bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface Moisture Induces Microcracks in the Cuticle of ‘Golden Delicious’ Apple
Authors: Knoche Moritz , Grimm Eckhard
Published: February 2019

Formation of microcracks in the cuticular membrane (CM) of epidermal segments (ES) of apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf., ‘Golden Delicious’, ‘Braeburn’, ‘Idared’, ‘Jonagold’, and ‘Topaz’; all grafted on ‘Malling.9’ rootstocks] fruit was studied after exposure of the surface of the ES to water. Potential strain of the CM on the ES was preserved by mounting a stainless steel washer on the fruit surface using an ethyl-cyanacrylate adhesive. Subsequently, ES were excised by tangentially cutting underneath the washer. The number of microcracks in the CM was established by light microscopy before and after a 48-h incubation period in deionized water. Within 48 h, the number of microcracks rapidly increased when the outer surface of ES of ‘Golden Delicious’ apple was exposed to water, but there was essentially no increase in microcracks when exposed to the ambient atmosphere. The occurrence of microcracks depended on the region of the fruit surface and increased from the rim of the pedicel cavity to the calyx. Increasing the relative humidity (greater than 75% relative humidity at 22 °C) above the outer surface of the ES exponentially increased the number of microcracks. Water-induced microcracking was not limited to ‘Golden Delicious’, but also occurred in ‘Braeburn’, ‘Jonagold’, ‘Topaz’, and, to a markedly smaller extent, in ‘Idared’ apple. The mechanism of formation of microcracks in the CM of apple fruit and their role in fruit russeting are discussed.
Study of Cold Tolerance in Blueberry Using EST Libraries, cDNA Microarrays, and Subtractive Hybridization
Authors: Rowland Lisa J. , Dhanaraj Anik L. , Naik Dhananjay , Alkharouf Nadim , Matthews Ben , Arora Rajeev
Published: February 2019

To gain a better understanding of changes in gene expression associated with cold acclimation in the woody perennial blueberry (Vaccinium corymbosum L.) and ultimately use this information to develop more freeze-tolerant cultivars, a genomics approach based on the analysis of expressed sequence tags (ESTs) and microarrays was undertaken. Initially, two standard cDNA libraries, constructed using RNA from cold-acclimated (CA) and nonacclimated (NA) floral buds of the blueberry cultivar Bluecrop, were used for the generation of ≈2400 ESTs, half from each library. Putative functions were assigned to cDNAs based on homology to other genes/ESTs from GenBank. From contig analyses, 796 and 865 unique transcripts were identified from the CA and NA libraries, respectively. The most highly abundant cDNAs, that were picked many more times from one library than from the other, were identified as representing potentially differentially expressed transcripts. A cDNA microarray was constructed and used to study gene expression under cold-acclimating conditions in the field and cold room. Results indicated that the abundance of transcripts of numerous blueberry genes change during cold acclimation, including genes not found previously to be cold-responsive in Arabidopsis, and, interestingly, more transcripts were found to be upregulated under cold room conditions than under field conditions. Finally, forward and reverse subtracted cDNA libraries were prepared from ‘Bluecrop’ RNA to enrich for transcripts that are expressed at higher levels in floral buds at 400 h and at 0 h of low-temperature exposure, respectively. Many genes encoding putative transcription factors and other proteins related to signal transduction were identified from both libraries.
Alkalinity Tolerance of Selected Provenances of Taxodium Rich
Authors: Denny Geoffrey C. , Arnold Michael A. , Mackay Wayne A.
Published: February 2019

Forty seedlings from each of 14 open-pollinated families of Taxodium distichum (L.) Rich. from the southeastern United States, central Texas, and south Texas/Mexico were evaluated in the summer of 2005 for foliar chlorosis in a field situation with alkaline soil. The families from Mexico and south Texas had the lowest levels of chlorosis followed by those from central Texas and then those from the gulf coast. Height growth and trunk diameter were inversely related to chlorosis levels. Open-pollinated families from the gulf coast also had a significantly lower foliar manganese content on an alkaline field site compared with the western families. When selecting plant material for an alkaline site, genotypes from Mexico and south Texas should be preferred followed by central Texas genotypes.
Assessing Morphological and Genetic Variation in Annatto (Bixa orellana L.) by Sequence-related Amplified Polymorphism and Cluster Analysis
Authors: Valdez-Ojeda Ruby , Hernández-Stefanoni José Luis , Aguilar-Espinosa Margarita , Rivera-Madrid Renata , Ortiz Rodomiro , Quiros Carlos F.
Published: February 2019

