• Barley Response to Soil Water Depletion Levels, 2000

      Husman, Stephen H.; Ottman, Michael J.; Wegener, R. J.; Rogers, M. T.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      This research represents the first year of a project to determine when to irrigate barley based on soil water depletion levels. The purpose of this work is to establish the optimum irrigation timing based on depletion of plant available water in the soil. A field experiment was conducted at the Maricopa Agricultural Center testing irrigation of barley at 35, 50, 65, and 80% depletion of plant available water in the soil for two barley varieties, Baretta and Max. Grain yields averaged over the two varieties were 8415, 7735, 7512, and 4553 lbs/acre for the 35, 50, 65, and 80% depletion levels, respectively. The results of this study indicate irrigating at 35% soil water depletion is optimal for barley grain yield.
    • Durum Response to Soil Water Depletion Levels, 2000

      Husman, Stephen H.; Ottman, Michael J.; Wegener, R. J.; Rogers, M. T.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      This research represents the second year of a project to determine when to irrigate wheat based on soil water depletion levels. The purpose of this work is to establish the optimum irrigation timing based on depletion of plant available water in the soil. A field experiment was conducted at the Maricopa Agricultural Center testing irrigation of wheat at 35, 50, 65, and 80% depletion of plant available water in the soil for two durum varieties, Kronos and Westbred 881. Grain yields averaged over the two varieties were 6787, 6494, 5460, and 3067 lbs/acre for the 35, 50, 65, and 80% depletion levels, respectively. The results of this study indicate irrigating at 50% soil water depletion or less is optimal for wheat grain yield.
    • Evaluation of Herbicides for Control of Littleseed Canarygrass in Wheat

      Tickes, Barry; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      The two herbicides currently registered for the control of canarygrass in Arizona work by inhibiting lipid biosynthesis. The levels of control with these herbicides have been variable, ranging from 60 to 90 percent. Crop safety has been good. Two newer herbicides utilizing a different mode of action have provided more consistent and higher levels of weed control but with increased crop injury. These are numbered compounds (MKH6561 and F130060) and they are ALS inhibitors.
    • Irrigation Pracitices and Solum Barley Test Weight and Yield, 2000

      Ottman, Michael J.; Rogers, M. T.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      Solum is a barley bred for reduced water use that tends to have low test weight. An experiment was conducted at the Maricopa Agricultural Center to determine the effect of the number of irrigations and their timing on test weight and grain yield of Solum barley. Applying an irrigation at planting and a second irrigation at jointing resulted in the lowest test weight (44.4 lbs/bu) and nearly the highest grain yield (4315 lbs/acre) recorded in the test. All other irrigation treatments resulted in acceptable test weights above 48 lbs/bu except for irrigating at planting plus tillering, which resulted in 47.0 lb/bu test weight. Irrigating at planting and then delaying the second irrigation until boot or later resulted in acceptable test weight but decreased grain yield by 9% or more compared to applying the second irrigation at jointing. Grain yields similar to that obtained by applying a second irrigation at jointing was obtained by delaying the second irrigation until boot and applying a third irrigation at milk or soft dough. This experiment will be conducted a second year before conclusions are drawn.
    • Seeding Rate Effects on Durum Grain Protein Concentration

      Ottman, Michael J.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      It has been observed in other wheat growing regions that stands that are thin rarely have problems with low grain protein. The purpose of this study was to determine if this is indeed the case in Arizona. A study was conducted at Maricopa where the durum varieties Duraking, Minos, and Turbo were sown at rates from 30 to 360 lbs seed/acre. Seeding rate had no effect on grain protein or yield in this study. The reported effects of thin stands on grain protein may be related to low yield rather than seeding rate per se.
    • Small Grain Variety Evaluation at Arizona City, Eloy, Maricopa, and Yuma, 2000

      Ottman, Michael J.; Rogers, M. T.; Moser, H. S.; Sheedy, Michael. D.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      Small grain varieties are evaluated each year by University of Arizona personnel and industry cooperators. 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.
    • Small Grain Variety Trials Safford Agricultural Center, 2000

      Clark, Lee J.; Carpenter, E. W.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      Small plot replicate trials were established to test thirteen durum wheat varieties, seven varieties of bread/feed wheat and nine varieties of barley. Platinum was the leading durum wheat variety with a yield of 4550 pounds per acre and Experimental BR 4836 from World Wide Wheat the highest yielding bread/feed wheat variety with 5893 pounds per acre. Patti was the highest yielding barley variety with a yield of 4724 pounds per acre.
    • Wheat and Barley Response to Nitrogen Fertilization at Safford Agricultural Center, 2000

      Clark, Lee J.; Carpenter, E. W.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      Yields of both wheat and barley were increased with the addition of nitrogen and the largest gain was seen when it was applied at the initiation of growth or at boot stage. Effects of applied nitrogen were somewhat masked by the addition of nitrogen through the use of well water. Nitrogen level in the well water added 21 pounds of nitrogen per acre foot of irrigation, adding 48 pounds of nitrogen throughout the growing season. With the low value of grain and the given cost of nitrogen fertilizer, added nitrogen did not increase profitability for the producer.
    • Wheat and Barley Response to Pre-plant Phoshorus at Safford Agricultural Center, 2000

      Clark, Lee J.; Carpenter, E. W.; Ottman, Michael (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      Bread wheat and barley were seeded in low phosphorus soils which had had varying rates of ammonium phosphate-sulfate (16-20-0) applied. Statistical increases in yield were seen in the wheat study. The increased bottom line with the lowest rate of phosphorus declined as rates of phosphorus increased. Low crop values and high fertilizer costs made high application rates uneconomical. Barley yields were not statistically increased with the addition of phosphorus and the economics of applying phosphorus for this crop were negative. A two year summary is included in this report.