bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing Multidisciplinary Team Training for Integrating Horticulture and Nutrition
Authors: Caldwell John S. , Prehm Marilyn S.
Published: October 2019

Twenty students from six disciplines in a farming systems course and in a human nutrition course were organized into four interdisciplinary teams during a joint laboratory. Through lectures, videotapes, and actual interviews of farm families, students were trained to work as a team collecting and processing information from informal interviews. Most students (63%) found the joint laboratory “very useful,” but 41% considered the overall work load excessive. Students rated achievement of team-related objectives significantly higher than course-related objectives. The actual interviewing of farm families was rated the most useful training technique. Student contributions to the team were more discipline-based than integrative, with 63% of the students contributing knowledge and skills from their own discipline. Students' gains from the team were more integrative, with 94% gaining from the team process, knowledge from other disciplines, and integration of disciplines, but only 31% gaining new knowledge or skills in their own disciplines.
Evidence by Gel Filtration for Solubilization of NAA by Nonionic Surfactant Micelles
Authors: Heredia Antonio , Bukovac Martin J.
Published: October 2019

Micelles of two nonionic surfactants (Triton X-114 and Neodol 91) were shown by gel filtration chromatography to solubilize nondissociated NAA molecules in aqueous solutions. Micelle solubilization of nonpolar active ingredients in aqueous spray systems alters the distribution of the chemical in the spray solution and may influence chemical deposit formation and penetration characteristics. Chemical names used: 2-(1-naphthyl)acetic acid (NAA), octylphenoxy polyethoxylate-7.5 POE (Triton X-114), linear alcohol (C9-11) polyethoxylate-6 POE (Neodol 91).
PHENOLIC METABOLISM AND INTERNAL BREAKDOWN (CHILLING INJURY) OF PEACH FRUIT
Authors: van Gorsel Hendrik , Kader Adel A.
Published: October 2019

Internal breakdown (IB) is the limiting factor in the storage and postharvest handling of stone fruits. The symptoms of IB appear when fruits are kept for prolonged periods at temperatures below 10C and include leatheriness, mealiness, browning and bleeding of the flesh, and failure to ripen normally. We investigated the changes in phenolic compounds associated with IB of stone fruits. Twenty-eight phenolic compounds were separated by HPLC. Ten of these components were significantly affected by chilling temperatures. The concentration of six phenols changed in response to ripening after chilling temperatures, parallel to the appearance of IB symptoms. Most phenols showed a concentration gradient from the inside to the outside of the fruit, Comparison between peach cultivars showed characteristic differences in phenol metabolism during ripening. In both cultivars the most predominant phenol, chlorogenic acid, showed little change in concentration during storage. The structure of key phenolic compounds will be determined in order to elucidate the biochemical relationship between the phenols and the related enzymes. In this respect, a method was developed to detect phenylalanine ammonia-lyase (PAL) activity in peach fruit.
A COOPERATIVE SYSTEM FOR SCREENING DRY BEANS FOR MULTIPLE DISEASE RESISTANCE, YIELD AND PERFORMANCE IN NEBRASKA
Authors: Nuland D. S. , Lindgren D. T. , Coyne D. P. , Steadman J. R.
Published: October 2019

The objective of this cooperative system is to establish reaction of both private and public developed dry beans to common blight, rust, and white mold as well as to document performance in the absence of disease constraints. All commercially available Great Northerns and Pintos plus entries from the Cooperative Dry Bean Nursery and selected entries from public and private breeding programs are included. Entry number ranges from 70 to 80 each year. Annual results are published in “Biological and Cultural Tests for Control of Plant Diseases”.
Using a Chill Unit/Growing Degree Hour Model to Assess Spring Freeze Risks for `Redhaven' Peach Trees
Authors: Logan Joanne , Deyton Dennis E. , LockWood David W.
Published: October 2019

Peach [Prunus persica (L.) Batsch] production in Tennessee has declined since 1985 due to the occurrence of freezing temperatures that kill the buds, usually in the spring. Analyses of long-term (1951-89) daily temperature data from four locations in Tennessee were used to evaluate the freeze risks for `Redhaven' peach tree buds at those sites. A model using daily accumulated chill units and growing degree hours (base 4.4C air temperature) was used to estimate the dates to begin and end chill unit accumulations and the dates of full bloom of `Redhaven' peach trees for each year in the climatological record. The actual dates of freezes with air temperatures at or below –2.2C and the estimated bud developmental stage on the date of each freeze also were determined. The model was tested using peach orchard records and was found to be an improvement over using only freeze data. The model indicated that Spring Hill had the highest risk for peach production and Jackson the lowest. Recent problems with spring freezes at Knoxville and Spring Hill were due to later than normal freeze dates rather than earlier development of the `Redhaven' peach tree buds. At Springfield, the recent freeze problems were due to earlier breaking of rest, earlier full bloom, and later freezes.
Reproductive Pecan
Authors: Hu Hening , Sparks Darrell
Published: October 2019

The effect of Zn deficiency on reproductive growth of `Stuart' pecan [Carya illinoensis (Wangenh.) C. Koch] was studied. At the most severe Zn-deficiency level, shoots were rosetted and produced neither. staminate nor pistillate inflorescences. At less severe Zn-deficiency levels, catkin length and weight decreased as Zn concentration in the leaf decreased. The number of fruits produced per shoot was reduced by Zn deficiency. Even though fruit abortion was not affected by Zn status of the shoot, fruit death and drying in situ increased with increasing Zn deficiency. Zinc deficiency dramatically suppressed fruit development and resulted in delayed and staggered shuck dehiscence.
Evaluation of Propagating Stock and Practices for Annual Rhubarb Production
Authors: Maynard D.N.
Published: October 2019