Annatto (Bixa orellana L.) is the sole source of bixin, a seed-specific red apocarotenoid pigment used worldwide. Genetic improvement of annatto has focused on increasing bixin content as well as fostering traits that favor higher content such as pod indehiscence and flower color, among others. Eighty-seven samples collected from two separate important agricultural regions of the southeast of Mexico were characterized morphologically and analyzed genetically for the first time. The sequence-related amplified polymorphism was used for genetic analysis. Two-step cluster analysis of the individuals based on morphological traits produced three groups: one containing individuals with desired morphological characteristics and two others with complementary traits. Like the morphological analysis, the genetic analysis indicated high genetic variation, although the dendrogram based on Nei and Li's similarity coefficient showed them to be dispersed by collection site. However, calculated similarity index values indicated all individuals exhibited high genetic variation. The results are an important advance toward a more effective genetic improvement of annatto because crosses between the different morphological and/or genetic groups described here have the potential to produce a recombination of desired traits in hybrid offspring.
Yield in Nonpungent Jalapeño Pepper Established at Different In-row Spacings
Authors: Russo Vincent M.
Published: February 2019

It is not known how plant spacing affects fresh yield in transplanted nonpungent jalapeño peppers (Capsicum annuum L.). Transplants of a nonpungent jalapeño, cv. Pace 105, were established at 8, 16, 24, 32, 40, and 48 cm between plants in mid-April of 2006 and 2007 and in early July in 2007. Fruit were harvested once when 5% of marketable-sized pods in rows were red. Distance to first flower and yield characteristics were determined. Fruit were culled based on pod size and presence of blemishes. Height on the stem to the first flower averaged 15.8 cm over all treatments. Plants in the Spring 2006 season had the highest marketable and cull yields. Numbers of marketable fruit/ha were higher at the 8-cm spacing than at the 40- or 48-cm in-row spacings. There was little difference in marketable yield as a result of in-row spacing. The greatest number of cull fruit per plant was on plants spaced 48 cm apart. Plant spacing had no effect on number of cull fruit or cull yield/ha. Culls accounted for ≈22% of total yield. Individual cull fruit weights were ≈50% less than for marketable fruit. Spacings tested did not appear to greatly affect development or yield of this pepper. This will allow producers to have the option of either using fewer plants on the same amount of land or more plants on less land without much reduction of quantity or quality of yield.
Scoring and Girdling, but not GA3, Increase Yield without Decreasing Return Bloom in ‘Triumph’ Persimmon
Authors: Steyn Willem J. , Ungerer Samuel F. , Theron Karen I.
Published: February 2019

The persimmon (Diospyros kaki Thunb.) cultivar Triumph is prone to poor fruit set, particularly in young orchards, in both Israel and South Africa where it is mostly grown. Two applications of 20 mg·L−1 gibberellic acid (GA3) at 30% and 70% full bloom (FB) are recommended as the industry norm to increase fruit set, but results obtained are often unsatisfactory. We conducted experiments during the 2005–06 and 2006–07 seasons in a young orchard (less than 5 years old) and a full-bearing orchard to determine the efficacy of GA3 application and scoring or girdling during FB to increase fruit set and yield in ‘Triumph’ persimmon. We also established the effect of 2005–06 treatments on return bloom in 2006–07. Although GA3 treatments were ineffective in increasing fruit set and reduced cumulative yield over the two seasons as a result of a reduction in return bloom, scoring increased the cumulative yield by 50% compared with the untreated control and by 92% compared with GA3 application in the young orchard. In the full-bearing orchard, scoring or girdling increased the cumulative yield over the 2005–06 and 2006–07 seasons by 52% compared with the industry standard GA3 application and by 22% compared with trees that received scoring/girdling in addition to GA3. Hence, scoring or girdling did not entirely offset the negative effect of GA3 application on return bloom. The increase in fruit numbers in response to fruit set treatment brought about a reduction in fruit mass. In conclusion, the ineffectiveness of GA3 in increasing fruit set and its negative effect on return bloom do not justify its further use to improve fruit set in young or full-bearing ‘Triumph’ orchards in South Africa. Either scoring or girdling can be used to increase yield but will need to be accompanied by pruning and thinning strategies to achieve adequate fruit size and to prevent the onset of alternate bearing resulting from overcropping.
Influence of Potassium and Genotype on Vitamin E Content and Reducing Sugar of Tomato Fruits
Authors: Caretto Sofia , Parente Angelo , Serio Francesco , Santamaria Pietro
Published: February 2019

