Bigtooth maple (Acer grandidentatum Nutt.) is indigenous to the southwestern United States. This species is not widely used in managed landscapes but the plant holds promise as a useful ornamental tree. Micropropagation might provide additional sources of selected genotypes for the nursery industry, but tissue culture has not been used successfully to propagate this species. We cultured double-node explants from greenhouse-grown, 2-year old seedlings of bigtooth maples that originated from Utah, Texas and New Mexico. Seedling height ranged from 15-90 cm. The shoot region was divided into three equal zones designated as terminal, intermediate and basal. Explants were selected from each of those zones. Explants were established on Murashige-Skoog (MS), Linsmaier-Skoog (LS), Woody Plant Medium (WPM) and Driver-Kuniyuki (DKW) tissue culture media. Shoot proliferation, area of the plate covered by callus and foliar pigment development (hue as determined by Royal Horticultural Society Color charts) were monitored for 17 weeks. Media affected shoot proliferation (P = 0.0042) but the zone of origin (P = 0.6664) of the explant did not. Callus area showed no significant difference among the four media and three zones (P = 0.2091) and averaged 3.60 centimeters2. After four subcultures, each lasting 30 days, explants on DKW media produced 10 shoots per explant. This media might hold promise for the micropropagation of bigtooth maple. Twenty-nine percent of all explants expressed foliar pigmentation, which ranged from red-purple to orange-red. Whether foliar pigment development in tissue culture correlates with expressed pigmentation in nature warrants further investigation.
Clare A. Bowen-O'Connor*, Rolston St. Hilaire, John Hubsten-berger, and Dawn VanLeeuwen
Genhua Niu and Denise S. Rodriguez
Use of recycled water to irrigate urban landscapes may be inevitable, because the freshwater supply has been diminishing and the population continues to grow in the arid and semiarid southwestern United States. However, little information exists on the performance of landscape plants irrigated with nonpotable water. Two greenhouse studies were conducted during the summer and the fall to characterize the relative salt tolerance of five herbaceous perennials by irrigating the plants with a saline solution at an electrical conductivity (EC) of 0.8 dS·m–1 (tap water), 2.0 dS·m–1, or 4.0 dS·m–1. In the summer study, after 10 weeks of treatment, Achillea millefolium L., Gaillardia aristata Foug., and Salvia coccinea Juss ex J. had an aesthetically acceptable appearance for landscape performance (visual quality scores of 4 points or more), whereas Agastache cana (Hook.) Woot. & Standl. and Echinacea purpurea (L.) Moench had relatively low tolerance to salinity. Dry weight of shoots of A. millefolium, A. cana, and G. arstata was lower at elevated salinity levels. In the fall study, A. millefolium, E. purpurea, G. arstata, and S. coccinea had acceptable growth and visual quality at elevated salinity levels, whereas A. cana had lower quality and reduced growth. Dry weight of shoots was lower in G. arstata and A. millefolium at an EC of 2.0 dS·m–1 or 4.0 dS·m–1. Leaf osmotic potential of all species in the summer experiment was significantly lower at higher salinity compared with the control. In the fall experiment, leaf osmotic potential in A. millefolium, E. purpurea, and G. aristata at 4 dS·m–1 was lower compared with lower salinity treatment and the control. Leaf osmotic potential in the fall was higher than that of the same species at the same salinity level in the summer experiment, indicating that plants in the fall were less stressed than in the summer. Combined the results from both experiments, the authors concluded that A. millefolium, G. arstata, and S. coccinea had a relatively high salt tolerance (as much as 4 dS·m–1 of irrigation water under greenhouse conditions) among the tested species, whereas A. cana and E. purpurea were not tolerant to salt and should not be irrigated with low-quality water.
