bluuebunny/crossref_metadata_2025 huggingface dataset:
Canopy Variation Among Three Sweet Corn Hybrids and Implications for Light Competition
Authors: Williams Martin M. , Boydston Rick A. , Davis Adam S.
Published: February 2019

Research in dent corn has found significant variation in crop/weed competition for light among hybrids. However, little has been published on the extent of variation in sweet corn competitive ability. Field studies were conducted under weed-free conditions to quantify canopy development and light environment among three sweet corn hybrids and to determine associations among canopy characteristics to crop yield. An early-season hybrid (Spirit) and two midseason hybrids (WHT2801 and GH2547) were grown at experimental sites located near Urbana, Ill., and Prosser, Wash., in 2004 and 2005. Maximum leaf area index (LAI) and intercepted photosynthetically active radiation (PAR) was typically highest for GH2547 and lowest for Spirit. Most differences in vertical LAI among hybrids was observed above 60 and 150 cm in Illinois and Washington, respectively, with WHT2801 and GH2547 having leaf area distributed higher in the canopy than Spirit. Both number and mass of marketable ears were positively correlated with maximum relative growth rate (correlation coefficients 0.60–0.81), leaf area duration (0.68–0.79), total LAI (0.56–0.74) at R1, and intercepted PAR (0.74–0.83) at R1. Differences in canopy properties and interception of solar radiation among Spirit, WHT2801, and GH2547 lead us to hypothesize that variation in weed-suppressive ability exists among hybrids. Future testing of this hypothesis will provide knowledge of interactions specific to sweet corn useful for developing improved weed management systems.
One-Time Pruning of Pecan Trees Induced Limited and Short-Term Benefits in Canopy Light Penetration, Yield, and Nut Quality
Authors: Lombardini Leonardo
Published: February 2019

Twenty-five-year-old `Cape Fear', `Desirable', and `Kiowa' pecan [Carya illinoinensis (Wangenh.) C. Koch] trees were either not pruned, or subjected to single selective or mechanical pruning using a mechanical hedger [or hedge pruning (HP)] in the dormant season 2003. Canopy light interception, yield, and nut quality were monitored during a period of three years. Leaf area index and light interception were significantly affected during the first growing season after treatment application, but after three years canopies grew back to control levels. In general, there were small positive effects observed on yield and nut quality after pruning. Minor improvements were recorded for `Desirable', in which yield was affected positively by both pruning strategies in 2004. However, most effects disappeared by the third year. `Desirable' responded better than `Cape Fear', whereas no beneficial effects were recorded on `Kiowa'. In 2005, yield was significantly reduced in HP trees of `Cape Fear' and `Kiowa'. Alternate bearing index was unaffected by pruning treatment or cultivar. Kernel percentage increased only in HP `Desirable' trees in 2003 and 2004. Kernel quality was improved in HP `Cape Fear' and `Desirable' in the first growing season after treatment application, but not in 2004. In 2005, quality was again improved in HP `Desirable'. The results of the current study indicate that one-time pruning of pecan trees induce positive short-term effect on light, but not necessarily an increase in productivity and nut quality.
Simulating Annual Irrigation Requirement for Citrus on Excessively Drained Soils
Authors: Wheaton T. Adair , Parsons Lawrence R. , Morgan K.T.
Published: February 2019

A water use simulation for citrus (Citrus sinensis) was used to estimate the effects of climate, soil-available water, rooting depth, allowable depletion of available water, and partial coverage irrigation on the annual irrigation requirements. The soil in the study was excessively drained Candler sand (hyperthermic, uncoated Typic Quartzipsamments) of the Central Florida Ridge. Variation of annual rainfall from 667 to 1827 mm had a relatively small impact on annual irrigation requirements. Soil-available water, depth of root zone, and allowable depletion of available water all affected irrigation management and the number of irrigations annually. Simulated annual irrigation requirements varied over a wide range depending on the allowable depletion of soil-available water, irrigation depth, and the fraction of the land area that is irrigated. Effective rain estimated by the TR21 method during months of high rainfall was higher than estimates by the water budget. Monthly irrigation requirements varied seasonally and peaked in normally dry spring months of April and May. The irrigation simulation is a useful tool for examining the range of management strategies that can be considered for citrus.
Organic Apple Production in Two Humid Regions: Comparing Progress in Pest Management Strategies in Iowa and New Zealand
Authors: Delate Kathleen , McKern Andrea , Turnbull Robert , Walker James T.S. , Volz Richard , White Allan , Bus Vincent , Rogers Dave , Cole Lyn , How Natalie , Guernsey Sarah , Johnston Jason
Published: February 2019

