• Effect of Powdery Mildew on Pecan Nut Weight and Quality

      Olsen, M.; Rasmussen, S.; Nischwitz, C.; Kilby, M.; Wright, Glenn; Kilby, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      Powdery mildew of pecan, caused by Microsphaera ulni, results in discoloration of pecan shucks, but its effects on yield and quality of kernels are not known. In 1999, powdery mildew was observed on pecan shucks by the latter part of June in a commercial pecan orchard near Sahuarita, Arizona. The fungus continued to be active throughout the summer. However, results of a field test comparing diseased and healthy nuts from two varieties of pecans indicate that powdery mildew did not affect nut weight or quality. Whole nut weights, kernel weights, color ratings or percentage of discarded nuts were not significant between paired clusters of nuts that were treated with fungicides and remained disease free and untreated nuts that were infected with powdery mildew. Although shucks may have a high percentage of area covered by powdery mildew, results from this trial indicate that fungicide treatments are not warranted.
    • Evaluation of Temik (aldicarb) for the Control of the Pecan Aphid Complex for Pecans Grown in Arizona

      Kilby, Michael W.; Wright, Glenn; Kilby, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      This experiment was conducted to extend the label for Temik use in Arizona pecan orchards for aphid control. Spring application of Temik controlled both yellow and black aphids throughout the season and significantly increased yield.
    • Pecan Variety Study on the Safford Agricultural Center

      Clark, L. J.; Carpenter, E. W.; Wright, Glenn; Kilby, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      In 1986 a replicated study of eight varieties of pecans was planted on the Safford Agricultural Center at an elevation of 2954 feet above sea level. The objective of the study was to determine which varieties would produce best under the saline conditions found in the Safford valley. WO-3, the highest overall producer of the study, produced the best yield in 1999, with a yield over 2600 pounds per acre. This paper also contains kernel percentages and other nut characteristics found in the study during the 1999 harvest seasons and a summary of the yields since 1997.
    • Performance of Mature Pecan Varieties in the Low Desert of Pinal County 1997-1999

      Kilby, Michael; Gibson, Richard; Wright, Glenn; Kilby, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      Twelve varieties of pecans were evaluated for yield, viviparity, and nut quality. The commercially recommended varieties 'Western Schley' and 'Wichita' produced the greatest yields but also had the highest percentage of pregermination. The varieties 'Cheyenne' and 'Sioux' exhibit great potential for commercial production in the low desert of Arizona.
    • Population Dynamics of Pecan Aphids and Their Green Lacewing Predators in Insecticide-Free Pecans

      Hunter, Martha; Petersen, Mette; McElween, Melinda; Kilby, Michael; Wright, Glenn; Kilby, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      Field surveys of aphids and their natural enemies were conducted in a 30 acre unsprayed block of 'Wichita' pecans in Southeastern Arizona (FICO, Sahuarita) during the growing seasons of 1997, 1998, and 1999. Each season showed a different pattern of aphid population development. In general, numbers of the more damaging black pecan aphid, Melanocallis caryaefoliae were always lower than those of the blackmargined pecan aphid Monellia caryella and no serious aphid damage by either species was observed. Two species of green lacewings were the dominant natural enemies in the orchard, and eggs could be found throughout the season.