• Influence of Seed Piece Size on Potato Yields

      Pew, W. D.; Park, J. H. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      During the past several years considerable experimenting has been aimed at developing methods for improving potato yields. One of the easiest and most effective ways found was to adjust the seed piece size and number of eyes per piece. Seed pieces were cut to meet the following size categories: 1/2, 1, 1-1/2, and 2 ounces and small whole tubers; 1-1/2, 2 and 2-3 ounces. Significant differences in yield were obtained between the various seed piece size treatments. The yield advantage was in favor of the larger size. The number of eyes per piece was less important except with the smallest size. In this case the seed pieces were incapable of adequately supplying plant growth from more than one eye. Small, whole tubers from good high yielding fields were found to be excellent for seed potato pieces.
    • Insect Control on Cabbage with New Pesticide Compounds

      Gerhardt, Paul D. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      A number of different chemicals have been evaluated for control of cabbage loopers and other lepidopterous pests of cole crops over the past several years. These materials are usually formulated as dusts or emulsifiable concentrates but some have been prepared as wettable powders or granular formulations. Some are more effective against one species of insect than another. Only a very few of the prospective pesticides passed all the required testing and became available commercially.
    • Irrigation Practices with Potatoes

      Pew, W. D.; Park, J. H. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      Data from five years of experimentation with irrigation and soil moisture levels indicate that a certain knowledge and general understanding of these factors is important in potato production. Nine treatments ranging from a constant very wet level to a constant dry treatment were used. Yield differences were significant and varied from a low of 321 cwt, from plants exposed to a very wet (18-20 centibars tension) level early in the season followed by a dry (75-80 centibars tension) condition during the last part of the growing season, to 416 cwt where the plants were kept at a dry level early and changed to a very wet level late in the season. Growers often unknowingly reduce yields and lower quality by applying excessive amounts of irrigation water.
    • Irrigation Studies with Carrots

      Pew, W. D.; Park, J. H. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      Data from four years of irrigation studies with carrots indicate this crop has a rather wide tolerance to varying soil moisture levels as measured by yield and quality of roots. Yields have varied between treatments from 514 to 665 crates per acre. Soil moisture levels ranging from a very wet level (18-20 centibars of tension) to a dry level (75-80 centibars of tension) have shown no significant differences in yield. Only from treatment 5, the very dry schedule, was the yield significantly lower than for all other treatments.
    • Irrigation Trials with Cabbage

      Pew, W. D.; Park, J. H. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      The influences of soil moisture are pronounced in cabbage grown under Arizona's semiarid conditions. An understanding of these effects is a must if the most effective cabbage production is to be achieved. High, constant levels of moisture reduces solidity, increases apparent size, reduces color and general market acceptance. On the other hand, dry soil moisture conditions increases solidity and color and reduces size and generally impairs market quality because of the smallness of size and the tough and woody texture of the cabbage thus produced. Best quality cabbage commensurate with acceptable yields and greatest effectiveness is obtained where moisture is kept at 75-80 centibars of tension.
    • Labor Requirements for Vegetable Crops in Arizona

      Pawson, Walter (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
    • Lettuce Insect Control with Experimental Insecticide Compounds

      Gerhardt, Paul D. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      A number of chemical compounds have been field evaluated as potential pesticides for control of insects on lettuce over the past several years. The important pests of fall planted lettuce being the cabbage looper, beet armyworm and corn earworm. In addition to the chemical compounds, the disease organism Bacillus Thuringiensis was used. It is slower in acting, but can be quite effective, particularly against the cabbage looper. Some of the chemical compounds which have been evaluated and are now available commercially are Sevin, Dibrom and Bidrin. This evaluation will continue as new and possibly more effective materials are made available.
    • Lettuce Nutrition as Influenced by Nitrogen, Phosphorus, Potassium and Magnesium Fertilization

      Stanersen, L. A.; Turner, Fred Jr. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
    • Lettuce Packing Procedures

      Oebker, N. F.; Grounds, R. E.; Foerman, B. R. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
    • Lettuce Variety Trials in Cochise County

