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  National Dry Bean Nursery Trials in Bonita, 1997

  Clark, L. J.; Carpenter, E. W.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  Results of the 1997 National Cooperative Dry Bean Nursery Trials are reported in this paper. Thirty five varieties of seven different classes of beans were included in this replicated, small plot trial. Ole, a variety from Ag Canada was the highest yielding variety in the study with a yield over 4800 pounds per acre. Both Ole and ISB 2001 had yields higher than Bill Z, the highest yielding pinto bean in the area. Four varieties had yields over the 4000 pound per acre level. Yields, seed per pound, aerial biomass, harvest index, plant population and percent splits are also reported.
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  Kenaf Varietal Comparisons at the Safford Agricultural Center, 1996-97

  Clark, L. J.; Carpenter, E. W.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  Growing conditions for Kenaf were not as favorable in 1997 as in 1996 lowering the highest yield to less than 5 tons per acre. The highest yielding variety, C118-92K, was also the highest yielding variety in 1996.
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  Winter Forage Cover Crop Trials

  Munda, Bruce; Knowles, Tim C.; Meen, Art; Wakimoto, Vic; Worthy, Bill; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  Several crops were evaluated at Worthy farms, near Marana, AZ, Wakimoto farms, Mohave Valley, near Bullhead City, AZ, and the Tucson Plant Materials Center for use as a winter cover crop following cotton with potential to reduce wind erosion and produce one to two hay cuttings. Hairy vetch (Vicia villosa), 'Lana' woolypod vetch (Vicia villosa ssp. varia), 'Papago' pea (Pisum sativum), and 'Biomaster' pea (Pisum sativum) were sown at the Tucson Plant Materials Center. Species sown at Worthy farm were: Papago pea, Lana vetch, and Biomaster pea. Species sown at Wakimoto farm were: Biomaster pea, Lana vetch, 'Seco' barley (Hordeum vulgare), and 'Multi-cut' berseem clover (Trifolium alexandrinum). Forage yield varied between locations due to sowning date, number of irrigations, and soil textures. Biomaster pea, Papago pea, and Lana vetch performed well at all three locations. However, Biomaster yields were more consistent and due to its shorter growing season may be the better choice as a winter cover between cotton crops. Additional trials are scheduled for the fall of 1998.
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  Planting Date and Sorghum Flowering at Maricopa, 1997

  Ottman, M. J.; Husman, S. H.; Gibson, R. D.; Rogers, M. T.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  A study was conducted at the Maricopa Agricultural Center to determine the influence of planting date on time to flowering of sorghum hybrids. Sorghum was planted on March 19, April 16, May 14, June 18, July 2, July 16, and July 30. A total of 17 sorghum hybrids varying in maturity groups from early to late were planted at each date. The number of days from planting to flowering was greatest at the March 19 planting date and decreased with each planting date thereafter. Growing degree days required to reach flowering likewise decrease as planting was delayed. In order to avoid the heat during pollination in the early part of the summer, early to medium maturity hybrids need to be planted in mid-March at Maricopa. July planting dates resulted in flowering occuring in late August and September.
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  Grain Sorghum Hybrid Evaluation at Gila Bend, Marana, and Maricopa, 1997

  Ottman, M. J.; Husman, S. H.; Gibson, R.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)
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  Corn Hybrid Evaluations, Bonita, 1997

  Clark, L. J.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  Results of two field studies are reported in this paper. One study had six Bt corn hybrids and a non-Bt check, the other had six non-Bt hybrids (including 3 experimentals) and a non-Bt check. Pioneer 33A14 was the highest yielding hybrid in the Bt study with a yield of 14548 pounds per acre. Its yield was 1000 pounds per acre higher than the next Bt hybrid and nearly 2000 pounds per acre higher than Pioneer 3162, the non-Bt check. In the non-Bt study, a Pioneer experimental yielded 15405 pounds per acre, nearly 2000 pounds per acre higher than the next highest hybrid.
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  Evaluation of Puma (Fenoxaprop) for Littleseed Canarygrass Control in Durum Wheat in Central Arizona (1998)