By 2003, organic apple [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] production had increased to 5626 ha in the United States and to 2964 ha in New Zealand by 2002. Common problems facing organic apple growers in the humid regions of New Zealand and the United States include effective management strategies for apple scab [Venturia inaequalis (Cooke)] and insect pests. Experiments conducted in Iowa in 2003–2004 demonstrated the effectiveness of a kaolin clay- and spinosad-based insecticide program in maintaining codling moth [Cydia pomonella (L.)] damage levels to less than 5% in the scab-resistant cultivars Enterprise, Liberty, Redfree, and Gold Rush. Similar pest management systems have been developed in New Zealand to comply with export standards and quarantines. The use of codling moth granulosis virus and a spinosad-based insecticide have led to reduced pest pressure and to an increase in organic exports with a 41% premium price over conventional apples. However, an association between spinosad use and woolly apple aphid [Eriosoma lanigerum (Hausmann)] population increase was observed in organic orchard surveys in 2006. An alternative to spinosad applications, insect disinfestation through controlled atmosphere (CA) treatment, was investigated to control quarantined pests and to extend the storage potential of scab-resistant cultivars. A CA treatment of 9 weeks of 2% O2 and 2% CO2 at 0.5 °C was determined to maintain firmness ratings to export standards in CA-stored, scab-resistant ‘Pinkie’ apples and to decrease internal ethylene concentration by 84% compared with apples stored in air. In addition, new scab-resistant cultivars with ‘Pinkie’ background under development in New Zealand show promise for organic production in humid regions. Few fruit quality differences were determined between ‘Pinkie’ fruits from integrated fruit production and organic production systems, although premium prices exist only for certified organic apples.
Chemical Alternatives to Methyl Bromide for Weed Control and Runner Plant Production in Strawberry Nurseries
Authors: García-Méndez Eva , García-Sinovas David , Becerril Maximo , De Cal Antońeta , Melgarejo Paloma , Martínez-Treceño Anselmo , Fennimore Steven A. , Soria Carmen , Medina Juan J. , López-Aranda Jóse M.
Published: February 2019

The phase out of methyl bromide (MB) requires effective alternatives for soil disinfestation, particularly in high-elevation strawberry (Fragaria × ananassa Duch.) nurseries. Methyl bromide alternative fumigants were evaluated over a 3-year period for weed control and runner plant yields at strawberry nurseries in Spain. Two types of field trials were carried out: replicated experiments and commercial-scale field demonstrations. In the replicated experiments, eight fumigant treatments were evaluated each year, including the nonfumigated control and commercial standard methyl bromide plus chloropicrin mixture (MB : Pic) (50 : 50 w/w). Among the treatments evaluated were dazomet, chloropicrin (Pic) alone, metam sodium plus chloropicrin (MS + Pic), 1,3-dichloropropene:chloropicrin (1,3-D : Pic) (61 : 35 w/w), DMDS plus chloropicrin (DMDS + Pic), and propylene oxide. The best alternative fumigant treatments from the replicated experiments were carried forward to the demonstration phase of the project. Treatments such as 1,3-D : Pic (300 kg·ha−1), the combination of metam sodium plus chloropicrin (Pic) (400 to 500 + 150 to 250 kg·ha−1), Pic alone (300 kg·ha−1) as well as dazomet (400 kg·ha−1) controlled weeds at the level of MB : Pic (400 kg·ha−1). Runner plant yields, in soils previously fumigated with alternative fumigants varied, among years, locations, and trial scale, i.e., commercial scale, or small plot. By comparison, runner plant yields in MB : Pic-fumigated soils were consistently high among years, location, and trial scale. Chemical names used are: 1,3-D, 1,3-dichloropropene; MB, methyl bromide; Pic, trichloronitromethane; MS, sodium N-methyldithiocarbamate; DMDS, dimethyl disulphide; dazomet, tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione; PO, propylene oxide
The Effect of Live Plants and Window Views of Green Spaces on Employee Perceptions of Job Satisfaction
Authors: Dravigne Andrea , Waliczek Tina Marie , Lineberger R.D. , Zajicek J.M.
Published: February 2019

A job satisfaction survey was posted on the Internet and administered to office workers in Texas and the Midwest. The survey included questions regarding job satisfaction, physical work environments, the presence or absence of live interior plants and windows, environmental preferences of the office workers, and demographic information. Approximately 450 completed responses were included in the final sample. Data were analyzed to compare levels of job satisfaction of employees who worked in office spaces with live interior plants or window views of exterior green spaces and employees who worked in office environments without live plants or windows. Statistically significant differences (P < 0.05) were found regarding perceptions of overall life quality, overall perceptions of job satisfaction, and in the job satisfaction subcategories of “nature of work,” “supervision,” and “coworkers” among employees who worked in office spaces with live interior plants or window views and those employees who worked in office environments without live plants or windows. Findings indicated that individuals who worked in offices with plants and windows reported that they felt better about their job and the work they performed. This study also provided evidence that those employees who worked in offices that had plants or windows reported higher overall quality-of-life scores. Multivariate analysis of variance comparisons indicated that there were no statistically significant differences among the categories of “age,” “ethnicity,” “salary,” “education levels,” and “position” among employees who worked in offices with or without plants or window views. However, there were gender differences in comparisons of males in that male participants in offices with plants rated job satisfaction statements higher when compared with males working in offices with no plants. No differences were found in comparisons of female respondents.
Effect of Two Fire Retardants on Postharvest Drying and Flammability of Douglas Fir and Fraser Fir Christmas Trees
Authors: Chastagner Gary , Hinesley L. Eric , Owen Jeff
Published: February 2019

