• Particle Film Technologies: Pest Management and Yield Enhancement Qualities in Lemons

      Kerns, David L.; Wright, Glenn C.; Wright, Glenn (2003)
      Surround WP and Snow were evaluated for their ability to manage citrus thrips populations in lemons on the Yuma Mesa, and their impact on lemon yield, fruit quality, and packout. Both Surround and Snow effectively controlled citrus thrips and prevented fruit scarring. Surround produced higher yields than either Snow or the commercial standard at the first harvest (#9 ring). There were no differences in yield among treatments for the second (strip) harvest, nor were their any differences in total yield. These data suggest that Surround may increase fruit earliness or sizing. There were no statistical differences among any of the treatments in fruit size frequency or quality for any of the harvests, and there was no apparent benefit from applying an additional application of Surround or Snow post thrips season solely for quality, fruit size, or yield enhancement. The activity of Surround does not appear to be adversely affected by the inclusion of the insecticides Danitol, Baythroid, Carzol, or Success, nor do these insecticides appear to be adversely affected by Surround. Foliar fertilizers did not appear to adversely affect the activity of Surround when tank mixed. However, there is some evidence that Surround may negatively affect the absorption of Fe and Mn when tank mixed with Zn, Fe, Mn lignosulfonate, but this data is not conclusive. The addition of a non-ionic surfactant appears to enhance the on-leaf distribution of Surround over light petroleum and paraffin based oils, but long term efficacy is not affected.
    • Pecan Leaf Tissue Nutrient Concentrations: Temporal Relationships and Preliminary Standards

      Walworth, James; Kilby, Michael; Wright, Glenn; Gibson, Rick (College of Agriculture, University of Arizona (Tucson, AZ), 2002-11)
      Leaf samples were collected from five trees each of Bradley, Cheyenne, Sioux, Western Schley, and Wichita at Picacho, Arizona and five trees each of Bradley, Western Schley, and Wichita at Las Cruces, New Mexico, and analyzed nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, copper, manganese, boron, and copper at two-week intervals from mid-May to Mid-October, 2000. Yield, average nut weight, and percent kernel data were collected for each individual tree. Leaf tissue analysis indicated that concentrations of nitrogen, phosphorus, potassium and sulfur decreased. The overall trends were for zinc levels to declined, although they increased at the end of the season. Boron, calcium, magnesium and manganese, and iron concentrations increased during the growing season. Copper concentrations were variable. Preliminary nutrient standards are presented and compared to existing standards. Most nutrients were within recommended ranges, but magnesium levels were much higher than the top of the Arizona and New Mexico sufficiency ranges. Manganese was higher than the Arizona sufficiency range, but within that of New Mexico, whereas zinc was higher than the New Mexico range, but within that of Arizona.
    • 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.
    • Pecan variety study on the Safford Agricultural Center 1997-1998

      Clark, L. J.; Carpenter, E. W.; Wright, Glenn; Kilby, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1999-11)
      In 1986 a replicated study of eight varieties of pecans were 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. This paper contains yield, kernel percentages and other nut characteristics found in the study during the 1997 and 1998 harvest seasons. Cheyenne and WO-3 were the highest yielding varieties in 1997 and 1998, respectively. The respective yields were 1894 and 2286 pounds per acre.
    • Pecan yields and nut quality as influenced by soil trenching and tree pruning

      Gibson, Richard; Nunan, Linda; Kilby, Michael; Wright, Glenn; Kilby, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1999-11)
      Trenching and pruning applications were placed on mature Wichita pecan trees in Maricopa, Arizona in 1998. Yield and nut quality data from the test are presented. Unfortunately, the cool, favorable growing weather minimized quality degradation during the growing season and confounded the test. Data presented probably do not reflect the true benefits of the treatments.
    • Performance of mature pecan varieties in the low desert 1997 and 1998