  McCloskey, William B.; Husman, Stephen H.; Ottman, Michael J.; Department of Plant Sciences, University of Arizona, Tucson AZ; Pinal/Pima County Cooperative Extension, University of Arizona (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  A field experiment was conducted in 1998 to determine the efficacy of Puma and Hoelon for littleseed canarygrass control in durum wheat. The herbicide treatments consisted of three rates of Puma, 0.83, 1.24, and 1.66 oz a.i./A, and one rate of Hoelon, 6.8 oz a.i./A, that were applied at two application timings. The early-postemergence (EPOST) applications when canarygrass had 2.2 leaves per plant did not result in commercially acceptable control due to water stress. Increasing rates of Puma applied mid-postemergence (MPOST) when canarygrass had 5 leaves per plant provided increasing canarygrass control (70 to 90 %) with the two higher rates of Puma providing commercially acceptable control. The two highest rates of Puma also resulted in better weed control than the commercial standard, Hoelon, which did not provide commercially acceptable weed control. No herbicide injury symptoms were observed on the wheat at any of the evaluation dates. Grain yield also increased as the rate of Puma applied MPOST increased and yields overall reflected the degree of weed control observed earlier in the season. These data indicate that the combination of Puma applications that killed or stunted emerged canarygrass combined with later season crop competition that suppressed stunted and later emerging canarygrass plants was sufficient to protect grain yields. The highest yielding Puma treatment was equivalent to 4150 lb/A compared to the Hoelon and control treatments which yielded the equivalent of 2753 and 1946 lb/A, respectively.
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  Small Grains Variety Evaluation at Marana, Maricopa, and Yuma, 1998

  Ottman, M. J.; Rogers, M. T.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  Small grain varieties are evaluated each year by University of Arizona personnel at one or more locations. 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. The results contained in this report will be combined with results from previous years in a summary available from Arizona Cooperative Extension.
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  Small Grain Variety Trials Safford Agricultural Center, 1998

  Clark, L. J.; Carpenter, E. W.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  Small plot replicate trials were established to test ten barley varieties, twenty one durum wheat varieties and seven varieties of bread/feed wheat. Yields were exceptionally high in 1998 which were attributed to overall growing conditions for the plants. Gustoe was the highest yielding barley variety with a yield of 8412 pounds per acre, YU894-162 (Western Plant Breeders) was the highest yielding durum wheat with a yield of 7986 pounds per acre and RSI 5 (Resources Seeds Inc.) was the highest yielding feed wheat. These varieties yielded 1458, 966 and 713 pounds per acre more than the number two varieties for barley, durum wheat and wheat, respectively.
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  Row Spacing and Direction Effects on Yield, Water Use, Tillering and Light Interception of One-Irrigation Barley

  Ottman, M. J.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  The one-irrigation barley variety Solum is adapted to wide row spacing, and sometimes yields higher in wide compared to narrow spacing. This study was initiated to determine the effect of row spacing and direction on Solum water use and yield components. Solum barley was planted at the Marana Agricultural Center at 6, 12, 18, and 24 inch row spacings in north-south and east -west rows in late November and late -February or early March over 2 growing seasons. Row spacing and direction had little effect on yield and yield components, water use, tillering, and light interception. Nevertheless, in some instances narrow row spacing resulted in more heads that were smaller and had lighter kernels than wide row spacing. We measured greater soil water depletion for the narrow row spacings at the late planting date one year due to greater stem density. The narrow rows intercepted more light than wide rows and the wide rows intercepted more light at solar noon in east-west compared to north -south rows. We were not able to confirm the theory that soil water is conserved in wide rows for use at more critical stages later in the season.
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  Irrigation Scheduling on Barley and Durum Wheat at the Safford Agricultural Center, 1998