Daniel Hargey, Benjamin Wherley, Casey Reynolds, Richard White, and Garrett Parker
Municipal water restrictions across the southern and southwestern United States have created additional challenges for maintaining safe playing surfaces on recreational turf facilities. In recent years, many cities within these regions have begun to impose irrigation restrictions during winter months. Although winter overseeding has been regularly practiced in these areas, interest and use of colorants as an alternative to overseeding has grown due to decreasing water availability and budget concerns. Data on relative performance of colorant-treated vs. overseeded dormant turf would be of interest to turf managers, because colorants may be more cost-effective and require less water than winter overseeding. The objectives of this 2-year field study were to evaluate effects of winter treatments on performance (green cover, surface hardness, and soil moisture attributes), turfgrass injury resulting from simulated traffic, and spring transition of ‘Tifway’ bermudagrass (Cynodon dactylon L. × Cynodon transvaalensis Burtt-Davy) under a 1-day per week irrigation schedule. Treatments included 1) untreated bermudagrass, 2) fall colorant-treated bermudagrass, 3) perennial ryegrass (Lolium perenne L.) overseeded bermudagrass, and 4) turf-type annual ryegrass (Lolium multiflorum Lam.) overseeded bermudagrass. In both years, treatment differences were detected for percent green cover, soil volumetric water content (VWC), percent visual turfgrass injury, surface hardness, and percent bermudagrass transition. Percent green cover and visual turfgrass injury levels were similar between annual and perennial ryegrass in year 1, whereas loss of green cover and greater turfgrass injury were noted in annual ryegrass during the spring of year 2. Residual benefits of fall colorant applications extended into February of year 1, but dissipated by late December of year 2, likely due to higher rainfall and warmer temperatures, which prevented full bermudagrass shoot dormancy. Overseeding reduced bermudagrass spring transition by up to 50% compared with untreated and colorant-treated plots. Fall colorant treatments did not accelerate bermudagrass transition compared with untreated plots. Results of the study demonstrate that environmental differences from season to season can impact the relative benefits derived from colorant applications, as well as the performance of annual and perennial ryegrass.
Garry V. McDonald, Michael A. Schnelle, and Michael A. Arnold
; Riffle and Craft, 2003 ). Studies investigating temperature trends in Texas and the southwestern United States from the years 1941 to 2000 show an overall warming trend post-1970 ( Englehart and Douglas, 2003 ). Warmer winters associated with this trend
Mexico State Univ. Coop. Ext. Serv. Publ. H335. 20 Aug. 2021. < https://aces.nmsu.edu/pubs/_h/H335.pdf > Yao, S. Heyduck, R. 2018 Ornamental jujube cultivar evaluation in the southwestern United States HortTechnology 28 557 561 https
Jay M. Lillywhite, Jennifer E. Simonsen, and Mark E. Uchanski
to foods.” Respondents were provided with information regarding the term “chile pepper” (as it is used in the southwestern United States) to clarify the difference between chile peppers and spicy peppers in general ( Fig. 2 ). Survey participants were
Shengrui Yao, Steve Guldan, and Robert Heyduck
in the southwestern United States HortScience 50 839 846 Yao, S. Guldan, S.J. Flynn, R.P. Ochoa, C. 2015b Challenges of strawberry production in high-pH soil at high elevation in the southwestern United States HortScience 50 254 258 Yao, S. Guldan, S
Gayle M. Volk and Christopher M. Richards
southwestern United States and that of the cultivated potato ( Solanum tuberosum ). He emphasized the value of collecting accurate georeferencing data during trips to that repeated visits so small populations can capture genetic shifts in population structure
Sanjit K. Deb, Parmodh Sharma, Manoj K. Shukla, Theodore W. Sammis, and Jamshid Ashigh
Salinity stress is an ever-present environmental constraint to crop productivity in arid and semiarid regions. The quality of irrigation water remains a primary factor influencing soil salinity. In the arid and semiarid southwestern United States
Humberto Núñez-Moreno, James L. Walworth, Andrew P. Pond, and Michael W. Kilby
per tree) had an average of 126 μg·g −1 Zn in leaves, and the cv was 60% ( Beverly and Worley, 1992 ). Optimum concentration in Mexico was determined to be 65 μg·g −1 ( Medina, 2004 ) and in the southwestern United States 174 μg·g −1 ( Pond et al