bluuebunny/crossref_metadata_2025 huggingface dataset:
Hothouse Bothers: A Case Study
Authors: Kuehny Jeff S. , McMahon Margaret J.
Published: December 2018

This decision case concerns production and marketing problems that many ornamental growers incur. At the retail level, popular ornamental crops are often used as loss leaders to draw the public into stores to make other purchases. As a result, retail buyers are concerned not with quality but with price and volume. To meet the needs of price-conscious buyers, growers may attempt to reduce their production costs by reducing the level of production inputs, with some sacrifice in product quality. The owners of Two Sisters Greenhouses must decide whether they are going to produce lower-quality plants, change marketing strategies, or grow alternative crops to retain their current profit margins. This case study was intended for use in greenhouse management, nursery management, and floriculture courses where students assume the role of a decisionmaker in poinsettia production and marketing.
Estimating Apple Diameter from Fruit Mass Measurements to Time Thinning Sprays
Authors: Marini Richard P.
Published: December 2018

The relationship between fruit mass and fruit diameter for apple fruit 2 to 26 mm (0.08 to 1.04 inches) in diameter was evaluated for two cultivars sampled from several orchards for three years. A single regression model was appropriate for all combinations of year, cultivar, and orchard. The model was used to develop a chart to quickly estimate fruit diameter from fruit mass. These fruit diameter estimates can be used by commercial fruit growers to time chemical thinner sprays.
Personalities of Landscape Company Managers and Landscape Horticulture Graduates are Similar
Authors: Voltz Daniel , Zimmerman Allen
Published: December 2018

The personalities in a population of landscape horticulture graduates at a 2-year technical college were found to be similar to those in a population of landscape company managers. However, the personalities of the landscape company managers do differ from those in a general population of college students in terms of their information acquisition, decision making, and lifestyle preferences. The typical landscape company manager in the population surveyed was found to be a 41-year-old male with a bachelors degree. This individual had been employed in the occupation for 20 years, worked ≥41 hours per week, and rated job satisfaction as high.
Susceptibility of Pecan to Black Pecan Aphids
Authors: Wood Bruce W. , Reilly Charles C.
Published: December 2018

The host-parasite interaction between the black pecan aphid (BPA) [Melanocallis caryaefoliae (Davis)] and pecan [Carya illinoensis (Wangenh.) K. Koch] was investigated. Three years of field observations of the ability of BPA populations to induce chlorotic blotches, or visual damage, on 32 pecan cultivars revealed considerable variation in cultivar susceptibility to BPA damage. Among the most commonly grown cultivars, `Sioux', `Cape Fear', `Farley', `Cowley', `Grabohls', and `Barton' exhibited the least damage, whereas `Choctaw', `Oconee', and `Sumner' exhibited the greatest, with `Sioux' and `Choctaw' exhibiting the greatest extremes in susceptibility. Subsequent evaluation indicated that the foliage of pecan genotypes can exhibit an antibiotic-like effect, resulting in the suppression of resident BPA populations. However, the relationship between the degree of this antibiotic effect and the degree of damage exhibited by trees, or field tolerance, was negligible (r = -0.10). For example, while `Choctaw' foliage greatly suppressed BPA population growth, this population was able to inflict relatively severe damage to leaves. An evaluation of feeding preference indicated that BPA alate viviparae (winged females) preferentially feed upon host cultivars on which they have been previously feeding. This feeding preference was eliminated by rinsing leaves with distilled water; hence, a water soluble factor(s) appears to be involved in host preference.
Interactions of Poultry Litter, Polyethylene Mulch, and Floating Row Covers on Triploid Watermelon
Authors: Baker J.T. , Earhart D.R. , Baker M.L. , Dainello F.J. , Haby V.A.
Published: December 2018

Triploid watermelon (Citrullus lanatus Thunb.) was grown on the same plots in 1990 and 1991 and fertilized with either poultry litter or commercial fertilizer. Additional treatments included bare soil or plots mulched with black polyethylene, and plots with or without spun-bonded fabric row covers over both bare soil and mulch. Watermelon yields were unaffected by fertilizer source in 1990 butwere significantly higher for poultry litter than for commercial fertilizer treatment in 1991. Polyethylene mulch significantly increased postharvest soil NO3 and leaf N concentrations in 1990 and increased yield and yield components in both years. There were no beneficial effects of row covers on yield in either year, presumably because no early-season freezes occurred.
Biostimulants and Soil Amendments Affect Two-year Posttransplant Growth of Red Maple and Washington Hawthorn
Authors: Kelting Matt , Harris J. Roger , Fanelli Jody , Appleton Bonnie
Published: December 2018

Humate-based products have been aggressively marketed as biostimulants that increase plant growth. Little data are available on their effect on tree establishment or their interaction with fertilizer and irrigation regimes. This experiment tested several types of biostimulants on posttransplant growth of Acer rubrum L. (red maple) and Crataegus phaenopyrum (Blume) Hara (Washington hawthorn) trees, both with and without irrigation and fertilization. Soil treatments were applied at planting as: 1) control (native backfill only); 2) compost (native backfill + yard-waste compost); 3) peat (native backfill + Canadian sphagnum peat); 4) granular humate, 100 g/tree; 5) granular humate, 200 g/tree; and 6) liquid humate +, a proprietary liquid mixture of humate, kelp extract, thiamine, and intermediate “metabolites.” Irrigation regime × soil treatment interaction was significant for red maple, but soil treatments did not increase height, stem diameter, top dry mass, or root length. For Washington hawthorn, soil treatments did not increase height, stem diameter, or root length, but top dry mass in all treatments as a group and in humate-treated trees in particular was greater than that of controls. Roots of peat-treated trees of both species were longer than those in other treatments. Granular humate applied at 200 g/tree increased total root length more than did 100 g/tree in Washington hawthorn but not in red maple. Fertilizing at planting with N at 14.5 g·m-2 had no effect on any parameter measured for either species.
Winter Raspberry Production in Greenhouses
Authors: Pritts Marvin P. , Langhans Robert W. , Whitlow Thomas H. , Kelly Mary Jo , Roberts Aimee
Published: December 2018

