bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Forchlorfenuron and Abscisic Acid on the Quality of ‘Flame Seedless’ Grapes
Authors: Peppi M. Cecilia , Fidelibus Matthew W.
Published: February 2019

Forchlorfenuron (CPPU), a synthetic cytokinin, applied after fruit set increases the size and firmness of table grapes (Vitis vinifera L.) beyond what is possible without CPPU treatment. However, treatment with CPPU may inhibit coloring of ‘Flame Seedless’ grapes, limiting its use in growing areas where color has been consistently poor. In contrast, application of abscisic acid (ABA) to ‘Flame Seedless’ grapes may cause fruit softening, which is undesirable, but its primary effect is to increase anthocyanin content and fruit color. Thus, we hypothesized that application of CPPU followed by ABA might increase the size and firmness of ‘Flame Seedless’ grapes without excessively inhibiting coloring. Grapes were treated with 0 or 20 g·ha−1 CPPU (applied at fruit set) and 0, 300, or 600 mg·L−1 ABA (applied at veraison) in 2005 and with 0, 5, 10, 15, or 20 g·ha−1 CPPU and 0, 200, 400, or 600 mg·L−1 ABA in 2006. Both plant growth regulators (PGRs) increased berry mass, but grapes treated with CPPU were as firm, or firmer, than nontreated grapes, whereas those treated with ABA were of similar or lesser firmness. Treatment with CPPU generally reduced soluble solids and red berry color, whereas treatment with ABA reduced titratable acidity and increased red color. The PGRs did not interact to affect any of the fruit quality variables measured, so beneficial effects of CPPU or ABA were apparent whether the grapes were treated with either or both PGRs. Thus, the combined use of CPPU and ABA may be a desirable cultural practice for ‘Flame Seedless’.
Response of Weeds and Ornamental Plants to Potting Soil Amended with Dried Distillers Grains
Authors: Boydston Rick A. , Collins Harold P. , Vaughn Steven F.
Published: February 2019

This research evaluated the use of dried distiller grains with solubles (DDGS) as a soil amendment to suppress weeds in container-grown ornamentals. DDGS is a byproduct of ethanol produced from corn, and developing new uses for DDGS could increase the profitability of ethanol production. Adding DDGS to a commercial pine bark potting mix reduced emergence and growth of common chickweed (Stellaria media) at concentrations of 5% (by weight) or greater and annual bluegrass (Poa annua) at concentrations of 10% (by weight) or more. Herbicidal activity of DDGS was maintained in methanol-extracted DDGS. Rosa hybrid ‘Red Sunblaze’, Phlox paniculata ‘Franz Schubert’, and Coreopsis auriculata ‘Nana’ transplanted into potting soil amended with 20% by weight DDGS were severely stunted and nearly all plants died. Plants survived when transplanted into potting soil containing 10% DDGS by weight, but growth was greatly stunted and flowering of rose and coreopsis was reduced. Addition of 20% DDGS decreased the C:N ratio from 90:1 to 24:1 for the potting mix and from 23:1 to 10:1 for a soil. The decrease in C:N ratio resulted in a twofold increase in microbial respiration at 3 d and 14 d of incubation for both the potting mix and soil. As a result of the phytotoxicity observed on ornamentals transplanted into DDGS-amended potting soil, subsequent studies evaluated surface-applied DDGS to suppress weeds. DDGS applied at 400 g·m−2 or less to the soil surface at transplanting did not reduce emergence or growth of common chickweed or annual bluegrass. DDGS applied at 800 and 1600 g·m−2 to the surface of transplanted ornamentals reduced number of annual bluegrass by 40% and 57% and common chickweed by 33% and 58%, respectively, without injury to transplanted ornamentals. DDGS may be useful for reducing weed emergence and growth in container-grown ornamentals applied to the soil surface at transplanting.
Grape Cultivar Feeding Preference of Adult Japanese Beetles
Authors: Gu Sanjun , Pomper Kirk W.
Published: February 2019

The Japanese beetle is a major insect pest of grapes in the eastern United States. An examination of Japanese beetle preference for currently grown grape cultivars would be useful to growers in developing pest control strategies with reduced chemical inputs. The objective of this study was to examine grape cultivar preference of Japanese beetles for commercially available grape cultivars in both cage choice and field experiments. Outdoor cage choice screening studies included 32 grape cultivars from various Vitis species and were conducted at the Kentucky State University Research Farm in Frankfort, KY. Feeding preference was determined by examining incidence of damage (percent of leaves damaged per vine) and leaf area loss, which was rated as 0 pt, 0%; 1 pt, 1% to 10%; 2 pt, 11% to 20%; 3 pt, 21% to 30%; 4 pt, 31% to 40%; 5 pt, 41% to 50%; 6 pt, 51% to 60%; and 7 pt, more than 60%, by leaf position from the first (shoot tip) to 10th leaves. Analysis of variance indicated that there were significant differences in Japanese beetle leaf damage for cultivar and leaf position main effects. Leaf damage by Japanese beetles varied by leaf position on the shoot, with the fourth through sixth leaves from the tip with the most severe damage. Generally, cultivars showing an incidence of damage greater than 70% were either European or French hybrid cultivars, and those with less than 70% incidence of damage were either American cultivars or American cultivars with a V. labrusca background. The grape cultivars Marquis, Reliance, Catawba, Concord Seedless, Concord, Edelweiss, and Einset showed promise as selections for growers interested in reduced chemical inputs for control of Japanese beetles.
Static Liquid Culture of Doritaenopsis Seedlings
Authors: Tsai Wei-Ting , Chu Chien-Young
Published: February 2019