Yield and quality of seedand vegetatively propagated rhubarb (Rheum rhabarbarum L.) for annual production were evaluated for four seasons. Selection of `Victoria' seedlings based on petiole color was not effective in increasing the proportion of red mature petioles. Yields from seed-propagated annual rhubarb were always higher than yields from single-bud crown divisions and from crown divisions in 1 of 2 years. Petiole color of vegetatively propagated rhubarb was always superior to that of seed-propagated rhubarb. GA applications increased early yield from single-bud divisions, but reduced petiole weight of early and total harvest of `McDonald' rhubarb. Chemical name used: gibberellic acid (GA).
Nutritional Studies of Christmas Bell
Authors: Lamont G.P. , Cresswell G.C. , Griffith G.J.
Published: October 2019

Eighteen-month-old seedlings of Christmas Bell (Blandfordia grandiflora Sm.) in 800-ml containers were top dressed with 8- to 9-month Osmocote controlled-release fertilizer 18N-2.6P-10K at 0, 0.625, 1.25, 2.5, 5.0, or 10 kg·m-3. Other plants were fertilized once or twice weekly with a complete liquid fertilizer supplying 100 mg N/liter based on an N : K ratio of either 1:0.6 or 1:1.5. The former ratio was the same as the Osmocote while the latter was the N : K ratio in tops of healthy wild-growing plants of B. grandiflora. The highest fresh weights occurred at the Osmocote rate of 5 kg·m-3 and with the once-weekly liquid feed of 1 N : 1.5 K ratio. Plants fertilized with low rates of Osmocote were pale green but had extensive root systems that were white and predominantly fibrous. As the rate of Osmocote was increased, plants became greener and produced smaller root systems in which fleshy storage organs were predominant over fibrous roots.
Nitrogen Form and Solution pH Effects on Root Anatomy of Cranberry
Authors: Finn Chad E. , Rosen Carl J. , Luby James J.
Published: October 2019

Root sections of cranberry (Vaccinium macrocarpon Ait. cv. Searles) were microscopically examined to document the typical anatomy of cranberry roots and changes in root anatomy in response to N-form and solution pH. Cranberry cuttings were rooted, then established in hydroponic conditions with three N and two pH regimes. The three N regimes with equal N levels were 1) NH4-N alone, 2) NH4/NO3-N in combination, or 3) NO3-N alone. pH was maintained at 4.5 or 6.5. Root apical regions were examined using phase contrast, bright field, and epifluorescence microscopy. The cranberry root tip develops with a closed apical organization with the tetrarchal vascular cylinder, cortex, and root cap traceable to independent meristem cell layers. The most obvious treatment difference was an accumulation of unidentified “granules” in the subepidermal layer, readily visible with epifluorescence microscopy with NO3-N alone. Roots produced at pH 4.5 branched less than those at 6.5 and had more “quiescent” root initials; at pH 6.5, these developed more frequently into branch roots.
Isozyme Verification of Interspecific Hybrids of Cuphea
Authors: Ronis Daniel H. , Thompson Anson E. , Dierig David A. , Johnson Earl R.
Published: October 2019

Five interspecific Cuphea hybrids were examined for isozyme banding patterns. In three of the five hybrids (C. viscosissima × C. lutea, C. ignea × C. angustifolia, and C. lanceolata × C. viscosissima), F1 plants could be distinguished from either parental species. Phosphoglucomutase and 6-phosphogluconic dehydrogenase enzyme stains produced distinct F1 band patterns for all three hybrids. Phosphoglucose isomerase and shikimate dehydrogenase enzyme stains produced distinct F1 band patterns for C. viscosissima × C. lutea and C. lanceolata× C. viscosissima, respectively. For the C. lanceolata × C. viscosissima hybrid. the banding patterns were used to identify 32 selfs among 161 putative F1 plants.
Laboratory Exercise Demonstrating the Importance of Leaves in the Rooting of Herbaceous Stem Cuttings
Authors: Marcotrigiano Michael , McGlew Susan P.
Published: October 2019

A teaching exercise that rapidly and inexpensively demonstrates the effects of leaf reduction on the rooting of stem cuttings is described. Coleus stem cuttings with whole leaves, half leaves, or no leaves are placed in sand on either misted or nonmisted greenhouse benches. Rooting response is recorded by ranking root systems by comparison to a diagram. A demonstration is also described that uses leafless cuttings cultured in vitro on solidified media containing a carbohydrate and/or auxin source. This demonstration gives students information that will help them speculate on the physiological reasons for the poor rooting response of leafless herbaceous cuttings.
Growth and Protein Content of Apple in Response to Root and Shoot Temperature following Chilling
Authors: Arnold Michael A. , Young Eric
Published: October 2019

Bare-root Malus × domestica Borkh. seedlings were chilled for 0, 600, 1200, or 1800 hours at 5C (CH). Seedlings were then placed with roots and/or shoots in all combinations of 5 and 20C forcing conditions (FC) for up to 21 days. Virtually no growth occurred at 5C FC. When the whole plant was forced at 20C, all measures of root and shoot growth increased in magnitude, occurred earlier and at a faster rate with increasing CH. Thus, roots and shoots responded similarly to chilling. When shoots or roots were subjected to 20C FC, while the other portion of the plant was at 5C, the responses were reduced in magnitude and delayed. However, the overall growth enhancement by chilling was not negated. Root and shoot growth enhancement by chilling appeared to be increased if the other portion of the plant was actively growing also, but not dependent on it. Growth of adventitious shoots on roots (root suckers) was greatly enhanced with increasing CH on plants subjected to 5C shoot and 20C root FC. While total root and shoot bark protein levels on a per-seedling basis were similar, protein concentrations were lower in root bark than in shoot bark. During chilling, total protein per seedling generally increased until just before the time that chilling requirements for vegetative budbreak were satisfied. Protein degradation then began, resulting in lower protein levels through 2300 CH. Rapid protein breakdown (1200 to 1800 CH, roots; 1000 to 1800 CH, shoots) occurred at about the same time that root (1000 to 1800 CH) and shoot (800 to 1800 CH) growth responses to chilling were increasing. Warm FC resulted in increased protein breakdown with increased CH and forcing time.
Environmental and Genotypic Regulation of Alstroemeria Seed Germination
Authors: King Joseph J. , Bridgen Mark P.
Published: October 2019