This research was conducted to determine the effect of potassium (K) and cultivar on important quality traits of tomato (Solanum lycopersicum L.), including reducing sugar, titratable acidity, and vitamin E content. Tomato plants were grown in a soilless system. Three K levels (low, middle, and high equal to 150, 300, and 450 mg·L−1 in the nutrient solution, respectively) and three cultivars (SVR, Kabiria, and Esperanza) were compared. Among cultivars, Kabiria, which is characterized by smaller fruits, showed 23% higher total soluble solids (TSS) than the average of the other cultivars. ‘Kabiria’ also showed a total tocopherol (vitamin E) content (18.5 mg·kg−1), markedly higher than SVR and Esperanza cultivars (12.2 and 10.3 mg·kg−1, respectively). Increased K levels in the nutrient solution resulted in increased contents of TSS, reducing sugar contents and titratable acidity in tomato fruits. Also, the vitamin E content of tomato fruits was significantly affected by differing K concentrations in the nutrient solution.
Photosynthetic Daily Light Integral during Propagation Influences Rooting and Growth of Cuttings and Subsequent Development of New Guinea Impatiens and Petunia
Authors: Lopez Roberto G. , Runkle Erik S.
Published: February 2019

A majority of commercial propagation of herbaceous ornamental cuttings occurs during the winter when the photosynthetic daily light integral (DLI) is relatively low. We quantified how the mean DLI influenced rooting and subsequent growth and development of two popular vegetatively propagated species, New Guinea impatiens (Impatiens hawkeri Bull.) and petunia (Petunia ×hybrida hort. Vilm.-Andr.). Three cultivars of each species were propagated under a mean DLI ranging from 1.2 to 10.7 mol·m−2·d−1. Cuttings were rooted in a controlled greenhouse environment maintained at 24 to 25 °C with overhead mist, a vapor-pressure deficit of 0.3 kPa, and a 12-h photoperiod. Rooting and growth evaluations of cuttings were made after 8 to 16 d. In a separate experiment, rooted cuttings under DLI treatments were then transplanted into 10-cm containers and grown in a common greenhouse at 21 ± 2 °C under a 16-h photoperiod to identify any residual effects on subsequent growth and development. In both species, rooting, biomass accumulation, and quality of cuttings increased and subsequent time to flower generally decreased as mean propagation DLI increased. For example, root number of petunia ‘Tiny Tunia Violet Ice’ after 16 days of propagation increased from 17 to 40 as the propagation DLI increased from 1.2 to 7.5 mol·m−2·d−1. In addition, cutting shoot height decreased from 6.3 to 4.5 cm, and root and shoot dry biomass of cuttings harvested after 16 days of propagation increased by 737% and 106%, respectively. Subsequent time to flower for ‘Tiny Tunia Violet Ice’ from the beginning of propagation decreased from 50 to 29 days as propagation DLI increased from 1.4 to 10.7 mol·m−2·d−1 regardless of the DLI provided after propagation. In New Guinea impatiens ‘Harmony White’, root and shoot dry weight of cuttings increased by 1038% and 82%, respectively, and subsequent time to flower decreased from 85 to 70 days as the propagation DLI increased from 1.2 to 10.7 mol·m−2·d−1. These experiments quantify the role of the photosynthetic DLI during propagation on the rooting and subsequent growth and development of vegetatively propagated herbaceous ornamental cuttings.
Regional Marketing Practices in U.S. Nursery Production
Authors: Behe Bridget K. , Dennis Jennifer H. , Hall Charles R. , Hodges Alan W. , Brumfield Robin G.
Published: February 2019