SafeTree Christmas Tree Fire Retardant was applied to freshly harvested Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] boughs, and RapidCool FRX Christmas Tree Retardant was applied to freshly cut Fraser fir [Abies fraseri (Pursh) Poir.] boughs. The flame retardants were sprayed onto the foliage. Fire retardant accelerated the drying rate of Douglas fir boughs, which increased flammability. RapidCool fire retardant did not slow the drying rate of Fraser fir boughs, and had no effect on moisture content (MC) at ignition, flame time, total burn time, or total foliage consumed. For both species, initial ignition and spread of flame occurred at 60% to 70% MC. Fresh boughs did not ignite in burn tests and were not a fire hazard. Twig MC of nontreated Fraser fir increased 20% during display in water, further decreasing the possibility of ignition when exposed to a flame. Neither product was effective as a fire retardant on boughs of Christmas trees.
Somatic Embryogenesis and Plant Regeneration from Immature Persimmon (Diospyros kaki Thunb.) Embryos
Authors: Sugiura Akira , Matsuda-Habu Yoshiko , Gao Mei , Esumi Tomoya , Tao Ryutaro
Published: February 2019

In persimmon, plant regeneration from cultured cells usually takes place through adventitious bud formation. If somatic embryogenesis were possible, the efficiency of mass propagation and genetic engineering would be greatly improved. We attempted to induce somatic embryogenesis from immature embryos and plant regeneration from the induced embryos. Hypocotyls and cotyledons from immature ‘Fuyu’ and ‘Jiro’ seeds were cultured in the dark in Murashige and Skoog medium solidified with gellan gum and supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzyladenine (BA) at various concentrations. Callus formation started at ≈2 weeks of culture, and the callus formation rate was highest at 3 or 10 μm combinations of 2,4-D and BA. The initially formed calli gradually became brown or black from which white embryogenic calli (EC) appeared secondarily. After ≈8 weeks of culture, globular embryos were formed from these EC, and the formation proceeded until 20 weeks of culture. Formation of globular embryos was higher with ‘Fuyu’ than ‘Jiro’, especially with hypocotyls. When EC with globular embryos were transferred to fresh medium with no plant growth regulators, ≈70% developed to the torpedo-type embryo stage in 6 weeks. The torpedo-type embryos thus formed were germinated and rooted in agar medium with or without zeatin in several weeks without entering dormancy. After germination and rooting, the plantlets were transferred to the same medium and acclimatized for another 4 weeks. As the embryos germinated and rooted simultaneously, the plantlets were easy to grow in pots without transplanting shock. This is the first report on plant regeneration through somatic embryogenesis of persimmon.
In Vivo Shoot Regeneration Promoted by Shading the Cut Surface of the Stem in Tomato Plants
Authors: Johkan Masafumi , Mori Genjirou , Mitsukuri Kazuhiko , Mishiba Keiichirou , Morikawa Toshinobu , Oda Masayuki
Published: February 2019

The aim of this study was to establish an alternative method to produce clones of tomato plants by modification of the complete decapitation method, which regenerates multiple shoots from the cut surfaces of the main and lateral stems of plants grown in vivo. Shading the stems of tomato plants drastically increased the number of regenerated shoots from 2.4 in controls with unshaded stems to 36.2 in shaded stems. In shaded stems, the concentrations of chlorophyll and phenolic compounds were stable for 3 weeks after cutting, whereas these amounts increased in unshaded stems. Inhibiting the production of phenolic compounds in the shaded stem tissues was associated with an acceleration of shoot formation in vivo.
Anthracnose on Strawberry: Its Etiology, Epidemiology, and Pathology, Together with Management Strategies for Strawberry Nurseries: Introduction to the Workshop
Authors: Poling E. Barclay
Published: February 2019

In recent years, anthracnose fruit rot (AFR) caused by Colletotrichum acutatum J.H. Simmonds, has become an even more serious threat to strawberry plant and fruit producers in major strawberry-growing areas of North America. This highly virulent pathogen causes fruit rot, crown rot, root rot, and lesions on petioles and stolons. In fruit-production fields, the best way to control AFR is to prevent the introduction of the pathogen into the field by using anthracnose-free transplants. A critical step in controlling the disease then, lies in effective nursery management practices. Participants in this workshop outlined several key management strategies, including methods to eliminate pathogen inoculum, cultural practices that reduce host plant susceptibility, and chemical and biological control measures. Industry members stressed the importance of giving research priority to developing improved methods of nursery field sampling and detection of C. acutatum in asymptomatic plants with latent infection. Being able to rapidly and economically diagnose C. acutatum in symptomless plant material at each step in the multiyear nursery plant propagation cycle (foundation, registered, and certified plants), will help nursery growers minimize the potential of selling C. acutatum-infected transplants to fruit growers. A video recording of the 4-h workshop was produced by ASHS Video Workshop Series (http://ashs.org/resources/videoworkshopseries.html).
Overview of 1-Methylcyclopropene Trials and Uses for Edible Horticultural Crops
Authors: Watkins Christopher B.
Published: February 2019

The inhibitor of ethylene perception, 1-methylcyclopropene (1-MCP), is the basis of a new technology that is increasingly being used to improve storage potential and maintain quality of fruit and vegetables. 1-MCP is registered for use on a number of crops, including apple, apricot, avocado, banana, broccoli, kiwifruit, pear, mango, melon, peach, nectarine, persimmon, plum, and tomato. The registered crop is often specific to country. The effects of 1-MCP on quality of these crops, as well as its effects on physiological disorders and pathological diseases, are reviewed. Most available literature on 1-MCP has focused on laboratory-based trials and little information exists about its effects on product quality at the commercial level. The apple is the most significant exception, being the first crop for which 1-MCP was used commercially and extensively around the world. The apple is a crop for which limited ripening after harvest is desirable. For many other fruit, successful commercialization of 1-MCP will require an appropriate balance between 1-MCP concentrations and exposure periods that will delay but not inhibit ripening. The effects of preharvest factors, cultivar, maturity, and postharvest practices are complex and will impact commercial success of 1-MCP-based technology. For leafy or nonfruit vegetables, the advantages of 1-MCP may only be apparent under abusive conditions such as high temperatures and exogenous ethylene exposure. Finally, commercial utilization of 1-MCP-based technology will be a function of the cost of its application relative to its benefits for each product.
Intersectional Hybridization among Trichostema Species
Authors: Dunn Bruce L. , Lindstrom Jon T.
Published: February 2019