Presowing treatments and temperature regimes were tested to improve germination of Alstroemeria hybrids 3 to 12 months following harvest. In addition, seeds from 20 intraspecific F1 hybrids of five selections were also tested 3 to 7 or 8 to 12 weeks following harvest. Seeds were pretreated by chipping the seedcoat above the embryo, general abrasion of the entire seedcoat, or soaking 12 hours in distilled water, GA, (0.029, 0.29, 2.9 mm), or KNO3 (0.5 and 1.0 m). Pretreatments were evaluated under three environmental regimes: 8 weeks at a constant 18-25C (warm), 4 weeks at 18-25C followed by 4 weeks at 7C (warm-cold), or 4 weeks at 7C followed by 4 weeks at 18-25C (cold-warm). There was an interaction between pretreatment and environmental regime for percent germination. Germination percentages for the water soak and GA, at 0.29 or 2.9 mm were significantly higher than for the other pretreatments, but were not significantly different from one another. The warm-cold environment yielded higher germination percentages than the other environments. The time to germination was longest for the cold-warm regime. This response depended on the genotype and the age of the seed. Chemical name used: gibberellic acid (GA3).
Influence of Plant Age on Nutrient Absorption for Marigold Seedlings
Authors: Tolman Deborah A. , Niemiera Alexander X. , Wright Robert D.
Published: October 2019

Seedlings of 30-, 35, 40-, -45, and 50-day-old marigold (Tagetes erecta Big. `Inca Gold') in 500-ml plastic pots containing a 1 peat: 1 perlite (v/v) medium were treated with several fertilizer levels (N at 20, 50, 80, and 110 mg·liter-1); solution nutrient levels in the medium were determined 6 hours later. Older/larger container-grown plants absorbed more N, P, and K from the medium solution than younger/smaller plants. Also, older plants (>40 days) absorbed at least 88% of the solution N regardless of N treatment. Nitrogen absorption, regardless of plant age, increased as N application rates increased. The latter result implies that even though total N absorption increases with plant age/size, nutrient levels in the medium solution for optimal growth and nutrient uptake may be similar regardless of plant size.
Comparison of Field Resistance to Phytophthora cinnamomi in Twelve Avocado Rootstock
Authors: Gabor B.K. , Guillemet F.B. , Coffey M.D.
Published: October 2019

Twelve avocado (Persea americana Mill.) rootstock selections were tip-grafted with a commercial scion, cv. Hass, and evaluated for their field resistance to Phytophthora cinnamomi Rands. Percentage difference in trunk cross-sectional area of the inoculated compared to uninoculated rootstock, the overall growth in trunk cross-sectional area, and visual rating of disease severity of the commercial scion were used to evaluate rootstock over 79 weeks. Avocado trees on the rootstock selections Thomas, Martin Grande (G75Sa, b, and c), Barr Duke, and D9 demonstrated the highest level of resistance to P. cinnamomi, whereas those on Topa Topa, Borchard, and G6 had the lowest levels. Trees on Duke 7, G1033, and Toro Canyon rootstock were intermediate in their levels of resistance. Among uninoculated rootstock, trees on Thomas and G6 exhibited the greatest growth in trunk cross-sectional area. whereas those on D9 showed the least.
Reduced Plant Populations Save Seed Costs Without Reducing Yield or Quality of `Alltop' Turnip Greens
Authors: Kahn Brian A.
Published: October 2019

Growers of turnip `greens [Brassica rapa L. (Rapifera Group)] are accustomed to planting 5.6 to 10 kg of seed per hectare. A study was conducted in 1985 to determine whether reduced plant populations could be used without reducing yield or quality for `Alltop', a hybrid cultivar with relatively expensive seed. A trial planted on 4 Apr. showed that populations could be reduced from 64 to 33 plants/m of row without reducing yield or quality. A second trial, planted on 30 Aug., used populations of 36, 26, and 16 plants/m of row. Again, there were no statistically significant reductions in yield or quality as populations decreased. However, yields from the 36 and 16 plants/m treatments differed by almost 7 t·ha-1, indicating substantial variability. A conservative approach would be to use a population of 33 to 36 plants/m of row (≈ 725,400 plants/ha) to provide a balance between seed costs and yield. This can be achieved by seeding rates of 2.2 to 2.8 kg·ha-1.
Nitrate and Ammonium Leaching Losses from N Fertilizers Applied to `Penncross' Creeping Bentgrass
Authors: Mancino Charles F. , Troll Joseph
Published: October 2019