Floricane-fruiting (summer-bearing) raspberries (Rubus idaeus L.) were grown outdoors in pots in upstate New York until mid-December when the chilling requirement was fulfilled. They were moved into a greenhouse and placed at a density that is three times higher than field planting. Bumble bees (Bombus impatiens Cresson) were introduced at flowering for pollination. Fruiting occurred from mid-February through mid-April, a time when the retail price for raspberries is between $3.00 and $6.00 for a half pint (180 g). Fruit quality was high, and individual 2-year-old plants averaged 11 half pints (2 kg) of marketable fruit. These yields and retail prices are equivalent to 19,000 lb and $142,000 per acre (21 t, $350,000 per ha). Raspberry production during winter allows growers to dramatically extend the harvest season and to produce a high-value crop at a time when greenhouses often are empty.
Response of Injury to Strawberry Crowns Caused by European Corn Borer Larvae
Authors: Maas John L. , Enns John M. , Hokanson Stan C. , Hellmich Richard L.
Published: December 2018

Larvae of several insects injure and kill strawberry (Fragaria ×ananassa Duchesne) plants by burrowing into and hollowing out plant crowns. Occasionally, these infestations are serious enough to cause heavy economic losses to fruit producers and nursery plant growers. In 1997 in Beltsville, Md., we observed wilting and dying mature plants and unrooted runner plants in two experimental strawberry plantings. Injury by larvae was extensive; large cavities occurred in crowns, and the central pith tissues were removed from stolons and leaf petioles. Often, insect frass was seen at entrance holes. Larvae removed from hollowed-out parts of injured plants were identified as the European corn borer (Ostrinia nubilalis Hübner) in their fifth instar stage. Their presence in this instance also was associated with a cover crop of millet [Setaria italica (L.) P. Beauv., `German Strain R'] planted between the strawberry rows for weed suppression. This is the first published report of the European corn borer attacking strawberry. Although this insect may occur only sporadically in strawberry plantings, it may become important in the future. Growers and other professionals should become aware of this new strawberry pest and recognize that its management in strawberry will be different from management of other crown-boring insects.
In-furrow Starter Fertilization Enhances Growth and Maturity in Early Sweet Corn
Authors: Swiader John M. , Shoemaker William H.
Published: December 2018

Field studies were conducted in 1994 and 1995 to evaluate the effects of in-furrow-placed (i.e., applied directly in the seed channel) starter fertilizer on the emergence, maturity, and yield response of early sweet corn. In both years, three starter fertilizer treatments were applied: APP, with N and P at 13 and 19 kg·ha-1, respectively (13N-19P kg·ha-1), either banded (5 cm below and 5 cm to the side of the seed) or placed in-furrow, and a control (no starter fertilizer). Additionally, in 1995, the rate of APP was increased to supply 26N-38P kg·ha-1 in combination with either band (5 × 5 cm) or in-furrow placement. Seedling emergence was delayed whenever starter fertilizer was applied with the seed; however, significant reductions (≈21%) in plant stand occurred only at the high rate of in-furrow placement. In both years, all starter treatments had a positive effect on seedling dry-matter production, and hastened silking. In-furrow application of 13N-19P kg·ha-1 increased marketable ear yields 34% in 1995, but had no effect in 1994. Lack of yield response to the high rate of in-furrow fertilizer in 1995 was primarily a function of reduced stand, as ear number and ear mass per plant, and average ear size were similar to those in the other starter treatments. Based on these results, in-furrow APP at 13N-19P kg·ha-1 appears to be an effective starter fertilization regime for early sweet corn, comparable in effect to banded 26N-38P kg·ha-1. However, high rates of in-furrow APP may reduce stands. Although significant yield response to in-furrow starter fertilizer may not always be realized, the increased early seedling growth may itself be a benefit, since fast-growing seedlings are more likely to be tolerant of adverse environmental conditions than are less vigorous plants. Chemical name used: ammonium polyphosphate (APP).
Developing Mechanized Systems for Producing, Harvesting, and Handling Brambles, Strawberries, and Grapes
Authors: Morris Justin R.
Published: December 2018

Mechanization of harvesting, pruning, and other cultural operations on many small fruit crops for the processing market has occurred in response to the scarcity and expense of hand labor. Scientists at the Arkansas Agricultural Experiment Station and other experiment stations in the United States and throughout the world have developed new cultural and fruit-handling systems and have determined the effects of these systems on fruit yield and quality. This research has resulted in the development of prototype and commercial machinery as well as production and handling systems that have assisted in mechanization systems for brambles, strawberries (Fragaria×ananassa Duch.), and grapes (Vitis sp.). Much of this body of work is in commercial use and much is simply available, awaiting circumstances that will be beneficial to implementation.
Response of Selected Sweet Corn Cultivars to Nitrogen Fertilization
Authors: Mullins C.A. , Straw R.A. , Pitt B. , Onks D.O. , Mullen M.D. , Reynolds J. , Kirchner M.
Published: December 2018