  Clark, L. J.; Carpenter, E. W.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  A study was done on durum wheat and barley to determine the economical consequences of irrigation scheduling. Delays of 3 days and 7 days were applied after AZSCHED software called for irrigations to similate a wait for water from the irrigation canal. Yields were reduced by the delays, but with the crop values reduced by the cost of irrigation no money was lost in delaying irrigations on the durum wheat and $8-9 per acre was lost on the barley.
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  Field-scale Demonstrations of the Timing of the Last Irrigation in Wheat

  Husman, S. H.; Ottman, M. J.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  The last irrigation of wheat can be applied at the soft dough stage or for a sandy loam soil according to crop water use calculations. The purpose of this study is to verify at what stage the last irrigation of wheat should be applied. Studies were conducted on 7 commercial fields where the last irrigation was applied at the soft dough stage or about 10 to 14 days after soft dough. Applying the final irrigation after the soft dough stage does not appear to increase yield on average according to the results of this study.
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  Durum Wheat Response to Pre-plant Phosphorus at Safford Agricultural Center, 1998

  Clark, L. J.; Carpenter, E. W.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  The economic effect of applying phosphorus at planting of durum wheat is directly correlated to the phosphorus that is available to the plants from the soil. For bicarbonate soluble phosphorus levels less than 6 ppm, there will likely be a positive economic effect from applying some phosphorus. At this site the soil phosphorus level was 4.8 ppm and the application of 200 pounds of 16-20-0 caused an increase in yield of 2101 pounds per acre. A cost of $23 per acre with a return of $168 per acre.
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  Influence of Ironite and Phosphorus on Yield of Oats and Content of Lead and Arsenic at Different Stages of Growth

  Eberhardt, P. J.; Clark, L. J.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  Ironite and phosphorus were applied to plots seeded to oats to find their effect on crop yield. The effects of both additives were positive, even though not statistically at the 90% level of confidence. The concern for lead and arsenic uptake by plants was also addressed as soil and plant samples were tested for these two elements. The results showed that no more arsenic nor lead were present in oat plants on Ironite plots than from check plots, as they approached maturity.
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  Developing Sap Nitrate Tests for Wheat and Barley, Maricopa, 1998

  Riley, E. A.; Thompson, T. L.; White, S. A.; Ottman, M. J.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  The standard procedure for determining nitrogen (N) status in small grains is to sample lower stem tissue for nitrate (NO₃) analysis. The tissues are then submitted to a laboratory for analysis. Sap nitrate (NO₃) can be analyzed in the field, immediately after collecting the sample, using a Cardy meter. Guidelines for sap analysis have not yet been determined. The objectives of this study were to: (i) correlate NO₃-N in dried stem tissue with sap NO₃-N, and (ii) develop sap NO₃ test guidelines for N management in durum and feed barley. In November 1997 one variety of durum (Kronos) and one variety of feed barley (Gustoe) were planted at the Maricopa Agricultural Center. Three N rates (80, 200, and 400 lbs N/acre) were applied in four split applications. Each treatment was replicated five times in a randomized complete block design. Samples were collected from lower stems at the 3-4 leaf 2 node, flag leaf visible, and heading growth stages. Grain yields ranged from 5185 lbs/A to 7156 lbs/A for Kronos and 6314 lbs/A to 7517 lbs/A for Gustoe. Maximum yields were achieved at 200 lbs N/A for both varieties. Correlation coefficients between stem NO₃-N and sap NO₃-N were 0.79 for Kronos and 0.84 for Gustoe. Sap NO₃-N analysis can be used to determine N status during the season for both Kronos and Gustoe.
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  Tissue Testing Guidelines for Nitrogen Management in Malting Barley, Maricopa, 1998