Combining frequent N applications and irrigations for turfgrasses grown in sandy soils is a common occurrence on golf course putting greens. A greenhouse study was conducted to determine leaching losses of nitrate and ammonium nitrogen from `Penncross' creeping bentgrass (Agrostis palustris L.) growing on an 80 sand:20 peat soil mixture following frequent, moderately heavy irrigations and light or moderate N fertilizer applications. Nitrogen sources included calcium nitrate, ammonium nitrate, ammonium sulfate, urea, urea formaldehyde and isobutylediene diurea. Application levels were 9.76 kg N/ha per 7 days and 19.52 kg N/ha per 14 days for 10 weeks. Irrigation equivalent to 38 mm·week-1 was applied in three equal applications. Overall, 46% of the applied water leached. Total leaching losses were <0.5% of the applied N. Nitrate represented the major portion of the leached N, with ammonium losses being negligible. There were no differences between sources when applied at these levels. In a second study, a single 48.8 kg N/ha application resulted in higher leaching losses of N, but only calcium nitrate and ammonium nitrate had total losses > 2% (2.80% and 4.13%, respectively, over an n-day period). Nitrate concentrations were found to exceed 45 mg·liter-1 for ammonium nitrate.
Conditioning of Florida Grapefruit to Reduce Peel Stress during Low-temperature Storage
Authors: Miller W.R. , Chun D. , Risse L.A. , Hatton T.T. , Hinsch R.T.
Published: October 2019

`Thompson' pink grapefruit (Citrus paradisi Macf.), waxed or film-wrapped, treated with thiabendazole (TBZ) or untreated, were used to determine the effect of high-temperature conditioning at 31C for 3 days on fruit during subsequent storage for 4 weeks at 1 or 10C. Chilling injury (CI) developed in all conditioned fruit stored at 1C, but was drastically reduced in film-wrapped compared to waxed fruit. Thiabendazole slightly reduced CI, and fruit held at 10C had fewer CI symptoms than those held at 1C for 4 weeks. Conditioning Florida grapefruit at 31C for 3 days did not allow subsequent storage at 1C without rind discoloration. Chemical name used: 2-(4'-thiazolyl)-benzimidazole (thiabendazol, TBZ).
Promotion of in Vitro Leaf Growth of Inner Scales Excised from Dormant Onion Bulbs
Authors: Yoo Kil Sun , Pike Leonard M. , Cobb B. Greg
Published: October 2019

Inner scales excised from dormant bulbs of the short-day `Texas Grano 1015Y' onion (Allium cepa L.) were cultured in vitro and leaf growth was examined. Light promoted leaf growth, but no differences in leaf growth were observed for media pH between 4 and 7. Leaf growth rate in darkness was highest at 24C, reduced at 15C, and greatly reduced at SC. Kinetin promoted leaf growth at 1, 10, and 100 μm. IAA was effective at 1 and 10 μM, but not at 0.1 and 100 μm. GA3 promoted growth at 0.1 μM. No inhibitory effects of ABA on leaf growth could be detected. Chemical names used: 1-H-indole-3-acetic acid (IAA), abscisic acid (ABA), gibberellic acid (GA3), 6-furfurylaminopurine (Kinetin).
Ornamental Tree Growth with Basin-applied Herbicides
Authors: Elmore Clyde L. , Costello Lawrence R. , Hamilton W. Douglas
Published: October 2019

Cider gum (Eucalyptus gunnii Hook. F.), Monterey pine (Pinus radiata D. Don), and camphor tree [Cinnamonium camphora (L.) J. Presl] were evaluated in a field study comparing the effects of herbicides on tree growth. Trees were planted on 13 May 1983 and treated on 20 May 1983, 10 Apr. 1984, and 4 Oct. 1984 with simazine, oryzalin, napropamide, and oxyfluorfen. Glyphosate was applied as a postemergence treatment in all basins on 20 Mar. 1984. None of the herbicides injured the trees. Trunk circumferencesin treated plots increased as much as 553% over untreated plots. All species showed a positive response to increasing weed control. Chemical names used: 6-chloro-N,N'-diethyl-1,3,5-triazine-2,4-diamine (simazine); 3,5-dinitro-N4,N4-dipropylsulfanilamide (oryzalin); N,N-diethyl-2-(1-naphthalenyloxy)-propanamide (napropamide); 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene (oxyfluorfen); N-(phosphonomethyl)glycine (glyphosate).
Pyrrolnitrin Delays Postharvest Fruit Rot in Strawberries
Authors: Takeda F. , Janisiewicz W.J. , Roitman J. , Mahoney N. , Abeles F.B.
Published: October 2019

Postharvest treatment with pyrrolnitrin (250 mg·liter-1) and low storage temperatures delay postharvest rot development in fall-harvested `Tribute' strawberries (Fragaria × ananassa Duch.). Untreated fruit stored at 18C developed gray mold fruit rot (Botrytis cinerea) and rhizopus rot (leak) by the second day. Fruit that did not develop gray mold or leak eventually developed blue mold rot (Penicillium spp.). No rot was observed at 1C, but gray mold and rhizopus rots developed after berries were transferred to 18C. Pyrrolnitrin delayed the appearance of the various rots by 2 to 4 days, but did not reduce the rate of rot development. Chemical name used: 3-chloro-4-(2'-nitro-3'-chlorophenyl)pyrrole (pyrrolnitrin).
Quality of Supersweet Corn Film-overwrapped in Trays
Authors: Risse L.A. , McDonald R.E.
Published: October 2019

Quality changes of supersweet corn (Zea mays L.) were monitored during storage at 1, 4, or 10C, unwrapped or wrapped in stretch or shrink film. Film-wrapping maintained freshness and reduced moisture loss better than lack of wrapping. Wrapping in shrink film resulted in lower O2 and higher CO2 concentrations within packages than wrapping with stretch film. Film-wrapping in shrink film maintained total soluble solids content better than stretch-wrapping or no wrapping.
Growing Conditions Alter the Relationship Between SPAD-501 Values and Apple Leaf Chlorophyll
Authors: Campbell Richard J. , Mobley Kendrick N. , Marini Richard P. , Pfeiffer Douglas G.
Published: October 2019