Methods for static liquid culture are described to improve the growth of Doritaenopsis (commercially known as Phalaenopsis) seedlings in vitro. The results showed that seeds not only germinated, but also grew faster in liquid medium. No hyperhydric seedlings were observed in liquid culture when liquid level was accurately controlled by culture density, medium volume, and sealing materials. Although the germination percent was unaffected by medium phase (liquid or solid), sowing density, medium volume, or sealing material, the growth of seedlings decreased as density increased or medium volume decreased. Seeds of 1.5 mg mixed with 20 mL of liquid medium per 9-cm petri dish sealed with two layers of parafilm prompted optimal results. Shoot growth also was enhanced while 75-day-old seedlings were subcultured in liquid media with or without support. Seedling growth was enhanced by adding 20 mL liquid media to 36 seedlings without support after 45 days of culture. It was expected that by static liquid culture, the period from sowing to ex vitro would be 1.5 months shorter than the traditional solid culture.
Organic Quarantine Treatments for Tree Fruits
Authors: Neven Lisa G.
Published: February 2019

Organic production of pome and stone fruits in the United States has greatly increased during the past few years. To compete and enter lucrative export markets, these fruit must meet stringent quarantine requirements. For some countries, these requirements dictate that the fruit crops must be treated with a synthetic chemical fumigant, which is not compliant with organic standards. Therefore, nonchemical quarantine treatments for organically produced pome and stone fruits have been developed using the Controlled Atmosphere/Temperature Treatment System (or CATTS) technology. This technology applies a short-term heat treatment under a low-O2/high-CO2 environment, and is effective in controlling the most prominent quarantine insect pests while maintaining commodity quality. The technology has progressed beyond laboratory-scale research units to 1- to 2-ton commercial units. The development of these treatments and their effect on both insect mortality and commodity quality are discussed.
Modeling the Effects of Temperature and Gibberellic Acid Concentration on Red Huckleberry Seed Germination
Authors: Lopez Omar A. , Barney Danny L. , Shafii Bahman , Price William J.
Published: February 2019

Low seed germination percentages have been reported for red huckleberry (Vaccinium parvifolium Smith). Attempts to improve germination percentages and the speed of germination for red huckleberry are described. Red huckleberry seeds from two collection sites were given gibberellic acid potassium salt (GA-K) treatments (0, 500, 1000, and 1500 mg·L−1) and were germinated under three temperature regimens [constant 22 °C, 22 °C day/5 °C night (22/5 °C), and 20 °C day/13 °C night (20/13 °C) with a 12-h photoperiod]. A logistic regression model was used to assess the effects of temperature regimens and GA-K treatments on the maximum cumulative germination percentages, rates of increase, and germination lag times. For seeds untreated with GA-K, the 20/13 °C temperature regime resulted in germination percentages ranging from 30% to 61% and lag times (i.e., time to reach one-half of the maximum cumulative germination percentage) of 29 to 35 d for the two accessions. In comparison, the 22/5 °C temperature regime produced germination percentages of 12% and 38% and lag times of 38 to 64 d. The 22 °C constant temperature produced germination percentages ≤1%. Maximum germination percentages of up to 75% were obtained with 1500 mg/L GA-K. Rates of germination were generally unaffected by GA-K treatments, and germination lag times were reduced by an average of 10 d when compared with without GA-K. Improved germination percentages and reduced lag times for red huckleberry seeds were obtained by using a 20/13 °C temperature regime and 1000 to 1500 mg·L −1 GA-K.
Spatial and Temporal Distribution of Soil Moisture in Drip-irrigated Vineyards
Authors: Davenport Joan R. , Stevens Robert G. , Whitley Kelly M.
Published: February 2019

In arid and semiarid areas, wine grapes are frequently managed using regulated deficit irrigation (RDI) to control vegetative growth. To understand the distribution of soil moisture using RDI in a drip-irrigated vineyard, we collected soil samples after several irrigation events around six drip emitters in two ‘Cabernet Sauvignon’ and two ‘Merlot’ vineyards from late July through Mar. 2002 and 2005. The March sampling depicts soil moisture status before budbreak after winter precipitation. Soil samples were collected in four depth increments at 16 locations in a half-circle radius from immediately below the emitter to a depth of 60 cm. Both gravimetric and volumetric soil moisture content were determined. Soil moisture varied by depth, distance from the emitter, and sampling time. During late-season irrigation events, 50% to 75% of the sampled area contained plant-available water, which was less than expected. When calculated as plant-available soil moisture, regardless of time of sampling, soil sampled across a 0- to 45-cm depth provided the most representative indication of soil moisture status. Additionally, sampling directly under the emitter or directly under the drip line could result in skewed measurements compared with the sampled area. The data suggest that collecting soil samples within a 20- to 40-cm radius, either diagonal or perpendicular to the drip line emitter position, will best reflect the amount of plant-available soil water. Additionally, monitoring should be conducted on both sides of the row around each emitter selected and then averaged to avoid any patterns from hilling or disruption in water flow patterns.
‘Kashi Madhu’: A New Muskmelon Cultivar with High Total Soluble Solids
Authors: Pandey Sudhakar , Rai Mathura , Prasanna H.C. , Kalloo G.
Published: February 2019