`Silver Queen', `Incredible', and `Challenger' sweet corn (Zea mays L.) cultivars were evaluated at different nitrogen (N) fertilization rates at Springfield, Tenn., in 1993, 1994, and 1995. `Incredible' was more productive than `Silver Queen' and `Challenger'. Of the three cultivars, `Silver Queen' had the tallest plants, longest ears, and most attractive ears. Nitrogen fertilization rates were 0, 50, 100, and 150 (100 lb/acre at planting and 50 lb/acre sidedressed) lb/acre (0,56, 112, and 168 kg·ha-1). The 100 lb/acre rate of N applied at planting appeared to be sufficient for producing sweet corn in soils with an annual cropping frequency. Height of plants and ear diameters were larger at the higher fertilization rates, but differences among treatments were not great and were usually not significant. The cultivars of different genetic types did not differ in response to N fertilization rates. Cultivar × year interactions were significant for most factors evaluated, but most other interactions were not significant.
Nursery and Landscape Performance of Ornamental Junipers in the Southern Rocky Mountains
Authors: Harrington John T. , Fisher James T.
Published: December 2018

Supplying landscape plants for expanding urban centers in the southern Rocky Mountains provides a solution to limited-resource producers wishing to convert from traditional agricultural crops to higher value horticultural crops in this region. Thirty-five cultivars of ornamental junipers (Juniperus sp.) were planted in an abandoned agricultural field in Mora, N.M., to evaluate their suitability for nursery production in this region. The plantings were measured after 4 years, and cultivars were ranked for nursery suitability. The planting was then grown for an additional 16 years to examine landscape performance. Nineteen cultivars were considered suitable for nursery production with five cultivars being highly recommended based on survival and growth. Twenty-five of the cultivars were considered suitable for landscape use in the foothill region of the southern Rocky Mountains based on the 20-year measurements. Nine cultivars were classified as highly recommended. Production of ornamental junipers provides an economical alternative to traditional agricultural production systems.
The Effect of Soil Moisture on the Motherstalk Method of Asparagus Production
Authors: Reiners Stephen , Garrison Stephen A.
Published: December 2018

The effect of soil moisture levels on the yield and dry matter accumulation of asparagus (Asparagus officinalis L) using the motherstalk method was examined in a greenhouse study. This technique allows for a spear to develop a mature fern while permitting harvest of later-developing spears. The motherstalk treatment resulted in significantly heavier spears as compared to the conventional practice without a motherstalk and harvesting all spears. In addition, crown weights between the motherstalk and the nonharvested treatment were similar at the end of the 12-week harvest period, but significantly lower when spears were harvested without the benefit of a motherstalk. Optimizing soil moisture significantly increased yield in the motherstalk treatment and increased the fern dry weight but had no effect on crown dry weight. Our results indicate that the motherstalk system may allow for extended asparagus harvest in temperate areas but soil moisture may need to be carefully monitored to use this technique.
Precision Seeder Uniformity Varies with Theoretical Spacing
Authors: Bracy Regina P. , Parish Richard L. , McCoy Joe E.
Published: December 2018

Precision vegetable seeders were found to have unexpected variation in seed spacing uniformity. A belt seeder and vacuum seeder were evaluated using cabbage (Brassica oleracea L. capitata group) seeded at different seed spacings to determine if seeder uniformity improved with increasing seed spacing. Seeding uniformity of the belt seeder was not affected by seed spacing, but uniformity of the vacuum seeder was. Variation in seed spacing with the vacuum seeder was consistent in absolute units, thus seed spacing nonuniformity (expressed as a percentage of theoretical spacing) decreased with increasing seed spacing. Operating the vacuum seeder with the air pressure seed release mechanism disengaged improved seeder precision. Uniformity and precision of the belt seeder were better than that of the vacuum seeder.
The Effect of Timing of the Final Seasonal Nitrogen Fertigation on Early Fruit Maturity, Fruit Diameter, and Leaf Nitrogen on Navel Oranges
Authors: Kallsen Craig
Published: December 2018

Previous research has shown that nitrogen fertilization rates may influence fruit quality characteristics of navel oranges [(Citrus sinensis) (L.) Osbeck]. The objective of this study was to determine, for equal seasonal N applications, if the timing of the last seasonal nitrogen fertigation promotes early fruit maturity or affects fruit size. The study consisted of four treatments with the total seasonal allocation of nitrogen fertilizer applied by ≈1 May, 1 June, 1 July, and 1 Aug. in an experimental site in a commercial orange grove in the southern San Joaquin Valley of California. The source of nitrogen was a liquid calcium ammonium nitrate injected through the irrigation system. No significant treatment differences in soluble solids concentration, titratable acidity, the ratio of soluble solids concentration to titratable acidity, percent juice, fruit color and fruit diameter were detected in fruit sampled in October. Similarly, in September, no significant differences in leaf nitrogen were found among treatments. These results do not support the hypothesis that applying the total seasonal application of nitrogen early in the season results in earlier orange maturity or larger fruit size, at least not for trees that have leaf N in the optimum range.
Effect of Ethrel on Bloom Delay, Harvest Date, and Fruit Weight of `Empress' Peach
Authors: Ebel Robert C. , Caylor Arnold , Pitts Jim , Boozer Bobby
Published: December 2018

