Rolston St. Hilaire

Water Budget Calculator Created for Residential Urban Landscapes in Albuquerque, New Mexico

AbstractThe current methods used to calculate urban landscape water budgets are limited because they lack site specificity. The objective of this study was to create a landscape water budget web interface based on ground-proofed information, such as plant coefficients (Ks), vegetation components, and reference evapotranspiration (ETo). Using Albuquerque, New Mexico as the base city, mixed landscape and monthly turf grass coefficients for each zip code in Albuquerque were developed. The spatial variability of zip code ETo and ETo weather anomalies was assessed because of their potential effect on water budgets. Evapotranspiration varied among zip codes, months, and El Nino Southern Oscillation (ENSO) phases. To improve the water budget estimate, the interface accounts for spatial and temporal variability of the monthly, historical (monthly and yearly), and the ENSO phases ETo. Because nonturf landscape plant Kss were unavailable for Albuquerque, the authors developed a Region Match Analysis to transfer non...

In vitro propagation of Acer grandidentatum Nutt

Bigtooth maple (Acer grandidentatum) is a promising ornamental tree that is not widely used in managed landscapes. Tissue culture has not been used successfully to propagate this taxon. We cultured single- and double-node explants from greenhouse-grown, 2-y old seedlings of bigtooth maples, which are indigenous to New Mexico, Texas, and Utah, on Murashige–Skoog (MS), Linsmaier–Skoog (LS), Driver–Kuniyuki Walnut (DKW), and Woody Plant (WPM) tissue culture media. Media affected shoot proliferation (P = 0.0242) but the zone of explant origin (P = 0.7594) did not. After four 30-d subcultures, explants on DKW media and WPM media produced 3.6 and 3.5 shoots per explant, respectively. Sprouting rates were highest on DKW, making DKW the best overall media for shoot proliferation. Double-node microshoots were rooted in vitro on DKW containing indole acetic acid (IAA). Microshoots represented six genotypes from three locations within Texas and New Mexico. Rooting percentage increased up to 15% as IAA concentration increased (P = 0.0040). There was 100% survival of rooted microshoots in vented Phytatrays containing one perlite: one peat moss (v/v). We conclude that DKW can be used to proliferate microshoots, and IAA induces rooting in microshoots of bigtooth maple.

Remote sensing used to detect moisture status of pecan orchards grown in a desert environment

Remote-sensing techniques can detect and up-scale leaf-level physiological responses to large areas, and provide significant and reliable information on water use and irrigation management. The objectives of this study were to screen leaf-level physiological changes that occur during the cyclic irrigation of pecan orchards to determine which responses best represent changes in moisture status of plants and link plant physiological changes to remotely sensed surface reflectance data derived from the Landsat Thematic Mapper and Enhanced Thematic Mapper Plus (ETM+). The study was conducted simultaneously on two southern New Mexico mature pecan orchards. For both orchards, plant physiological responses and remotely sensed surface reflectance data were collected from trees that were either well watered or in water deficit. Remotely sensed variables included reflectance in band 1, the ratio between shortwave infrared (SWIR) bands (B5:B7), the normalized difference vegetation index, and SWIR moisture indices. Midday stem water potential (Ψsmd) was the best performing leaf-level physiological response variable for detecting moisture status in pecans. The B5:B7 ratio positively and significantly correlated with Ψsmd in five of six irrigation cycles while multiple linear regression weighted with six remotely sensed surface reflectance variables revealed a significant relationship with moisture status in all cycles in both orchards (R2 > 0.73). Because changes in the B5:B7 band ratio and multiple regression of spectral variables correlate with the moisture status of pecan orchards, we conclude that remotely sensed data hold promise for detecting the moisture status of pecans.

Composition of soilless substrates affect the physiology and fruit quality of two strawberry (Fragaria × ananassa Duch.) cultivars

Abstract Leaf-level physiology, yield, and fruit quality of two strawberry (Fragaria × ananassa Duch.) cultivars, “BG4.370” and “Splendor” grown in five growing substrates were assessed. Substrate ratios were T1: tuff (0–4 mm), T2: cocopeat + perlite 4:1, T3: peatmoss + perlite 4:1, T4: tuff + cocopeat 4:1, and T5: tuff + peatmoss 4:1. Strawberry parameters were greatly affected by substrate composition but not cultivars. Plants grown in cocopeat + perlite 4:1 had the highest photosynthesis, transpiration, radical scavenging activity, and fruit firmness while those grown in peatmoss + perlite 4:1 had the highest yield, total phenolics and nitrate concentration compared to other substrates. Given that peat-based growing substrate has raised concerns over the environmental impacts such as, a reduction of wet-lands and loss of soil organic carbon, the lower environmental impact and higher fruit quality grown on cocopeat justifies the use of cocopeat as an alternative substrate to peatmoss.