• Feed Quality of Common Summer Grass and Broadleaf Weeds in Alfalfa Hay

      Knowles, Tim C.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Late summer grassy weed control is a questionable practice since it reduces alfalfa hay tonnage during summer slump, and the reduction in hay feed quality caused by these weeds in horse hay is questionable. A field experiment was conducted at the September alfalfa cutting to examine the feed quality of grassy and broadleaf weeds found in western Arizona hay fields at this time which corresponds with annual summer slump. These weeds included bermudagrass, junglerice (watergrass), Mexican sprangletop, Johnsongrass, purple nutsedge, and common purslane. Since hay cut during this period is used primarily for dry dairy cow and horse hay this study examined the suitability of alfalfa hay infested with these summer weeds as a feed for these animals. Based on this study, horse owners could benefit financially if they waited until late summer when hay prices slump, and purchase off-grade alfalfa hay containing less than one half grassy summer weeds for an economical, nutritious feed source.
    • Evaluation of Jojoba Clones at Two Locations in Arizona

      Nelson, J. M.; Palzkill, D. A.; Hart, G. L.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Little information is available to the jojoba industry on the performance of clones selected from superior female plants. Nineteen jojoba clones from the U.S., Chile and Australia were planted in the spring of 1995 in replicated tests at the University of Arizona Maricopa and Citrus Agricultural Centers. The Maricopa location is being used to evaluate clones for cold hardiness and the Citrus Farm location will provide growth and production comparable to commercial growing areas in Arizona. The planting at Maricopa was evaluated for frost damage following the 1995-96 and 1996-97 winters which had temperatures low enough to injure foliage and kill flower buds. The Citrus Farm had milder winter temperatures and seeds were produced in 1996 and 1997. In order to determine seed yield potential of jojoba clones it is necessary to measure yields for at least five years after planting.
    • Efficacy of Imazameth (Cadre) for Nutsedge Control in Parker Valley Alfalfa

      Knowles, Tim C.; McGuire, Jerry; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Summer weeds including purple nutsedge are of economic concern to alfalfa growers in western Arizona. Application rates of Cadre 2 ASU, a new sulfonylurea herbicide chemistry currently registered for experimental use in peanuts, for purple nutsedge control in a roadway bordering established alfalfa were examined in a two year duration, replicated field study. Fair to good (35- 65%) purple nutsedge control was obtained when Cadre was applied at the 3 oz/acre rate to a severe initial nutsedge infestation (80- 100%). Control was most effective when Cadre was applied in late summer compared to early spring, and repeat split applications were necessary under the high weed pressure observed in this study.
    • Irrigation Scheduling on Barley at the Safford Ag Center, 1997

      Clark, L. J.; Carpenter, E. W.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      An irrigation study on barley was made to determine the economical consequences of irrigating the crop when an irrigation scheduling program called for an irrigation compared to waiting 3 to 6 days for a water turn, from the ditch. The plots irrigated when the soil moisture depletion level reached 40% produced the highest yield. Yields were decreased 700 and 1000 pounds respectively for waiting 3-4 days and 6-7 days, respectively. The economics of using the pump are discussed and a chart is given to help determine a break - even point.
    • Bermudagrass Control in Alfalfa Using Clethodim (Prism) and Two Formulations of Sethoxydim (Past Plus, Ultima)

      Husman, Stephen H.; McCloskey, William B.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Two successive applications of Poast Plus (60 oz. product /A, 0.47 lb. sethoxydim /A), Ultima 160 (46 oz. product /A, 0.47 lb. sethoxydim /A), and Prism (34 oz. /A, 0.25 lb clethodim/A) were made on May 31 and June 27, 1996 to control bermudagrass (Cynodon dactylon) in a commercial alfalfa field. A crop oil concentrate was added to all herbicide solutions. Applications were made two days after the irrigations that followed removal of the cuttings. The bermudagrass density was high with extensive stolon development; the grass formed almost a complete mat in most of the plots. Percent control was visually estimated on June 27 (prior to second application) and on July 25, 28 days following the second application and after cutting of the alfalfa. Percent control was 84.5, 71.2, and 65% for Poast Plus, Ultima, and Prism, respectively, after one application. Percent control was 87.5, 72.5, and 90.5% for Poast Plus, Ultima, and Prism, respectively, after two applications. A single application of Poast Plus resulted in good bermudagrass control but single applications of Ultima or Prism resulted in marginal control. The second application of Prism significantly improved bermudagrass control but the second application of Poast Plus or Ultima did not improve control. The Poast Plus formulation of sethoxydim appeared to be superior to the Ultima 160 formulation of sethoxydim.
    • Overview of Alfalfa Production and Market Trends in La Paz County