      Oebker, N. F.; Page, C.; Foster, R. E.; Bessey, P. M. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      Lettuce varieties were compared in Cochise County for late spring and early fall harvests. The Great Lakes 659 types consistently performed as well as any in the trials for these times of year in this area.
    • Low Volume Spray Applications of Technical Malathion to Vegetable Crops

      Gerhardt, Paul D. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      An experimental application of technical grade malathion was made by helicopter to a mixed planting of vegetables on the University of Arizona Mesa Experiment Station. Technical malathion at the rate of one pint per acre was not phytotoxic to onions, carrots, lettuce, cabbage, broccoli and cauliflower. This dosage did not satisfactorily control cabbage loopers and beet armyworms.
    • Mechanical Harvesting of Lettuce

      Harriott, B. L. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      Research work aimed at developing a selective mechanical harvester for crisphead lettuce was initiated in 1961. During the course of the project, two experimental machines were constructed. Commercial development of the harvester was assumed by Lockwood Grader Corporation in 1964 under terms of a contract between Lockwood and the Arizona Research Foundation. Lockwood is now in the process of constructing a four row prototype harvester that will be capable of harvesting 1.5 acres of lettuce per hour.
    • Potato Fertilization

      Pew, W. D.; Park, J. H. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      Results from experiments with varying levels of nitrogen, phosphorus and potassium have shown that the ratios of 1 - 2.5 - 0 to 1 - 3 - 0 produce the highest yields. While the ratio between nitrogen and phosphorus appears important, the water solubility of the phosphorus seems to be the most important factor in proper fertilization. Proper placement of the fertilizer as well as irrigation and other cultural practices are musts in potato production.
    • Potato Insect Control with Granular Systemic Insecticides

      Gerhardt, Paul D. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      Ten percent granular formulations of phorate and Di-Syston at 20 pounds per acre will effectively control psyllids, aphids and thrips on potatoes. Two years study varying the placement of granular systemic insecticides in the soil in relation to the seed piece has not produced any significant differences in the insect control. The yields from plots in which the granules were placed four inches to the side and two inches below the seed piece were greater. All were better than the untreated check. Of two new systemic insecticides applied as granules at planting time, the material US-21149 (Temik R) gave outstanding insect control and above average yields on Kennebec variety potatoes. Compound NIA-10242 gave less effective insect control and yields below UC-21149.
    • Potato Soft-Rot Diseases

      Stone, William J. H. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      Investigations on the problem of black-leg and tuber rots have revealed an interaction between two pathogenic organisms, a bacterial species and Pythium aphanidermatum.
    • Precision Planting Lettuce

      Harriott, B. L. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      Compared to current planting practices using naked lettuce seed, precision planting coated lettuce seed can result in substantially reduced thinning costs, increases in number of marketable lettuce heads per acre, and higher average head weight. The use of coated seed, however, requires more attention to seedbed preparation, planting depths, irrigation schedules, and stand maintenance. Hill - dropping naked seed does not appear to offer advantages over conventional planting practices except in a slight reduction of seed cost per acre.
    • Response of Dry Onions to Varying Levels of Soil Moisture

      Pew, W. D. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      Onions respond favorably to increasing levels of soil moisture as measured by increase in bulb size and total yields. Maintaining a soil moisture level of 18-20 centibars of tension (nearly field-holding capacity) produces the greatest yields of bulbs. However, dry onions so produced are somewhat softer in texture, tended toward thick -neck growth, matured slower, and are more difficult to cure adequately in the normal length of time. Onions grown on lesser amounts of water tend to have the reverse characteristics. Costs of production are similarly increased under high soil moisture levels because of the need for replacing nitrogen leached out of the root zone. Also, the costs of the water and its application must be increased. Therefore, the economics involved would be a required consideration.
    • Sclerotiniose or Drop of Lettuce

      Stone, William J. H. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)
      Preliminary tests have been initiated in a program for control of Sclerotiniose, or drop of lettuce. Damping-off problems are concurrently being investigated.
    • Studies on Fall Production Problems with Irish Potatoes in Arizona

      Bessey, Paul M. (College of Agriculture, University of Arizona (Tucson, AZ), 1965-08)