‘Kashi Madhu’ (Cucumis melo L.) is a new muskmelon cultivar released for agroecological zone IV of India comprising the states of Uttar Pradesh, Uttaranchal, Delhi, Punjab, and Bihar. The cultivar was developed through selection from a local landrace. Plants bear androemonoecious flowers, round and yellow fruits with prominent green sutures and orange flesh color. The fruits become ready for first harvest in ≈90 days from seed sowing. The fruits have a distinct flavor and higher total soluble solids as compared with other cultivars recommended for cultivation in India after evaluation under different agroecological zones of India under the All India Coordinated Research Project on Vegetable Crops. The release of this cultivar was announced at the XIII meeting of Central Sub-committee on Crop Standard Notification and Release of Varieties for Horticultural Crops.
Pollination of Dendrobium Hybrids Using Cryopreserved Pollen
Authors: Vendrame Wagner A. , Carvalho Virginia S. , Dias José M.M. , Maguire Ian
Published: February 2019

Pollination effectiveness was evaluated for pollen (pollinia) from two Dendrobium hybrids, ‘Sena Red’ and ‘Mini WRL’, submitted to cryopreservation using a vitrification protocol. Parameters evaluated included pollinia exposure to a previtrification solution (PVS2) under ice (0 °C) or room (27 ± 2 °C) temperatures from 1 to 4 hours before cryopreservation (LN). On removal from cryopreservation, pollinia were used to pollinate flowers of the same hybrids to verify viability and germination. All pollinia showed high percentages of germination (greater than 80%) after crosses were performed, except for pollinia from Dendrobium ‘Sena Red’ submitted to 3 hours of precooling (0 °C) in PVS2 followed by LN (60%) and for pollinia submitted to PVS2 for 3 hours at room temperature with no precooling (70%). Capsules were formed for both hybrids and seeds were successfully produced. The seed viability test revealed high viability (90% to 95%) for all treatments for both hybrids. Seeds observed under a microscope contained well-formed embryos and no abnormalities were identified. Seeds from all treatments germinated. Germinating seeds developed into healthy seedlings with well-formed leaves and roots. Cryopreservation of pollinia was successfully accomplished either by direct storage in liquid nitrogen without cryoprotection treatments or by using a PVS2 vitrification protocol.
Phenolic Content and Antioxidant Capacity of Pawpaw Fruit (Asimina triloba L.) at Different Ripening Stages
Authors: Kobayashi Hideka , Wang Changzheng , Pomper Kirk W.
Published: February 2019

Pawpaw [Asimina triloba (L.) Dunal], a native species of the eastern United States, bears the largest edible fruit of all indigenous trees. Chemoprotective properties of fruits have been partly attributed to phenolics such as gallic acid and chlorogenic acid, and the phenolic content generally correlates with antioxidant capacity for various kinds of fruits. Despite many reports of commonly available fruits, little information is available on phenolic content or antioxidant capacity for currently underused fruits. The objectives of this study were to determine the phenolic content (PC) and antioxidant capacity (AC) in fruit of two pawpaw cultivars at different stages of ripening. Sample extraction of pawpaw was achieved by adding acetone (2 mL/1g of sample) to the pulp of ‘PA-Golden (#1)’ and advanced selection 1-23, and then vortexing (30 s) and sonicating (15 min.) the sample and solvent before centrifuging it (15 min) twice at 2987 g. Folin-Ciocalteu assay and ferric reducing/antioxidant power assay were used for the estimation of PC and AC, respectively. PC and AC tended to decrease with ripening of fruit. The highest AC was found in the semiripe ‘PA-Golden (#1)’ puree (22.06 μmol TE/g fresh weight), whereas the puree of ripe fruit contained the lowest AC (17.04 μmol TE/g fresh weight), about a 23% decrease. In contrast, the greatest PC and AC were observed in intermediate fruits for 1-23. A positive correlation was found between PC and AC of fruit of ‘PA-Golden (#1)’ (r = 0.62) and 1–23 (r = 0.82). These results suggest that phenolic components of pawpaw pulp have a major effect on AC, as reported for other fruits and vegetables. The relatively high AC found in pawpaw pulp may motivate more health-conscientious people to consume pawpaw fruit. The diversity in PC and AC between pawpaw cultivars emphasizes the need for additional screening to identify cultivars with high AC and health-promoting potential.
Pollen Viability of Selected Diploid Watermelon Pollenizer Cultivars
Authors: Freeman Josh H. , Olson Stephen M. , Kabelka Eileen A.
Published: February 2019

In the Spring and Fall 2006, the pollen viability of four diploid watermelon pollenizers was evaluated in Quincy, FL. Triploid watermelon plants [Citrullus lanatus (Thunb.) Matsum. & Nakai.] do not produce sufficient viable pollen to pollenize themselves and a diploid cultivar must be interplanted as a pollen source. Recent studies have illustrated differences in triploid watermelon yields as a result of the pollenizer cultivar used. The viability of the pollen produced by pollenizer cultivars may greatly influence the fruit set and fruit quality in the triploid watermelon crop. Pollen samples were taken from ‘Companion’, ‘Jenny’, ‘Mickylee’, and ‘SP-1’ and were stained to determine their viability. There were no significant differences in pollen viability among cultivars and all cultivars had high average viability. Pollen viability was never lower than 95% for any cultivar. This study indicates that pollen viability of the cultivars evaluated should not influence their effectiveness as pollenizers.
Effects of Perimeter Trap Crop Pollen on Reproduction in Butternut Squash (Cucurbita moschata)
Authors: Hladun Kristen R. , Adler Lynn S.
Published: February 2019

