Bernd Leinauer

Water Repellency Varies with Depth and Season in Sandy Rootzones Treated With Ten Wetting Agents

A study was conducted at New Mexico State University during the summer months of 2003 and 2004 to investigate the effects of several wetting agents on sand-based rootzone hydrophobicity and putting green turf appearance. The efficacy of wetting agents varied over depth and was most pronounced at depths of 2.5 cm or less. All treated plots with the exception of Naiad and Respond 2 plots exhibited lower water repellency than the untreated plots at a depth of 0.5 cm. Plots treated with Aqueduct and LescoFlo showed consistently lower water repellency at rootzone depths of 0.5, 1.5, and 2.5 cm than the untreated plots. Naiad-treated rootzones exhibited greater hydrophobicity at depths of 0.5, 1.5, 2.5 and 3.5 cm compared to the untreated rootzones. In 2003 plots treated with Brilliance, Cascade Plus, HydroWet, LescoFlo, and Primer Select had higher turfgrass quality than the untreated plots, while Naiad-treated plots showed lower quality and color ratings than other plots. There were no differences in color or quality, among the treatments in 2004.

Moderate Salinity Does Not Affect Germination of Several Cool‐ and Warm‐Season Turfgrasses

Germination of warm- and cool-season turfgrasses was assessed at salinity levels commonly found in recycled irrigation water. Cool-season grass seeds included in the study were Thermal Blue hybrid bluegrass [Poa arachnifera (Torr.) x pratensis (L.)]; Barlexas II, Southeast, and Tar Heel II tall fescue [Festuca arundinacea (Schreb.)]; Brightstar SLT and Catalina perennial ryegrass [Lolium perenne (L.)]; Salty and Fults alkaligrass [Puccinellia distans (Jacq.)]; and Dawson red fescue [Festuca rubra trichophylla (L.)]. Warm-season grass seeds used in the study were bermudagrass Numex Sahara, Princess 77, and Transcontinental [Cynodon dactylon (L.)]; Companion zoysiagrass [Zoysia japonica (Steud)]; and Seaspray seashore paspalum [Paspalum vaginatum (Swartz)]. Each grass was incubated at salinity levels from 0.6 to3.0 dS/m. Germination was considered successful upon radicle emergence and the first leaf growing past the coleoptile. Despite species and cultivar variation in germination success, germination was not inhibited in any of the tested cultivars at the salinity levels used in this study, suggesting that germination may not be the most salt-sensitive stage in turfgrass development.

Usefulness of Non-Chemical Water Conditioners for Managing Turfgrasses and their Rootzones

Physical water conditioning products have been used on golf courses to improve turfgrass quality, improve rootzone salinity, and to reduce irrigation water use. A four-year study was conducted at New Mexico State University to investigate the effects of non-chemical in-line water conditioners (two catalytic, one magnetic, one hydro-electric, and a control treatment) on turfgrass establishment, and on turfgrass quality and rootzone salinity of a perennial ryegrass stand. Conditioning treatments were applied under potable [Electrical conductivity (EC) = 0.6 dS/m] and saline (EC = 3.1 dS/m) irrigation. Conditioning treatments did not affect perennial ryegrass establishment, only saline irrigation delayed establishment. Turfgrass quality on control plots did not differ from conditioner treated plots for both water qualities on all but one sampling date. The rootzone salinity results were inconclusive; no clear consistent trends were found for individual measured parameters. After four years of research, a consistent positive impact of these conditioning units on turf quality and rootzone salinity could not be substantiated.