The Desert Whale: the boom and bust of hemp in Arizona.

BACKGROUND: This paper examines the factors that led to the collapse of hemp grown for cannabidiol (CBD) in Arizona, the United States of America (USA), and particularly in Yuma County, which is a well-established agricultural area in the state. METHODS: This research uses a combination of mapping analysis along with a survey of hemp farmers to assess the reasons why the hemp industry collapsed as well as to foster solutions to these problems. RESULTS: In 2019, 5430 acres were sown with hemp seed in Arizona with 3890 acres inspected by the state to determine if they could be harvested. By 2021, there were only 156 acres planted, and only 128 of those acres were inspected by the state for compliance. (Crop mortality accounts for the difference between acres sown and acres inspected.) CONCLUSIONS: A lack of knowledge about the hemp life cycle greatly contributed to the failure of high CBD hemp crops in Arizona. Other problems included noncompliance with tetrahydrocannabinol limits, poor sources for seeds and inconsistent genetics of the hemp varieties sold to farmers, and diseases that hemp plants were susceptible to such as Pythium crown and root rot and beet curly top virus. Addressing these factors will go far in making hemp a profitable and widespread crop in Arizona. Additionally, hemp grown for other traditional uses (e.g., fiber or seed oil) as well as new applications (e.g., microgreens, hempcrete, and phytoremediation) offers other pathways for successful hemp agriculture in this state.

Uptake of uranium into desert plants in an abandoned uranium mine and its implications for phytostabilization strategies.

This research assessed a variety of native desert plant species for their ability to accumulate toxic elements in an abandoned uranium mine in the Sonoran Desert. Paired soil and plant samples were collected for six species of plants that had naturally re-colonized the mine. The mine soils had a median uranium concentration of 56.0 mg kg-1 (range: MDL to 696) while the plant samples had concentrations of 3.7 mg kg-1 (range: MDL to 20.0). The results showed uranium bioconcentration factors (BCFs) were between 0.051 and 0.234 with the longer-living, woody species having higher concentrations than short-lived herbaceous species. These BCF values were near the high end of values reported in the literature which implies that these desert species were either better at acquiring elements or they have fewer mechanisms to eliminate elements (e.g. litterfall). The life histories of the species were then evaluated on four criteria, namely uranium BCF, inedibility, longevity, and root depth, to assess which species would be best for phytostabilization, which is the use of plants to stabilize the soil to prevent water or wind erosion that might transport contaminants off site. The goal was to select a species that would stabilize the soil without accumulating uranium in the above ground biomass where it could enter the food web and be transported off site. Ultimately, brittlebush (Encelia farinosa A. Gray ex Torr.) was selected because of its low BCF, shallow roots and reasonable longevity.

Variability in capsaicinoid content and Scoville heat ratings of commercially grown Jalapeño, Habanero and Bhut Jolokia peppers.

The variability of capsaicinoid content of three common, commercially-available hot pepper varieties, namely Jalapeño, Habanero and Bhut Jolokia, was investigated. For each variety tested, ten peppers were acquired from each of ten different suppliers resulting in 100 peppers per variety that were individually analyzed. The results showed that different pepper varieties had different distribution types. The Habanero peppers showed a normal distribution; the Bhut Jolokia showed a skewed distribution and the Jalapeño peppers showed a very skewed distribution. The source of variability was also different; the Habaneros were very consistent within a given pepper supplier so most of the overall variation resulted from differences between suppliers. The Jalapeño peppers were the exact opposite with a very high degree of variability within a given supplier and relatively low variation between suppliers. A bootstrap statistical simulation was conducted on the data to suggest a minimum number of peppers to analyze to characterize the variation in a population. The simulations indicated that small sample sizes are effective at estimating the mean concentrations, but a sample size of ten or more is necessary to describe the population and capture the high-end tail of the distributions, which are the very hottest peppers.