Perimeter trap cropping (PTC) uses an attractive crop to concentrate pests at borders and reduce pesticide use while maintaining yield. A possible disadvantage of PTC could be pollen flow between border and main crops that are not interfertile. The effects of pollen composition and amount on seed and fruit production were investigated between a main crop species, butternut squash (Cucurbita moschata Duch. ex Poir), and a PTC species, blue hubbard (C. maxima Duch.). Butternut squash plants were hand pollinated in the greenhouse with three pollen composition treatments crossed with four pollen amounts. Pure butternut squash pollen and mixed pollen produced more seeds per fruit and heavier seeds than pure blue hubbard pollen, revealing some incompatibility between butternut and blue hubbard. Saturating pollen amounts produced up to six times more seeds than lower pollen amounts. Pollen composition did not influence fruit set or fruit weight, which are of central importance for crop yield. This study suggests that pollen flow between blue hubbard borders and butternut squash should not interfere with crop production as long as sufficient conspecific pollen is deposited on stigmas.
Postharvest Challenges for Organically Grown Orchard Fruit
Authors: Perkins-Veazie Penelope , Lester Gene
Published: February 2019

Switching from conventional to organic production requires a philosophical shift and recognition of different production system inputs plus postharvest handling challenges. First, and most obvious, is the replacement of common and readily available manufactured chemical inputs with approved “natural” or “nature-made compounds” (i.e., organic) for organic production. Many of these organic inputs may require new knowledge for successful implementation or may be less effective than conventional counterparts. Good orchard practices (e.g., cleanliness, bookkeeping) must be followed in an organic system just as they are in a conventional system. In addition, if processing (cider, sauces, or frozen fruit-sectioning preparations) is going to be part of the harvested operation, approved organic products will have to be used, and strict guidelines followed and documented. Organic versus conventional production system inputs can affect changes in the phytochemical and nutrient content of foods, and even change ripening patterns, which can affect harvest operations, marketing qualities, and consumer acceptance.
In Search of Key Soil Functions to Assess Soil Community Management for Sustainable Sweet Cherry Orchards
Authors: Moore-Kucera Jennifer , Azarenko Anita Nina , Brutcher Lisa , Chozinski Annie , Myrold David D. , Ingham Russell
Published: February 2019

Organic growers are required to maintain or improve soil chemical, biological, and physical properties and thus need to integrate biological processes into fertility management. However, few guidelines exist for satisfying tree nutrient demands ecologically. Sound nitrogen (N) management is a key component for overall orchard productivity whereas poor N management may result in multiple environmental impacts, including runoff to surface or leaching to groundwater sources. Many growers substitute synthetic inputs with rapid-release, approved N fertilizers that have little effect on long-term soil health and fertility. The authors seek an alternative approach for synchronizing nutrient availability with tree demand that relies on managing soil biological communities to attain their maximum potential functionality and thus meet tree nutrient demand. This paper outlines a new conceptual framework with which to evaluate a variety of soil functions that are quantified using biological, microbial, and biochemical properties in relation to overall orchard performance. By combining information gathered from soil faunal indices (nematode community structure and diversity analyses) with data obtained by biochemical and microbial analyses of the soil samples, a new, in-depth view of soil communities and their response to management practices will be obtained. As a result, a better understanding of the effects of differing management practices on soil fertility and community structure will be gained. This approach is currently being investigated by our group in organic and integrative sweet cherry orchards. Our goal is to determine which soil parameters may be used to help orchardists optimize soil health while maintaining orchard productivity. Furthermore, we wish to validate a number of assumptions that are commonly made regarding each soil parameter tested across multiple management, soil, and climate types.
Developing an Organic Production System for Highbush Blueberry
Authors: Sciarappa William , Polavarapu Sridhar , Barry James , Oudemans Peter , Ehlenfeldt Mark , Pavlis Gary , Polk Dean , Holdcraft Robert
Published: February 2019

Four significant developments have occurred that amplify opportunity for certified organic growers to grow highbush blueberry (Vaccinium corymbosum) successfully. First, there is the 2002 U.S. Department of Agriculture national organic standard that defines organic production practices and crop labels that creates clarity and evens competition. Second, we have the continued increase of smallfruit and vegetable sales related to nutritional and human health reasons and the related market perception valuing organic produce more highly. Third, new tools are becoming available to organic growers that reduce the risk from pest problems such as the recent Organic Materials Review Institute listing of spinosad registered as a wettable powder (Entrust) and a fruit fly bait (GF-120 NF Naturalyte). Finally, the Rutgers Blueberry Working group has made considerable progress in refining integrated pest management practices and in developing new tools for organic production systems. This “work-in-progress” is investigating alternative approaches to some current agricultural practices in soil building, fertility, cultural approaches, and pest management. The authors' 7-year program has demonstrated organic methods in managing new sources of mulch, two key insect pests, two common diseases, and several weed species in establishing a commercial organic production system for highbush blueberries. As a programmatic result, organic acreage in New Jersey has increased from 0 to more than 150 acres, and more than 40 organic growers have adopted parts of this holistic production system in North America.
Organic Apple Systems: Constraints and Opportunities for Producers in Local and Global Markets: Introduction to the Colloquium
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