Nursery production contributed $18.1 billion to the U.S. economy in 2002 and created nearly two million jobs. A U.S. Department of Agriculture multistate research committee on economics and marketing has conducted The National Nursery Survey four times at 5-year intervals (1988, 1993, 1998, and 2003) to help fill the void of publicly available information on production, marketing, and management for the nursery industry. In 2003, the committee conducted the National Nursery Survey using a standard sampling methodology targeting 15,588 total firms representing 44 states with 2,485 nurseries responding. The objective of this analysis was to provide a regional profile of the marketing practices of nursery producers. Regional differences were present in several areas of sales management, selling practices, pricing, and advertising. Generally, the coastal regions had a higher percentage of wholesale sales, whereas interior regions had a higher percentage of retail sales. Newsletters and yellow pages were the most important form of advertising in the Great Plains; trade journals were the most important method in the south central and southeast regions; and catalogs were the most important advertising method for all other regions. The percentage of sales to repeat customers varied from a low of 65.6% in the Great Plains to a high of 76.2% in the southeast. The Appalachian (26.9%) and southeast (26.8%) regions had the highest percentage of negotiated sales, whereas the northeast had the lowest. Although significant differences generally existed among regions in the percentage of sales spent on various transaction methods, nurseries in all regions used in-person, telephone, and mail order as their three most important sales transaction methods, except for the southeast where trade shows were the third most important method of sales transactions. Landscape professionals, rewholesalers, and single-location garden centers were the major market outlets in all regions. Respondents in all regions identified production, personnel, and marketing as limitations for expansion.
Efficient Water Use in Residential Urban Landscapes
Authors: Hilaire Rolston St. , Arnold Michael A. , Wilkerson Don C. , Devitt Dale A. , Hurd Brian H. , Lesikar Bruce J. , Lohr Virginia I. , Martin Chris A. , McDonald Garry V. , Morris Robert L. , Pittenger Dennis R. , Shaw David A. , Zoldoske David F.
Published: February 2019

In the United States, urban population growth, improved living standards, limited development of new water supplies, and dwindling current water supplies are causing the demand for treated municipal water to exceed the supply. Although water used to irrigate the residential urban landscape will vary according to factors such as landscape type, management practices, and region, landscape irrigation can vary from 40% to 70% of household use of water. So, the efficient use of irrigation water in urban landscapes must be the primary focus of water conservation. In addition, plants in a typical residential landscape often are given more water than is required to maintain ecosystem services such as carbon regulation, climate control, and preservation of aesthetic appearance. This implies that improvements in the efficiency of landscape irrigation will yield significant water savings. Urban areas across the United States face different water supply and demand issues and a range of factors will affect how water is used in the urban landscape. The purpose of this review is to summarize how irrigation and water application technologies; landscape design and management strategies; the relationship among people, plants, and the urban landscape; the reuse of water resources; economic and noneconomic incentives; and policy and ordinances impact the efficient use of water in the urban landscape.
The Effects of Stomatal Size on Feeding Preference of Azalea Lace Bug, Stephanitis pyrioides (Hemiptera: Tingidae), on Selected Cultivars of Evergreen Azalea
Authors: Kirker Grant T. , Sampson Blair J. , Pounders Cecil T. , Spiers James M. , Boyd David W.
Published: February 2019

Azalea lace bug (ALB), Stephanitis pyrioides (Scott), is an important economic pest of azaleas in the southeastern United States. In this study, 33 commercially available cultivars of evergreen azalea, Rhododendron spp., were evaluated for S. pyrioides feeding preference in both choice and no-choice feeding bioassays. Mean stomatal length and area, which were hypothesized to affect ALB feeding preference, were also measured for each of 33 cultivars and results were correlated with indices of ALB feeding (mean feces) and fecundity (mean eggs). An azalea cultivar, Fourth of July, was least preferred by ALB in both no-choice and choice tests, whereas ‘Watchet’ was most preferred. Cultivars Fourth of July and Delaware Valley White had the smallest mean stomatal areas despite their disparate susceptibilities to ALB feeding. Although stomates through which ALB insert their proboscides vary in size among azalea cultivars, they confer no obvious resistance to ALB feeding preference. Therefore, the mechanism for lace bug resistance in azalea remains elusive.
1-Methylcyclopropene Counteracts Fry Color Darkening Attributable to Carbon Dioxide and Ethylene Interaction
Authors: Daniels-Lake Barbara J. , Prange Robert K. , Bishop Stephanie D. , Hiltz Kimberly
Published: February 2019