Controlled reciprocal crosses between Trichostema lanatum Benth. (section Chromocephalum F.H. Lewis) with Trichostema arizonicum A. Gray (section Paniculatum F.H. Lewis) and Trichostema purpusii Brandegee (section Rhodanthum Lewis) were successful in generating the first artificial hybrids in the genus. Crosses where T. lanatum was used as the female were unsuccessful. Leaf and floral morphology among the hybrids was typically intermediate. Female sterility was seen in the T. arizonicum × T. lanatum hybrids, and these hybrids also produced abnormally small, nonviable pollen grains. Propagation procedures are also presented. Although these species may be in different sections, their crossability suggests that they are closely related.
Remote Sensing of Canopy Cover in Horticultural Crops
Authors: Trout Thomas J. , Johnson Lee F. , Gartung Jim
Published: February 2019

Canopy cover (CC) is an important indicator of stage of growth and crop water use in horticultural crops. Remote sensing of CC has been studied in several major crops, but not in most horticultural crops. We measured CC of 11 different annual and perennial horticultural crops in various growth stages on 30 fields on the west side of California's San Joaquin Valley with a handheld multispectral digital camera. Canopy cover was compared with normalized difference vegetation index (NDVI) values calculated from Landsat 5 satellite imagery. The NDVI was highly correlated and linearly related with measured CC across the wide range of crops, canopy structures, and growth stages (R2 = 0.95, P < 0.01) and predicted CC with mean absolute error of 0.047 up to effective full cover. These results indicate that remotely sensed NDVI may be an efficient way to monitor growth stage, and potentially irrigation water demand, of horticultural crops.
Effects of Inoculations with Mycorrhizal Fungi of Soilless Potting Mixes During Transplant Production on Watermelon Growth and Early Fruit Yield
Authors: Westphal Andreas , Snyder Nicole L. , Xing Lijuan , Camberato James J.
Published: February 2019

Watermelon, Citrullus lanatus (Thunb.) Matsum. & Nakai, crops are continuously exposed to soilborne diseases. In many areas of the United States, greenhouse-raised watermelon seedlings are transplanted to the field to allow for early crop establishment and early fruit production. This practice can result in weakened root systems, which potentially make the plant prone to premature senescence and reduce crop productivity. Mycorrhizal fungi have been reported to improve plant growth in many crops through enhanced root growth and function. We hypothesized that amending potting mixes with commercial inocula of mycorrhizal fungi during seeding of watermelon in a greenhouse would improve watermelon production when seedlings were transplanted to the field. Colonization of watermelon roots with mycorrhizal fungi from three commercial formulations was compared with the colonization of onion roots to confirm the efficacy of the mycorrhizae. Two inocula of mycorrhizal fungi that resulted in colonization of watermelon roots were tested in the field and glasshouse for their potential to improve watermelon production. MycoApply improved early plant growth in two tests, one under Meloidogyne incognita-infested conditions in loamy sand and another at two phosphorus fertilizer levels (0 or 22 kg·ha−1 P) in a loam soil. Mycor Vam Mini plug improved early fruit yield in soil infested with M. incognita. Application of Myconate (formononetin), a potential enhancer of colonization with mycorrhizae, increased early fruit yield in M. incognita-infested soil. Myconate had positive effects when potting mixes were not amended with inoculum of mycorrhizal fungi, but reduced watermelon growth when mycorrhizal fungi were supplied in the potting mix. In glasshouse tests, inoculation with mycorrhizal fungi did not suppress disease. Mycorrhizal fungi inoculations improved early plant establishment and increased the most valuable early fruit yield under some environmental stress conditions but did not increase total fruit yields.
Consumer Preferences for Price, Color Harmony, and Care Information of Container Gardens
Authors: Mason Shannon C. , Starman Terri W. , Lineberger R.D. , Behe Bridget K.
Published: February 2019

Retail sales of container gardens have increased dramatically in recent years, rising 8% from 2004 to 2005, to $1.3 billion. The objective of this study was to determine consumer preferences for three attributes of container gardens; color harmony, price, and amount of care information provided with the purchase. A hierarchical set of levels for each attribute was used in a 3 × 3 × 3 factorial conjoint analysis. A Web-based survey was conducted on 18 Oct. 2006 with 985 respondents. Survey participants were asked to complete a series of questions on a 7-point Likert scale. Survey participants also answered questions about past experiences with and future purchase intentions of container gardens as well as demographics. The three attributes accounted for 99.8% of the variance in container garden preference. Relative importance decreased from price (71%) to amount of care information (23%) to color harmony (6%). Survey participants preferred a container garden with a price point of $24.99, extensive care information, and complementary color harmony. A large portion (76%) of participants in this study indicated that they would be more likely to purchase a container garden if extensive care information was included with the purchase and 85% of participants said they would be willing to visit an Internet Web site that would provide more information on how to care for and maintain a container garden. Results of this study show that there is a potential to increase the value of a container garden through providing educational material with the purchase.
Detention and Recycling Basins for Managing Nutrient and Pesticide Runoff from Nurseries
Authors: Mangiafico Salvatore S. , Gan Jay , Wu Laosheng , Lu Jianhang , Newman Julie P. , Faber Ben , Merhaut Donald J. , Evans Richard
Published: February 2019

