC M substrate on only the first sampling date (12 June 2004) during the evaluation of bermudagrass turf establishment from the sprouting of existing rhizomes ( Fig. 10 ). In this case, the
Nikolaos Ntoulas, Panayiotis A. Nektarios and Glykeria Gogoula
Bohan Liu and Peter J. Landschoot
improvements in the crop yield or rate of turf establishment compared with N fertilizer with low amounts of P, fertilizer with no P, and, occasionally, fertilizer with no N and no P ( Reicher et al., 2000 ; Roth et al., 2006 ; Vetsch and Randall, 2000
Stephanie C. Hamel and Joseph R. Heckman
Recent changes in soil testing methodology, the important role of P fertilization in early establishment and soil coverage, and new restrictions on P applications to turf suggest a need for soil test calibration research on Kentucky bluegrass (Poa pratensis L.), tall fescue (Festuca arundinacea Schreb), and perennial ryegrass (Lolium perenne L.). Greenhouse and field studies were conducted for 42 days to examine the relationship between soil test P levels and P needs for rapid grass establishment using 23 NJ soils with a Mehlich-3 extractable P ranging from 6 to 1238 mg·kg–1. Soil tests (Mehlich-1, Mehlich-3, and Bray-1) for extractable P were performed by inductively coupled plasma–atomic emission spectroscopy (ICP). Mehlich-3 extractable P and Al were measured to evaluate the ratio of P to Al as a predictor of need for P fertilizer. Kentucky bluegrass establishment was more sensitive to low soil P availability than tall fescue or perennial ryegrass. Soil test extractants Mehlich-1, Bray-1, or Mehlich-3 were each effective predictors of need for P fertilization. The ratio of P to Al (Mehlich-3 P/Al %) was a better predictor of tall fescue and perennial ryegrass establishment response to P fertilization than soil test P alone. The Mehlich-1, Bray-1, and Mehlich-3 soil test P critical levels for clipping yield response were in the range of 170 to 280 mg·kg–1, depending on the soil test extractant, for tall fescue and perennial ryegrass. The Mehlich-3 P/Al (%) critical level was 42% for tall fescue and 33% for perennial ryegrass. Soil test critical levels, based on estimates from clipping yield data, could not be determined for Kentucky bluegrass using the soils in this study. Soil testing for P has the potential to aid in protection of water quality by helping to identify sites where P fertilization can accelerate grass establishment and thereby prevent soil erosion, and by identifying sites that do not need P fertilization, thereby preventing further P enrichment of soil and runoff. Because different grass species have varying critical P levels for establishment, both soil test P and the species should be incorporated into the decision-making process regarding P fertilization.
James J. Camberato and S. Bruce Martin
Bermudagrass (Cynodon sp.) greens are overseeded annually with rough bluegrass (Poa trivialis L.) in the coastal southeastern United States, where irrigation water is often saline. Salinity may slow seed germination and delay turf establishment. Cultivar and seed lot differences in sensitivity to salinity may be substantial. Our objective was to determine the effects of salinity on germination of commercially available rough bluegrass cultivars and seed lots. To accomplish this, we examined the effects of salinity (0, 1.8, 3.4, and 5.0 dS·m-1 established with NaCl in deionized water) on germination of 33 cultivars/seed lots of rough bluegrass in vitro. Fifty seeds of each cultivar/seed lot were placed on pre-moistened germination paper in petri dishes, sealed with parafilm, and placed in growth chambers with 12-hours light/12-hours dark at 20/10 °C, respectively. Germination was scored from 4 to 25 days after seed placement. Rough bluegrass germination rate varied among cultivars/seed lots, ranging from less than three seeds/day to nearly seven seeds/day. Salinity slowed rough bluegrass germination rate from about six seeds/day at 0 dS·m-1 to five seeds/day at 5 dS·m-1. Increasing salinity reduced early germination of some cultivar/seed lots more than that of others. Impact was substantial in three cultivar/seed lots, where early germination at 5.0 dS·m-1 was less than 15% of that at 0 dS·m-1. For most cultivar/seed lots, the reduction in early germination with salinity at 5.0 dS·m-1 was about 50% of that at 0 dS·m-1. Final germination was reduced only 3% by increasing salinity. In view of differences in germination rate and response to salinity among seed lots of rough bluegrass cultivars, we suggest the planting of multiple cultivars and seed lots of rough bluegrass to insure rapid establishment.