Ethrel [(2-chloroethyl)phosphonic acid] was applied at 0, 100 or 200 ppm (mg·L-1) for 3 years to the early maturing `Empress' peach [Prunus persica (L.) Batsch] to determine if bloom delay by Ethrel reduces fruit weight at harvest. Trees were hand thinned at 0 or 3 weeks after full bloom to equalize cropload across Ethrel treatments and to determine if any reduction in fruit weight by Ethrel can be compensated by harvest with earlier thinning. Ethrel at 200 ppm (mg·L-1) delayed bloom by 3, 0, and 7 days in 1994, 1996 and 1997, respectively. Despite bloom delay, Ethrel did not delay harvest or reduce fruit weight. Thus, earlier hand thinning was not necessary. Ethrel did not affect blossom density and was not phytotoxic to vegetative or reproductive organs. These results indicate that even with the shorter fruit growth period of early maturing peach cultivars such as `Empress', there is sufficient time for fruit growth to recover on Ethrel treated trees so that fruit weight at harvest is not reduced.
Incorporating Water Harvesting into Plasticulture Production of Muskmelon
Authors: Dainello Frank J. , Stein Larry , Fipps Guy , White Kenneth
Published: December 2018

Competition for limited water supplies is increasing world wide. Especially hard hit are the irrigated crop production regions, such as the Lower Rio Grande Valley and the Winter Garden areas of south Texas. To develop production techniques for reducing supplemental water needs of vegetable crops, an ancient water harvesting technique called rainfall capture was adapted to contemporary, large scale irrigated muskmelon (Cucumis melo var. reticulatus L.) production systems. The rainfall capture system developed consisted of plastic mulched miniature water catchments located on raised seed beds. This system was compared with conventional dry land and irrigated melon production. Rainfall capture resulted in 108% average yield increase over the conventional dry land technique. When compared with conventional furrow irrigation, rainfall capture increased marketable muskmelon yield as much as 5355 lb/acre (6000 kg·ha-1). As anticipated,the drip irrigation/plastic mulch system exceeded rainfall capture in total and marketable fruit yield. The results of this study suggest that rainfall capture can reduce total supplemental water use in muskmelon production. The major benefit of the rainfall capture system is believed to be in its ability to eliminate or decrease irrigation water needed to fill the soil profile before planting.
High Temperatures Reduce Postharvest Flowering of Specialty Floral Crop Species
Authors: Williams Millie S. , Starman Terri W. , Faust James E.
Published: December 2018

The effect of increasing temperatures on the duration of postharvest flower development was determined for three specialty crop species: marguerite (Argyranthemum frutescens Webb ex Schultz-Bip.) `Butterfly' and `Sugar Baby'; swan river daisy (Brachycome hybrid Cass.) `Ultra'; and bacopa (Sutera cordata Roth.) `Snowflake'. Plants were grown in a greenhouse at 18 °C (65 °F) until flowering, and then transferred into a phytotron to determine heat tolerance. Plants were stored for 8 weeks at constant temperatures of 18, 23, 28, and 33 °C (65, 73, 82, and 91 °F) for 2-week intervals. Flower bud and flower number were recorded weekly. Sutera cordata `Snowflake' and B. hybrid `Ultra' had the greatest flower number at the 23 °C temperature, decreasing in the 28 °C environment. Argyranthemum frutescens `Butterfly' and `Sugar Baby' had greatest flower number at 28 °C, but flowers were of lower quality thanat 23 °C. Flower development of all cultivars ceased at 33 °C, at the end of 8 weeks at increasing temperatures, but when plants were returned to the 18 °C production greenhouse, flower development resumed. High temperatures (28 °C) reduce the postharvest performance of S. cordata, B. hybrid, and A. frutescens plants grown in hanging baskets; therefore, these species should be marketed as spring-flowering products since summer performance may be unsatisfactory in warm climates.
Effect of Auxin and Wounding on Adventitious Root Formation of Prickly-pear Cactus Cladodes
Authors: Lazcano Carlos A. , Davies Fred T. , Estrada-Luna Andrés A. , Duray Sharon A. , Olalde-Portugal Victor
Published: December 2018

Mature cladodes of prickly-pear cactus (Opuntia amyclaea Tenore. `Reina') were treated with five wounding methods and four concentrations of potassium salt indole-3-butyric acid (K-IBA) to stimulate adventitious root formation. The wounding method and K-IBA had highly significant effects on root number and root dry mass of cladodes. Interaction between K-IBA and wounding methods showed that greater root number was obtained at the higher auxin concentrations and with wounding methods that had the greatest cut surface area. K-IBA concentrations from 4,144 to 41,442 μm (1,000 to 10,000 mg·L-1) increased root dry mass. Only the wounding method affected rotting of cladodes. Treatments allowing suberization had a higher percentage of nonrotted cladodes. This research validates the commercial practice of allowing cladodes to suberize early in the propagation cycle. K-IBA altered rooting polarity and stimulated adventitious root formation along the wounded cladode surfaces. The vertical nonsuberized wounding methods and auxin treatments are an excellent classroom demonstration for manipulating rooting polarity. Auxin application and wounding could be of commercial benefit for enhanced rooting in the clonal regeneration of new selections for prickly-pear cactus orchards.
Spathiphyllum Cultivars Vary in Flowering Response after Treatment with Gibberellic Acid
Authors: Henny R.J. , Mellich T.A. , Norman D.J.
Published: December 2018