      Gibson, Richard; Nunan, Linda; Kilby, Michael; Wright, Glenn; Kilby, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1999-11)
      Mature pecan trees at Picacho, Arizona were evaluated for variety performance during 1997-98. Total average yield per tree, percent kernel and percent viviparity were observed. During 1997, a severe viviparity year, only Bradley, Cheyenne, Souix and Tejas showed viviparity values of 20% or lower. Tejas did not return an acceptable percent kernel leaving Bradley, Cheyenne and Souix as potential varieties able to withstand low desert growing conditions on a regular basis. In 1998, the cool growing season confounded the test and no conclusions were drawn from the data.
    • 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.
    • Performance of Various Lemon Types in Southwest Arizona

      Fallahi, E.; Rodney, D. R.; Butler, Marvin (College of Agriculture, University of Arizona (Tucson, AZ), 1988-12)
      Long term comparisons of 8 types of lemons (Citrus limon Bunn. F.) on Macrophylla (Alemow) (C. macrophylla) rootstock regarding yield, tree growth, and quality under the arid conditions of the Southwest were studied. 'Foothill Lisbon' showed significantly higher cumulative yield and total acid than 'Monroe Lisbon', 'Prior Lisbon', Eureka strains, and Villa Franca, and had larger fruit than other Lisbon strains. 'Prior Lisbon' produced larger tree canopy than all other strains. Overall, Eureka strains and 'Villa Franca' had lower relative cumulative yield, yield efficiency, canopy volume, soluble solids, total acid and fruit seed content , but higher soluble solids to acid ratio than Lisbon strains. All factors considered 'Foothill Lisbon' and 'Prior Lisbon' have good potential for planting in the arid climate and sandy soil of Southwest, when Macrophylla rootstock is to be used.
    • Pest Management and Yield Enhancement Qualities of Particle Film Technologies in Citrus

      Kerns, David L.; Wright, Glenn C.; Wright, Glenn; Gibson, Rick (College of Agriculture, University of Arizona (Tucson, AZ), 2002-11)
      Surround WP and Snow were evaluated for their ability to manage citrus thrips populations in lemons on the Yuma Mesa, and their impact on lemon yield, fruit quality, and packout. Both Surround and Snow effectively controlled citrus thrips and prevented fruit scarring, but their ability to manage Yuma spider mite was inconclusive. Preference tests indicated that both Surround and Snow act primarily by repelling the thrips, but also induce some mortality. Surround produced higher yields than Snow at the first harvest (#8 ring), but did not differ from the commercial standard. There were no differences in yield among treatments for the strip harvest, nor were their any differences in total yield. These data suggest that Surround may have some yield or increased fruit earliness enhancement qualities and that Snow may be slightly detrimental. There were no statistical differences among any of the treatments in fruit size frequency or quality for any of the harvests, and there was no apparent benefit from applying an additional application of Surround or Snow post thrips season solely for quality, fruit size, or yield enhancement.
    • Pesticide Efficacy Trials for Citrus Flat Mites on Oranges, 1988

      Byrne, D. N.; Butler, M. D.; Draeger, E. A.; Butler, Marvin (College of Agriculture, University of Arizona (Tucson, AZ), 1988-12)
    • Phosphorus Response in Wine Grapes

      Creekmore, Cathy E.; Stroehlein, J. L.; Kilby, Michael W.; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990-12)
    • Photosynthetic Acclimation of Leaves of Three Apple Cultivars as Affected by Growth Under Full Sun or 85 Percent Shade and Subsequent Transfer to the Contrasting Light Regime

      Moon, J. W. Jr.; Fallahi, E.; Jordan, K.; Kilby, Michael W.; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990-12)
    • Phymatotrichum (Cotton Root Rot) Resistant Grape Rootstocks

      Kilby, Michael W.; Kilby, Michael W.; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990-12)
    • Phytophthora Gummosis and Root Rot of Citrus-Effect of Temperature on Disease Development

      Matheron, M.; Matejka, J.; Butler, Marvin (College of Agriculture, University of Arizona (Tucson, AZ), 1991-01)
      Experiments were conducted to examine the effect of temperature on development of Phytophthora gummosis and root rot of citrus as well as the influence of temperature on sporulation of Phytophthora citrophthora and P. parasitica. Maximum production of sporangia by each fungus occurred at 25 C, while slight or no sporangia production occurred at 10, 15, and 35 C. Minimal growth of lesions was observed when stems of rough lemon were inoculated with P. citrophthora or P. parasitica and incubated at 5 and 30 C or 10 and 30 C, respectively. The inhibitory and stimulating effect of certain temperatures on sporulation and disease development could be useful for determination of optimum times for application of fungicides or other disease control measures.
    • Pistachio Rootstock Evaluation

