• 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 Cochise County, Arizona, 1996

      Clark, L. J.; Carpenter, E. W.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Fourteen alfalfa varieties with fall dormancy ratings from 6 to 9 were tested in replicated small plot trials on the Kibler farm in Stewart District northwest of Willcox. The leading variety after two year of testing was DeKalb 189 with a dry matter yield of 8 tons per acre. Heat units with temperature thresholds of 77 °F and 40 °F are given for each cutting .
    • 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.
    • Barley and Durum Response to Phosphorus at Buckey, Maricopa, and Yuma, 1997

      Ottman, M. J.; Husman, S. H.; Tickes, B. R.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Soil tests were developed in the 1930's as a guideline for phosphorus fertilizer application. The phosphorus soil test for the calcareous soils in the Western U.S. is based on bicarbonate extraction and is often called the Olsen P method. Phosphorus fertilizer recommendations for small grains based on this test are remarkably similar across the Western states. Despite the availability of this test, its proven accuracy (93% in California), and its low cost ($1 /acre), most farmers in Arizona apply phosphorus fertilizer to their small grains crops without the benefit of a preplant soil test. The purpose of this study was to demonstrate the effectiveness of the soil test in predicting a response to phosphorus fertilizer. At Maricopa, the soil test P was 8.1 ppm, a variable response to P fertilizer was expected, and a variable response to P fertilizer was obtained. We were able to detect a response to P fertilizer at this site with only 1 out of 4 varieties, and the response averaged across varieties was 336 lbs /acre or a 6% increase. No response to P fertilizer was obtained on a commercial farm in Buckeye where the soil test P was 22 ppm and a response was not expected. At the Yuma-Mesa site, the preplant P level was also 22 ppm, and a yield increase of29% (1442 lbs /acre) was measured on barley even though a response was not expected. The soil on the Yuma -Mesa is 95% sand and perhaps the soil test for P needs to be adjusted for this soil type, but at the other sites tested, the current soil test recommendations for P seem to be accurate.
    • 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.
    • 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.
    • 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.
    • 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.
    • Effect of Soil Sunburst on Yield and Quality of First Year Alfalfa

      Rethwisch, Michael D.; Kruse, Michael D.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Soil Sunburst was applied at the rate of one quart per acre at two treatment levels (single vs. two applications, applied once per cutting) in irrigation water to a first year stand of CUF 101 alfalfa. Treatments were applied in the first irrigation after the previous cutting in May and June 1996. Treatments applied in May increased relative feed value by over 10% compared to the untreated check in the first cutting (June) after application. This increased alfalfa quality rating from fair to good which increased value of hay by approximately $14 /acre. Mean yields between the treatments and untreated plots were similar, although average yields in untreated plots were 50-90 lbs /acre greater than in treated plots. Yields and quality data were not able to be obtained the second harvest (July), not allowing differences, if any, between one and two applications to be determined immediately after the second application. Yields and hay quality values for treatments in the August harvest were almost identical, indicating that treatment effects noted from the May application (and possibly those of the June application) were short term effects, as they did not continue through the August cutting.
    • 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.
    • 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.
    • Efficacy of Norflurazon for Nutsedge Control in Parker Valley Alfalfa

      Knowles, Tim C.; McCloskey, Bill; McGuire, Jerry; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Summer weeds such as nutsedge are of economic concern to alfalfa growers in western Arizona. A two year replicated evaluation of the effectiveness of granular norflurazon herbicide for purple nutsedge control was conducted on an established alfalfa field in La Paz County. Zorial Rapid 80 WP and Evital 5G herbicides were tested for their effectiveness at controlling purple nutsedge when applied following hay harvest but prior to irrigation in early spring and late summer. Zorial 80 WP was applied at 2.0 lb a. i. /acre. Evital 5G was applied in spring 1996 at application rates of 1.0, 1.5, 2.0, and 3.0 lb a. i. /acre. Split applications were made the following summer to four plots for a total of 2.0, 3.0, and 4.0 lb a. i. /acre/year. In 1996, purple nutsedge control resulting from a single application of Evital 5G at 2.0 lb a. i. /acre was 41, 82, and 35% at 35, 63, and 99 DAT, respectively. However, Zorial 80 WP applied at 2.0 lb a. i. /acre provided poor purple nutsedge control due to poor soil incorporation since the liquid was unable to penetrate the dense nutsedge foliage. The treatments were reapplied in spring and summer of 1997.
    • 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.
    • 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.
    • 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.
    • Influence of Folocron Nitrogen Fertilizer Applied in Summer on Alfalfa Yield During Summer Slump

      Knowles, Tim C.; Ottman, Michael J.; Wakimoto, Victor; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 1997-10)
      Established alfalfa reportedly does not benefit rom applications of N fertilizer since it is a leguminous crop that is capable of fixing its own N from atmospheric N. Some growers feel that nitrogen (N) fixing nodules found on the roots of the alfalfa plant are ineffective during Arizona's hot summers . Thus, N fertilizer is sometimes applied in early summer to established alfalfa to enhance growth and possibly delay or lessen the severity of summer slump to increase alfalfa tonnage. A field experiment was conducted to determine the effect of inorganic and controlled release N fertilizer applied in summer on alfalfa hay yield at the first cutting during summer slump. Three treatments consisted of an unfertilized check plot, broadcast 18-46-0 applied at 27 lbs. N /acre, and Folocron water run at a rate of 30 lbs. N /acre in August to three year old 'CUF 101' alfalfa grown on a silt loam soil. Maximum alfalfa hay yield at the September cutting (0.91 ton/acre) was obtained without N fertilizer application.
    • 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.
    • 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.