The fry color of potatoes (Solanum tuberosum L.) stored for processing remains an important quality characteristic that can be affected by many factors, including ethylene gas from various sources and the interaction of very low concentrations of ethylene gas (less than 1 μL·L−1) and accumulated CO2. Because previous studies show that pretreatment with 1-methylcyclopropene (1-MCP) can substantially reduce fry color darkening attributable to applied ethylene, we hypothesized that 1-MCP could also reduce fry color darkening attributable to the interaction of ethylene and CO2. Trials were conducted over two storage seasons, using ‘Russet Burbank’ tubers, either untreated or treated with 0.5 μL·L−1 ethylene gas ± 2 kPa CO2 and ± 1-MCP. Tubers exposed to ethylene gas had darker fry color than untreated tubers, whereas the fry color of tubers exposed to ethylene plus CO2 was darker still. However, the fry color of tubers pretreated with 1-MCP was as light as that of the untreated tubers. This provides a potential new tool for the potato industry to manage potato fry color of stored processing potatoes.
Hot Water Treatment for Chilling Injury Reduction of Astringent ‘Rojo Brillante’ Persimmon at Different Maturity Stages
Authors: Besada Cristina , Salvador Alejandra , Arnal Lucía , Martínez-Jávega Jose María
Published: February 2019

The effects of hot water treatments (HWTs) on chilling injury (CI) of ‘Rojo Brillante’ persimmon treated at different maturity stages and stored at 1 °C have been investigated. HWT temperatures ranging from 45 to 55 °C were applied for periods of time of between 2.5 and 40 min. Reduction of CI by HWT depended on the maturity stage. HWTs reduced softening when they were applied to fruit at an early stage of maturity, but caused skin cracking and skin browning in middle and advanced stages of maturity. Incidence and severity of these disorders increased as HWT temperatures and treatment times increased and in more mature fruit.
Micropropagation of the Fiber-rich Amazonian Species Ananas erectifolius (Bromeliaceae)
Authors: Pereira Flávia D. , B.P. Pinto José Eduardo , Rosado Luciana D.S. , Rodrigues Helen C.A. , Bertolucci Suzan K.V. , Lameira Osmar A.
Published: February 2019

The aim of the study was to develop a method for the in vitro propagation of Ananas erectifolius (Bromeliaceae), a fiber-rich Amazonian species. In vitro cultures were established from axillary buds of field-grown plants cultured on medium without plant growth regulators (PGRs). Stumps were excised from in vitro plantlets and incubated under dark conditions on medium supplemented with different combinations of 1-naphthaleneacetic acid (NAA), kinetin, and gibberellic acid (GA3). The most efficient induction of etiolated shoots occurred on explants cultured in the presence of NAA at 10.74 μm (T1 medium) or NAA at 5.37 μm + GA3 at 3 μm (T2 medium). Apical tips and nodal segments of the etiolated shoots were recultured under a 16-h photoperiod in medium without PGRs, and the effects of residual PGRs were evaluated by determining the numbers and lengths of plantlets that regenerated within 30 days. Residual PGRs exhibited no effect on the length of the regenerated plantlets but significantly affected the number of plantlets regenerated from nodal segments but not from apical tips. Nodal segments and apical tips derived from etiolated shoots produced, respectively, on T2 and T1 medium were most appropriate for plantlet regeneration. Nearly all (98%) regenerated plantlets formed roots when cultured in liquid medium without PGRs, and all plantlets survived acclimatization under greenhouse conditions. The stumps originating from etiolated shoots regenerated new etiolated shoots when recultured in the dark on medium without PGRs, thus providing a supply of new explants for plant regeneration.
Soil and Redosier Dogwood Response to Incorporated and Surface-applied Compost
Authors: Cogger Craig , Hummel Rita , Hart Jennifer , Bary Andy
Published: February 2019