The global market for total organic product sales was $20 billion in 2005, continuing an annual growth rate of 20% to 35%. In the United States, there were 937,000 ha of certified organic land in 2003 with 5626 ha of organic apples [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.]. Increases in organic fruit production have been associated with improved pest management methods, the use of disease-resistant cultivars, and organic-focused marketing schemes. Often constrained by lower apple yields and smaller fruit size compared with conventional counterparts, key challenges for organic growers include regulation of nutrient cycling processes to maintain crop yields while minimizing the need for external inputs. In local or regional organic markets, disease-resistant apple cultivars, such as ‘Enterprise’, ‘Liberty’, ‘Redfree’, and ‘Gold Rush’, have gained increased acceptance, whereas exporting countries have continued their use of cultivars susceptible to scab [Venturia inaequalis (Cooke)]. Integrated insect pest management approaches, including the use of kaolin clay, codling moth granulosis virus, and spinosad-based insecticides, have been successfully developed to comply with export standards and quarantines, and to meet market demand. Key pests, such as codling moth [Cydia pomonella (L.)], have been managed at damage levels less than 5% using these approaches. Future pest management strategies in organic apple production will focus on development of scab-resistant cultivars with enhanced storage capability and reduction in inputs associated with negative environmental and health effects.
Management, Survival Strategies, and Host Range of Colletotrichum acutatum on Strawberry
Authors: Freeman Stanley
Published: February 2019

Colletotrichum spp. are broad-range pathogens, meaning that many species can infect a single host and a single species can infect diverse hosts. For example, Colletotrichum acutatum J.H. Simmonds affects a wide range of crops, causing disease symptoms on apple, almond, anemone, citrus, lupin, peach, pecan, strawberry, and others, whereas Colletotrichum gloeosporioides Penz. (Penz. & Sacc.) can affect many of the previous hosts as well. Anthracnose is one of the major fungal diseases of strawberry occurring worldwide. In Israel, the disease is caused primarily by the species C. acutatum. The pathogen causes irregular leaf spot, bud rot, petiole and stolon necrosis, and black spot on fruit. The pathogen is most destructive when it causes root necrosis and crown rot, which usually kill the plants in nurseries and transplants in the field. To maintain a disease-free crop, nuclear and foundation stock material, as well as field nurseries, must be routinely monitored and tested for presence of the pathogen. Strawberry cultivation using plasticulture as an overhead cover of the crop can significantly control anthracnose disease incidence by reducing inoculum spread and infection, both in nurseries and in production fields. C. acutatum from strawberry can survive on several cultivated plant species, such as pepper, eggplant, tomato, bean, and weed species, without causing disease symptoms. This indicated that they may serve as a potential inoculum reservoir for strawberry infection between seasons. Although C. acutatum survives in soil under certain conditions, no specific resting structures have been observed indicating that the pathogen does not behave as a typical soilborne fungus.
Epidemiology and Pathology of Strawberry Anthracnose: A North American Perspective
Authors: Smith Barbara J.
Published: February 2019

Three Colletotrichum species—Colletotrichum acutatum J.H. Simmonds (teleomorph Glomerella acutata J.C. Guerber & J.C. Correll), Colletotrichum fragariae A.N. Brooks, and Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. in Penz. [teleomorph Glomerella cingulata (Stoneman) Spauld. & H. Schrenk]—are major pathogens of strawberry (Fragaria ×ananassa). Strawberry anthracnose crown rot has been a destructive disease in commercial strawberry fields in the southeastern United States since the 1930s. The causal fungus, C. fragariae, may infect all aboveground plant parts; however, the disease is most severe when the fungus infects the crown, causing crown rot, wilt, and death. Colletotrichum gloeosporioides was responsible for an epidemic of anthracnose crown rot in strawberry nurseries in Arkansas and North Carolina in the late 1970s. The anthracnose fruit rot pathogen, C. acutatum, was first reported in 1986 on strawberry in the United States. Since the 1980s, increased losses due to anthracnose fruit and crown rots in the United States may be related to changes in cultivars and to widespread use of annual plasticulture production rather than the matted-row production system. Anthracnose investigations in the United States have concentrated on its epidemiology and differences among the three causal Colletotrichum spp. in their cultural, morphological, and molecular characteristics; their infection processes; and their pathogenicity. Results from these studies have resulted in a better understanding of the diseases and have led to better disease control. Strawberries grown in soils with high nitrogen levels are more susceptible to anthracnose than are those grown in soils with lower nitrogen levels or those amended with calcium nitrate. Anthracnose is spread more rapidly in fields that have overhead irrigation and plastic mulch than in fields where drip irrigation and straw mulch are used. Fungicide efficacy has been determined in in-vitro, greenhouse, and field studies, and pathogen resistance to some fungicides has been detected. Anthracnose-resistant cultivars are a major objective of most strawberry breeding programs in the southern United States.
Special Problems in Nursery Propagation of Day-neutral Strawberry Cultivars Susceptible to Colletotrichum acutatum
Authors: Sjulin Thomas M.
Published: February 2019

Susceptible day-neutral strawberry (Fragaria ×ananassa Duch.) cultivars are readily infected by Colletotrichum acutatum J.H. Simmonds during nursery propagation. The fungus infects strawberry flowers and fruit under warm, moist conditions and spreads rapidly throughout the nursery planting during repeated cycles of infection. Plants transplanted from infected nurseries into fruit-production fields have increased plant mortality and yield loss. This paper reviews practices adopted by California strawberry nurseries that reduce or eliminate sources of fungal inoculum, reduce strawberry plant susceptibility, or reduce pathogen spread in the nursery. California nurseries are currently using a combination of these practices to produce specific pathogen-free planting stock of susceptible day-neutral cultivars.
Use of 1-Methylcyclopropene in Ornamentals: Carnations as a Model System for Understanding Mode of Action
Authors: Reid Michael S. , Çelikel Fisun G.
Published: February 2019