      Knowles, Tim C.; Winans, S. Sherwood; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Alfalfa producers in the Colorado River region of La Paz County have experienced some shifting trends in markets and production over the last 15 years. Acreage has increased steadily from a low of 25,000 acres in the early 1980's to a high of nearly 45,000 acres in 1997. Average annual alfalfa hay yields in La Paz County have maintained a fairly flat trend ranging from 7.5 to 8.5 tons per acre during this time. Alfalfa hay prices were severely depressed during the summer of 1986, from summer of 1991 through winter of 1992, and during the summer of 1995. In contrast, La Paz County alfalfa hay producers experienced the strongest markets during the winters of 1984, 1990, and 1995. More recently, since the winter of 1996, producers have experienced the strongest alfalfa hay market in the history of La Paz County with on farm prices reaching an all time high of $136 per ton.
    • Effects of Dry Seed+ Applied at Planting on Alfalfa Yield and Quality

      Rethwisch, Michael D.; McGuire, Steven; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      This experiment tested the effects of a cytokinin containing product (Dry Seed +) on CUF 101 alfalfa when applied with the seed at planting on October 24, 1996, at the rate of 1 /lb product to 100 lb of alfalfa seed. Data indicated a non - statistical yield response averaging 200 lbs an acrefrom treated fields the first cutting, valued at $11 /acre, but yields were identical the second harvest. Alfalfa quality means were very similar for both harvests. A positive net return of $9.76 /acre was noted by using Dry Seed +. More testing is suggested to confirm these findings.
    • 1995-1997 Alfalfa Yields of Five Varieties Planted October 1994 on the Colorado River Indian Tribes Reservation

      Rethwisch, Michael D.; Baldwin, Bill; Baldwin, John; Leivas, Danny; Kruse, Michael; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      This report covers the first 2.5 years of production of five alfalfa varieties (CUF 101, SW 14, SW8210, Pioneer 5888, and a grower selection originating from CUF 101 and noted as Baldwin Select) that were planted in October, 1994, into large plots (0.75 acres) to obtain actual field harvest data. Data are reported from 22 harvests thus far in the study, including five from 1997. Varietal hay yields were very similar in 1995 until mid summer, when area soil temperatures reached above 100°F at the four inch depth for a period of about 6 weeks. During the summer months of 195 -1996 Baldwin Select had significantly higher yields than other varieties tested. Statistical differences in accumulated hay yields were noted beginning in August 1995 and have continued. during 1996. Baldwin Select has the highest yielding variety each year thus far, producing 8.8% more than CUF 101, worth $233 /acre. Alfalfa varieties have been very similar in relative feed value when tested. Yellowing from Empoasca spp. leafhoppers was greatest during the 1995 -1996 winter on varieties with fall dormancy ratings of 9 or greater. Weed infestations during late summer 1996 appear to be inversely correlated with fall dormancy, for which Baldwin Select significantly higher than CUF 101.
    • Alfalfa Hay Yields for Two Years of Eight Varieties Planted in February 1995 on the Colorado River Indian Tribes Reservation

      Rethwisch, Michael D.; Sokiestewa, Hipkoe; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Eight alfalfa varieties were evaluated for forage production during 1995 and 1996 following a Feb. 1995 planting. DK 189 yielded the most tonnage in both years of production (104.4% of CUF 101) and Mecca II the least amount (95.9% of CUF 101). Although five varieties had higher yields than CUF 101 during the second year of production, only DK 189 and WL 525 HQ averaged higher yields than CUF 101 for the two year duration of this study.
    • Alfalfa Variety Performance at Maricopa, 1995-97