Production nurseries may be significant sources of nutrients and pesticides in runoff as a result of the intensity at which fertilizers, pesticides, and irrigation water are applied. Concentrations of nutrients and pesticides in runoff from production nurseries are not extensively documented. Runoff from 11 production nurseries in southern California using either recycling or detention basins was monitored for nutrients and pesticides. For six sites, runoff volume was determined and nutrient loads in runoff were calculated. Water use data, percentage of water recycled, and construction costs were determined for sites with recycling systems. Nutrient concentrations, mass loads, and pesticide detections in runoff from some sites would have been of concern without the implementation of detention or recycle basins. There were few differences in nutrient concentrations or pesticide detections between runoff from irrigation and that from precipitation events. This suggests the need for management practices and technologies that address runoff from both irrigation and precipitation events. Water use and cost data suggested that the implementation of recycling systems may be more beneficial and cost-efficient for larger facilities.
Postharvest Senescence and Deterioration of ‘Thoroughbred’ and ‘Carlo’ Green Beans (Phaseolus vulgaris L.) in Response to 1-Methylcyclopropene
Authors: Cho MiAe , Hurr Brandon M. , Jeong Jiwon , Lim Chaill , Huber Donald J.
Published: February 2019

Nonclimacteric commodities produce low levels of ethylene yet remain quite sensitive to the growth regulator. 1-Methylcyclopropene (1-MCP; SmartFresh Quality System), an inhibitor of ethylene action, allows analysis of the effects of endogenous ethylene on the senescence of nonclimacteric commodities during storage. Two commercial cultivars (Thoroughbred and Carlo) of fresh green beans (Phaseolus vulgaris L.) were treated with 0.5 μL·L−1 1-MCP followed by storage at 7 °C. 1-MCP was effective in delaying color change, brown spot incidence, and watersoaking in both cultivars. 1-MCP was effective at delaying yellowing as indicated by a decline in surface hue and chroma; however, lightness was not significantly different between control and 1-MCP-treated beans. Respiration in both cultivars was suppressed, but ethylene production was stimulated late during storage in response to 1-MCP. The appearance of brown spot, a surface disorder possibly reflecting low-temperature injury, was delayed by ≈5 days, and the progression of the disorder was reduced in 1-MCP-treated beans. The incidence of watersoaking in ‘Carlo’ was reduced by 50% in 1-MCP-treated compared with control beans. 1-MCP alleviated symptoms of senescence and chill injury of green beans during long-term storage, implicating a role for endogenous ethylene in the senescence of nonclimacteric commodities after harvest.
Optimizing the Storage Temperature and Humidity for Fresh Cranberries: A Reassessment of Chilling Sensitivity
Authors: Forney Charles F.
Published: February 2019

Studies were conducted over three seasons to determine the relationship of temperature and humidity on the storage life of fresh cranberry (Vaccinium macrocarpon Aiton) fruit. Each year, cranberries harvested from four commercial bogs were stored at temperatures ranging from 0 to 10 °C in combination with relative humidities (RH) ranging from 75% to 98%. Fruit were stored under these conditions for up to 6 months and were evaluated monthly for marketability, decay, physiological breakdown, weight loss, and firmness immediately after removal and after an additional week at 20 °C. The percentage of marketable fruit declined substantially over time in all storage conditions with 41% to 57% becoming unmarketable after 2 months as a result of both decay and physiological breakdown. Relative humidity had a greater effect on fruit storage life than temperature and after 5 months, the amount of marketable fruit stored in high (98%) and medium (88%) RH was 71% and 31% less than that stored in low (75% to 82%) RH. Rates of fresh weight loss increased as RH in storage decreased and was 0.41%, 0.81%, and 0.86% per month in fruit stored in high, medium, and low RH, respectively. Fruit firmness was not significantly affected by RH. The effects of storage temperatures ranging from 0 to 7 °C on marketable fruit after 2 to 5 months of storage were not significant. Only fruit stored at 10 °C consistently had fewer marketable fruit when compared with fruit stored at lower temperatures. Storage temperature had no significant effect on decay incidence. However, physiological breakdown was greatest in fruit stored at 10 °C. Rates of fresh weight loss increased with storage temperature, ranging from 0.35% to 1.17% per month for fruit stored at 0 to 10 °C, respectively. Contrary to previous reports, no evidence of chilling injury was found in cranberry fruit stored at 0 °C. Results suggest that cranberry fruit should be stored at 0 to 7 °C and 75% to 82% RH to retain marketable fruit.
In Vitro Clonal Propagation of Vanilla (Vanilla planifolia ‘Andrews’)
Authors: Lee-Espinosa Hilda E. , Murguía-González Joaquín , García-Rosas Benjamín , Córdova-Contreras Ana L. , Laguna-Cerda Antonio , Mijangos-Cortés Javier O. , Barahona-Pérez Luis F. , Iglesias-Andreu Lourdes G. , Santana-Buzzy Nancy
Published: February 2019