  Riley, E. A.; Thompson, T. L.; White, S. A.; Ottman, M. J.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  Malting barley is not a widely planted crop in the Southwest, due to grain protein contents that can sometimes exceed the industry standard of 11.4 %. To achieve < 11.4% grain protein, careful nitrogen (N) management is needed. Tissue testing guidelines for N management for reduced grain protein and acceptable yields have not yet been determined for malting barley in the Southwest. The objectives of this study were to: (i) correlate NO₃-N in dried stem tissue with sap NO₃-N, and (ii) develop stem NO₃-N guidelines for N management in malting barley. In November 1997 two varieties of malting barley, Morex and Crystal, were planted at the Maricopa Agricultural Center. Five N rates (0, 60, 120, 180, and 240 lbs/acre) were applied in four split applications. Each treatment was replicated three times in a randomized complete block design. Samples were collected from lower stems at the 3-4 leaf 2 node, and flag leaf visible growth stages. Grain yields ranged from 1765 lbs/A to 3439 lbs/A for Morex and 2104 lbs/A to 4274 lbs/A for Crystal. Grain protein ranged from 7.6- 10.5% (Morex) and 7.0- 10.7% (Crystal). Correlation coefficients between stem NO₃-N and sap NO₃-N were 0.80 for Morex and 0.84 for Crystal. For Morex and Crystal, grain protein was within the malting industry grain protein range of 10.5- 11.4% at 240 lbs N/A, and yield was optimized at 180 lbs N/A. Sap NO₃ analysis can be a useful tool for determining N status of malting barley. Stem NO₃-N concentrations at 180 lbs N/A were generally within the optimum range for NO₃-N in small grains.
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  Late Season Tissue Tests for Critical Grain Protein Content in Durum, Maricopa, 1998

  Riley, E. A.; Thompson, T. L.; White, S. A.; Ottman, M. J.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  Proper nutrient management is necessary for successful production of durum wheat in the desert. If grain protein content is less than 13 %, significant economic losses to growers can result. Late season nitrogen (N) fertilization can resolve this problem, but tissue test guidelines have not yet been established. The objectives of this study were to: (i) correlate NO₃-N in dried stem tissue with sap NO₃-N, (ii) determine the minimum NO₃-N concentration in lower stem tissue at heading associated with the critical grain protein content, and (iii) determine whether flag leaf head, or whole plant total N at heading can be used as indicators of N status. In November 1997 two varieties of durum wheat, Mohawk and Kronos, were planted at the Maricopa Agricultural Center. Five N rates (0, 100, 200, 300, and 400 lbs/A) were applied in four split applications. Each treatment was replicated three times in a randomized complete block design. Samples were collected from the lower stem, flag leaf head, and whole plant from each plot at heading and analyzed for total N. Grain yields ranged from 1663 to 6916 lbs/A for Mohawk and 1529 to 7060 lbs/A for Kronos. Maximum yields were achieved at 200 lbs N/A for both varieties. Grain protein content averaged 8.6% to 13.4% (Mohawk) and 9.1% to 13.8% (Kronos). Correlation coefficients between stem NO₃-N and sap NO₃-N were 0.96 for Mohawk and 0.97 for Kronos. Lower stem sap critical NO₃-N concentration in Kronos is 1100 ppm NO3 N and 1700 ppm NO₃-N for Mohawk at heading for a grain protein content of 13 %. Lower dried stem tissue critical NO₃-N concentration in Kronos is 5500 ppm NO₃-N and 7500 ppm NO₃-N for Mohawk for a grain protein content of 13 %. Nitrogen concentration in flag leaves, heads, and whole plants were highly correlated with N rate. Therefore, N concentration in these tissues could potentially be used as indicators of late-season N status.
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  Field-scale Demonstration of Prevention of HVAC Dockage in Kronos Durum by Late Season Nitrogen Application

  Husman, S. H.; Ottman, M. J.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  Grain quality is important to growers and buyers of durum. Growers are usually docked if their HVAC drops below 90% or their grain protein is below 13 %. The purpose of this study was to demonstrate the ability of nitrogen fertilizer application near flowering to increase HVAC and grain protein. Six commercial sites were chosen for this study and Kronos was the variety. The application of about 50 pounds of nitrogen per acre increased HVAC by from 81 to 93% and increased grain protein from 11.2 to 12.3% on average, similar to results obtained in the past.
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  The Use of Norflurazon (Zorial 5G) in Parker Valley Alfalfa for Purple Nutsedge Suppression in 1997-98