      Ottman, M. J.; Smith, S. E.; Fendenheim, D.; Parsons, D. K.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
    • Alfalfa Variety Trial in Graham County, Arizona, 1996

      Clark, L. J.; Carpenter, E. W.; Cluff, R. E.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Twenty four alfalfa varieties with Fall Dormancy ratings of 8 or 9 were tested in a replicated small plot trial on a heavy clay loam soil on the Safford Agricultural Center. This was the first year of a new study and there were some difficulties caused by irrigation management on the heavy soil. Pioneer 5888 was the highest yielding variety with a yield just over 9 tons per acre in 6 cuttings. Heat units with thresholds of 77 F and 40° F are included for each cutting in the study.
    • Intensive Cereal Management for Durum Production, Buckeye and Yuma, 1996-97

      Ottman, M. J.; Husman, S. H.; Tickes, B. R.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      The highest wheat yields in the world are obtained using a growing system called intensive cereal management (ICM). High yielding varieties are planted at high seeding rates, treated with foliar fungicides, plant growth regulators are applied to control lodging, and high nitrogen fertilizer rates are used to obtain high yields. The ICM system adapted to Arizona does not include fungicide treatments due to our lack of leaf diseases. We tested the effect of ICM on yield, grain protein, and other characteristics at three commercial farms in Arizona. ICM resulted in higher protein in one case due to increased nitrogen application and reduced height in another case due to the plant growth regulator. However, in most cases, we were not able to detect an affect of ICM on the crop, and the increased input cost was not paid for by increased crop performance. Intensive cereal management does not appear to hold much promise under our conditions except perhaps in cases where lodging is predictable or yields do not reach their potential.
    • Use of Agrotain to Prevent Urea Volotilization in Irrigated Wheat Production, Casa Grande 1996

      Ottman, M. J.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
    • Late Season Water and Nitrogen Effects on Durum Quality, 1996

      Ottman, M. J.; Doerge, T. A.; Martin, E. C.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Durum grain quality is affected by many factors, but water and nitrogen are factors that the grower can control. The purpose of this research was to determine 1) the nitrogen application rate required at pollen shed to maintain adequate grain protein levels if irrigation is excessive or deficient during grain fill and 2) if nitrogen applications during grain fill can elevate grain protein. Field research was conducted at the Maricopa Agricultural Center using the durum varieties Duraking, Minos, and Turbo. The field was treated uniformly until pollen shed when nitrogen was applied at rates of 0, 30, and 60 lbs /acre. During grain fill, the plots were irrigated based on 30, 50, or 70% moisture depletion. In a separate experiment, nitrogen fertilizer was applied at a rate of 30 lbs N /acre at pollen shed only, pollen shed and the first irrigation after pollen shed, and pollen shed and the first and second irrigation after pollen shed. Increased irrigation frequency during grain fill decreased HVAC from 93 to 81%. Increasing nitrogen rate at pollen shed from 0 to 30 and 30 to 60 lbs N /acre increased protein from 11.6 to 12.5% and 12.5 to 13.3% and increased HVAC from 79 to 89% and 89 to 94 %. Nitrogen fertilizer application at the first irrigation after pollen shed increased grain protein content from 12.9 to 13.6% and application at the first and second irrigation after pollen shed increased grain protein content further to 14.1% averaged over varieties. Nitrogen fertilizer application during grain fill may not be too late to increase grain protein content.
    • Barley and Durum Response to Seeding Rate at Maricopa and Yuma, 1996-97