Although compost can improve soil properties related to plant growth and water quality, the value of amending landscape beds for trees and shrubs has been questioned. This research assesses short and midterm effects of compost application and bark mulch on soils and plants in landscape beds and compares the effects of compost applied to the surface or incorporated. Trees and shrubs were established in 2001 in a replicated field experiment with the following treatments: 1) unamended control; 2) compost (7.6-cm depth) applied to the surface; 3) 7.6 cm compost incorporated by rototilling to a depth of 20 cm; 4) bark mulch (7.6 cm); 5) compost surface-applied (7.6 cm) + bark mulch (7.6 cm); and 6) compost incorporated + bark mulch. Soil measurements were made one or more times between 2001 and 2007, including bulk density, compaction, infiltration, aggregate stability, soil moisture tension, total carbon (C) and nitrogen (N), nitrate-N, Bray-phosphorus, exchangeable potassium, and pH. Bark and compost mulch depths were determined three times and plant growth measured annually. Half the depth of surface-applied compost and 26% to 41% of the initial soil C increase from incorporated compost remained 5 years after application; and significant changes in bulk density, compaction, infiltration, and nutrients were apparent. Compost incorporation had a greater effect than surface application on soil C, N, and bulk density. Infiltration was similar in incorporated and surface treatments, and nutrient availability was similar except for N. Soil moisture retention was improved with surface-applied compost. Bark had similar effects as surface-applied compost on bulk density, soil moisture retention, and infiltration. During the first 4 years after transplanting, dogwoods in the compost incorporated + bark mulch treatment typically had larger shoot growth indices. By Year 5, treatment no longer influenced shoot growth. Plants in compost-treated plots had darker green leaves. Surface application of compost could provide significant benefits where incorporation is not feasible.
Adapting the Pour-through Medium Extraction Method to Phalaenopsis Grown in Sphagnum Moss
Authors: Yao Huan-Ying , Chung Ren-Shih , Ho Sheng-Bin , Alex Chang Yao-Chien
Published: February 2019

Sphagnum moss, which has very different chemical and physical characteristics compared with other soilless media, is commonly used as a substrate to grow Phalaenopsis in countries such as Japan and Taiwan. Pour-through (PT) is a nondestructive, effective, and convenient medium extraction method developed for peat-based media. To know if PT can be applied to sphagnum moss and to set up a standard procedure, experiments were conducted to test the effects of volume and electrical conductivity (EC) of the displacing solution and the timing of leachate collection on leachate properties. Results demonstrated that applying distilled water with a volume less than 70 mL to 10.5-cm pots 1 h after fertigation did not influence leachate EC and pH. Applying displacing solution with EC between 0.001 and 0.93 dS·m−1 1 h after fertigation did not affect leachate EC or pH. Thus, in theory, a variety of solutions may be used for displacement. Leachate properties were found to remain consistent when collected between 20 and 160 min after fertigation. These results demonstrated that PT can be successfully used in Phalaenopsis cultivation with sphagnum moss. Furthermore, substrate EC obtained by PT extraction was highly correlated with that by the press method, confirming that PT is a feasible medium extraction method for sphagnum moss in Phalaenopsis cultivation.
Red Light Affects Flowering Under Long Days in a Short-day Strawberry Cultivar
Authors: Takeda Fumiomi , Glenn D. Michael , Stutte Gary W.
Published: February 2019

July-plugged transplants of short-day cv. Strawberry Festival (Fragaria ×ananassa) flowered in October and November although they were grown under long photoperiods and warm temperatures (greater than 21 °C) in July and August. These unexpected results were attributed to a high plant density (320 transplants/m2) that provided continuous and heavy leaf cover, which eliminated red light (less than 700 nm) from reaching the crowns. This hypothesis was tested by illuminating crowns of transplants growing in 50-cell packs for 16 h·d−1 with red light-emitting diode lamps (maximum wavelength at 639 nm and 80% of output between 617 and 655 nm). Red light treatment caused a significant reduction in fall flowering. It is proposed that a high ratio of far-red light to visible light reaching the crown will play a role in floral bud induction, possibly as early as mid-August. Transplants of some short-day cultivars started as plug plants in early July have the capacity to flower and fruit in the fall and the next spring, enabling growers in the mid-Atlantic coast region to obtain two harvests within 1 year from a single planting.
Response of Kentucky Bluegrass (Poa pratensis L.) Cultivars and Selections to Bispyribac-sodium Herbicide
Authors: Shortell Robert R. , Hart Stephen E. , Bonos Stacy A.
Published: February 2019

Annual bluegrass (Poa annua L.) is a problematic weed in Kentucky bluegrass (Poa pratensis L.). Bispyribac-sodium herbicide can effectively control established annual bluegrass in other cool-season turfgrasses, but unacceptable injury to Kentucky bluegrass has been reported. However, only a few Kentucky bluegrass cultivars have been evaluated. The objective of this study was to determine the extent of intraspecific variability among Kentucky bluegrass cultivars and selections to sequential applications of bispyribac-sodium herbicide. Field experiments were conducted in 2004 and 2005 in New Jersey to determine the response of 55 Kentucky bluegrass cultivars and selections to bispyribac-sodium. The herbicide was applied at 188 g·ha−1 followed 3 weeks later by a second application of 281 g·ha−1. Kentucky bluegrass injury ranged from 8% to 93% 8 weeks after initial treatment (WAIT). ‘Blackstone’, ‘Serene’, and A98-962 were the most tolerant to bispyribac-sodium, exhibiting less than 20% injury 8 WAIT. Conversely, ‘Washington’, 95AN-10, and ‘Avalanche’ were the most susceptible with up to 93% injury 8 WAIT. The range in tolerance to bispyribac-sodium within Kentucky bluegrass indicates the potential for the identification and development of cultivars with improved tolerance to bispyribac-sodium herbicide.
Kernel Color of Three Black Walnut Cultivars after Delayed Hulling at Five Successive Harvest Dates
Authors: Warmund Michele Renee
Published: February 2019