A complete and efficient regeneration protocol was developed for Vanilla planifolia ‘Andrews’, an endangered orchid species that represents an important crop in several tropical countries. Axillary buds excised from the first to the eighth node, considering the first to fourth nodes as “young” (zone 1) and the fifth to eighth as “mature” (zone 2), were cultured on Murashige and Skoog (MS) medium supplemented with 5.73, 7.64, 9.55, or 11.46 μm 6-benzylaminopurine (BA) for shoot induction and in combination with 4.45 μm naphthalene acetic acid (NAA) to induce multiple shoot proliferation. Cytokinin concentration and bud position in the stem had a significant effect on the number of shoots regenerated. The greatest shoot formation per explant, for the two tested zones, was obtained with 9.55 μm BA on MS medium supplemented with 100 mg·L−1 myoinositol, 150 mg·L−1 citric acid, 100 mg·L−1 ascorbic acid, and 20 g·L−1 sucrose. Young buds from zone 1 were able to form an average of 18.5 ± 2.4 shoots per explant, whereas buds from zone 2 induced a maximum of 11.0 ± 1.0 shoots per explant. Plants of 2 to 3 cm height developed a root system in half-strength MS medium supplemented with 0.44 μm NAA and, once they reached 5 cm height on average, were transferred to greenhouse conditions for their acclimatization where a 100% rate survival was achieved. The optimal use of both young and mature buds from each mother plant to induce adventitious shoots permitted a marked increase in the number of shoots per explant. By using all buds from the upper stem part (zone 1 + zone 2) and subculturing every 90 d, the multiplication rate was 1.1 to 1.86 × 105 shoots per bud per year.
Growing Black Chokeberry (Aronia melanocarpa) in Cut-over Peatlands
Authors: Bussières Julie , Boudreau Stéphanie , Clément–Mathieu Guillaume , Dansereau Blanche , Rochefort Line
Published: February 2019

This project was established to evaluate the feasibility of black chokeberry [Aronia melanocarpa (Michx.) Ell.] culture on Canadian cut-over peatlands and to define its appropriate production practices. We tested the effects of different fertilizer rates, application methods, and mulches on the vegetative development and berry production of seedlings over a 6-year period (2000 to 2006). Fertilization was essential for survival of the plants. A low fertilizer rate (131 g/plant of 1.7N–4.1P–12K) ensured adequate vegetative development for good establishment. Applying such a rate for 2 consecutive years proved to be more beneficial than a single dose of fertilizer for increasing plant height, crown width, and height growth. However, fruit yield was best when fertilized with the highest dose tested (550 g/plant of 3.4N–8.3P–24.2K). Black plastic mulch had a positive effect on height, width, and growth of the plants. More weeds were observed when the fertilizer was applied to the surface as compared with soil incorporation. However, this study revealed that black chokeberry is tolerant of weeds. Based on these results, black chokeberry is a promising plant for the management of cut-over peatlands for both vegetative growth and fruit production.
Mineral Nutrition, Growth, and Germination of Antirrhinum majus L. (Snapdragon) when Produced Under Increasingly Saline Conditions
Authors: Carter Christy T. , Grieve Catharine M.
Published: February 2019

The conservation of quality water is of special concern, especially in California, as the need for quality water increases with a growing population. Reusing saline wastewaters to irrigate salt-tolerant floral crops provides a viable option to produce quality marketable cut flowers while conserving the highest quality water for other purposes. A completely randomized design with three replications was used to investigate the effects of five salinity treatments [2.5 (control), 5, 8, 11, 14 dS·m−1] and two water ionic compositions: concentrations of Colorado River water (CCRW) and dilutions of sea water (SWD), on the mineral uptake, germination, growth, and quality of two cultivars of Antirrhinum majus (‘Monaco Rose’ and ‘Apollo Cinnamon’). Seeds of both cultivars were sown in 30 greenhouse sand tanks. Leaves were collected 2 months after planting and analyzed for concentrations of Ca2+, Mg2+, Na+, Cl−, K+, total P, and total S. As salinity increased, Ca2+, Mg2+, Na+, Cl–, and total S increased in plant tissues, whereas K+ and total P decreased in plant tissues for both cultivars in both irrigation solutions. Leaf nutrient composition was related to the interactions of ions within the substrate solutions and their ability to compete for uptake at the site of root membranes. Phenotypic measurements, made when plants were harvested, showed only slight decreases as salinity increased. A 2 × 5 factorial design was used to determine the effects of water ionic composition and salinity on the germination of seeds. Four replicate Petri dishes each with 25 seeds were exposed to constant temperature (20 °C) and an 8-h dark : 16-h light photoperiod to promote germination. Germination was checked daily for 16 d. Snapdragons can be produced from seed when exposed to salinities up to 14 dS·m−1 using both SWD and CCRW ionic solutions for irrigation because germination remained at 92% or greater. Quality of the flowering stems was rated according to standards developed by the Society of American Florists. Marketable stems of both cultivars were produced in all treatments. Overall, quality of stems produced with saline waters ranging from 2.5 to 11 dS·m−1 was very high (“special”). Irrigation with more saline water (14 dS·m−1) resulted in a slight reduction in quality and stems were rated as “fancy” depending on the cultivar. Both cut flower cultivars can be produced for commercial use under saline conditions up to at least 14 dS·m−1.
Yield and Composition of Ocimum basilicum L. and Ocimum sanctum L. Grown at Four Locations
Authors: Zheljazkov Valtcho D. , Cantrell Charles L. , Evans William B. , Ebelhar M. Wayne , Coker Christine
Published: February 2019