Marco Volterrani, Simone Magni, Monica Gaetani and Filippo Lulli
The stoloniferous-rhizomatous growth habit of bermudagrass [Cynodon dactylon (L.) Pers.] is a key feature for fast turf establishment and effective recovery from wear and divots. Trinexapac-ethyl (TE) is a plant growth regulator used extensively to reduce the need for mowing. However, vertical growth suppression of vertical growth has the potential to reduce horizontal growth. Furthermore, side effects reported on several physiological functions could affect node ability to generate new plants. In a greenhouse trial, ‘Tifway’ hybrid bermudagrass (C. dactylon × C. transvaalensis Burtt Davy) grown in pots was treated with increasing rates of TE (untreated control, 0.015, 0.075, 0.150, and 0.300 g·m−2). The treatment effects on the number of stolons produced and their linear growth rate, node production, node vitality, and daughter plant characteristics were investigated. The effects of growth inhibition because of TE application on nodes and daughter plants and the relative duration were also assessed. Starting from 2 weeks after treatment (2 WAT), TE application resulted in reductions of stolon length of 24.6% and 52.9% compared with the untreated control, while at 3 and 4 WAT only 0.150 and 0.300 g·m−2 application rates produced significant reductions in stolon length with values of 37.1% and 52.9% at 3 WAT and of 34.1% and 48.3% at 4 WAT, respectively. The number of nodes per stolon was unaffected by treatments. No effect was observed in node vitality but daughter plants showed a postinhibition growth enhancement when nodes were excised at 4 WAT. TE application at the labeled rate did not affect the number of stolons produced by ‘Tifway’ hybrid bermudagrass compared with untreated control, while a reduction in stolon growth rate was recorded only at 2 WAT. Application at higher rates reduced stolon growth rate longer than labeled rate but not stolon production. None of the treatments reduced the number of vital nodes. Application rates higher than labeled rate produced a postinhibition growth enhancement in plants that originated from nodes excised at 4 WAT.
Diego Gómez de Barreda, Jialin Yu and Patrick E. McCullough
, 2007 ). Ethofumesate, mesotrione, and siduron are herbicides used during cool-season turf establishment but inconsistent efficacy, cost, and application regimens limit the effectiveness of these herbicides ( Johnson, 1983 ; McElroy and Breeden, 2007
Cécile Bertin, Andy F. Senesac, Frank S. Rossi, Antonio DiTommaso and Leslie A. Weston
, 2 full years following turf establishment. Seedling vigor is also an important factor influencing weed infestation in turf, as a vigorous, well-established turf results in reduced weed establishment ( Turgeon, 1999 ). Spring green-up. Spring green
Ronnie W. Schnell, Donald M. Vietor, Richard H. White, Tony L. Provin and Clyde L. Munster
Discussion Turf establishment. Before the first fertilizer N application, 2 weeks after sprigging, turfgrass coverage was 64% greater ( P = 0.001) for soils with than without CMB ( Table 1 ). The greater coverage with CMB was attributed, in part, to greater
Thomas V. Reed and Patrick E. McCullough
making two applications of glyphosate (Roundup Pro; Monsanto Co., St. Louis, MO) at 5 kg a.i./ha in September and then seeding ‘Titan’ tall fescue at 195 kg·ha −1 in October. Fields were irrigated to promote turf establishment. Tall fescue was mowed
Patrick E. McCullough and William Nutt
reestablish in treated areas. Simazine is generally safe for actively growing bermudagrass, but soil residual activity may influence turf establishment ( Lawson et al., 2002 ; Syngenta, 2008 ; Cummings et al., 2009 ). In Georgia, simazine applied at 1.1, 2