Thirty-one spathiphyllum (Spathiphyllum Schott.) cultivars were evaluated for flowering response following treatment with gibberellic acid (GA3). Greenhouse-grown plants were treated once with 250 mg·L-1 (ppm) GA3 applied as a foliar spray. Within 16 weeks after treatment all GA3-treated plants had flowered but none of the untreated controls produced flowers. `Vickilynn' (14.1 flowers/plant after 16 weeks), `Piccolino' (12.8), `Mascha' (12.6), `Chris' (11.7), `Alpha' (11.7), and `Daniel' (11.0) produced significantly more flowers than other cultivars. The cultivars producing the fewest flowers per plant after 16 weeks were `Sierra' (2.5), `S1008' (3.2), `Rica' (3.4), `Sonya' (4.3), `Vanessa' (5.1), `S18' (5.5) and `S4002' (5.6). `Alpha,' `Textura,' `Daniel,' `Mascha,' `S1007', and `Showpiece' had significantly better flower quality. `S1008,' `Codys Color', and `Petite' had poor flower quality. `Mascha' was the earliest cultivar to bloom producing maximum flower counts during weeks 9 to 10 after treatment while `Vanessa' was the latest to flower with peak bloom occurring 15 to 16 weeks after treatment. Most cultivars reached peak bloom at 11 to 13 weeks after treatment. Results indicate sufficient genetic variability in spathiphyllum flowering response to GA3 treatment exists to permit cultivar selections based on differences in flowering time, number of flowers and flower quality.
Effects of Application of Various Reduced-risk Pesticides to Tomato, with Notes on Control of Greenhouse Whitefly
Authors: Sclar D. Casey , Gerace Daniel , Tupy Andrea , Wilson Karen , Spriggs S. Aaron , Bishop R. Jason , Cranshaw Whitney S.
Published: December 2018

Experiments conducted in greenhouse and field environments investigated the acute and chronic phytotoxic effects of several house-hold and commercially available soaps, detergents, and oils applied to tomato (Lycoperiscum esculentum Mill.). In addition, the effect of these treatments on greenhouse whitefly, Trialeurodes vaporarium (Westwood), was investigated. In the greenhouse experiments, the number of whiteflies observed was negatively correlated with phytotoxicity (i.e., higher phytotoxicity = fewer whiteflies). Ivory Clear detergent at two rates of application (0.5% or 2.0%) caused the greatest phytotoxicity to seedling tomato plants. Addition of vegetable oils to a 0.5% Ivory Clear detergent solution did not affect phytotoxicity to the plants. While commercially available insecticidal soap (M-Pede) and a neem seed extract (Margosan-O) had little phytotoxicity, they provided only a slight reduction of whitefly populations. A field experiment conducted in the absence of insect pressure showed phytotoxic effects to tomato plants as a result of continued treatment with New Ivory detergent. Significantly lower yield from this treatment resulted from reduced flower and/or fruit production. None of the other compounds in the field experiment significantly affected the yield of tomato plants.
Ethylene from `Bartlett' Pears Promotes Early Ripening of `d'Anjou' Pears when Packed Together in Modified Atmosphere Bags
Authors: Chen Paul M. , Varga Diane M.
Published: December 2018

`D'Anjou' pears (Pyrus communis L.) harvested at commercial maturity and stored in air at 30 °F (-1 °C) for up to 7 weeks were still incapable of ripening normally at 68 °F (20 °C) for 7 days. `D'Anjou' fruit at this stage were termed as under-chilled fruit. Ziploc bags [1-gal (3.8-L)] perforated with a number of small holes [1/8 inches (0.32 cm) in diameter] were used to pack five `d'Anjou' pears and five `Bartlett' pears [a total net weight of 5 ± 0.2 lb (2.3 ± 0.1 kg)]. The mixed fruit packed in the same bags were placed into a room at 68 °F. When under-chilled `d'Anjou' fruit packed with `Bartlett' fruit in the bags perforated with 6, 8, or 10 holes, `Bartlett' fruit became fully ripe after 5 days while `d'Anjou' fruit were capable of ripening normally after 7 days at 68 °F. Ripened fruit of both pear cultivars developed high dessert quality. The concentration of ethylene in these bags accumulated to ≈50 ppm (mg·L-1) on day 4 while CO2 concentration did not increase to above 3% and O2 concentration maintained at 18%. Ethylene generated naturally by `Bartlett' pears during ripening at 68 °F and accumulated in the bag perforated with 6 to 10 holes was sufficient to induce the normal ripening activities of under-chilled `d'Anjou' pears. This packaging technology may be used to promote early marketing for both pear cultivars.
Optimizing Flat Design for Forced-air Cooling of Blueberries Packaged in Plastic Clamshells
Authors: Leyte Jerry C. , Forney Charles F.
Published: December 2018

Forced-air cooling rates of highbush blueberries (Vaccinium corymbosum L.) packaged in 6-oz (177-mL) or 1-pt (473-mL) clamshell containers were affected by positions of vent holes in corrugated flats. Most rapid cooling occurred in flats with vents across the top of the flat. Additional vents aligned in front of clamshells resulted in more rapid and uniform cooling than vents placed between clamshells. Vent holes in the bottom of flats had no effect on cooling rates. Clamshells cooled more slowly in the front of the pallet where cold air entered than in the back of the pallet where cold air exited. Fruit in 6-oz clamshells cooled faster than fruit in 1-pt clamshells.
Bedding Plant Growth in Greenhouse Waste and Biosolid Compost
Authors: Klock-Moore Kimberly A.
Published: December 2018

