John Wesley Powell had a profound understanding of the western territories of the United States (US) and he made a strong effort to influence the geographical boundaries of territories and states that were formed in the 19th century. Had he been successful with those efforts, our state lines would more closely follow watershed boundaries and the nature of the negotiations for water in the west would be significantly different.
Powell was born in Mount Morris, New York in 1834. Powell’s family moved to Ohio then Wisconsin before settling in Illinois in 1851. From an early age he was always interested in history, literature, botany, zoology, and a broad range of natural sciences. In 1852 he became a teacher and attended several colleges but never did receive a degree.
When the Civil War broke out in 1861, Powell enlisted in the Union Army at 27 years old, serving as a first lieutenant topographer, cartographer, and military engineer. On 6 April 1862 at the Battle of Shiloh in Tennessee, Powell was hit with a minié ball in his right arm, and it was amputated by field surgeons at the elbow. After recuperation, he returned to service and was promoted to the rank of Major before the end of the war (Ross, 2018 and Cope, 2019).
After the war, Powell directed much of his interested and energies to the open territories in the western U.S. The one-armed war veteran organized his first expedition to explore the Green and Colorado Rivers that began on 24 May 1869. The expedition was completed on 30 August 1869 when Powell and five other men climbed out of the canyon. Powell’s second expedition on the Colorado River extended from 22 May 1871 to 7 September 1872. The second trip offered Powell and his team an opportunity to focus on the collection of scientific data and information that included photographs, detailed maps, and observations that were later used for the development of scientific publications.
He became the second director of the United States Geological Survey (USGS) from 1881 to 1894 (Figure 1). His experiences in the west had huge influences on Powell and he became an ardent advocate for strict water resource conservation policies for the American West’s river systems. He saw this as particularly important at the time since most American policy makers in Washington and in the western territories did not want to accept the basic facts regarding the aridity of the west and the limitations of development due to water.
In 1869 at the Montana Constitutional Convention, Powell stated that “All the great values of this territory have ultimately to be measured to you in acre feet.”, which was not fully comprehended or incorporated into water policy. Another good example of Powell’s prophetic opinions on the management of western water was offered in Los Angeles at the 1893 Irrigation Congress where he stated, “I tell you, gentlemen, you are piling up a heritage of conflict and litigation over water rights, for there is not sufficient water to supply these lands.” and that advice was also generally ignored.
In 1891 the USGS published its 11th Annual Report (USGS, 1891) that contained several excellent maps. Perhaps the most famous map from that publication is a map of the arid region of the U.S. (Figure 2) and it is commonly referred to as the John Wesley Powell Map. This map defined the arid region of the U.S. extending west of the 100th meridian to the Pacific Coast Range. Working in the west today, that line is still a good demarcation opening the arid lands of the western U.S.
He resigned from his duties as the USGS Director in 1894 due to the resistance and heavy opposition to his water resource conservation efforts from western politicians. Dealing with the water resource challenges that we have in the west today, particularly in the Colorado River basin, we can recognize the wisdom and good advice that Powell offered. We can also see the consistency of political operators tending to ignore natural resource facts and limitations. Some things do not change.
Now we are primarily dealing with conflicts regarding Colorado River allocations between the upper and lower basins, consisting of states defined by political boundaries and straight survey lines. We are dealing now with many of the problems that John Wesley Powell was trying to warn people about and possibly prevent or reduce the levels of conflict.
Thus, it is interesting to consider the Powell Map versus the state maps that we have and what those implications might have been. We can at least appreciate his capacity to look ahead and the importance of our being able to do so today.
Figure 1. John Wesley Powell at his desk in the
USGS office, ca. 1891.
Figure 2. John Wesley Powell’s Map of the Arid Region of the United States,
published in the Eleventh Ann. USGS Report, Part II, PL LXIX, 1891.
References
Cope, M. 2019. Major John Wesley Powell: 1834-1902. Utah Geological Survey, September 2019.
Ross, J.F. 2018. The Visionary John Wesley Powell Had a Plan for Developing the West, But Nobody Listened. Smithsonian, 3 July 2018.
USGS. 1891. Eleventh Annual Report, United States Geological Survey, 1891.
This study was conducted at the Yuma Valley Agricultural Center. The soil was a silty clay loam (7-56-37 sand-silt-clay, pH 7.2, O.M. 0.7%). Spinach ‘Meerkat’ was seeded, then sprinkler-irrigated to germinate seed Jan 13, 2025 on beds with 84 in. between bed centers and containing 30 lines of seed per bed. All irrigation water was supplied by sprinkler irrigation. Treatments were replicated four times in a randomized complete block design. Replicate plots consisted of 15 ft lengths of bed separated by 3 ft lengths of nontreated bed. Treatments were applied with a CO2 backpack sprayer that delivered 50 gal/acre at 40 psi to flat-fan nozzles.