‘Emma K’, ‘Kwik Krop’, and ‘Sparrow’ black walnuts (Juglans nigra L.) were collected weekly in Sept. and Oct. 2007 to determine the effect of delayed hulling of fruits on kernel color at successive harvest dates. Delayed hulling of fruits resulted in lower kernel color values, including L*, chroma, hue angle, and LCH sum (L* + chroma + hue angle values) than those of fruits that were immediately hulled after harvest. ‘Sparrow’ kernels were visually the darkest brown color after delayed hulling. However, the effect of delayed hulling (i.e., change in kernel LCH sum values) over all harvest dates was greatest for ‘Emma K’. LCH sums of kernels generally decreased as the time of harvest was delayed. For ‘Sparrow’, mean kernel LCH sums from immediately hulled fruits decreased sharply from the third week of harvest on 20 Sept. (i.e., the “normal” date of harvest) to the next week. This decrease in LCH sums represented a change in kernel color classification from medium brown at Week 3 to dark brown in Week 4. Visual color changes for ‘Kwik Krop’ were less apparent as a result of the narrow range of color over harvest dates.
Leaf Area Estimation Model for Small Fruits from Linear Measurements
Authors: Fallovo Carlo , Cristofori Valerio , Mendoza de-Gyves Emilio , Rivera Carlos Mario , Rea Roberto , Fanasca Simone , Bignami Cristina , Sassine Youssef , Rouphael Youssef
Published: February 2019

Accurate and nondestructive methods to determine individual leaf areas of plants are a useful tool in physiological and agronomic research. Determining the individual leaf area (LA) of small fruit like raspberry (Rubus idaeus L.), redcurrant (Ribes rubrum L.), blackberry (Rubus fruticosus L.), gooseberry (Ribes grossularia L.), and highbush blueberry (Vaccinium corymbosum L.) involves measurements of leaf parameters such as length (L) and width (W) or some combinations of these parameters. A 2-year investigation was carried out during 2006 (on seven raspberry, seven redcurrant, six blackberry, five gooseberry, and two highbush blueberry cultivars) and 2007 (on one cultivar per species) under open field conditions to test whether a model could be developed to estimate LA of small fruits across cultivars. Regression analysis of LA versus L and W revealed several models that could be used for estimating the area of individual small fruit leaves. A linear model having LW as the independent variable provided the most accurate estimate (highest R
2, smallest mean square error, and the smallest predicted residual error sum of squares) of LA in all small fruit berries. Validation of the model having LW of leaves measured in the 2007 experiment coming from other cultivars of small fruit berries showed that the correlation between calculated and measured small fruit berries LAs was very high. Therefore, these models can estimate accurately and in large quantities the LA of small fruit plants in many experimental comparisons without the use of any expensive instruments.
Yield and Chemical Composition of Brussels Sprout (Brassica oleracea L. gemmifera) as Affected by Boron Management
Authors: Turan Metin , Ataoglu Nizamettin , Gunes Adem , Oztas Taskin , Dursun Atilla , Ekinci Melek , Ketterings Quirine M. , Huang Yuh Ming
Published: February 2019

Boron (B) deficiency is widespread in the Anatolia region of Turkey. This could impact production and quality of Brussels sprout (Brassica oleracea L. gemmifera). A 2-year field experiment was conducted to study yield and quality response of four cultivars (Star, Brilliant, Oliver, and Maximus) to B addition (0, 1, 3, and 9 kg·ha−1 B). The optimum economic B rate (OEBR) ranged from 5.5 to 6.3 kg·ha−1 B resulting in soil B levels of 0.94 to 1.13 mg·kg−1. Independent of cultivar, B application decreased tissue nitrogen, calcium, and magnesium but increased tissue phosphorus, potassium, iron, manganese, zinc, and copper content. We conclude a B addition of 6 kg·ha−1 is sufficient to elevate soil B levels to nondeficient levels. Similar studies with different soils and initial soil test B levels are needed to conclude if these critical soil test values and OEBR can be applied across the region.
Plant Breeders' Perspectives on Improving Yield and Quality Traits in Horticultural Food Crops
Authors: Luby James J. , Shaw Douglas V.
Published: February 2019