      Ottman, M. J.; Tickes, B. R.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      A poor stand as a result of a low seeding rate can cost the grower due to decreased yield potential. A seeding rate higher than optimum can also cost the grower not only due to increased seed cost but also due to increased susceptibility to water and nitrogen stress and frost damage. Seeding rates in small grains are usually expressed on a pound per acre basis, but since varieties differ in seed size, different amounts of seed can be planted at equivalent seeding rates. Defining optimum seeding rates are also complicated by the fact that the number of seeds that actually emerge can vary depending on planting conditions. In our studies, emergence varied from 50 to 100% emergence. At the Maricopa location, the optimum seeding rate was obtained with 12 seedlings per square foot, which corresponded to a seeding rate of 75 lbs /A for the small seeded Brooks wheat and 125 lbs seed /A for the large seeded Kronos durum. No differences in yield were detected at the Yuma Mesa location for barley seeding rates ranging from 75 to 150 lbs seed/A or at the Yuma - Valley location for durum seeding rates from 200 to 250 lbs seed/A. Growers generally seed at rates higher than the optimum suggested by this and other studies, but current commercial seeding rates are seen as cheap insurance against stand establishment problems and may or may not be warranted depending on seedbed conditions and percent emergence.
    • Hay Yield and Quality of Sudangrass and Sorghum-Sudangrass Hybrid Varieties Grown for Export from Western Arizona

      Knowles, Tim C.; Ottman, Michael J.; Lloyd, Jim; Quist, Aron; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Two common sudangrass varieties (Piper and Sweet Sudan), four sudangrass hybrids (NK Trudan 8, Cargill HS 35, NC+ 200, and Germaine 's G 555), and three sorghum - sudangrass hybrids (DK SX 17, TE Haygrazer II, and Pioneer 877F) were evaluated for hay yield and quality at four cuttings in large field plots located at Quail Mesa Farms in southwest La Paz County. Results from four hay cuttings at one location are presented showing that of the nine sudangrass varieties examined in this study, Piper, NC+ 200, and Germaine 's G 555 sudangrass varieties had superior hay tonnage and quality.
    • Comparisons of Lorsban 4E and Spinosad 4SC for Control of Summer Insects in Alfalfa

      Rethwisch, Michael D.; Kruse, Elizabeth; Kruse, Michael D.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Anew chemistry (Spinosad 4SC) was tested for control of beet armyworm and other summers insects in alfalfa. This product did not control beet armyworms as well as the top of label rate of Lorsban 4E, and at one day post treatment had more beet armyworms than the lowest rate of Lorsban tested At three days post treatment both rates of Spinosad 4SC had fewer beet armyworms than the lowest rate of Lorsban tested. Few differences were noted between Spinosad 4SC for beet armyworm control, although fewer alfalfa caterpillars were noted with usage of the higher Spinosad rate, although significantly more beneficial insects were noted at three days post treatment with the lower rate of Spinosad. Lorsban chemistries significantly lowered yellows and hopperburn damage ratings compared with other treatments and a difference was noted between the two Spinosad rates although Empoasca sp. leafhopper numbers were similar.
    • Barley Variety Trial on the Safford Agricultural Center, 1997

      Clark, L. J.; Carpenter, E. W.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Sixteen varieties of barley were tested at the Safford Agricultural Center in 1997. Nebula, a new variety from Western Plant Breeders, was the highest yielding variety in the trial with a yield over 5100 pounds per acre. Nebula also had the highest bushel weight of the varieties tested.
    • Kenaf Varietal Evaluation in the High Desert of Southeastern Arizona

      Clark, L. J.; Carpenter, E. W.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Several Kenaf varieties have been grown at the Safford Agricultural Center over a period of 5 years. Plants harvested green have produced yields in excess of 40 tons per acre. Air dried stems that would be useful for commercial products have yielded as high as 9.5 tons per acre and two varieties, Tainung 2 and Everglades 71, have averaged nearly 7 tons per acre. In addition to yields and other agronomic values of the varieties tested, an economical discussion is made on the feasibility of Kenaf production on southeastern Arizona.
    • National Dry Bean Nursery Summary, 1992-95

      Clark, L. J.; Carpenter, E. W.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      A yield summary of selected varieties from the National Dry Bean Nursery from 1992 to 1995 are contained in this paper. Average and individual yields vary from year to year depending on the planting dates and the weather of the given year. Looking at a four year average for a variety gives a better estimate of its yield potential than any single year study.