Sweet basil (Ocimum basilicum L.) and holy basil (Ocimum sanctum L.) are the most widely grown basil species in the world either for the fresh market or for essential oil production. Both species are considered to be promising essential oil crops in the southeastern United States; however, research on oil production and composition of these species in Mississippi and the southeastern United States is lacking. The objective of this study was to evaluate biomass productivity, oil content, and oil composition of sweet basil (Ocimum basilicum L.) cvs. German and Mesten and holy basil (Ocimum sanctum L.) cv. Local grown at four locations in Mississippi. Overall, the three basil cultivars grew well; the fresh herbage and essential oil yields at three of the locations were high and comparable to basil yields reported in the literature. Essential oil content in air-dry herbage and the essential oil yields were as follows: 0.07% to 0.50% and 0.7 to 11.0 kg·ha−1 in sweet basil cv. Mesten, 0.2% to 0.5% and 1.4 to 13.0 kg·ha−1 in sweet basil cv. German, and 0.08% to 0.40% and 0.6 to 5.3 kg·ha−1 in holy basil cv. Local, respectively. The main constituent of sweet basil cultivars was (–)-linalool with other constituents being (–)-camphor, α-humulene, eucalyptol, eugenol, (–)-bornyl acetate, methyl chavicol, (–)-trans-caryophyllene, α-trans-bergamotene, and cadinol. The main constituents of holy basil were methyl chavicol, eugenol, and eucalyptol with other constituents being α-humulene, humulene-epoxide II, (–)-trans-caryophyllene, α-trans-bergamotene, and γ-cadinene. Our results suggest sweet and holy basils have a potential as new essential oil crops for Mississippi and possibly the southeastern United States and can provide oil yields and composition typical for the respective species.
Estimating U.S. Consumers' Choice of Floral Retail Outlets
Authors: Yue Chengyan , Behe Bridget K.
Published: February 2019

Competition among floral retailers has promulgated industrywide structural changes while giving consumers more choices in locations for purchase. Consumer panel data collected by the American Floral Endowment from 1992 to 2005 were used to evaluate consumers' choice of different floral retail outlets among box stores (BS), traditional freestanding floral outlets (TF), general retailer (GR), other stores (OS), and direct-to-consumer (DC) channels. Since 1992, market share and percentage of transactions decreased through TF but increased for BS. Mean expenditure per transaction in TF was higher than in BS and GR. Consumers who made floral gift purchases were more likely to patronize TF, but those who bought floral products for themselves were more likely to purchase from BS. Consumers patronizing TF or DC were more likely to buy arranged flowers rather than unarranged flowers. Consumers who purchased foliage plants and outdoor bedding or garden plants were more likely to buy them from BS. Reasons consumers who choose BS and GR cited for using those outlets included convenience and lower prices, whereas consumers who purchased from TF and DC cited delivery, reputation, and service as major drivers impacting their use. Demographic and geographic differences were also identified among consumers using the aforementioned outlets.
Morpho-physiological Responses of Several Fescue Grasses to Drought Stress
Authors: Wang Jianping P. , Bughrara Suleiman S. , Nelson C. Jerry
Published: February 2019

Identification and screening of grasses with excellent drought tolerance is a desirable strategy in breeding drought-tolerant turf and forage cultivars. Not all fescue selections and cultivars may be equally drought tolerant. An Atlas fescue (Festuca mairei St. Yves) selection and three tall fescue (Festuca arundinacea Schreb.) cultivars—Barolex, Kentucky 31, and Falcon II—were subjected to increasing drought stress for a 12-week period. Soil water content (SWC), leaf elongation (LE), leaf water content (LWC), and leaf water potential (Ψw) were measured weekly, and root length (RL) and biomass (RM) were recorded after 12 weeks. The SWC declined progressively during the 12-week drought treatment for all grasses. However, for the three tall fescue cultivars, the SWC decreased at a faster rate than for Atlas fescue. This indicated that Atlas fescue extracted soil water more slowly and developed less-intensive stress than the three tall fescue cultivars. The LE, LWC, and leaf Ψw decreased in drought-treated plants of all grasses; nevertheless, the values for the Atlas fescue remained similar to control plants for a longer period of time than the values for the three tall fescue cultivars. Drought stress significantly reduced root biomass and root length of the grasses. These four Festucas avoid drought stress through changes in leaf and root morphology and probably through osmotic adjustment to maintain sufficient turgor pressure in the growing zone for leaf elongation. The slower decrease in LE, LWC, and leaf Ψw for Atlas fescue during the drought-stress period suggested greater drought tolerance and the potential value for improving this character in a breeding program.
Comparison of Weed Suppression and Mandarin Fruit Yield and Quality Obtained with Organic Mulches, Synthetic Mulches, Cultivation, and Glyphosate
Authors: Abouziena H.F. , Hafez O.M. , El-Metwally I.M. , Sharma S.D. , Singh M.
Published: February 2019