The first commercial use of 1-methylcyclopropene (1-MCP) was with cut flowers and potted plants, and treatment with this compound is still the preferred strategy for protection of most ethylene-sensitive crops. Research is continuing into optimum treatment conditions and strategies for efficient application in commerce. In studies using carnation (Dianthus caryophyllus L. ‘White Sim’) petals to determine the optimal conditions for commercial treatment, we noted some aspects of the inhibition response that were not consistent with the current competitive inhibition model of 1-MCP action. Our data are better explained by an alternative model in which 1-MCP binds to a site that is exposed during the allosteric changes that accompany the enzymatic activities of the binding site in the absence of ethylene.
How 1-Methylcyclopropene Has Altered the Washington State Apple Industry
Authors: Mattheis James P.
Published: February 2019

Commercialization of 1-methylcyclopropene (1-MCP) has provided a new tool to storage operators for management of fruit quality in the postharvest environment. For apple as an example, availability of the commercial 1-MCP product SmartFresh has brought an additional dimension to decisions regarding postharvest chemical treatments, storage temperature regimes, storage atmospheres, and planned storage duration based on fruit maturity at harvest. Poststorage impacts of 1-MCP use at harvest on handling and packing procedures have also become apparent with commercial use. Marketing programs have also been impacted because the “tails of the manifest” (large/small sizes, lower color grades) can be held longer in cold storage after packing primarily as a result of slower loss of firmness in many cultivars. Although some quality issues, primarily related to physiological disorders occurring on specific cultivars, are yet to be fully resolved, continuing widespread use of 1-MCP is indicative of its commercial usefulness.
Tolerance Response to Iron Chlorosis of Prunus Selections as Rootstocks
Authors: Jiménez Sergio , Pinochet Jorge , Abadía Anunciación , Moreno María Ángeles , Gogorcena Yolanda
Published: February 2019

The use of rootstocks tolerant to iron deficiency represents the best alternative to prevent Fe chlorosis for peach production in calcareous soils. Early detection laboratory screening procedures allow the selection of new Fe-efficient rootstock genotypes. Seventeen Prunus rootstocks were tested for root ferric chelate reductase (FC-R) enzymatic activity, leaf SPAD values, and field performance. Some rootstocks were used as a reference to compare with new Prunus selections. Micropropagated plants were grown in hydroponic culture with half-strength Hoagland's nutrient solution containing 90 μm Fe(III)-EDTA as a control treatment. Plants were transferred to iron-free fresh solutions for 4 days and were thereafter resupplied with 180 μm Fe(III)-EDTA for 1 or 2 days. In vivo FC-R activity was measured in all treatments, i.e., control, Fe-deficient, and 180 μm Fe(III)-EDTA resupplied plants. The FC-R activity after Fe resupply was higher in Fe-efficient genotypes such as AdesotoPVP, FelinemPVP, GF 677, Krymsk 86™, and PAC 9921-07 than in the controls. No induction of FC-R activity was found in other genotypes such as Barrier, Cadaman™-AvimagPVP, PAC 9907-23, and PAC 9908-02. An intermediate response was observed in GarnemPVP, Gisela 5PVP, Krymsk 1PVP, Torinel™-AvifelPVP, VSL-2™, and PAC 9904-01. According to the induction of FC-R activity after Fe resupply, genotypes were classified as tolerant, moderately tolerant, or nontolerant to iron-induced chlorosis. These results were compared with SPAD values of plants grown under controlled conditions and in the nursery. Rootstocks that show high induction of FC-R activity also showed high or very high SPAD values in the field.
Dianthus gratianopolitanus Vill. ‘Bath's Pink’ has a Near-obligate Vernalization Requirement
Authors: Padhye Sonali R. , Cameron Arthur C.
Published: February 2019

The flowering response of Dianthus gratianopolitanus Vill. ‘Bath's Pink’ was characterized after varying durations at vernalizing temperatures. Genetically identical clonally propagated plants were treated at 5 °C for 3, 6, 9, 12, or 15 weeks in Expt. I; at 0, 5, or 10 °C for 2, 4, 6, or 8 weeks in Expt. II; and at 0, 5, 10, or 15 °C for 1, 2, 4, 6, or 8 weeks in Expt. III. Dianthus gratianopolitanus ‘Bath's Pink’ exhibited a quantitative vernalization response after treatment at 0 to 10 °C and did not vernalize after 8 weeks at 15 °C, which was the longest duration tested. Complete flowering was achieved after 4 or more weeks at 0 °C, 3 or more weeks at 5 °C, and 8 weeks at 10 °C. Based on time to anthesis and node number at anthesis, the flowering response was saturated after vernalization treatment at 0 °C for 4 or more weeks and 5 °C for 3 or more weeks. However, maximum flowers at anthesis were produced after 8 weeks at 0 °C and 6 or more weeks at 5 °C. Flowering was delayed after the 8-week treatment at 10 °C compared with 6 or more weeks at 0 °C and 4 or more weeks at 5 °C. Based on the minimum vernalization duration required to achieve the maximum flowering response, the order of efficacy of vernalizing temperatures was 5 °C > 0 °C ≫ 10 °C.
Preharvest 1-Methylcyclopropene Delays Fruit Maturity and Reduces Softening and Superficial Scald of Apples During Long-term Storage
Authors: McArtney Steve J. , Obermiller John D. , Schupp James R. , Parker Michael L. , Edgington Todd B.
Published: February 2019