The relationship between SPAD-501 meter readings (SPAD) and total chlorophyll content (TCHL) was evaluated for `Delicious' apple (Malus domestica Borkh.) leaves grown in various environments. Regression models were developed between SPAD and TCHL for each of six separate experiments and were evaluated for statistical coincidence. SPAD was linearly related in a positive manner to TCHL in five of the six experiments; however, models differed between experiments, particularly between field- and greenhouse-grown trees. Thus, the relationship between SPAD and TCHL must be determined for each experiment.
Low Cost, Computer-aided Landscape Design Using the Macintosh Computer
Authors: Beyl Caula A.
Published: October 2019

Computer-aided design (CAD) is rapidly becoming an indispensable tool for landscape architects and designers. This has created the need for a simple-to-use, inexpensive, and readily available configuration for introducing computer-aided design on a limited budget to landscape students. This introduction to computer-aided landscape design can be accomplished easily and accurately using the 512K Macintosh computer and the software package MacDraw. Techniques are reported for shading, layering, and customizing plant and groundcover symbols, allowing a personal touch that is lacking in some more-advanced CAD packages. Computer-generated pages can be collaged to make full-sized landscape drawings, which are then copied onto reproduction vellum. In this manner, the design capability is not limited by the size of the minter. This design configuration is currently in use and was used to generate the design and the symbol illustrated.
THE EFFECTS OF BENZYLAMINOPURINE AND CHLORFLURENOL ON SEEDLING MORPHOLOGY OF FOUR CONIFER SPECIES
Authors: Tuskan Gerald A. , Poisson Emile J. , Sargent Wayne A.
Published: October 2019

Benzylaminopurine and chlorflurenol were applied to 2-1 nursery stock of Scots pine and ponderosa pine and 2-0 nursery stock Colorado blue spruce and Black Hills spruce to determine if crown morphology was influenced by varying combinations of the two plant growth regulators. Four levels of benzylaminopurine, 0, 250, 750 and 1250 ppm, and two chlorflurenol levels, 0 and 1% (v/v) were tested. Morphological response to treatments was significantly enhanced when treatments were applied to open, elongating buds. Benzylaminopurine significantly increased bud and shoot formation, while chlorflurenol significantly reduced height and increased branch length at species dependent concentrations. The two plant growth regulators lacked positive synergistic effects.
RESISTANCE TO THE COLORADO POTATO BEETLE AND GREEN PEACH APHID IN INTERSPECIFIC SOLANUM HYBRIDS.
Authors: Mooney Jim , Jansky Shelley H.
Published: October 2019

Resistance to the Colorado potato beetle (CPB) and green peach aphid (GPA) would be valuable if it could be effectively transferred from wild potato species to the cultivated potato. Eighteen diploid interspecific hybrids have been developed using Solanum tuberosum Gp. Tuberosum haploids (2n = 2x = 24) and the diploid wild species S. berthaultii (ber), S. chacoense (CHC), S. jamesii (jam), and S. tarijense (tar). Twenty-five genotypes per family were screened for resistance to CPB and GPA. Feeding trials were carried out on intact leaves. The degree of resistance to CPB was determined by the stage of instar development and weight of larvae after a four day feeding period; resistance to GPA was evaluated by aphid reproduction and survival after a fifteen day feeding period. Highly CPB or GPA resistant clones, compared to `Norgold Russet',, have been identified thus far. Some clones express high levels of resistance to both CPB and GPA. Crosses between resistant clones and S. tuberosum will be carried out at the diploid level in an attempt to combine resistance with good tuberization qualities.
Growth and Interior Performance of Poinsettia in Media Containing Composted Cotton Burrs
Authors: Wang Yin-Tung , Blessington Thomas M.
Published: October 2019

Rooted cuttings of Euphorbia pulcherrima Willd. ex Klotzsch cv. Gutbier V-14 Glory were planted in 2-liter containers with growth media having 0% to 75% composted cotton burrs (CCB) in combination with sphagnum peat and/or composted pine bark. Leachates from media with 50% or more CCB had higher initial electrical conductance (EC) (3.7 to 4.0 dS·m-l) than that from media with 25% or no CCB (2.8 to 3.0 dS·m-l) 2 weeks after planting. The differences in leachate EC declined after an additional 9 weeks. Media containing CCB produced slightly shorter and narrower plants with 10% smaller inflorescences and less dry weight than plants grown in a medium consisting of equal volumes of peatmoss and bark. Number of branches and bracts, days to bloom, and plant grade after 30 days under 15 μmol·s-l· m-2 photosynthetic photon flux were unaffected by media.
Ethylene Evolution by Tomato Plants Receiving Nitrogen Nutrition from Urea
Authors: Barker Allen V. , Corey Kenneth A.
Published: October 2019

Urea fertilization of `Heinz 1350' tomato (Lycopersicon esculentum Mill.) in sand or soil culture did not enhance ethylene evolution or restrict growth relative to plants receiving \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathbf{NO}_{\mathbf{3}}^{\mathbf{-}}\) \end{document} whereas \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathbf{NO}_{\mathbf{4}}^{\mathbf{+}}\) \end{document} nutrition doubled the relative rates of ethylene evolution and restricted relative growth. Inhibitors of N transformations in media (nitrapyrin, Np; hydroquinone, HQ; and phenylphosphorodiamidate, PPD) had no apparent stimulator effects on ethylene evolution of plants grown on urea or \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathbf{NO}_{\mathbf{3}}^{\mathbf{-}}\) \end{document} nutrition in sand or soil. Ethylene evolution was enhanced by PPD relative to that by Np or HQ for plants receiving \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathbf{NO}_{\mathbf{4}}^{\mathbf{+}}\) \end{document} nutrition. Each inhibitor had toxic effects on plant growth. Increasing K+ supply from 0 to 8 mm in nutrient solutions decreased ethylene evolution and increased plant growth with urea fertilization. Urea had low phytotoxicity if its hydrolysis to \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathbf{NO}_{\mathbf{4}}^{\mathbf{+}}\) \end{document} was prevented in the media. Chemical names used: p-dihydroxybenzene (hydroquinone); benzenephosphorodiamide (phenylphosphorodiamidate); 2-chloro-6-(trichloromethyl)pyridine (nitrapyrin).
Mature `Starkrimson Delicious' Apple Tree Response to Paclobutrazol Application Method
Authors: Lehman Laura J. , Unrath C.R. , Young Eric
Published: October 2019

