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Shade stress is a common problem encountered in turfgrass management situations worldwide. Shade reduces photosynthetic photon flux (PPF), alters light quality, reduces air movement, and may introduce tree root competition. As a species, Kentucky bluegrass (Poa pratensisL.) possesses relatively poor shade tolerance, which limits its use in reduced light environments. However, genetic alteration of the gibberellic acid enzyme pathway has shown promise in some plant species for improving growth in shade. The objective of this 2‐year field study was to determine the comparative performance under reduced PPF and determine minimal daily light integral (DLIm) requirements for acceptable quality of a conventional (CONV) Kentucky bluegrass (KBG) blend and gibberellic acid 2‐oxidase (GA2ox) transformed “ProVista” (PV) KBG. A 2‐year field study was conducted under neutral density shade treatments producing monthly daily light integrals averaging from ∼5.8 (90% shade) to 48 mol m−2day−1(full sun) for mid‐June through October study periods. Based on nonlinear regression of mean monthly DLI during the study period versus turfgrass quality (TQ) at the end of each study period, DLImwas found to range from 7.5 to 10 mol m−2day−1for PV and from 22.5 to 26.2 mol m−2day−1for CONV KBG. Improved TQ of PV under low light intensities may be associated with reduced rates of leaf elongation, greater stand density, higher chlorophyll concentrations, and darker green color compared to CONV KBG. Although shade duration did not exceed 4 months, the results suggest that GA2ox‐transformed PV KBG possesses improved tolerance to reduced PPF compared to CONV KBG. Limited data are available on minimal light requirements of Kentucky bluegrass cultivars.ProVista shows improved turf quality and color and reduced vertical regrowth relative to conventional under low photosynthetic photon flux.ProVista required minimal daily light integral of 7.5–10 mol m−2day−1, while conventional Kentucky bluegrass requires 22–26 mol m−2day−1.

‘Chisholm’ (Reg. No. CV‐273, PI 666039) is a zoysiagrass (Zoysia japonicaSteud.) approved for release by Texas A&M AgriLife Research, Dallas, TX, and the Kansas Agricultural Experiment Station, Manhattan, KS. Chisholm is a clonal selection made in 1997 from a germplasm nursery established in 1983 in Dallas. It was originally evaluated under the designation TAES 4436 and included in the 2002 National Turfgrass Evaluation Program Zoysiagrass Variety Test under the designation DALZ 0102. Chisholm has a texture coarser than ‘Meyer’ and intermediate to ‘JaMur’ and ‘Palisades’. Freezing tolerance of Chisholm is equivalent to, or slightly poorer than, Meyer, but it is superior to Meyer for establishment rate from vegetative plugs; turfgrass quality; growth under shade; fall color; resistance to bluegrass billbug (Sphenophorus parvulusGyllenhal), zoysiagrass mite (Eriophyes zoysiaeBaker, Kono, and O'Neill), and take all patch [caused by Gaeumannomyces graminisvar. graminis(Sacc.) Arx & D.L. Olivier]; recovery from divots; and seed head production (fewer produced). Improvement over Meyer in these traits will potentially increase the utility of zoysiagrass in the transition zone. Chisholm is well suited for use on lawns and golf courses in the transition zone, particularly those areas in zones 6b or higher on the USDA Plant Hardiness Zone map.

‘DALSA 0605’ (Reg. No. CV‐274, PI 671959) is an embryo rescue‐derived interploid hybrid of St. Augustinegrass [Stenotaphrum secundatum(Walt.) Kuntze] resulting from a cross between TAES 5382 (African triploid PI 291594) and ‘Palmetto’ (diploid). DALSA 0605 was evaluated under the designation TAES 5471‐18 and TXSA 19 and was approved for release as a new cultivar by Texas A&M AgriLife in 2014. DALSA 0605 is a vegetatively propagated, genetically stable, and uniform cultivar. It is distinguished from other cultivars of St. Augustinegrass for traits and characteristics that include (i) tolerance to gray leaf spot disease (caused by Magnaporthe griseaCouch), (ii) significantly reduced levels of fecundity and juvenile development of southern chinch bugs (Blissus insularisBarber) as compared to ‘Raleigh’ and ‘Texas Common’, and (iii) superior drought resistance conferred through a combination of tolerance to drying soil, deep rooting potential, and rapid recovery following drought. In addition, DALSA 0605 exhibited percentage rates of establishment and turfgrass quality ratings (normal and drought‐stress conditions) comparable to commercial checks in multilocation (seven) and multiyear (two) field evaluations. DALSA 0605 is well suited for use on residential and commercial lawns, as well as other recreational sites, throughout the southern and southeastern United States.

