• Garbanzo Bean Weed Control Study

      Umeda, K.; MacNeil, D.; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      Pendimethalin (Prowl7) and oxyfluorfen (Goal7) applied preemergence (PREE) caused minimal injury and gave very good weed control (>90%). Goal and sulfentrazone alone applied postemergence (POST) gave very good weed control at 6 WAT. The combination of Prowl followed by Goal or sulfentrazone gave complete control of all weeds. Goal and sulfentrazone applied POST following PREE treatments gave nearly complete weed control with good crop safety. Clomazone (Command7) caused significant crop injury and stand reduction when applied PREE. Metribuzin (Sencor7) applied POST completely reduced the crop stand and gave complete control of all weeds. Metolachlor (Dual7), dimethenamid (Frontier7), Sencor, flumetsulam, and imazamox generally did not provide acceptable control of Chenopodium desiccatum (narrowleaf lambsquarters) and Sonchus oleraceus (sowthistle). Bentazon (Basagran7), acifluorfen (Blazer7), and fomesafen (Reflex7) were not effective against narrowleaf lambsquarters but gave adequate control of the other weeds.
    • Green Bean Variety Trial, Safford Agricultural Center, 1998

      Clark, L. J.; Walser, R.; Carpenter, E. W.; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      Twelve green bean varieties were grown in a replicated small plot trial on the Safford Agricultural Center in 1998. Varieties were picked regularly during the growing season. Yields are shown in tabular form and also graphically to indicate how each variety performed throughout the season. Rapids produced the highest yield with a total over 1.3 tons per acre. Two other varieties, Shade and HMX 6999, also performed well with yields over 1.0 tons per acre.
    • Implementation of a Pest Monitoring Network for Vegetable Growers in Yuma County

      Palumbo, John; Kerns, David; Mullis, Clay; Reyes, Francisco; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      An insect pest monitoring network spanning the major growing areas in Yuma was implemented in 1998-1999. This project was designed to measure the relative activity and movement of adult populations during the growing season and provide important information to growers and PCA’s. A series of pheromonebaited and yellow sticky traps were placed in 11 locations among the growing areas in the Yuma, Gila and Dome Valleys in Yuma county. Numbers of adults / trap /night were recorded weekly from September-April. Seasonal differences in insect species activity and abundance among locations were observed, but difficult to precisely explain because of the lack of historical trap data. Information gathered from the trapping network will provide historical baseline data for pest activity on an area wide basis from which relationships between insect trap captures and seasonal factors that influence their activity and abundance may be explained. The results of the monitoring network during the 1998-1999 growing season for is provided in this report.
    • Influence of Cultivar and Planting Date on Strawberry Growth and Development in the Low Desert

      Maurer, Michael A.; Umeda, Kai; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      A field study was designed to determine the effects of cultivar and planting date on growth and yield of strawberries (Fragaria x annanasa D.) in the low desert. The study was conducted at the University of Arizona, Citrus Agricultural Center near Waddell, AZ. Treatments included two strawberry cultivars 'Camarosa' and 'Chandler' and three planting dates of 29 Aug., 7 Oct. and 24 Oct. 1997. There were no significant differences in fruit weight between cultivars . However, fruit number was significantly greater for 'Chandler' strawberries compared to 'Camarosa' and, therefore, fruit size was significantly smaller for 'Chandler' compared to 'Camarosa' berries. Fruit weight and number were significantly greater for both cultivars planted 29 Aug. with nearly 4 times greater production compared to the 7 Oct. and 24 Oct. plantings. Initial results of this study suggest summer planting (late Aug.) of strawberries in the low desert is necessary to produce economically viable yields.
    • Leafminer Control in Cantaloupes

      Umeda, Kai; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      Cantaloupe leaf damage from leafminer activity was minimal to non-existent when evaluated at 6 days after treatment (DAT) following each of the first four weekly application dates. At 13 DAT-4, the number of mined leaves increased tremendously over the previous observation date. The untreated cantaloupes showed an increase from 30.8 to 81.8 mined leaves compared to the previous week. Agri-mek and the alternation treatment of Trigard, Success7, and Agri-mek applied on cantaloupes showed the fewest number of mined leaves at about 22 mined leaves. Trigard and Success treated cantaloupes had increased number of mined leaves ranging from 44 to 56.8. Agri-mek and the alternation treatment consistently had the fewest number of mined leaves during the course of the test period. Trigard and Success treatments performed similarly and reduced the number of mined leaves relative to the untreated cantaloupes. Success at the higher rate appeared to be slightly more active by showing numerically fewer mined leaves than the lower rate of application. Success treated melons yielded nearly twice as much compared to the other treatments and the untreated. Success treated melons also offered a higher number of marketable fruit at better than 80% compared to about 60% for the other treatments. Less stickiness was observed on the Success treated cantaloupes. There appeared to be an effect from Success applications on whitefly to reduce the honeydew stickiness.
    • New Fungicides Evaluated for Control of Powdery Mildew of Cantaloupe in 1998