Mature spur-type `Delicious'/seedling apple trees (Malus domestica Borkh.) were examined for 2 years after paclobutrazol (PB) foliar sprays with or without a soil cover to direct spray runoff away from the root zone, soil sprays, or a trunk drench. Foliar sprays with runoff reduced shoot number and fruit pedicel length in the year of treatment, but had no effect on shoot length. Trees that received foliar sprays with no runoff had fewer and shorter shoots and shorter pedicels the year after treatment. Soil sprays or a trunk drench reduced shoot number and pedicel length for 2 years after application, while only soil sprays reduced fruit weight, diameter, and length. Chemical name used: β- [(4-chlorophenyl)methyl]- α -(1,1-dimethylethyl)-1 H -1,2,4,-triazol-1-ethanol (paclobutrazol).
Growth of Okra and Fruiting Pattern as Affected by Growth Regulators
Authors: Marsh Lurline , Jones Rufus , Ellersieck Mark
Published: October 2019

Growth and fruiting pattern of okra (Abelmoschus esculentus L. Moench) cv. Clemson Spineless as affected by the growth regulators Alar (N -dimethylaminosuccinamic acid) and ethephon (2-chloroethyl phosphoric acid) were evaluated in field studies. Eight treatments consisting of Alar at 600, 1200, 2400, and 3600 μl·liter-1 and ethephon at 200, 400, 600, and 800 μl·liter-1 and water control were applied as foliar sprays at the three- to four-true-leaf stage. Both growth regulators depressed shoot growth and leaf production. Ethephon reduced shoot length. Total fruit yield was not significantly affected by the treatments. However, ethephon-treated plants tended to produce fewer fruits and lagged behind Alar-treated plants and the control plants in Fruit production during the early harvests.
`Tifway' Bermudagrass Responses to Plant Growth Regulator Application Dates
Authors: Johnson B.J.
Published: October 2019

A field experiment was conducted over 2 years to determine the effects of treatment dates with plant growth regulators (PGRs) on performance of `Tifway' bermudagrass [Cynodon transvaalensis Burtt-Davy] × [C. dactylon (L.) Pers.]. For flurprimidol at 0.84 kg·ha-1, the highest injury occurred from 16 or 28 June application in 1987 and from 17 May or June application in 1988. The injury was similar from treatment dates with flurprimidol + mefluidide or paclobutrazol + mefluidide. The PGRs were applied over a longer period in 1987 than 1988 without affecting vegetative suppression of `Tifway' bermudagrass. However, in 1988, the suppression from the 17 May treatment was equal to or better than that obtained when treatment dates were delayed until 1 June or later. Chemical names: α-(1 -methylethyl)- α -[4-(trifluoromethoxy)phenyl]-5-pyrimidinemethanol (flurprimidol); N -[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl]amino]phenyl]acetamide (mefluidide); (±)-(R*R*) β -[(4-chlorophenyl)-methyl]- α -(1,1-dimethylethyl)- 1H -1,2,4-triazole- 1-ethanol (paclobutrazol).
Control of Tall Fescue in Kentucky Bluegrass Turf with Selective Herbicides
Authors: Goatley J.M. , Powell A.J. , Witt W.W. , Barrett M.
Published: October 2019

Chlorsulfuron, diclofop, and sulfometuron were evaluated for potential use in selective control of tall fescue (Festuca arundinacea Schreb.) in Kentucky bluegrass (Poa pratensis L.). Polynomial trend analyses indicated highly significant linear and quadratic response curves for percentage of tall fescue reduction for each herbicide. Fall and spring treatments with chlorsulfuron and diclofop provided significant tall fescue control, with slight to moderate initial Kentucky bluegrass phytotoxicity. Fall and spring applications of sulfometuron resulted in excellent tall fescue control, but initial Kentucky bluegrass damage was severe and would be unacceptable for high maintenance turf. Chemical names used: 2-chloro- N -[[(4-methoxy-6-methyl-l,3,5-triazin-2-yl)amino]carbonyl]-benzenesulfonamide (chlorsulfuron); 2-[4-(2,4-dichlorophenoxy)phenoxy]proponoate (diclofop); N -[[(4,6-dimethylpyrimidin-2-yl)amino]carbonyl]-2-methoxycarbonyl-benzenesulfonamide (sulfometuron).
Photosynthesis as an Index of Turfgrass Growth Following Application of Herbicides
Authors: Willard T.R. , Peacock C.M. , Shilling D.G.
Published: October 2019