Municipal water restrictions have become commonplace throughout much of the southern United States. The objectives of this 2‐yr study were to (i) determine supplemental irrigation requirements necessary for achieving acceptable quality in 15 zoysiagrass (Zoysia japonicaand Zoysia matrella) and bermudagrass (Cynodonssp.) cultivars when managed under a 2 d/wk irrigation frequency, (ii) determine the effects of mowing height on irrigation requirements, and (iii) evaluate root development differences between the species and cultivars at the completion of the study. A linear gradient irrigation system (LGIS) was used to provide an irrigation gradient across field plots. Plots were evaluated along the gradient six times over two summers to determine the level of supplemental irrigation, relative to reference evapotranspiration (ETo), necessary for maintaining acceptable visual quality. The fine‐textured, sports‐type bermudagrass cultivars required the least supplemental irrigation (∼10 to 15% × ETo) to maintain acceptable quality in the study. The medium‐textured amenity bermudagrasses and Japanese lawngrass (Zoysia japonicaSteud.) cultivars required similar but somewhat greater irrigation requirements (∼15 to 20% × ETo) than the fine‐textured bermudagrasses. Manilagrass cultivars (Z. matrella) required the highest supplemental irrigation requirements (∼25 to 33% × ETo) for maintaining acceptable appearance within 2 d/wk irrigation regime. Mowing height did not consistently affect irrigation requirements for either group of bermudagrass but affected the Zoysiaspecies differently. Tall mowing heights generally reduced irrigation requirements in Z. japonicabut increased irrigation requirements for Z. matrellacultivars. While few intraspecific root development differences occurred within the 0 to 25 cm soil depth, Z. matrellaroot development was limited relative to bermudagrass and Z. japonicacultivars within deeper (25–50 cm) soil, which may have contributed to the higher irrigation requirements for the species. The results emphasize differences in supplemental irrigation levels needed for maintaining acceptable appearance among warm‐season turfgrass species and cultivars during 2 d/wk irrigation.

Effective water conservation in the landscape requires identification of cultural management practices that maximize the genetic rooting potential of establishing turfgrass sod. Nitrogen is critical for successful turfgrass establishment; however, there has recently been debate over whether to restrict N fertilization during summer periods in parts of Florida and the United States. This study was undertaken to examine within four warm‐season turfgrass species, the relative influences of cutting height and N fertility on the (i) rate of root extension and (ii) root biomass produced over a 10‐wk period. ‘Tifway 419’ bermudagrass (Cynodon dactylon(L.) Pers. × C. transvaalensisBurtt Davy), ‘Empire’ zoysiagrass (Zoysia japonicaSteud.), ‘Argentine’ bahiagrass (Paspalum notatumFlugge), and ‘Floratam’ St. Augustinegrass (Stenotaphrum secundatumWalt. Kuntze) were established from 10‐cm diam. by 5‐cm deep plugs of turfgrass sod into 90‐cm tall, clear acrylic tubes. Experimental treatments were arranged in a complete factorial that was repeated over two growing seasons. Rates of root extension were calculated from weekly measures of the deepest visible root in each column. Root extension rates ranged from ∼1.0 to 1.8 cm d−1during the studies, with bahiagrass exhibiting the most rapid root extension of the four species. The results demonstrated that increasing N fertility during establishment increased rates of root extension into deep soil, particularly in bermudagrass. Height of cut had no effect on rate of root extension for most species, but higher cutting height did promote more rapid root extension in bermudagrass. Although not significantly accelerating vertical root extension in most species, maintaining sod at the higher cutting heights resulted in significantly greater root proliferation within both upper and lower soil depths for all species. The results emphasize the importance of proper N fertility and cutting heights for optimizing root development of different turfgrass species during sod establishment.

The influence of deciduous foliage shade on turfgrass development has not been fully investigated. Previous research neglects changes in spectral distribution, e.g., red:far‐red light (R:FR) ratios common of foliage shade. Turfgrass plants may respond simultaneously but in different ways to changes in light intensity and spectral composition. A field study was conducted in 2001–2002 at the Ohio Turfgrass Research and Educational Facility, Columbus, OH. Two tall fescue (Festuca arundinaceaSchreb.) cultivars of differing shade tolerance were established under low photosynthetic photon flux (PPF) in approximately 8% of full sunlight with high (>1) and low (<1) R:FR ratios to distinguish between developmental effects of R:FR ratio (spectral composition) and PPF (light intensity) on turfgrass photomorphogenesis. Few morphological differences in shade tolerance between the two cultivars were observed during the 2‐yr study. However, under low PPF, high R:FR ratios led to increased tillering, leaf blade width and thickness, and chlorophyll contents. Root mass declined under reduced PPF regardless of R:FR ratio. Results suggest that while turfgrass photomorphogenesis in shade is influenced by changes in PPF, many characters are further influenced by changes in the R:FR ratio.