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  • Author or Editor: D. E. Johnson x
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Golf facilities account for 2.3 million acres in the United States. Numerous turfgrass species are managed on US golf facilities, but golf facilities may change turfgrasses depending on numerous variables. Knowing which turfgrasses are grown and how turfgrass selection has changed would provide important information to scientists, turfgrass managers, and policymakers. The objective of this survey was to measure turfgrass use on US golf facilities in 2021 and to determine whether changes in turfgrass selection have occurred since 2005. A survey was developed and distributed via e-mail to 13,938 US golf facilities, with 1861 responding. From 2005 to 2021, the total projected area of maintained turfgrass on US golf facilities decreased by 14.2%, which was likely a result of course closures and maintenance operations. Nationally, bermudagrass (Cynodon sp.) and Kentucky bluegrass (Poa pratensis) remained the most common warm- and cool-season turfgrasses, respectively. The area of winter-overseeded turfgrass declined by 60% between 2005 and 2021. The percentage of golf facilities that used zoysiagrass (Zoysia sp.) and seashore paspalum (Paspalum vaginatum) increased depending on region and specific playing surface, albeit a pragmatically minor increase. In general, turfgrass selection on golf facilities in northern climates did not change, whereas turfgrass selection in southern climates favored a change from cool- to warm-season species, depending on the playing surface. Whether in historically cool-season or warm-season regions, it appears that many golf facilities are exploring alternatives to their traditional turfgrass species.

Open Access

Five-year old `Sharpblue' southern highbush blueberry plants (Vaccinium corymbosum L.) were self- and cross-pollinated (`O'Neal') to study peroxidase (POD) activity, isozyme patterns, and histological localization during fruit development. Cross-pollination resulted in larger and earlier-ripening fruit. Activities of soluble and bound POD were very high during fruit growth period I, with peaks at 10 and 20 days after self- and cross-pollination. Activity was much higher for cross-pollinated fruit. During fruit growth period II, POD activities were low in both pollination treatments. During ripening, soluble POD increased, then declined in both treatments. Bound POD activities increased during the color transition from blue to dark blue, with the increase greater in self-pollinated fruit. Banding patterns of soluble and bound POD isozymes and their histological localization varied by pollination treatment as well as fruit developmental stage. During fruit ripening, soluble POD activity appeared to be associated with color transition from light blue to blue, while bound POD activity appeared to be associated with color transition from blue to dark blue.

Free access

Ovule abortion occurred between 5 and 10 days after pollination (DAP) in self- and cross-pollinated `Sharpblue' blueberry (Vaccinium corymbosum L.) fruit. More ovule abortion occurred with self-pollination (35%) than with cross-pollination (22% for `Sharpblue' × `O'Neal' and 29% for `Sharpblue' × `Gulfcoast'), and there were more poorly developed ovules with self-pollination (88.1%) than with cross-pollination (× `O'Neal', 33.6%; × `Gulfcoast' 50.8%). The increase in ovule area correlated exponentially with fruit growth during early developmental stages, regardless of pollination treatment. However, cross-pollination resulted in significantly greater ovule area and fruit mass during early fruit development as well as at ripening. Ovule area was maximum at 25 to 30 DAP for both pollination treatments, followed by exponential fruit growth (stage III). Cross-pollination resulted in greater fruit growth and a shorter stage III. At 10 DAP, ovules from cross-pollination were larger than those from self-pollination, suggesting that cross-pollination initiated ovule growth immediately after fertilization. This research suggests that southern highbush blueberry fruit growth and development is intimately associated with ovule growth and development, which is affected by pollen sources.