Three experiments were undertaken to evaluate the effects of different preharvest 1-methylcyclopropene (1-MCP) spray treatments on apple (Malus × domestica Borkh.) fruit maturity at harvest and quality after long-term storage in a regular atmosphere or controlled atmosphere (CA). Trees were sprayed within 7 days of the anticipated harvest date (H) and fruit for long-term storage were sampled at either H in the case of ‘Law Rome’ or at harvest dates that were delayed by up to 21 days (H + 21) in the case of ‘Golden Delicious’ and ‘Law Rome’. Preharvest 1-MCP sprays within 7 days of H reduced fruit drop, internal ethylene concentration, and starch index and reduced firmness loss during long-term storage of fruit at delayed harvest dates but had only minor effects on fruit maturity at H. Preharvest 1-MCP sprays reduced the incidence of superficial scald on ‘Law Rome’ apples more effectively than either diphenylamine or CA storage. Application of 1-MCP within 7 days of H may be used to delay harvest date, thereby allowing continued fruit growth without a concomitant advance in fruit maturity and to reduce firmness loss and superficial scald during long-term storage both for normal and delayed harvests.
Differential Resistance Among Crape Myrtle (Lagerstroemia) Species, Hybrids, and Cultivars to Foliar Feeding by Adult Flea Beetles (Altica litigata)
Authors: Cabrera Raul I. , Reinert James A. , McKenney Cynthia B.
Published: February 2019

Field (choice) and laboratory (no choice) studies were conducted to evaluate the susceptibility of 12 crape myrtle (Lagerstroemia) cultivars, representing two species and their interspecific hybrids, to feeding damage by the flea beetle (Altica litigata Fall). The results indicate that as a group, the L. indica L. cultivars were more susceptible to attack and significant herbivory damage by Altica beetles, whereas all the L. fauriei Koehne cultivars and most of the interspecific L. indica × fauriei hybrids were resistant. Significant differences in feeding damage were observed between the new and older leaves in the susceptible hybrid ‘Biloxi’ and L. indica ‘Whit IV’, but not in the rest of the cultivars. Mineral nutrient content differences were observed between species with L. indica cultivars having a significantly contrasting nutrient status profile compared with the L. fauriei and interspecific hybrid cultivar groups. The results indicate that the factors influencing Altica flea beetle-feeding preferences and damage are inherited and therefore will allow the implementation of pest management practices that minimize damage and optimize chemical control strategies. In addition, opportunities may exist for breeding and selection efforts that could lead to superior cultivars with insect resistance.
Preliminary Evaluation of Apple Germplasm from Kazakhstan for Resistance to Postharvest Blue Mold in Fruit Caused by Penicillium expansum
Authors: Janisiewicz Wojciech J. , Saftner Robert A. , Conway William S. , Forsline Philip L.
Published: February 2019

Blue mold of apples, incited by Penicillium expansum, causes extensive losses on stored apples worldwide. Despite the severity of this problem, apple breeders do not evaluate their crosses for resistance to this disease, because there has been little resistance to blue mold in the gene pool of the germplasm used. A new apple germplasm collection from the center of origin in Kazakhstan, maintained in Geneva, NY, and representing a much broader gene pool, was evaluated for resistance to blue mold. Apples were harvested from the Elite collection trees that were clonally propagated from budwood collected in Kazakhstan and from seedling trees originating from seeds of the same trees as the Elite budwood or from other wild seedling trees in Kazakhstan. Fruit from 83 such accessions were harvested at the preclimacteric to climacteric stage, wound-inoculated with P. expansum at 103, 104, and 105 mL−1 conidial suspension, incubated for 5 d at 24 °C, and evaluated for decay incidence and severity. Two accessions were classified as immune (no decay at 103 and 104 mL−1), four as resistant (no decay at 103 mL−1), 53 as moderately resistant (lesions less than 10 mm at 103 mL−1), and 24 as susceptible. There were positive correlations (r = 0.92, 0.86, and 0.91) between decay severity and all three inoculum levels. Our results indicate a greater genetic diversity among the Kazak apple collection than among cultivated apples as evidenced by their broad range of fruit maturity, quality, and disease resistance patterns. The immune and resistant accessions may serve as a source of resistance in breeding programs and can be useful in explaining the mechanism of resistance to blue mold in apples.
Taxonomic Diversity of Rhizosphere Bacteria in Golf Course Putting Greens at Representative Sites in the Southeastern United States
Authors: Elliott Monica L. , McInroy J.A. , Xiong K. , Kim J.H. , Skipper H.D. , Guertal E.A.
Published: February 2019