Growth of `Oasis Scarlet' begonia (Begonia ×semperflorens-cultorum Hort.) and `Super Elfin Violet' impatiens (Impatiens wallerana Hook. f.) was compared in substrates containing compost made from used greenhouse substrates and yard trimmings (GHC) and in compost made from biosolids and yard trimmings (SYT). Treatments consisted of 100% compost (GHC or SYT) or compost combined with control substrate components at 60%, 30%, or 0%. Substrates containing SYT compost produced significantly larger begonia and impatiens plants than substrates containing GHC compost. Higher initial substrate nutrient concentrations in substrates containing SYT probably prompted increased begonia and impatiens growth because substrates containing SYT compost had significantly higher initial soluble salt, nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) concentrations than substrates containing GHC compost. Begonia and impatiens shoot dry mass and size linearly increased as the percentage of SYT compost in the substrate increased from 0% to 100%. However, no difference in begonia or impatiens growth was observed among the different percentages of GHC compost. Initial soluble salt, N, P, K, Ca, and Mg concentrations also linearly increased as the percentage of SYT increased while only initial P, K, and Ca concentrations linearly increased as the percentage of GHC increased.
Postharvest Development and Transmission of Watermelon Fruit Blotch
Authors: Rushing James W. , Keinath Anthony P. , Cook Wilton P.
Published: December 2018

Watermelon fruit blotch (WFB) symptoms did not appear on healthy watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] fruit placed in contact with the diseased surface of other fruit and stored at either 52 or 68 °F (11 or 20 °C) for 1 week. After 3 weeks in storage, some WFB transmission was observed and the frequency of transmission was greater at 68 than 52 °F. Surface abrasion of either the healthy fruit, diseased fruit, or both fruit did not promote transmission of WFB compared with unabraded controls. Some healthy fruit harvested from a field with diseased fruit developed very minor symptoms of WFB in postharvest storage, but the symptoms were not severe enough to cause market problems. Harvesting appeared to halt the spread of WFB symptoms on individual fruit with less than ≈10% of the fruit surface affected at harvest. If care is taken during harvest and grading to exclude diseased fruit, and if proper precooling and subsequent temperature management is implemented for marketable fruit, WFB does not appear to be of concern for the marketing of watermelons.
Comparison of Micronutrient Sources for Container Rhododendron
Authors: Rose Mary Ann , Wang Hao
Published: December 2018

Micronutrient supplements were applied to container rhododendron (Rhododendron L. × `Girards Scarlet' [Girard Evergreen Hybrid Group]) in three forms: uncoated micronutrient fertilizer; slow-release, NPK-plus-minors fertilizer; and biosolids compost (15% v/v). Control plants received no supplement. While all micronutrient treatments had significantly higher foliar Mn or Cu concentrations than controls 1 year after potting, they did not increase growth (dry weight) or plant quality. At 1, 3, and 12 months after potting, the compost treatment had significantly higher diethylenetriaminepentaacetic acid (DTPA)-extractable levels of Mn, Fe, and Zn in the medium. Only one micronutrient fertilizer treatment increased extractable micronutrient concentrations (Cu) on all testing dates. Correlations between medium-extractable and foliar micronutrient concentrations were low (r2 < 0.30). Vigorous growth in the control treatment suggested that adequate levels of micronutrients were supplied by the pine bark-hardwood bark-peat-sand medium. September concentrations [ppm (mg·L-1)] as low as 2.0 Mn, 17.8 Fe, 0.3 Cu, 4.2 Zn, and 0.9 B in DTPA extracts produced acceptable growth in rhododendron through the following June.
Dose and Timing of Brushing to Control Excessive Hypocotyl Elongation in Cucumber Transplants
Authors: Björkman Thomas
Published: December 2018

Brushing is an effective method to control hypocotyl elongation in cucumbers (Cucumis sativus L. `Turbo') grown in plug trays for transplanting. The amount of daily brushing and the number of days to brush for best performance was determined. Treatment with 10 strokes per day for the 4 days of maximal hypocotyl elongation was sufficient to reduce final hypocotyl length by 25%. More brushing did not meaningfully reduce elongation further. Inhibition of dry weight gain, which is detrimental, was minor (<10%) compared with the height control achieved. Despite seasonal differences in absolute elongation, the effects of brushing were the same.
Soil Physical Properties and Potato Yield in No-till, Subsurface-till, and Conventional-till Systems
Authors: Mundy Charlotte , Creamer Nancy G. , Wilson L. George , Crozier Carl R. , Morse Ronald D.
Published: December 2018

