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- Author or Editor: D. R. Smith x
Water-sorbing polymers have been used in greenhouses and in arid and semiarid regions to improve soil water properties. Laboratory and field studies were conducted to investigate the effects of a cross-linked polyacrylamide polymer when incorporated into a silt loam. The soil treatments consisted of 0%, 0.06%, 0.12%, and 0.25% polymer by weight. The laboratory study consisted of four soil columns each containing a treatment. Water was added at a rate of 6.1 mm to the columns every 2 days. Soil moisture and volume was measured daily. The field experiment contained apple trees planted into soil amended with the different rates of polymer and covered with a polypropylene weed barrier. Tree growth and fruit yield were recorded from 1996-1998. The volume and bulk density of the soil-polymer matrix were dependent on the moisture content due to the swelling properties of the polymer. Bulk density was highest when no polymer was added and lowest for soil containing 0.25% polymer. Soil moisture measured by time delay reflectometry showed multiple wetting fronts in the soil columns after water was added. During the 1996 growing season, soil moisture was higher for field plots containing the weed barrier and amended with polymer; however, this trend was reversed in 1997. Tree growth was not effected in any of the years data was taken. Fruit yields did not differ between treatments in 1997. Fruit set and yield in 1998 was greater for trees planted without the weed barrier and polymer. The addition of polymer was not found to benefit apple tree growth or yields.
A peach and nectarine cultivar and training trial was planted in 1989. Training methods were open center (OC) and central leader (CL). The orchard was divided into three sections for early, mid-, and late season peaches with 10 individual-tree replications. The following characteristics were measured from 1989 to 1994: trunk cross sectional area, fruit yield, number of fruit, and fruit color. Early season peaches, those ripening with and before `Salem' in the OC system had significantly greater TCSA at the end of the fifth growing season. At the end of the sixth growing season, however, there was a significant training cultivar interaction. There were no differences between the mid- or late season cultivars. Measurable yields were obtained in 1991 through 1993. In all years, greater yields per tree were observed from trees in the CL system, although not significantly different for the late season cultivars. `Redhaven' and `Newhaven' had the highest yields for the early season cultivars, `Glohaven' for the mid-season cultivars, and `Cresthaven' and Biscoe for the late season cultivars. Trees in the CL system tended to have higher tree efficiency than trees in the OC system. Fruit color at harvest varied by year and training system.
Prevalence of diseases, particularly anthracnose, fusarium wilt, and gummy stem blight, is a major factor limiting production of watermelons in the southern United States. Although satisfactory control of anthracnose and gummy stem blight may be accomplished with the proper application of organic fungicides during normal weather conditions, chemical control is not effective during periods of high humidity and rainfall. Furthermore, the 3 leading cultivars, Charleston Gray, Jubilee, and Crimson Sweet, are not resistant to either anthracnose or gummy stem blight (1,2, 7).
‘AUrora’ is a multiple disease resistant muskmelon (Cucumis melo L.) cultivar developed by the Dept. of Horticulture, Alabama Agricultural Experiment Station, Auburn Univ., adapted to growing conditions in the Southeastern United States. ‘AUrora’ has resistance to downy mildew (Pseudoperonospora cubensis), powdery mildew, (Spherotheca fuliginea), and gummy stem blight (Didymella bryoniae). ‘AUrora’ is especially suited for home, local and commercial markets where “jumbo” size fruit is preferred.
In the article “AU-Jubilant' and ‘AU–Producer’ Watermelons“ by J.D. Norton, R.D. Cosper, D.A. Smith, and K.S. Rymal (HortScience 21:1460–1461, Dec. 1986), the following corrections should be noted: The legends to Figs. 3 and 4 were reversed. The legend to Fig. 3 should read “Fruit of ‘AUProducer’ watermelon.”; the legend to Fig. 4 should read “Fruit of ‘AU–Jubilant’ watermelon.” In the legend to Fig. 1, the word should be “Pedigree”. In the literature citations, ref. 1 should read J. Amer. Soc. Hort Sci. instead of HortScience, and, in ref. 7, the volume number should read 105 instead of 195.
A study was conducted to evaluate the possibility of producing and processing immature cowpea (Vigna unguiculata) green pods by using the same technology used for green beans (Phaseolus vulgaris). The cowpea cultivar Bettersnap developed for green pod production and the green bean cultivars Benton and OSU-5402 were produced under the same cultural conditions. `Bettersnap' yielded less than 0.5 ton/ha, while `Benton' and `OSU-5402' produced about 2.5 ton/ha in once-over simulated mechanical harvest. `Bettersnap' had long vines and dense foliage, which resulted in plants with more width and less erectness than `Benton', the predominant green bean cultivar. Uneven pod setting and long pods (23.8 cm) in `Bettersnap' constitute potential problem for mechanical harvest. Canned cowpea pods of sieves 2 and 3 had darker green color, smaller seeds, and higher shear value, fiber content, and sloughing than green bean pods. Our study indicates that there is a need to develop cultivars with high yield potential and concentrated pod setting adapted to mechanical harvest with pods containing less fiber and less tendency to sloughing.
`Fantasia' nectarines (Prunus persica L.Batsch) were either stored immediately at 0.5C or subjected to a 48-h delay at 20C in air or with 5% CO2 in air before storage. Samples were evaluated at harvest and after 18, 25, 32, 39 and 46 days storage in air or in 5% O2 with 0%, 4%, 8%, or 12% CO2. All samples were evaluated at optimum ripeness. A combination of delayed storage and elevated CO2 in storage effectively delayed chilling injury (CI) symptoms. Control of CI increased with increasing CO2 level in delayed and nondelayed treatments. Delayed storage was not effective without elevated levels of CO2 in the storage atmosphere. Fruit that was stored without delay did not soften normally during the ripening period and developed a dry, rubbery texture. The effect was enhanced as CI progressed, resulting in increased firmness of ripened fruit with increased storage time. The delayed storage treatments softened normally during ripening, but CI fruit had a dry, mealy texture. Internal conductivity measurements correlated well with CI development. Off-flavors were detected at the higher levels of CO2 storage.
Two studies were conducted to evaluate recycled newspaper mulch for landscape plantings. In the first study, two paper products (pellets and crumble) were tested at three depths. Application of either 25 or 50 mm provided excellent control of prostrate spurge. Of the four annuals grown, ageratum exhibited severe stunting of roots and shoots. In the second study, three annual species were mulched with the two recycled paper products applied at 25 mm each and adjusted with P at 0, 3.75, or 7.5 ppm to bind excess Al. When no P was added, ageratum growth was about half that of the control plants. Addition of P at either rate resulted in similar growth compared to control plants. Marigold and geranium were less affected by recycled paper mulch; however, when P was added growth was always similar to nonmulched control plants.
Vegetable garden planning software for personal computers is gaining in popularity (3). The program described herein (GARD-PLAN) provides a listing of vegetable crops from which the user makes selections. Cultural recommendations are made, and yields are projected based on the selections made in the program. A 3-year study to determine the dollar value of vegetable gardens in the 40 counties in North Dakota showed that the average value per garden was about $400, with the highest-valued garden at over $1200 (1). Therefore, vegetable gardening can result in significant savings relative to fresh produce purchased during the growing season.