      Matheron, Michael E.; Porchas, Martin; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      Powdery mildew of cucurbits, which include cantaloupe, honeydew, watermelon, cucumber and squash, occurs every year in Arizona. Moderate temperatures and relative humidity, succulent plant growth and reduced light intensity brought about by a dense plant canopy are factors that promote development of powdery mildew, which is caused by the pathogenic fungus Sphaerotheca fuliginea. Potential new fungicides were evaluated and compared to existing chemicals for control of powdery mildew of cantaloupe in a field trial conducted during the spring of 1998 at the Yuma Agricultural Center. A high level of disease had developed by crop maturity (June 23). On the upper leaf surface where spray coverage was good and disease severity on nontreated leaves was moderate (24% of upper leaf surface infected), all treatments significantly reduced the severity of powdery mildew. These treatments included Sovran, Flint, Procure, Topsin M, Quadris, Benlate, quinoxyfen, Rally, Trilogy, Actigard, Bravo, JMS stylet oil, Kaligreen and Bayleton. In contrast, on the lower leaf surface where spray coverage was not as good and disease severity on nontreated leaves was very high (94% of lower leaf surface infected), the best disease control was achieved with chemistries that have systemic properties. Treatments that held the infected lower leaf surface to 20% or less included Sovran, Flint, Procure, Topsin + Microthiol, and Quadris. The potential availability of new chemistries for management of powdery mildew of cantaloupe and other cucurbits could help improve overall control of powdery mildew as well as the implementation of fungicide resistance management strategies, which strive to minimize the risk of resistance development by the pathogen to these compounds.
    • New Insecticides and Tank Mix Combinations for Worm Control in Lettuce

      Kerns, David L.; Tellez, Tony; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      Proclaim and a normal use rate of 5 oz/ac of Success were highly effective against cabbage looper, Heliothis and beet armyworm. A low rate of 1.5 oz/ac of Success provided sufficient control of Heliothis and beet armyworm, but was weak against cabbage looper. While a low rate of 2.56 oz/ac of Warrior was not especially active against any of the target species. However, when this rate of Warrior was mixed with the low rate of Success, control across all the species was good, and was statistically similar to the higher rate of Success. Although Intrepid appeared slightly more active than its sister compound Confirm, it appears that it too will benefit from the addition of a pyrethroid for control of Heliothis and cabbage loopers on large lettuce plants.
    • Nitrogen Transfer in an Integrated System of Tilapia and Summer Bibb Lettuce

      Azevedo, Celicina; Olsen, Mary W.; Maughan, O. Eugene; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      Nitrogen transfer from aquaculture to agriculture in integrated systems has been difficult to quantify, and the contribution of fish effluent to nitrogen utilization by crop plants is poorly documented. Therefore, labeled nitrogen, ¹⁵N, was used in a small scale integrated system in a controlled environment greenhouse to determine nitrogen transfer from the fish system and its utilization by plants. Tilapia fish were grown in m³ tanks and fed a complete diet that was amended with ¹⁵N ammonium sulfate. Fish effluent amended with ingredients of a basic nutrient solution and 0%, 25%, 50% and 100% of the recommended mineral nitrogen was used to irrigate Summer Bibb lettuce in 5 gal lysimeters in two trials. In trial 1, percent ¹⁵N recovered by lettuce was significantly higher in effluent amended with 50% mineral nitrogen as opposed to 0% or 100%. Dry weight of lettuce was significantly lower only when irrigated with effluent only (no mineral nitrogen added). In trial 2, percent ¹⁵N recovered by lettuce was significantly higher in effluent amended with 25% mineral nitrogen as opposed to 0% or 50%. In treatments with the same amount of mineral nitrogen added, addition of effluent did not affect dry weight. Although ¹⁵N recovery demonstrated efficient nitrogen transfer from the fish feed to the plants, results indicate that effluent alone does not supply sufficient nitrogen for lettuce production.
    • Pepper Variety Trial Safford Agricultural Center, 1998

      Clark, L. J.; Walser, R.; Carpenter, E. W.; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      Eight varieties of bell peppers, three varieties of long green chile, two varieties of jalapeños, two varieties of yellow wax and one Serrano pepper were grown in a replicated small plot trial on the Safford Agricultural Center in 1998. Varieties were picked regularly during the growing season.
    • Postemergence Herbicide Weed Control in Cantaloupes

