• Effects of foliar fertilizers and carbohydrates on alfalfa yields and quality during the summer slump period

      Rethwisch, Michael D.; Reay, Mark; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2003-09)
      Six treatments containing carbohydrates and/or fertilizer were applied to alfalfa shortly after cutting in July 2002 to help ascertain if foliar applied carbohydrates would be helpful in overcoming summer slump of alfalfa hay production in the desert southwest. No significant differences were noted for any treatment for yield or quality when compared with the untreated check, although a trend for increased quality from treatments was noted. Highest yielding treatment was DC34, which increased tonnage by less than 0.1 tons/acre compared with the untreated check. DC34 was also among the highest in alfalfa quality. Alfalfa treated with Amaze® had the highest quality, but no affect on yield. As applications were made when little green foliage was available, most of the applied treatments did not actually contact green tissue but brown/dessicated alfalfa tissue or bare soil. Applying treatments during the regrowth cycle when more foliage is available may result in improved results as suggested by the trends noted from this experiment's treatments, however further testing will be necessary to verify such results.
    • Evaluation of multiple-rate biosolid applications on Sudangrass yield

      Norton, Eric J.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2003-09)
      A field experiment was conducted during the 2003 growing season to evaluate the effect of multiple application rates of biosolids material on Sudan grass yield. Growers in the Mohave Valley region of the state have been using biosolids for the past several years principally as a source of nitrogen (N) and secondarily as a soil amendment. Mineralization rates vary widely based on environmental factors, in particular temperature and soil moisture. Little research been conducted in this particular growing region to refine recommended application rates. The objective of this study was to compare the typical agronomic rate that is currently recommended to several other rates and determine the effects on Sudan grass yield. Results showed that the current recommended application rates produced the greatest yield. However, due to space limitations and logistics, the study was laid out in large treated blocks and was not replicated. As such, definitive conclusions from results are difficult to draw.
    • Evaluation of various miticidal products for two-spotted spider mite, alfalfa caterpillar, and beet armyworm control in alfalfa

      Rethwisch, Michael D.; Griffin, Bradley J.; Grudovich, Jessica L.; Hawpe, Jessica; Bolin, Krystyl; Plemmons, Shirley; Hayden, Ben; Barron, Marlo; Lau, Alvin; Reay, Mark; et al. (College of Agriculture, University of Arizona (Tucson, AZ), 2003-09)
      "A number of products with miticidal activity were applied both in the spring and summer of 2002 to alfalfa in the Blythe, CA, area to evaluate their efficacy for twospotted spider mite (Tetranychus urticae) control. These two application periods differed in regards to presence of western flower thrips (Frankliniella occidentalis), a predator of spider mites. Western flower thrips populations were high in the spring but essentially absent during the period following the summer application, providing contrasting data for effects of western flower thrips interactions with many miticides for spider mite control. Miticides tested included those currently utilized for mite control in alfalfa hay production as well as a number of new and/or potential products for alfalfa hay. In the spring testing, most treatments had more spider mites than the untreated check at three days post treatment when western flower thrips were present and actively feeding on spider mites. Two fertilizer treatments that contained high amounts of sulfur also had more spider mites than the untreated check at three days post treatment, thought due to repellency of adult western flower thrips. Many of the treatments that had more spider mites than the check following the spring application are known to have thrips activity (Zephyr, Trilogy, Dimethoate, Lorsban, etc.). Fewer motile (adults and immatures, not eggs) spider mites than in the check were noted only from the Capture + Dimethoate 400, Capture, and the combination of the two Gowan numbered products (1528, 1549) at three days after treatment. Products that provided excellent (90%+) control throughout the duration of the summer part of the experiment included two numbered compounds from Gowan (1528 and 1549), Capture + Dimethoate 400, Danitol, Zephyr + Trilogy, and a numbered compound from Valent USA (V-1283). The wide disparity in the two data sets indicate that western flower thrips presence/absence should be considered as part of the decision making process for spider mite control. "
    • Irrigation scheduling on small grains using AZSCHED for Windows - Safford Agricultural Center, 2003

      Clark, Lee J.; Ellsworth, Keller F.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2003-09)
      The AZSCHED irrigation scheduling software was developed in the early 1990's to be used in a DOS environment on computers (1). Since it’s development it has been extensively used for irrigation scheduling on the Safford Agricultural Center. Changes in computer systems from DOS to Windows has made it imperative that a new Windows version of AZSCHED be developed. That version has been developed and is now in use at our location (2). This report covers the use of this software in scheduling irrigation for barley and wheat.
    • Preharvest control of broadleaf weeds in wheat

      Tickes, Barry; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2003-09)
      Nine herbicide treatments were evaluated for the control of mature nettleleaf goosefoot in durum wheat that was ten days from harvest. The only effective treatments were combinations of Glyphosate (Roundup Ultra Max and Touchdown) and Paraquat (Gramoxone). Applications of Aim, Gramoxone, and Glyphosate alone were ineffective.
    • Small Grains Variety Evaluation at Arizona City, Maricopa, and Yuma, 2003

      Ottman, Michael J.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2003-09)
      Small grain varieties are evaluated each year by University of Arizona personnel. The purpose of these tests is to characterize varieties in terms of yield and other attributes. Variety performance varies greatly from year to year and several site-years are necessary to adequately characterize the yield potential of a variety. A summary of small grain variety trials conducted by the University of Arizona can be found online at http://ag.arizona.edu/pubs/crops/az1265.pdf.
    • Spider mite management in spring alfalfa utilizing swather applied treatments, 2003

      Rethwisch, Michael D.; Grudovich, Jessica; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2003-09)
      An experiment was initiated utilizing a swather based sprayer to determine if miticides applied at cutting would be an effective control method of spider mites in low desert alfalfa hay. Two treatments (Trilogy, Trilogy + Kinetic) were applied the morning of May 23, 2003, to alfalfa with very high numbers of spider mites. Treatments had five replications, with plots sampled on June 2, 9 and 18. Data indicated a severe reduction in spider mite numbers as of June 2 in all treatments (including untreated) thought due to high temperatures experienced shortly after cutting that exceeded lethal thresholds for spider mite survival. Differences in treatments for spider mites or western flower thrips were not noted until June 18, when significantly fewer spider mites were noted in Trilogy treated plots than untreated check plots. Trilogy + Kinetic treatments resulted in numerically fewer spider mites than the untreated check on this sample date, but numerically more than Trilogy treatment.
    • Wheat response to pre-plant phosphorus at Safford Agricultural Center, 2001-03

      Clark, Lee J.; Ellsworth, Keller F.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2003-09)
      The 2003 study was a follow up of the 2001 and 2002 studies, but the major differences were the selection of a high quality durum wheat with values significantly higher that those seen in the previous two studies and the untreated check was eliminated and a higher level of phosphorous was applied. Treatments applied were 100, 200, 400 and 600 pounds of 16-20-0 planted with the seed through the grain drill. Phosphorus applied at planting improved yields with increasing application rates. In this study, the highest rate of application of phosphorus produced the highest profit.