  Knowles, Tim C.; McCloskey, William B.; McGuire, Jerry; Ottman, Michael J.; La Paz County Cooperative Extension, University of Arizona, Parker, AZ; Department of Plant Sciences, University of Arizona, Tucson, AZ (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  Two experiments were conducted during 1997 -98 to study the use of norflurazon (Zorial 5G) for purple nutsedge control in alfalfa. In experiment 1, Zorial 5G was applied in spring 1996 and 1997 at application rates of 1.0, 1.5, 2.0, and 3.0 lb a.i./A. Split applications were made each summer in four of eight treatments for total annual Zorial 5G rates of 2.0, 3.0, and 4.0 lb a.i./A-year. In the fall of 1997, each plot was divided into two subplots. One set of subplots was disced twice and replanted with alfalfa. Alfalfa planted into these subplots was not affected by the residual soil concentrations of norflurazon. In the other set of undisturbed subplots, the residual soil concentrations of norflurazon continued to provide substantial suppression of purple nutsedge in 1998. However, by August 1998, the 3 lb a.i. /A -year rate only provided fair nutsedge suppression (51 %), while the 4 lb a. i. /A -year rate still provided satisfactory suppression (75 %). At rates of 2 lb a.i. /A-year or less, the residual effects of norflurazon declined to low levels in 1998 and did not keep purple nutsedge population levels from rebounding to pretreatment levels. In experiment 2, the efficacy of single spring (April 30) applications of Zorial 5G (norflurazon) at rates of 1.0, 1.5, 2.0, 2.5, and 3.0 lb a.i./A; of Treflan TR10 (trifluralin) at a rate of 2 lb a.i. /A, and of Visor 5G (thiazopyr) at rates of 0.25 and 0.50 lb a.i. /A were evaluated. As of August 4, 1998, purple nutsedge was the predominate weed species in this experiment. Zorial 5G applications at rates ranging from 1.5 to 3.0 lb a.i. /A provided moderate (57-68 %) purple nutsedge suppression. Rates above 1.5 lb a.i./A did not significantly improve purple nutsedge control suggesting that in new alfalfa stands, 1.5 lb a.i/A may be an appropriate rate for the first part of a split application. To date, single applications of Visor 5G at 0.25 and 0.50 lb a.i./A and Treflan TR-10 at 2 lb a.i./A have provided poor (17-33 %) purple nutsedge suppression.
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  Effect of Granular Norflurazon (Zorial 5G) on Alfalfa Establishment in Parker Valley

  Knowles, Tim C.; McCloskey, William B.; McGuire, Jerry; Ottman, Michael J.; La Paz County Cooperative Extension, University of Arizona, Parker, AZ; Department of Plant Sciences, University of Arizona, Tucson, AZ (College of Agriculture, University of Arizona (Tucson, AZ), 1998-10)

  The tolerance of seedling alfalfa to norflurazon applied at planting or 6, 14, or 20 weeks after planting was evaluated in Parker Valley in the spring of 1998. At each application date, rates of 0, 1.5, 2, 3, or 4 lbs a.i./A of norflurazon formulated as a 5% sand granule (Zorial 5G) were applied using a ground driven Valmar granule applicator. Zorial 5G at rates ranging from 1.5 to 4.0 lbs a.i./acre applied no earlier than 6 weeks after planting had no effect on alfalfa seedling emergence and stand establishment. These applications also did not reduce the fresh weight of foliage harvested on July 1, 1998. For effective spring and summer purple nutsedge control, the first spring application of Zorial 5G should not be any earlier than 14 weeks after planting alfalfa or late January which ever is later. In a newly planted alfalfa field prone to high purple nutsedge weed pressure, spring Zorial 5G application rates ranging from 1.5 to 2.0 lbs a.i. /acre should be considered.

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