      Umeda, Kai; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      The addition of an adjuvant, Agridex, to halosulfuron or Basagran7 (bentazon) did not increase crop injury significantly compared to treatments without Agridex. The addition of Agridex to halosulfuron slightly improved morningglory (Ipomoea hederacea) control compared to without the use of an adjuvant. Bentazon at 1.0 lb/A plus Agridex gave very good morningglory control at 92%. At 2 WAT on 20 Aug, cantaloupe injury decreased for halosulfuron and bentazon treatments. A second application of halosulfuron at 0.05 lb/A did not cause additional crop injury.
    • Potential of Particle Film Technology for Insect Management in Crisp Head Lettuce

      Kerns, David L.; Tellez, Tony; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      A new insect management technology known as "particle film" technology (Surround) was evaluated for it potential for control early fall pests of head lettuce in Yuma, AZ. Surround did appear to slightly reduce larval population of cabbage looper, beet armyworm and Heliothis, but not enough to be considered a commercially effective treatment. Additionally, Surround appeared to antagonize Success’s activity towards cabbage loopers. Against whiteflies, Surround did appear to reduce ovipositioning, but resultant impact on the nymph population could not be adequately assessed. Overall, Surround does not appear to have good fit in the pest management system in leafy vegetables in Yuma, AZ.
    • A Practical Approach for Managing Lepidopterous Larvae with in Head Lettuce

      Palumbo, John C.; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      During the past 5 years, the efficacy and field performance of several new insecticides for control of Lepidopterous insects on desert lettuce crops has been investigated in small plot trials at the Yuma Agricultural Center and in produce fields with commercial cooperators. The objective has been to determine how these new chemistries will fit into pest management programs in Arizona. Thus, research programs have been focused on studies to define use patterns for these insecticides chemicals that can be integrated into our local management programs in the most cost-effective way possible. This report was created to provide an overview of the new chemistries being developed, their field activity and characteristics, and guidelines for use in head lettuce. In addition, an approach for sustaining the long-term efficacy of these products is discussed.
    • Preemergence Herbicide Combinations for Onion Weed Control

      Umeda, K.; MacNeil, D.; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      Most herbicides applied alone preemergence (PREE) caused minimal crop injury (<10%) when furrow irrigated. Pendimethalin (Prowl) applied at 0.5 lb AI/A plus bensulide (Prefar) at 6.0 lb AI/A under sprinkler irrigation in Tolleson caused crop injury that was highly unacceptable and the crop stand was severely reduced. Onion yields were significantly reduced for the Prowl plus Prefar treatments. Prowl at 0.25 or 0.5 lb AI/A alone provided very good (>90%) weed control of all weeds. Combination treatments of Prowl plus other herbicides provided very good weed control but did not offer enhanced control of weeds already controlled by Prowl alone. The combinations of ethofumesate (Nortron) with metolachlor (Dual) or dimethenamid (Frontier) gave improved weed control compared to when either was applied alone.
    • Preliminary Examination of the Population Dynamics and Control of the Lettuce Aphid on Romaine

      Palumbo, John C.; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      Several small plot studies were conducted during the spring of 1999 to examine the population growth, distribution and control of the lettuce aphid on romaine. The lettuce aphid population developed to greater numbers more quickly and spread among plants more rapidly when compared with other aphids species under late spring growing conditions. Most of the lettuce aphids sampled were found on the hearts of the plants rather than the frame and wrapper leaves. Our preliminary efficacy studies suggest that foliar sprays, when timed properly and with proper coverage, can provide adequate control of the lettuce aphid for up to 14 days. Furthermore, significant suppression of apterous lettuce aphid populations was observed in plots where pyrethoid treatment were sprayed for thrips control. The implications of these results for future research and management of lettuce aphids in desert lettuce is discussed.
    • Prowl and Prefar for Onion Weed Control

      Umeda, K.; MacNeil, D.; Lund, N.; Robertz, D.; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      Pendimethalin (Prowl7) applied preemergence (PREE) at 0.25 to 0.50 lb AI/A caused no observable injury and did not affect yields of onions that were furrow irrigated . Prowl applied PREE at 0.50 lb AI/A caused significant crop stand and yield reduction compared to lower rates or the untreated check under sprinkler irrigation. Prowl applied preplant incorporated (PPI) at rates ranging from 0.25 to 0.75 lb AI/A did not significantly injure onions or cause a significant yield reduction. Combination treatments of Prowl plus bensulide (Prefar7) applied PREE did not cause any measurable crop height or stand reduction compared to the standard treatment or untreated check. Prowl at 0.25 lb AI/A plus Prefar at 4.0 lb AI/A adequately controlled cheeseweed, yellow sweetclover, sowthistle, and London rocket.
    • Refinement of Release Techniques for Whitefly Parasitoids