Downy mildew (caused by Peronospora farinosa f. sp. spinaciae)was first observed in plots on Mar 5 and final reading was taken on March 6 and March 7, 2025. Spray date for each treatments are listed in excel file with the results.
Disease severity was recorded by determining the percentage of infected leaves present within three 1-ft2areas within each of the four replicate plots per treatment. The number of spinach leaves in a 1-ft2area of bed was approximately 144. The percentage were then changed to 1-10scale, with 1 being 10% infection and 10 being 100% infection.
The data (found in the accompanying Excel file) illustrate the degree of disease reduction obtained by applications of the various tested fungicides. Products that provided most effective control against the disease include Orondis ultra, Zampro, Stargus, Cevya, Eject .Please see table for other treatments with significant disease suppression/control. No phytotoxicity was observed in any of the treatments in this trial.
New automated/robotic ag technologies are coming out all the time. Ever wonder how they function in the “real world” and whether they are cost effective? Western Growers recently released a case study report on the economic impact of Carbon Robotics LaserWeeder on overall weeding costs. The study tracked expenses, productivity, and labor savings of the machine operating over one year on several thousand acres at two commercial farms, Braga Fresh and Triangle Farms. It is a well done, detailed study enriched by insightful comments and practical recommendations made by the farm managers responsible for machine operations. It’s an easy read and well worth the time for those interested in the economic and overall feasibility of laser weeding. Check it out hereby clicking the image below. I don’t want to be a spoiler, but I was surprised to learn that despite the initial high cost of the laser weeder ($1.2 million), overall weeding costs at both farms were reduced by about 40% (>$250/acre) in high-density organic crops such as spring mix and spinach.
Stay tuned. Western Growers plans to release five more automation technology case study reports within the next year. Upcoming reports include grower case studies experiences with automated weeding machines from Stout Industrial Technology, Inc. and Ecorobotix; and with autonomous ag platforms from Burro, GUSS Automation, and Bluewhite.
Fig. 1. Western Growers case study report on the economic impact of Carbon
Robotics laser weeding machine on weeding costs at two commercial leafy
green vegetable farms. Click here or on the figure to view. (Photo credit: The
Western Growers Center for Innovation & Technology)
There are many different types of pests that affect crops grown in Arizona. The three types of pests most often cited as the source of most problems are insects, diseases and weeds. These are the same types of pests that are cited as causing the major agricultural pest problems across the U.S. and worldwide. Graphs 1-3 illustrate, however, that the relative importance of these types of pest problems differ in Arizona from the rest of the U.S. and worldwide. In terms of pesticide use, worldwide herbicides accounted for 36% of total usage, insecticides 25%, and fungicides 10% and other 29% (nematicides, rodenticides, fumigants, bird, fish and aquatic pests). In the U.S., herbicides accounted for 44%, insecticides 10%, fungicides 6%, and other 40% of pesticide use. In Arizona, however, insecticides accounted for 58%, herbicides 17% and fungicides 12%. This is only an indirect measure of the relative importance of these three areas of pest management and may be heavily influenced by the amount of pesticides used. For instance, it is common to spray for insects five or more times per season while it is uncommon to spray for weeds more than twice. None the less, these graphs illustrate that weeds are the predominant pest problem in agricultural areas across the U.S. and worldwide.
We wanted to share the information above obtained from the PCA Study Guide Section VI prepared by our "amigo" Barry Tickes who is teaching the Applied Weed Science Class at the University of Arizona this semester.
Results of pheromone and sticky trap catches can be viewed here.
Corn earworm: CEW moth counts down in all traps over the last month; about average for December.
Beet armyworm: Moth trap counts decreased in all areas in the last 2 weeks but appear to remain active in some areas, and average for this time of the year.
Cabbage looper: Moths increased in the past 2 weeks, and average for this time of the season.
Diamondback moth: Adults increased in several locations last, particularly in the Yuma Valley most traps. Below average for December.
Whitefly: Adult movement remains low in all areas, consistent with previous years
Thrips: Thrips adult movement continues to decline, overall activity below average for December.
Aphids: Winged aphids still actively moving but declined movement in the last 2 weeks. About average for December.
Leafminers: Adult activity down in most locations, below average for this time of season.