Conservation tillage using residue from a cover crop grown before potato (Solanum tuberosum L.) production has been infrequently and inconclusively studied. The objectives of this study were to 1) conduct a field study to evaluate soil physical properties, and potato growth and yield, in conventional-tillage (CT), no-tillage (NT), and subsurface-tillage (SST) systems and 2) conduct a greenhouse study to evaluate the effect of soil bulk density (ρb) on potato growth and yield. Potatoes (`Atlantic') were planted into residue of sorghum-sudangrass [Sorghum bicolor (L.) Moench × S. sudanense (Piper) Staph] at two sites in eastern North Carolina—Plymouth into Portsmouth fine sandy loam and Lewiston into Norfolk sandy loam. Potatoes in the NT and SST system emerged more slowly than potatoesplanted conventionally. There were no differences in plant population or size by 8 weeks after planting at Plymouth, but plant population and size were less in NT and SST systems at Lewiston. Reducing tillage also affected soil compaction, increased soil moisture early in the season at both sites, and increased ρb at Lewiston. Yield of U.S. No. 1 potatoes planted in NT and SST systems were comparable to potatoes planted in a CT system at Plymouth, but were less than potatoes planted in a CT system at Lewiston. There were no differences in yield between potatoes planted with NT and SST. In the greenhouse study, ρb did not affect leaf area or tuber yield or tuber grade. Specific sites and soils may allow for comparable potato production with no or SST, but further research, conducted on different soil types would promote further understanding of the impacts of reducing tillage in potato production.
Determination of Field Capacity in a Florida Sandy Soil and Drainage Time at Different Depths
Authors: Zekri Mongi , Parsons Lawrence R.
Published: December 2018

The development of improved equipment for measuring soil water content has created the need for a better understanding of soil water drainage and movement. Without this understanding, it is impossible to know if an observed decrease in soil water content at a particular depth is due to evapotranspiration and/or continual drainage. This study was designed to determine the length of time for different soil depths of a Florida Candler fine sand to reach field capacity. A field site with no vegetation on it was saturated with water and covered with a plastic tarp to prevent evaporation. At 6- to 24-hour intervals, soil water content was measured gravimetrically in the top 15 cm (6 inches) and with the neutron probe from 30 to 150 cm (12 to 59 inches). The 15-cm depth reached field capacity after one day, but it took 4 days for the 30- to 150-cm depths to reach field capacity because of rewetting by water draining form higher horizons. The time required for drainage to stop must be considered when evaluating changes in soil water status at a particular depth. This is important for distinguishing between plant water uptake and drainage for different soil layers.Soil water characteristic curves of undisturbed soil samples, bulkdensity, porosity, and field capacity in situ were also determined for this soil. Field capacity values found in situ were compared to those found using the pressure plate technique. Laboratory values were higher than field values because the laboratory data were closer to hydrostatic conditions than the field data and the degree of saturation provided during wetting of the cores was higher in the laboratory. Water was not readily retained in Candler fine sand because the soil was very porous, infiltration rates were high, drainage was rapid, and water storage capacity was limited. Using field measurements, field capacity values of soil at different depths ranged from 4.8% to 6.2% volume for Candler fine sand. These are considered to be low values when compared to other types of soil.
Adoption of Landscape Management Practices by Florida Residents
Authors: Israel Glenn D. , Easton Janice O. , Knox Gary W.
Published: December 2018

The Florida Cooperative Extension Service (FCES) teaches residents the importance of proper landscaping practices. FCES offers several educational programs that teach residents how to integrate energy and water conservation, pest management, and waste recycling practices into their home landscapes. In 1997, extension staff and volunteers planned and conducted environmental landscape management (ELM) programs resulting in >800,000 customer contacts. A survey was conducted to measure the adoption of recommended best management practices by program participants and nonparticipants. Results show that, of 39 practices examined, Master Gardener trainees increased the number of practices used by an average of 7.3, while educational seminar and publications-only participants increased by an average of 4.5 and 2.8 practices, respectively. Nonparticipants showed essentially no change. When practices are examined one at a time, the Master Gardeners made statistically significant increases in 28 of the 39 recommended practices. Educational seminar and publications-only participants made similar gains in 31 and 6 practices, respectively, and the nonparticipant comparison group made significant increases in 2 practices and decreases in 8. The results suggest that the publications-only strategy for delivering information to homeowners is less effective than strategies combining educational seminars or intensive training with relevant publications.
Yield, Ear Characteristics, and Consumer Acceptance of Selected White Sweet Corn Varieties in the Southeastern United States
Authors: Simonne Eric , Boozer Robert , Simonne Amarat
Published: December 2018

White sweet corn (Zea mays L.) is widely grown in the southeastern United States. Although `Silver Queen' has been a popular variety in that region for over 20 years, many other varieties are now available. Selecting a variety for commercial or home production is a complex decision because varieties vary considerably with regard to field performance, ear characteristics, and eating quality. Because limited information is available on overall evaluation of sweet corn varieties, the objectives of this study were to 1) evaluate field performance, ear characteristics and eating quality of selected white sweet corn varieties, 2) globally compare varieties using an overall rank-sum index (ORSI), and 3) determine if `Silver Queen' is still the best variety or if it benefits from name recognition. Significant differences among varieties were found for most of the attributes evaluated. When a variety needs to be selected on the basis of a single group of attributes, our results suggest that the best varieties for field performance, ear characteristics and eating quality were `Even Sweeter' and `Treasure', `Silver Queen' and `Rising Star', and `Silverado', respectively. When ranks for all attributes were pooled together, the ORSI for all varieties fell within the 40 to 60 median range for ORSI. These results suggest that while marked differences between varieties can be found for a selected attribute, overall all selected varieties showed similar potential for commercial production. Panel response on sweet corn variety names and the rate of correct blind identification of `Silver Queen' suggested that while it is still among the best varieties, `Silver Queen' did benefit from name recognition.
Physiological Factors Affecting Biennial Bearing in Tree Fruit: The Role of Seeds in Apple
Authors: Dennis Frank G. , Neilsen John C.
Published: December 2018