The effects of sethoxydim, cloproxydim, and fluazifop on photosynthesis and growth of St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze `Floralawn'], bahiagrass (Paspalum notatum var. saurae Parodi `Pensacola'), and centipedegrass [Eremochloa ophiuroides (Munro.) Hack.] were evaluated to determine if photosynthesis could be used as a rapid, nondestructive measure of relative susceptibility. Field and greenhouse studies were conducted using infrared CO2 analysis to estimate photosynthesis. Under field conditions, St. Augustinegrass was susceptible to sethoxydim and fluazifop applications, as indicated by a 40% and 38% reduction in apparent photosynthesis, respectively. Bahiagrass incurred a respective 62% and 51% reduction in apparent photosynthesis from sethoxydim and fluazifop application. Growth of these species, as measured by foliage dry weight, was also inhibited by both herbicides. Centipedegrass growth was unaffected by sethoxydim, but was reduced 48% by fluazifop. Under greenhouse conditions, centipedegrass apparent photosynthesis was reduced by sethoxydim and cloproxydim (41% and 51%, respectively), while fluazifop caused a 71% reduction. Growth of centipedegrass was significantly reduced only by fluazifop (83%). These studies indicated that in vivo photosynthetic measurements may provide a sensitive, rapid, and nondestructive method for determining the susceptibility of turfgrasses to postemergence grass herbicides. chemical names used: 2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio) propyl]-3-hydroxy-2-cyclohexen-l-one (sethoxydim); (E,E) -2-[1-[[(3-chloro-2-propenyl) oxy]imino]butyl] -5-[2-(ethylthio) propyl]-3-hydroxy-2-cyclohexen-l-one (cloproxydim); and butyl ester of 2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]-propanoate(fluazifop).
Ripening Behavior of Papaya Genotypes
Authors: Zhang Li-Xin , Paull Robert E.
Published: October 2019

Four papaya (Carica papaya L.) lines that may have commercial value were surveyed for variability in ripening characteristics. Skin and flesh yellowing, fruit softening, respiration rate, and ethylene production were compared. Skin yellowing and flesh softening followed a similar sigmoid pattern for all lines. However, the temporal relationship between skin yellowing and flesh softening differed among the lines. Fruit from lines RL-1-3 and RL-1-12 did not begin to soften until the skin was 80% yellow, compared to 40% yellow for the commercial cultivars Kapoho and Sunrise. Fruit from RL-1-3 and RL-1-12 took 12 and 16 days, respectively, to reach 100% yellow from color break, which was two to three times as long as that of `Kapoho' and `Sunrise' at 22C. All lines showed typical climacteric respiration and ethylene patterns. The time between the start of skin yellowing and the rise in respiration varied from ≈2 days in `Kapoho' and `Sunrise' to ≈4 days in line RL-1-3 and 8 days in line RL-1-12. The respiratory peak was greatly reduced in RL-1-12. The patterns of softening in lines RL-1-3 and RL-1-12 differed from `Kapoho' and `Sunrise': RL-1-3 softened slowly, but reached similar firmness values to other lines 4 days after 100% yellow skin color; RL-1-12 had a much slower rate of softening and the fruit were still firm 4 days after the fruit reached 100% yellow. The ripening patterns of line RL-1-3 and RL-1-12 could be useful in postharvest handling and provide material for studying the genetic control of fruit softening.
Sodium Helps Overcome Potassium Deficiency Effects on Water Relations of Cauliflower
Authors: Sharma C.P. , Singh Sandhya
Published: October 2019

When grown in refined sand with one-twentieth normal K supply, cauliflower (Brassica oleracea L. var. botrytis L. cv. Pusi) had lower dry matter and tissue concentration of K than the controls and developed visible symptoms characteristic of K deficiency. In K-deficient plants, the specific leaf weight, diffusive resistance, and proline concentration in leaves were significantly higher and relative water content (RWC), leaf water otential (ψ), stomatal aperture, stomatal density, and transpiration rate were significantly lower than in control plants. When K-deficient plants were supplied additional Na to the extent K was deficient, Na concentration in the plants increased and the plants recovered from the K deficiency effect on free proline concentration, RWC, leaf water potential, stomatal aperture, stomatal density, specific leaf weight, diffusive resistance, and transpiration.
Low Temperature Alters Carbohydrate Metabolism in Easter Lily Bulbs
Authors: Miller William B. , Langhans Robert W.
Published: October 2019

Easter liliy (Lilium longiflorum Thunb. `Nellie White') bulbs were stored in moist peatmoss for up to 85 days at – 1.0 or 4.5C. Bulbs were periodically removed from storage and analyzed to determine levels of soluble carbohydrates and starch. Storage at – 1.0C induced large accumulations of sucrose, mannose, fructose, and oligosaccharide in both mother and daughter scales. Starch concentration declined substantially during this period. Storage at 4.5C resulted in less dramatic alterations in bulb carbohydrates, although trends toward increased soluble carbohydrates and reduced starch levels were seen. The accumulation of mannose suggests that glucomannan, a secondary storage carbohydrate, was also degraded during – 1.0C storage.
Onion Seed Size, Weight, and Elemental Content Affect Germination and Bulb Yield
Authors: Gamiely Sayed , Smittle D.A. , Mills H.A. , Banna G.I.
Published: October 2019

Yields of `Granex 33' and `Behairy' onions (Allium cepa) closely correlated with the weight of the seeds used to establish the stand. Elemental content was consistently higher in heavier seeds, but elemental concentrations in the seeds were generally negatively related to seed weight, onion growth, and yield. A combined size-aspiration grading was an effective means of eliminating seed with low-yield potential.
Transit Duration × Temperature and Fertilization of Prefinished Caladiums Affect Subsequent Growth
Authors: Harbaugh Brent K.
Published: October 2019

Caladium × hortulanum Birdsey `Candidum' tubers were forced in pots until at least one-half the visible sprouts were 2 cm above the soil surface. These prefinished plants were subjected to simulated transit durations of 2, 4, or 6 days in the dark at 12.5, 15.5, 18.5, 21.0 or 24C. Plants were then grown for 4 weeks in a greenhouse and were either fertilized weekly with 100 ml of a solution containing 500 N-218P-415K (mg·liter-1) or were not fertilized. Interactive effects between transit duration and temperature were significant for all measured growth responses. Transit temperature maintained for 2 days had little effect on subsequent growth and only moderate effects after 4 days. With transit duration of 6 days, an increase in temperature resulted in increased plant height, fresh weight, number of leaves, white coloration of leaves, and percent of plants judged marketable (finished) in 4 weeks. Holding at ≈ 18.5C was most favorable for transit durations of 4 or 6 days. Use of fertilizer during finishing improved plant growth regardless of transit conditions, but did not totally negate deleterious effects from transit conditions.
Aromatic Volatile Composition of Celery and Celeriac Cultivars
Authors: Van Wassenhove Fredy , Dirinck Patrick , Vulsteke Georges , Schamp Niceas
Published: October 2019