Organic crop production, whether for export or local consumption, is increasing to avoid the residual effects of synthetic herbicides in foods, soil, and water, toxicity to other nontarget organisms, and herbicide-resistant weed populations. Organic farmers consistently ranked weed management as one of their most important production problems. Therefore, a 2-year study was conducted under 15-year-old mandarin trees to compare the effects of rice straw mulch, cattail mulch, black plastic mulch, hand hoeing, cultivation, glyphosate, and unweeded control treatments on weed control, fruit yield, and fruit quality. The greatest control (94%–100%) of weeds occurred with the plastic mulch (200 or 150 μm) and three mulch layers of rice straw or cattail. Covering soil with cattail or rice straw mulch (two layers) gave 85% to 98% control of weeds. Uncontrolled weeds in the weedy control caused significant reduction in yield and fruit quality and decreased the yield/tree by 62% compared with hand hoe treatment. Plastic mulches of 200 and 150 μm, cattail (Cyprus articulatus L.) mulch (two or three layers) and two mulch layers of rice (Oryza sativa L.) straw treatments significantly increased the fruit yield/tree by 24%, 18%, 20%, 11%, and 12% more than cultivation treatment, respectively, without significant differences among these superior treatments. Soil mulching with three layers of rice straw, cultivation, glyphosate, and 80-μm plastic mulch treatments caused a significant reduction in weed density and weed biomass, but gave lower yield than superior treatments. Total soluble solids of fruits was unaffected by any of the weed management strategies, whereas values of total acidity and vitamin C were significantly lower in the unwedded control than most weeded treatments. These results demonstrate that two layers of cattail or rice straw mulch could be used effectively for controlling weeds in citrus groves. Their effectiveness in controlling weeds may increase their use in agriculture systems with a concomitant decrease in the need for synthetic herbicides. Further studies are needed to evaluate their side effects on beneficial organisms, diseases, and insects.
Differential Nitrogen and Phosphorus Recovery by Five Aquatic Garden Species in Laboratory-scale Subsurface-constructed Wetlands
Authors: Polomski Robert F. , Bielenberg Douglas G. , Whitwell Ted , Taylor Milton D. , Bridges William C. , Klaine Stephen J.
Published: February 2019

Intensive production of container-grown nursery and greenhouse crops in soilless substrate may result in significant leaching of nutrients and pesticides. The resulting runoff can escape from production areas and negatively impact surface and ground water. Constructed wetlands (CWs) have been shown to be a simple, low-technology method for treating agricultural, industrial, and municipal wastewater. We investigated the nitrogen (N) and phosphorus (P) removal potential by a vegetated, laboratory-scale subsurface flow (SSF) CW system. Over an 8-week period, five commercially available aquatic garden plants received a range of N and P (0.39 to 36.81 mg·L−1 N and 0.07 to 6.77 mg·L−1 P) that spanned the rates detected in nursery runoff. Whole plant dry weight was positively correlated with N and P supplied. Highest N and P recovery rates were exhibited by Thalia geniculata f. rheumoides Shuey and Oenenathe javanica (Blume) DC. ‘Flamingo’, Phyla lanceolata (Michx.) Greene also had high P recovery rates. The potential exists for using SSF CWs to concomitantly produce aquatic garden plants and attenuate nutrients in a sustainable nursery enterprise.
Phosphorus Rate, Leaching Fraction, and Substrate Influence on Influent Quantity, Effluent Nutrient Content, and Response of a Containerized Woody Ornamental Crop
Authors: Owen James S. , Warren Stuart L. , Bilderback Ted E. , Albano Joseph P.
Published: February 2019

Production of containerized nursery crops requires high inputs of water and mineral nutrients to maximize plant growth to produce a salable plant quickly. However, input efficiencies remain below 50% resulting in major quantities of water and nutrients leached. This study was conducted to determine if production factors could be altered to increase water and phosphorus uptake efficiency (PUE) without sacrificing plant growth. The effects of a pine bark substrate amendment (clay or sand) and a 50% reduction in both P application rate (1.0 g or 0.5 g) and leaching fraction (LF = effluent ÷ influent) (0.1 or 0.2) were investigated. Containerized Skogholm cotoneaster (Cotoneaster dammeri Schnied. ‘Skogholm’) was grown on gravel floor effluent collection plots that allowed for calculation of water and nutrient budgets. Pine bark amended with 11% (by vol.) Georgiana 0.25 to 0.85 mm calcined palygorksite-bentonite mineral aggregate (clay) increased available water 4% when compared with pine bark amended with 11% (by volume) coarse sand. Decreasing LF from 0.2 to 0.1 reduced cumulative container influent 25% and effluent volume 64%, whereas total plant dry weight was unaffected by LF. Reduction of target LF from 0.2 to 0.1 reduced dissolved reactive P concentration and content by 8% and 64%, respectively. In a sand-amended substrate, total plant dry weight decreased 16% when 1.0× P rate was reduced to 0.5× P, whereas total plant dry weight was unaffected by rate of P when pine bark was amended with clay. Plant content of all macronutrients, with the exception of N, increased when pine bark was amended with clay versus sand. Reducing P rate from 1.0× to 0.5× increased PUE 54% or 11% in a clay or sand-amended substrate, respectively. Amending pine bark with 11% (by volume) 0.25 to 0.85 mm calcined palygorksite-bentonite mineral aggregate produced an equivalent plant with half the P inputs and a 0.1 LF, which reduced water use 25% and P effluent losses 42% when compared with an industry representative substrate [8 pine bark : 1 sand (11% by volume)].