The evidence for several hypotheses regarding the mechanism(s) controlling biennial bearing in apple (Malus×domestica Borkh.) are reviewed, citing relevant evidence from work with citrus (Citrus sp.) species and pear (Pyrus communis L.). The view that flowering is inhibited by withdrawal of nutrients, primarily carbohydrates, by apple fruit is questionable, given the effects of seed development in inhibiting flowering in facultatively parthenocarpic (normally seedless) apple cultivars. The hypothesis that seeds inhibit flowering by exporting hormones, chiefly gibberellins (GAs), is an attractive one, given a) the effects of application of GAs in inhibiting flowering and b) the high concentrations of GAs in seeds. However, an alternative hypothesis, namely that seeds compete with apices for hormones that are required for flowering, is equally tenable.
The Development of Seed Quality in Brassicas
Authors: Still David W.
Published: December 2018

Brassica crops have indeterminate growth and flower over an extended period of time. Harvested seed is therefore comprised of seed of varying degrees of physiological maturity and quality. Using population-based threshold models, broccoli (Brassica oleracea L. Group Italica), brussels sprouts (B. oleracea L. Group Gemmifera), red cabbage (B. oleracea L. Group Capitata), and rapeseed (B. napus L.) were characterized during seed development with respect to sensitivity to abiotic stress (reduced water potential) and shelf life. Using these models our data suggests that the physiological patterns of seed development are the same in all brassica crops we have tested to date. These population-based models can be used to provide a biological basis in which to evaluate cultural, postharvest and storage practices to ensure the production and maintenance of seed vigor.
Limitations and Possibilities for Some Conservation Tillage Systems with Vegetable Crops in the Southern Plains of the United States
Authors: Roberts Warren , Shrefler James , Duthie James , Edelson Jonathan , Cartwright Bob , Roe Nancy
Published: December 2018

We conducted several experiments to determine the best system for production of spring cabbage (Brassica oleracea L. Capitata group) with conservation tillage (CT) in the southern plains of the United States. Rye (Secale cereale L.) was selected as the best cover crop to cover the soil in a short time. Raised beds were formed in the fall and planted with rye. With most studies, the rye was allowed to remain on the soil surface rather than being tilled into the soil. Planting densities, rates of nitrogen fertilizer, and herbicide materials were evaluated to determine the best system for cabbage production. In each study, various cover crop practices were compared with bare soil production systems. Soil erosion was reduced by the use of rye cover crops. Cabbage was produced in the CT system, but cabbage yields were higher in bare soil plots than in the rye-covered plots. We are also in the process of developing a system of CT that involves permanent bermudagrass [Cynodon dactylon (L.) Pers.] pastures and watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai]. This system allows both crops to be grown simultaneously on the same land.
Experiences with Conservation Tillage Vegetables in Tennessee
Authors: Rutledge Alvin D.
Published: December 2018

Research yields of conservation tillage (CT) snap beans (Phaseolus vulgaris L.) and sweet corn (Zea mays L. var. rugosa Bonaf.) have been less than those produced under conventional tillage. This has been due to soil conditions at planting, the cover crop used, weed control and a lack of proper design in equipment for CT. However, some growers have been successful with CT for sweet corn using hairy vetch (Vicia villosa Roth.) as the cover crop. On-farm demonstrations of CT with cabbage (Brassica oleracea L. Capitata Group), pumpkins (Cucurbita pepo L.), tomatoes (Lycopersicon esculentum Mill.) and watermelons [Citrullus lanatus (Thunb) Matsum. & Nak.] have been successful and with good management it is commercially feasible under Tennessee conditions. Advantages include reduced soil erosion, cleaner products, more efficient application of crop protection chemicals, quicker planting after rainfall, lower energy costs and facilitation of harvest in wet weather. Disadvantages include reduced weed control, modifications of existing equipment, less uniformity in seed coverage and problems with transplanting, cover crop residue in mechanically harvested crops, possible delays in early harvest of fresh market crops due to delayed maturity and limited application of soil protective chemicals.
Greenhouse Performance of Six Potted Anthurium Cultivars in a Subtropical Area
Authors: Wang Yin-Tung
Published: December 2018

Vegetatively propagated liners of six hybrid anthurium cultivars (Anthurium Schott), `Pink Aristocrat', `Patty Anne', `Purple Viking', `Royal Pink', Royal Orange', and `Royal Red', were planted in pots and grown under warm [maximum 30 °C (86 °F)] or hot [maximum 35 °C or (95 °F)] conditions with or without a single foliar application of 500 mg·L-1 (ppm) GA3 and evaluated after 7, 9, and 13 months. GA3, when applied 7 months after planting, did not promote flower production or result in taller plants. Plants in warm and hot areas, except for `Pink Aristocrat', had similar degrees of foliage injury in April, but those in the warm environment had better quality in July than those in the hothouse. Yellow leaves and necrosis on leaf margins were apparent on plants in the hot area. `Pink Aristocrat' was the most (>20 flowers) and `Royal Red' was the least (2 flowers) floriferous after 1 year. Flower color of `Royal Red' was unaffected by high temperature, whereas flowers of the other cultivars faded under heat. Growing these anthurium cultivars at maximum 30 °C (86 °F) air temperatures is recommended for good quality and high flower count.