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.
Hi, I’m Chris, and I’m thrilled to be stepping into the role of extension associate for plant pathology through The University of Arizona Cooperative Extension in Yuma County. I recently earned my Ph.D. in plant pathology from Purdue University in Indiana where my research focused on soybean seedling disease caused by Fusarium and Pythium. There, I discovered and characterized some of the first genetic resources available for improving innate host resistance and genetic control to two major pathogens causing this disease in soybean across the Midwest.
I was originally born and raised in Phoenix, so coming back to Arizona and getting the chance to apply my education while helping the community I was shaped by is a dream come true. I have a passion for plant disease research, especially when it comes to exploring how plant-pathogen interactions and genetics can be used to develop practical, empirically based disease control strategies. Let’s face it, fungicide resistance continues to emerge, yesterday’s resistant varieties grow more vulnerable every season, and the battle against plant pathogens in our fields is ongoing. But I firmly believe that when the enemy evolves, so can we.
To that end I am proud to be establishing my research program in Yuma where I will remain dedicated to improving the agricultural community’s disease management options and tackling crop health challenges. I am based out of the Yuma Agricultural Center and will continue to run the plant health diagnostic clinic located there.
Please drop off or send disease samples for diagnosis to:
Yuma Plant Health Clinic
6425 W 8th Street
Yuma, AZ 85364
If you are shipping samples, please remember to include the USDA APHIS permit for moving plant samples.
You can contact me at:
Email: cdetranaltes@arizona.edu
Cell: 602-689-7328
Office: 928-782-5879
Our newly constructed self-propelled steam applicator is designed to inject steam into the soil and raise soil temperatures to levels sufficient to kill weed seed and soilborne pathogens (140°F for > 20 minutes). After the soil cools (< ½ day), the crop is planted into the disinfested soil. We have done some preliminary testing and are very encouraged. Results show that the machine is able to reach target temperatures at reasonable travel speeds, provide uniform temperature distribution across the bed and form nicely shaped beds suitable for subsequent planting. We still have some bugs to work out and identified improvements to make before shipping the unit to Salinas, CA where we will conduct field trials with crops this summer. If you are interested in seeing the machine operate or more information about soil steaming for soilborne pest control, please feel free to contact me.
Check out a video of the machine operating by clicking here or on the image below.
Fig. 1. Initial testing of self-propelled steam applicator video.
Acknowledgements
This project is sponsored and funded in part by the Propane Education and Research Council (PERC), Arizona Specialty Crop Block Grant Program and USDA-NIFA. We greatly appreciate their support.
These types of herbicides are also called contact herbicides. PPO inhibitor means they slow down the production of the protoporphyrinogen oxidase (PPO) enzyme, which is used in chlorophill production. This inhibition also results in the formation of highly reactive molecules that attack and destroy lipids and protein membranes which ultimately affect cell membranes. This result in leaky cells and disintegration of the tissue.
Goal (Oxyfluorfen) is one of the earliest registered of these products (1980) but has only been used widely over the about the last 16 years. This is the only one of these that has problems with “lift off” or codistillation with water. (1)
According to University of CA IPM “In dry bulb onions, GoalTender may be tank-mixed with other pesticides such as bromoxynil, but tank mixes must only be used on older onions with well-developed cuticles to avoid unacceptable crop injury. Unacceptable injury may occur if applied to small onions without adequate cuticle development, and in conditions such as after cloudy or rainy weather. Follow the label closely to avoid crop injury when tank mixing.
Oxyfluorfen has some residual soil activity after application. It controls small broadleaf weeds, some grasses, and nightshade, and controls little mallow (cheeseweed) well ”. (1)
Other PPO herbicides are: Aim or Shark, Chateau, Sharpen or Treevix, ET, and Spartan. They work as contact herbicides and do not move through the plant.
Most of these products don’t have preemergence activity but when used at higher rates Goal and Chateau do.(2) As the plant emerges from the soil and contacts the herbicide it dies, so it is recommended to avoid disturbing soil after the application of these products.
This week in Yuma oxyfluorfen uses:
References
This time of year, John would often highlight Lepidopteran pests in the field and remind us of the importance of rotating insecticide modes of action. With worm pressure present in local crops, it’s a good time to revisit resistance management practices and ensure we’re protecting the effectiveness of these tools for seasons to come. For detailed guidelines, see Insecticide Resistance Management for Beet Armyworm, Cabbage Looper, and Diamondback Moth in Desert Produce Crops .
VegIPM Update Vol. 16, Num. 20
Oct. 1, 2025
Results of pheromone and sticky trap catches below!!
Corn earworm: CEW moth counts declined across all traps from last collection; average for this time of year.
Beet armyworm: BAW moth increased over the last two weeks; below average for this early produce season.
Cabbage looper: Cabbage looper counts increased in the last two collections; below average for mid-late September.
Diamondback moth: a few DBM moths were caught in the traps; consistent with previous years.
Whitefly: Adult movement decreased in most locations over the last two weeks, about average for this time of year.
Thrips: Thrips adult activity increased over the last two collections, typical for late September.
Aphids: Aphid movement absent so far; anticipate activity to pick up when winds begin blowing from N-NW.
Leafminers: Adult activity increased over the last two weeks, about average for this time of year.