      Byrne, David N.; Bellamy, David E.; Byrne, David N.; Baciewicz, Patti; Department of Entomology (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      Although they are currently effectively controlled by chemicals, sweet potato whiteflies have the potential to once again be a dominant pest in Arizona vegetables. We need to explore alternatives such as biological control so that we are not reliant solely on pesticides. We have been examining dispersal by the whitefly parasitoid Eretmocerus sp. in order to find more effective ways to deploy these agents in the field. We have learned in the laboratory that these wasps are efficient flyers since they are capable of moving into strong winds for more than 30 min. We also now know that most flight takes place within a short distance of the release point. We also have a better understanding of differences between male and female flight. This, along with other information we have obtained, will lead to our ability to effectively release these and parasitoids of other insect pests as well.
    • Residual Efficacy of New Insecticide Chemistries Against Cabbage Looper in Head Lettuce

      Palumbo, John C.; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      Several new insecticide chemistries were evaluated and compared with standard chemistries for residual efficacy against cabbage looper in lettuce. Four field trials were conducted at thinning, and heading stages of lettuce. These replicated trials clearly demonstrate that the new insecticides provide a solid 7 day residual efficacy (>90% control) following spray applications. Overall, Success at rates ranging from 4.5-6.0 oz/acre appeared to provide the most consistent residual activity on larvae present on plants at time of application. Confirm, appeared to have less consistent residual, but control was generally similar to Success. The newer compounds Proclaim and Avaunt, showed good residual efficacy for up to 7 days, and will be a welcome additions to the growers insecticide arsenal. Finally, the fact that all of these compounds are effective against large larvae, in part explains their consistent residual activity on lettuce.
    • S-1812 Lepidopterous Insect Pest Control in Broccoli Study

      Umeda, K.; Strickland, B.; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      A single application of S-1812 (Valent) at 0.15 and 0.20 lb AI/A effectively reduced Plutella xylostella (diamondback moth, DBM) in broccoli compared to the untreated check. S-1812 at 0.15 lb AI/A performed similar to thiodicarb (Larvin) at 1.0 lb AI/A. S-1812 significantly reduced the DBM at 5 days after treatment (DAT) and control was effective for up to 14 DAT. S-1812 was less effective against Trichoplusia ni (cabbage looper, CL) compared to DBM control efficacy or Larvin. S-1812 reduced the development of small CL to larger sized larvae.
    • Soil-Applied Insecticides for Whitefly Control in Fall Cantaloupes

      Umeda, K.; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      CGA-293343 and Admire applied to the soil at planting time provided good control of WF at rating dates 34, 45, and 52 DAP. Cantaloupes treated with CGA-293343 at 0.09 lb AI/A showed a greater increase in number of immatures after 45 DAP compared to the CGA-293343 at 0.18 lb AI/A applied on melons. At 59 DAP, the higher rate of CGA-293343 continued to reduce the number of immatures compared to the lower rate and untreated check. Admire treated melons with or without a subsequent foliar insecticide treatments showed reduced WF nymphs at 45 and 52 DAP or 10 and 17 days after treatment (DAT) of foliar applications. Foliar applications of Applaud or Asana plus endosulfan did not significantly reduce WF immatures compared to a single at-planting time application of Admire. The application of either foliar treatment did not extend the length of control beyond that offered by the Admire treatment.
    • Studies of Resistance of Beet Armyworm (Spodoptera exigua) to Spinosad in Field Populations from the Southern USA and Southeast Asia

      Moulton, J. K.; Pepper, D. A.; Dennehy, T. J.; Byrne, David N.; Baciewicz, Patti; Extension Arthropod Resistance Management Laboratory, Department of Entomology (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)
      Susceptibility to spinosad (Success®/Tracer®) of beet armyworm (Spodoptera exigua) from the southern U.S.A. and Southeast Asia was determined through exposure of third instar larvae to dipped cotton leaves. LC₅₀ values of field populations ranged from 0.6 to 14 μg spinosad/ml. Field populations were 3.0 to 70-fold less susceptible to spinosad than was a susceptible reference population. The least susceptible population was collected from Thailand. We hypothesized that this population was resistant to spinosad because: (1) it was significantly less susceptible to spinosad than all other populations evaluated and than any other reports in the literature; (2) it regained susceptibility while in culture; (3) it was collected from a region of very intensive insecticide use and severe insect resistance problems; and (4) it exhibited significant survivorship on field-treated cabbage leaves. Piperonyl butoxide (PBO), diethyl maleate (DEM), and S,S,S tributyl-phosphorothiolate (DEF) failed to synergize spinosad in this resistant Thailand population, and PBO failed to do so in the least susceptible domestic population evaluated, the Parker, AZ, field strain. However, the synergist and field residue studies were conducted using a Thailand population that had levels of resistance that declined while in laboratory culture.