Low Temperature Is Critical for Jujube Grafting Success in Frost-prone Northern New Mexico

The increased popularity of jujube (Ziziphus jujuba) combined with the difficulty of grafting have limited supplies of grafted trees in the United States. From 2011 to 2020, grafting was practiced for cultivar amplification after importation and cultivar trials in frost-prone northern New Mexico. Grafting success was related to not only grafting techniques but also climate factors. Bark grafting, whip/tongue grafting, and cleft grafting were commonly used in nurseries. Low temperatures had a critical role in jujube grafting success in marginal regions and were more important than the grafting technique. If frost occurs before or near the leafing time, then grafting should be delayed until the rootstocks are determined to be healthy and alive. If frost occurs after grafting, then grafting failure and/or thin and small plant percentages increased. If only branchlets appear after grafting, then pinching branchlets could stimulate new shoot growth.

Response to Comment on “Evidence of humans in North America during the Last Glacial Maximum”

Madsen et al . question the reliability of calibrated radiocarbon ages associated with human footprints discovered recently in White Sands National Park, New Mexico, USA. On the basis of the geologic, hydrologic, stratigraphic, and chronologic evidence, we maintain that the ages are robust and conclude that the footprints date to between ~23,000 and 21,000 years ago. Madsen et al . ( 1 ) question the veracity of calibrated radiocarbon ages used to constrain the antiquity of human trackways discovered recently at White Sands National Park (WHSA) Locality 2, New Mexico, USA ( 2 ). The ages were derived from seeds of the aquatic plant Ruppia cirrhosa , which they suggest may suffer from hard-water (or reservoir) effects, making them too old, potentially by thousands of years. We were well aware of this possibility, investigated it, and presented several lines of evidence that argued against such a problem. Here we respond to each of their four primary points.

Comment on “Evidence of humans in North America during the Last Glacial Maximum”

Bennett et al . (Reports, 24 September 2021, p. 1528) report human footprints from Lake Otero, New Mexico, USA ~22,000 years ago. Critical assessment suggests that their radiocarbon chronology may be inaccurate. Reservoir effects may have caused radiocarbon ages to appear thousands of years too old. Independent verification of the ages of the footprint horizons is imperative and is possible through other means.

Taxonomy and valve ultrastructure of new and interesting freshwater fossil diatoms (Bacillariophyta) of Miocene age from the Espanola Formation of New Mexico, U.S.A. II. Description of a New Grunowia species with comments on the genus

We describe a new species of the diatom genus Grunowia, G. mannii Kociolek & A.Danz, sp. nov., from a Miocene fossil deposit in New Mexico, USA. The species has wide fibulae, a keel that is off-center externally, with distinct proximal raphe ends, both internally and externally. The species is differentiated from others in the genus in the narrow valves that are swollen and rounded in the center. We formally transfer two species from Nitzschia to Grunowia, making the new combinations, Grunowia constricta (Chen & Zhu) Kociolek & A.Danz, comb. nov. and Grunowia pseudosinuata (Hamilton & Laird) Kociolek & A.Danz, comb. nov. We discuss the distribution of the genus over time and space. This report from the Miocene represents the oldest known member of the genus Grunowia in the fossil record.

Introduction to teaching science with three-dimensional images of dinosaur footprints from Cristo Rey, New Mexico

In this paper we discuss the use of three-dimensional (3-D) imagery and virtual field trips to teach pre-university and non-major university geoscience courses. In particular, 3-D PDF (Portable Document Format) files can be used to either prepare students for or completely replace a field trip when logistical problems make the actual trip too difficult to be effective or when some students need an alternative accommodation. Three-dimensional images can replace or supplement classroom activities, such as the identification of rocks and minerals from hand samples or the identification of geologic structures from 2-D photographs and limited field observations. Students can also become involved in data collection and processing to further their understanding of photogrammetry and visualization. The use of 3-D imagery can make additional time available to instructors to cover more advanced topics and teach students more about the role of science in geologic research. We use an example from Cristo Rey, New Mexico, where dinosaur footprints and tracks are present but difficult to see in many cases, and they are often in places that are hard to access for many people. At this site, approximately 10 000 photographs were collected and processed as 3-D images to show one approximately 72 m2 area of known footprints. However, we also conducted some very simple digital manipulations of the images that allowed us to identify new footprints and tracks that were not apparent when viewed in the field. The photographs and 3-D images have been donated to the Insights El Paso Science Center (denoted Insights Museum herein) that owns the fossil site, and they are now being used to develop educational materials and lessons for the nearby communities.