A two-dimensional capillary gas chromatographic method was developed to separate and quantify aromatic volatiles of celery in one analysis. The isolation, identification, and quantification of the volatile compounds of four cultivars of blanching celery (Apium graveolens L. var. dulce) and six cultivars of celeriac (Apium graveolens L. var. rapaceum) are described. The qualitative composition of Likens-Nickerson extracts of both cultivars is similar. The concentration of terpenes and phthalides, the key volatile components, found in various cultivars of both celery and celeriac varied over a wide range.
Somatic Embryogenesis and Plant Development in Eight Cultivars of Pecan
Authors: Yates I.E. , Reilly C.C.
Published: October 2019

The influence of stage of fruit development and plant growth regulators on somatic embryogenesis and the relation of cultivar response on somatic embryogenesis and subsequent plant development have been investigated in eight cultivars of pecan [Carya illinoensis (Wangenh.) C. Koch]. Explants from the micropylar region of the ovule were more embryogenic when removed from fruits in the liquid endosperm stage than were intact ovules from less-mature fruits or from cotyledonary segments of more-mature fruits. Explants conditioned on medium containing auxin alone or auxin + cytokinin produced more somatic embryos than medium containing cytokinin alone. Under the conditions of this study, frequency of embryogenesis, as well as the germination of somatic embryos leading to plant development, indicated appreciable variation among cultivars. Plant development was greatest by far from somatic embryos of `Schley' than other cultivars studied.
EFFECTS OF MACRONUTRIENT CONTENT OF CELL LAYER MEDIA ON SURVIVAL, DIAMETER AND PLATING EFFICIENCY OF `RUSSET BURBANK' POTATO PROTOPLASTS.
Authors: Langille Alan R. , Bucher D.M.
Published: October 2019

In order to determine the appropriate nutritional conditions for survival, mesophyll protoplasts cv. “Russet Burbank” were cultured in three cell layer media. Each contained the MS macronutrients at either 0, 1 or 4 times the concentration recommended by Shepard (1980). During the 14 day culture period, cells were evaluated and counted, diameter determined and plating efficiency calculated. Results will be discussed.
Feasibility of Broccoli as a New Enterprise—A Systems Approach
Authors: Sterrett S.B. , Mapp J.W. , Coale C.W.
Published: October 2019

An interdisciplinary systems approach was used to explore the potential of fall, fresh-market broccoli as a new enterprise for eastern Virginia. Thirteen cultivars were evaluated in three plantings. Crop value was estimated at each harvest based on weekly market prices. The market window was open from mid-October until late November, with production of 160 cartons/ha, each at 11 kg. However, production of 120 cartons/ha narrowed the window to 2 weeks. Yield of some cultivars exceeded 160 cartons/ha in the first planting; yield of others was below the target production in the second planting. Low yield and low prices during most of the harvest period for the second planting suggests that the optimum harvest season ends in mid- to late November. Problems with poor plant establishment must be addressed before growers can fully capitalize on potential of broccoli as a new enterprise.
Scheduling Irrigations for Carrots
Authors: Kruse E. Gordon , Ells James E. , McSay Ann E.
Published: October 2019

A 3-year irrigation scheduling study on carrots (Daucus carota L.) was conducted at the Colorado State Univ. Horticulture Research Center near Fort Collins to determine the irrigation schedule that produced the best combination of high water use efficiency and marketable yields with the least amount of water and fewest irrigations. This study used an irrigation scheduling program developed by the U.S. Department of Agriculture/Agricultural Research Service with crop coefficients calculated for carrots. Maximum carrot production and water use efficiency were obtained when the scheduling program simulated a 30-cm rooting depth at planting, increasing linearly to 60 cm in 75 days. Best yields and water use efficiency were attained by irrigating whenever 40% of the available water in the root zone had been depleted. The computer program for irrigation scheduling is available on diskette from the authors.
Chlormequat Chloride Growth Retardant Reduces Spider Mite Infestations of Hibiscus rosa-sinensis
Authors: Osborne L.S. , Chase A.R.
Published: October 2019

Hibiscus rosa-sinensis L. plants treated three times with 850 mg·liter-1 of the growth retardant chlormequat chloride (CCC) were less susceptible to infestation with Tetranychus urticae (Koch) than water-treated control plants. The difference in mite numbers was noted within 8 days after releasing mites onto test plants. Mean number of mites per treated plant was 3.7, compared to 30 on nontreated plants. This activity was observed on all treated plants 6 months after applying CCC. Significant differences were observed on treated plants that were defoliated and allowed to produce new foliage before being evaluated. Therefore, surface chemical residues were not responsible for reducing mite infestations on CCC-treated plants.
Weed Interference in Container-grown `San Jose' Juniper
Authors: Walker Kandy L. , Williams David J.
Published: October 2019

Experiments in two consecutive years indicated that barnyardgrass (Echirzochloa crusgalli L.), large crabgrass (Digitaria sanguinalis L.), and giant foxtail (Setaria faberi Herrm.) reduced growth of container-grown `San Jose' juniper (Juniperus chinensis L. `San Jose') 83 days after transplanting grass seedlings into the containers. Grass densities of one to six weeds per container reduced `San Jose' juniper growth. By 83 days of grass interference, juniper shoot dry weight was reduced as much as 43% by six weeds per container.