Ground water has traditionally been considered safe for human consumption without treatment. However, it is an increasingly significant cause of human disease. Although ground water accounts for only approximately 20% of the nation's water supply, over 50% of the waterborne disease outbreaks in the United States are due to the consumption of contaminated ground water. It has been estimated that 65% of the cases of illness in these outbreaks are caused by enteric viruses. Little, however, is known about the persistence of viruses in ground water. The purpose of this study was to try to determine the chemical, physical, and biological factors influencing virus survival in ground water. This information will be helpful in developing criteria for determining safe distances between drinking water wells and sources of potential contamination such as septic tanks and waste application sites. Ground water samples were obtained from eleven sites throughout the United States. In addition, twenty samples were collected from the Tucson basin. The water temperature was measured at the time of collection. Several physical and chemical characteristics (including pH, nitrates, turbidity, and hardness) were determined for each sample. Separate polypropylene tubes containing 50 ml of water were inoculated with each of three viruses: poliovirus-1, echovirus-1 and MS-2 coliphage. Duplicate tubes containing water which had been filtered to remove the indigenous bacteria were also inoculated with viruses. The tubes were incubated at the in situ ground water temperature; selected samples were incubated at two additional temperatures. One-ml subsamples were withdrawn at predetermined intervals over a 30-day period and assayed to determine the number of microorganisms remaining. Multiple regression analysis revealed that temperature was the only water characteristic significantly correlated with the decay rates of all three viruses. Bacteria did not have a consistent effect on the decay rate of the viruses. In addition, no significant differences were found among the decay rates of the three viruses, suggesting that MS-2 coliphage may be able to be used as a model of animal virus behavior in the environment.

This study identifies the historical factors that impacted Pima agriculture, water use and water rights in south-central Arizona between 1848 and 1921. Federal land and resource policies, especially federal Indian policies, impacted the dynamics of Pima agriculture and water use during these crucial years when the federal government utilized economic liberalism to open the West to homesteading and facilitate the development of the region's vast resources.As an agricultural people, the Pima did not passively accept these policies and events. Rather, they proved adaptive, demonstrating their resourcefulness in important ways. In response to water deprivation and infringement of their water rights, the Pima reduced the amount of land they cultivated. While before 1880 they had increased their cultivated acreage and expanded their trade networks, in the years after they creatively found ways to keep land in production despite water shortages. As the water crisis deepened, the Pima abandoned their least productive lands. In the midst of great deprivation, they relocated (or abandoned) a number of villages and scores of fields in an attempt against great odds to maintain their agricultural economy. To make the most of their diminishing water resources, the Pima adapted by growing small grains such as wheat and barley, even when these crops no longer proved to be economically viable in Arizona. While not new to their crop rotation, the Pima relied almost exclusively upon these crops by the 1910s since they required considerably less water than others.Because the Pima had prior and paramount rights to the water and were wrongfully deprived of their rights to the use of water, their water rights struggle raised a metaphorical Damoclean sword above the heads of those non-Indian farmers who used the water. This study, therefore, focuses on the history of water use and agricultural production among the Pima Indians between 1848 and 1921 and argues that without infringement of their rights to water, the Pima would have equaled and perhaps surpassed the local agricultural economy.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

A feasibility study of short season management in Pima cotton, using short season genotypes, was initiated in 1993. Four short season genotypes, a full season check, and a short season check were evaluated in replicated tests under short season and full season regimes. In this first preliminary year of data, no significant yield loss could be attributed to management regime or to earliness of genotypes. Three of the putative early maturing genotypes exceeded the full season Pima S-7 check in yield. Results were contrary to expectations. The short season test is planned for repeat in 1994. An investigation of a virescent mutant discovered in 1990 (CM-1-90) was conducted in 1991, 1992, and 1993. Crosses of the mutant to Pima S-6 to determine inheritance, and to various virescent mutants to determine allelism produced results which were anamolous to normal, nuclear inheritance. Reciprocal crosses to PS-6 and to various virescent mutants confirmed that the new mutant was cytoplasmicaly inherited.

Pima experimental strains P73, P75, P76, P77, and the cultivars Pima S-6 (PS-6) and Pima S-7 (PS-7) were grown in replicated regional tests at twelve locations across the Pima belt in 1993. Tests were machine harvested for yield determination, plant heights were measured, and lint samples were collected for fiber analysis. Considerable genotype by environment interaction for yield potential occurred across tests in 1993. Across all locations, the strain P76 ranked first in yield followed by the cultivar PS-7 and strain P75. Strains P73 and P76 produced fiber of equal or greater length, strength, and elongation than PS-7. Plant heights were greatest for the entries PS-6 and P75. Entries PS-7 and P73 were intermediate in height, while P76 and P77 were the shortest of the entries tested. Considering yield and fiber properties concurrently, P76 was the superior entry of the 1993 tests.

Twelve Pima varieties and experimental strains were grown in a replicated trial at the Maricopa Agricultural Center. Lint yield, boll size, lint %, gin turnout %, plant population and fiber property data are presented in this report.

Sixteen long staple cotton varieties (including 4 Pima experimental lines) were tested in a replicated small plot trial on the Safford Agricultural Center. Plots were machine harvested twice to determine yield and percent first pick Small hand samples were taken to determine boll size, percent lint turnout and fiber qualities. Pima S-6 was the highest yielding variety with 1110 pounds per acre of lint. Five of the sixteen varieties yielded over 2 bales per acre. A new variety OA 312 looks particularly promising with yield very close to S-6, fiber quality better than S-6 and an earliness that approaches that of S-7.

A short season feasibility study, using early maturing Pinta genotypes was conducted for a second season. Four early maturing genotypes, a short season check (P62) and a full season check variety (PS-7) were evaluated in replicated tests under short season and full season regimes. In both 1993 and 1994, most genotypes reached cutout around August 4, with 2759 accumulated heat units. All genotypes were earlier maturing than PS-7, as indicated by plant growth measurements and by sequential harvests. In 1994, the four early maturing experimental genotypes produced yields equal to or slightly better than the longer season cultivar PS-7. No differences in yield occurred between the short season and standard practice management systems in either year. A fiber improvement project was initiated in 1989 with the primary goals of increasing the fiber length and strength potential of Pima cotton. In 1989 the early maturing, short statured Pima strain P62 was crossed to Giza 45 and Giza 70 to transfer the fiber strength of those varieties into a heat tolerant, earlier maturing, productive Pima background. Likewise, P62 was crossed to the Sea Island cultivar St. Vincent V-135 with the objective of transferring the latter cultivar's long fiber length into an agronomic Pima background. Two resulting lines, one possessing high fiber strength and the other possessing high fiber length are planned for release in 1995-96.

Ten long staple varieties (including two Pima experimental lines) were tested in a replicated small plot trial on the Safford Agricultural Center in Graham county at an elevation of 2950 feet. Even though the total number of heat units received during the season was nearly as high as the previous year, the average yield was nearly 300 pounds per acre lower. Olvey and Associates OA 304 was the highest yielding variety with a yield of 776 pounds per acre of lint and only two varieties broke the bale and a half mark. Yield and other agronomic data as well as fiber quality data are contained in this paper.

Nine Pima varieties and experimental strains were grown in a replicated trial at the Maricopa Agricultural Center. Lint yield, boll size, lint percent, plant population and fiber property data are presented in this report.