      Young, Deborah; Beede, Bob; Starlings, Talbott; Kilby, Michael W.; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990-12)
    • Pollination of W. Murcott Afourer Mandarins

      Wright, Glenn C.; Wright, Glenn; Department of Plant Sciences, U. of A., Yuma Mesa Agriculture Center, Yuma, AZ (College of Agriculture, University of Arizona (Tucson, AZ), 2007-10)
    • 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.
    • Population Dynamics of the Citrus Leafminer in Arizona

      Kerns, David L.; Wright, Glenn (2003)
      Citrus leafminer (CLM) was monitored in a five year old block of lemons on the Yuma Mesa for one year. Unlike 2001, no CLM were found in the spring or early fall. From mid-November through mid-December CLM populations were very light ranging from 1 to 4% infested flush. In early January 2003, the CLM population began to increase peaking on 23 January at 68% infested flush. Although 68% appears to be a large infestation, the CLM population was not numerically high since there was not a great deal of fresh flush growth in the grove at that time. Thus, the CLM were concentrated on what little flush was present. Additionally, CLM larvae were tagged and monitored in January and February 2003. Of the 25 CLM larvae tagged, within five weeks only 9 had survived. Most of those killed appeared to have been killed by predators; most likely Yuma spider mite, Eotetranychus yumensis, and to a lesser extent Tydeus spp. Six of the larvae were killed by parasitoids, comprising two species; Cirrophilus coachellae and an unknown species that was damaged and could not be identified.
    • Potential Rootstocks for "Redblush" Grapefruit in the Desert

      Fallahi, E.; Rodney, R.; McDonald, H.; Butler, Marvin (College of Agriculture, University of Arizona (Tucson, AZ), 1988-12)
      Effects of 12 rootstocks on yield, yield efficiency, bearing potential and quality of 'Redblush' grapefruit were measured and potential rootstocks recommended for the arid climate of southwest Arizona. Trees on 'Palestine' sweet lime and 'Volkamer' lemon produced high cumulative yield but small fruit. Trees on Macrophylla (Alemow) produced higher yields after 5 years of planting and had significantly higher mean yield efficiency than trees on other rootstocks. Thus, Macrophylla rootstock could be a good choice for 'Redblush' at the standard spacing and perhaps at high density spacing in southwest Arizona. Fruit of trees on 'Carrizo' and 'Troyer' citranges were largest. Trees on 'Savage' citrange had lowest yield thinnest peel and highest levels of total soluble solids and soluble solids /acid ratio. Fruit of trees on 'Swingle' citrumelo or C.P.B. 4475 rootstock consistently had higher percentage acid than those on other rootstocks. Considering yield and /or various quality factors, 'Volkamer' lemon, rough lemon , 'Palestine' sweet lime, 'Oklawaha' sour orange and particularly 'Carrizo' citrange are suitable for 'Redblush' grapefruit in the arid Southwest. 'Savage' citrange, 'Ichang' pummelo , 'Cleopatra' mandarin, and 'Swingle' were poor yielding rootstocks for 'Redblush ' grapefruit, and therefore undesirable for planting under the standard spacing of this experiment. 'Savage' and 'Swingle' might be good choices at higher densities because they have yield efficiency, high maximum bearing potential and quality.
    • Potential Use of Esteem for Control of Woolly Whitefly in Citrus

      Kerns, David L.; Wright, Glenn; Kilby, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 2002-02)
      Esteem was evaluated for its efficacy towards woolly whitefly in grapefruit and Minneola tangelos. Esteem was efficacious, but because of spray coverage problems on large trees, failed to offer complete control. Higher rates should be used where infestations are severe, or the trees are large and coverage difficult. Follow-up applications may be necessary to maintain control.