Taxonomic diversity of bacteria associated with golf course putting greens is a topic that has not been widely explored. The purpose of this project was to isolate and identify culturable bacteria from the rhizosphere of creeping bentgrass (Agrostris palustris Huds.) at two sites (Alabama and North Carolina) and hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy] at two sites (Florida and South Carolina) for a minimum of 3 years with sampling initiated after the construction process. Randomly selected colonies were identified using gas chromatography for analysis of fatty acid methyl ester profiles. Over 9000 isolates were successfully analyzed. When a similarity index of 0.300 or higher was used, the average number of unidentifiable isolates was 38.6%. The two dominant genera in both bentgrass and bermudagrass rhizospheres were Bacillus and Pseudomonas with Bacillus dominant in bermudagrass and Pseudomonas dominant or equal to Bacillus in bentgrass. Other genera that comprised at least 1% of the isolates at all four sites were Clavibacter, Flavobacterium, and Microbacterium. Arthrobacter also comprised a significant portion of the bacterial isolates in the bentgrass rhizosphere, but not the bermudagrass rhizosphere. Overall, there were 40 genera common to all four sites. At the species level, there were five that comprised at least 1% of the isolates at each location: B. cereus, B. megaterium, C. michiganensis, F. johnsoniae, and P. putida. As has been reported for many grasses, we found considerable taxonomic diversity among the culturable bacterial populations from the rhizospheres of bentgrass and bermudagrass grown in sand-based putting greens.
Carbohydrate Metabolism and Efficiency of Photosystem II in Mown Creeping Bentgrass (Agrostis stolonifera L.)
Authors: Howieson Mark J. , Christians Nick Edward
Published: February 2019

Regrowth of leaf tissue after mowing is necessary to form photosynthetic leaf area required for CO2 assimilation and plant growth and development. Leaf tissue regrowth often is dependent on levels of reserve carbohydrates stored in leaf sheaths and leaf bases. The objective of this study was to quantify mowing injury by measuring levels of fructan, sucrose, glucose, and fructose and efficiency of photosystem II (PSII) in not-cut, rolled, single-cut, and double-cut creeping bentgrass (Agrostis stolonifera L.) grown in a greenhouse. Efficiency of PSII was reduced in double-cut grasses by as much as 9% compared with not-cut grasses. Fructan levels were reduced in single- and double-cut grasses compared with not-cut grasses by 52% and 45%, respectively, 36 h after mowing. Glucose levels were 31% lower in double-cut grasses compared with not-cut grasses. No differences were observed in sucrose and fructose levels among not-cut, rolled, single-cut, and double-cut grasses. Mowing transiently reduced fructan and glucose levels in mowed grasses. Duration of reduction of fructan levels, magnitude of reduction in glucose levels, and efficiency of PSII were greatest in double-cut grasses, suggesting that multiple cuttings may be more damaging to plant vigor than single cutting.
Glucosinolates in Chinese Brassica campestris Vegetables: Chinese Cabbage, Purple Cai-tai, Choysum, Pakchoi, and Turnip
Authors: Chen Xinjuan , Zhu Zhujun , Gerendás Joska , Zimmermann Nadine
Published: February 2019

Brassica campestris vegetables play an important role in the Chinese diet. The objective of this study was to evaluate the composition and content of glucosinolates (GSs) in five species of Chinese Brassica campestris vegetables by high-performance liquid chromatography. The compositions and contents of GSs varied significantly among and within species and cultivars. The contents of total GSs were 100 to 130 mg/100 g fresh weight (FW) in turnip (B. rapifera), 50 to 70 mg/100 g FW in purple cai-tai (B. chinensis var. purpurea), and 14 to 35 mg/100 g FW in Chinese cabbage (B. pekinensis), choysum (B. chinensis var. utilis), and pakchoi (B. chinensis var. communis). In Chinese cabbage, the predominant individual GSs were glucobrassicin for both cultivars, neoglucobrassicin only for ‘zaoshuwuhao’, and gluconapin only for ‘zaoshuwuhao’. The predominant individual GSs were glucobrassicanapin and gluconapin in purple cai-tai and choysum and gluconapin in pakchoi and turnip. The relative content of total aliphatic GSs was 80% to 90% in purple cai-tai and choysum, 60% to 65% in pakchoi and turnip, and 17% to 50% in Chinese cabbage. The relative content of total indolic GSs was 37% to 75% in Chinese cabbage, 25% to 27% in pakchoi, and 5% to 17% in purple caitai, choysum, and turnip. The relative content of aromatic GSs was 28% to 36% in turnip, 8% to 14% in Chinese cabbage and pakchoi, and 2% to 4% in choysum and purple cai-tai. These results suggest that there are significant genotypic variations in composition and content of glucosinolates in Chinese Brassica campestris vegetables.
Winter-hardy Mammoth™ Series Garden Chrysanthemums ‘Red Daisy’, ‘White Daisy’, and ‘Coral Daisy’ Sporting a Shrub Plant Habit
Authors: Anderson Neil , Ascher Peter , Gesick Esther , Klossner Lee , Eash Neal , Fritz Vincent , Hebel James , Poppe Stephen , Reith-Rozelle Judith , Wagner Roger , Jacobson Susan , Wildung David , Johnson Patricia
Published: February 2019

Three new Chrysanthemum ×hybrida, garden chrysanthemum cultivars: Red Daisy, White Daisy, and Coral Daisy, are the first in the Mammoth™ series that are advanced interspecific hybrids derived from an open-pollinated cross between hexaploid C. weyrichii (Maxim.) Tzvelv. × C. ×grandiflora Tzvelv. These cultivars are backcross or inbred derivatives of the original interspecific F1 hybrids. All three cultivars are U.S. Department of Agriculture Z3b (−34.4 °C to −37.2 °C) winter-hardy herbaceous perennials exhibiting a shrub habit with the cushion phenotype. Additional traits exhibited by these three cultivars are butterfly attractants, frost tolerance of the flowers, and genetic ‘self-pinching.’ These Mammoth™ cultivars are clonally propagated, virus indexed, protected by U.S. Plant Patents and Canadian Plant Breeder's Rights, and are available from the North American exclusive licensee Ball Seed Company.