Free access

Continued reduction in limited natural resources worldwide increasingly necessitates the incorporation of low-maintenance and low-input plant materials into urban landscapes. Some fine-leaved Festuca grass species have been used in formal gardens and native urban landscapes because of their inherent tolerance to abiotic stresses, but native, ornamental types (tall and non-spreading with multicolored culms and panicles) are not common in landscapes of the western United States. A native fine-leaved Festuca collection made in Montana (designated FEID 9025897) by the U.S. Natural Resources Conservation Services possesses such ornamental characteristics but has not been evaluated for its horticultural potential. Therefore, a study was designed to assess its phenotypic and genotypic attributes by cloning 270 FEID 9025897 plants and evaluating them along with native F. idahoensis and F. ovina PIs (five) and commercial checks (five) for genetic diversity and plant morphology for 2 years (2010–11). Plant genetic constitution was determined using amplified fragment length polymorphism (AFLP) analysis. Plant height, width, biomass, relative vigor (visual rating of 0 = dead to 5 = green, abundant growth), persistence (number of plants alive per plot), and regrowth after clipping (visual rating of 0 = none to 5 = most) were estimated by evaluation of plants under replication at Hyde Park, UT. Based on AFLP-based coancestry analysis, FEID 9025897 plants possessed considerable genetic affinities with F. idahoensis. Morphological traits as averaged over both years varied in height (13.9 to 105.0 cm), width (9.9 to 66.2 cm), biomass (0 to 170.4 g), vigor (0.2 to 4.7), persistence (0 to 3.9), and regrowth (0 to 4.0). Based on these differences, 19 (7%) FEID 9025897 plants were identified for their ornamental potential that possessed multicolored (red, orange, and yellow) culms and varied in morphology with 2-year means of height (79.8 cm), width (45.2 cm), biomass (88.5 g), vigor (2.9), persistence (1.8), and regrowth (3.7).

Free access

Abstract

An inexpensive chamber for controlled freezing of large container-grown plants up to 2 m in height was constructed using liquid nitrogen as a refrigerant. A microcomputer-based system was developed to control the cooling sequence and to collect data on tissue temperature, air temperature, and exotherms. Versatile software was written that allowed the programmed rate of temperature drop to be based on either tissue temperature or air temperature.

Open Access

Abstract

‘Ruston Red’ peach [Prunus persica (L.) Batsch] was released by the Louisiana Agricultural Experiment Station (LAES) to provide a high quality, large freestone fruit that ripens about 5 days before ‘Elberta’ or about July 20 in north Louisiana. ‘Ruston Red’ has exhibited high resistance to bacterial leaf spot [Xanthomonas Campestris pv. pruni (Smith 1903) Dye 1978] even when grown in orchards next to trees that were severely infested with the bacterium.

Open Access

Abstract

‘Ouachita Gold’ peach (Prunus persica (L.) Batsch) was released by the Louisiana Agricultural Experiment Station to provide a high quality, large freestone fruit that ripens about 20 days after ‘Elberta’ or about August 5 in north Louisiana.

Open Access

Nutrient use on United States golf courses increases management costs and has the potential to influence ecosystems. Therefore, it is critical to assess nutrient use and management practices to develop and teach best management practices. The objectives of this survey were to measure nutrient use and management practices on United States golf courses in 2021, and to determine if changes occurred since 2006. A survey was developed and distributed via e-mail to 14,033 United States golf facilities, with 1444 responding. From 2006 to 2021, the total projected nitrogen (N), available phosphorus (P2O5), and soluble potash (K2O) applied declined by 41%, 59%, and 54%, to 54,376, 13,761, and 41,386 tons, respectively. These reductions were attributed to course closures, reduced fertilized acres, reduced application rates, and nutrient use restrictions. The percentage of facilities that did not apply P2O5 increased to 21%, which is likely a result of P2O5 application restrictions. Soil testing was associated with greater application rates of N, P2O5, and K2O. Returning clippings, using precision fertilizer applications, reducing turfgrass acreage, and considering N release from soil organic matter were associated with reduced application rates of P2O5. Golf course superintendents have contributed to nationwide reductions in N, P2O5, and K2O, as evidenced by the reduction in fertilized acres and the reduction in nutrient use rates from 2006 to 2021.

Open Access

Integrated pest management (IPM) is an important component of golf course maintenance and includes conventional chemical pesticide use as well as nonchemical cultural management practices. Determining how frequent pest management practices are used on golf courses is critical when developing educational and outreach programs. The objective of this study was to determine the frequency of pest management practices and pesticide mixing and storage facilities on US golf courses. A survey was sent to 14,033 operational US golf facilities with 10% responding. Reliance on all conventional chemical pesticides increased from 2015 to 2021. The reliance on biological control products declined to 14% and reliance on the nonpesticide practice of using plant growth regulators remained equivalent to 2015. The most common pest management practices included monitoring weather patterns and scouting for pests, with 93% of golf facilities reporting the use of both. The use of written IPM and pesticide application plans increased from 44% to 63% of golf facilities between 2015 and 2021, respectively. Generally, mixing and storage facilities remained unchanged from 2015 to 2021. US golf facilities continue to use nonchemical pest management practices, but reliance on chemical pesticides has increased.

Open Access