Breeders of horticultural food crops are usually concerned with multiple traits related to yield and quality as well as other traits such as biotic and abiotic stresses. Yield in these crops is not solely tonnage of biomass produced in the field. Rather, it is the proportion of the crop that can be harvested and brought to market in a condition and at a price acceptable to the consumer. Quality may include flavor, color, shape, size, degree of damage, nutrient levels, and traits that permit greater perceived food safety or environmental sustainability. Some traits may exhibit phenotypic associations. Traits with unfavorable associations will be of concern to the breeder if the cause is unfavorably correlated genetic effects, especially those resulting from pleiotropy. Several multiple trait selection schemes have been developed, including independent culling levels, tandem selection, and index selection. These schemes can result in improvement even for traits with unfavorable associations. However, the breeder must have a strong rationale for each trait addressed in a breeding program because each additional trait necessitates larger breeding populations and more resources. Thus, the breeder's first challenge for each crop is to determine which traits are most important and which issues are most amenable to a breeding solution.
Heritability and Correlations Among Popping Characteristics and Seed Weight in a Broad-based Temperate-adapted Nuña Bean (Phaseolus vulgaris L.) Population
Authors: Vorwald Jesse , Nienhuis James
Published: February 2019

Nuña beans are a type of common bean (Phaseolus vulgaris L.) from the Andean region of South America that possess the unique property of popping. To develop temperate-adapted nuña bean cultivars, knowledge is needed regarding the inheritance and relationships among popping characteristics and seed weight. Nuña bean landraces are often photoperiod-sensitive; thus, to obtain estimates of the genetic parameters associated with seed characteristics, populations adapted to the long days of northern temperate climates were developed. Four sets of 10 families, sampled from a temperate-adapted population, were crossed in a Design II mating design. The heritabilities of seed weight, popping percentage, and the coefficient of expansion were relatively high, 0.77 ± 0.04, 0.87 ± 0.07, and 0.74 ± 0.09, respectively. Large positive phenotypic (0.773) and additive genetic (0.539) correlations were observed between popping percentage and the coefficient of expansion. Correlations with seed weight were not significant. The results indicate that direct selection for either increased popping percentage or coefficient of expansion will simultaneously improve both traits with little or no change in seed weight.
Production of Lily Symptomless Virus-free Plants by Shoot Meristem Tip Culture and In Vitro Thermotherapy
Authors: Nesi Beatrice , Trinchello Debora , Lazzereschi Sara , Grassotti Antonio , Ruffoni Barbara
Published: February 2019

To produce virus-free plants, a simple and original protocol was established by combining several techniques: repeated shoot meristem excision before and during in vitro culture and thermotherapy applied to bulblets in vitro. Lily symptomless virus (LSV) is a major virus that decreases plant growth vigor and the quality of cut flowers, yet infected plants show no distinct symptoms. Stock bulbs of pollenless Asiatic hybrid lily (L. × elegans Thunb) lines (‘409’ and ‘599’) were used as explant. Shoot meristems were excised and micropropagated. Thermotherapy (42 days at 35 °C) was applied to in vitro growing bulblets and a second meristem cut was then made from heat-treated material. Leaf tissues from bulblets formed before or postheat treatments were analyzed either by enzyme-linked immunosorbent assay or by reverse transcriptase–polymerase chain reaction. Line ‘499’ produced LSV-free plants without heat treatment, but line ‘599’ produced LSV-free plants only after heat treatment. The virus-free lily bulblets grew vigorously in vitro and acclimatized promptly. It is suggested that thermotherapy given to in vitro growing bulblets effectively eliminated the virus and induced a fast and efficient micropropagation technique for virus-free mother plant stock.
Leaf Blotching in Caladium (Araceae) Is Under Simple Genetic Control and Tightly Linked to Vein Color
Authors: Deng Zhanao , Harbaugh Brent K.
Published: February 2019

Cultivated caladiums (Caladium ×hortulanum Birdsey) are valued as important pot and landscape plants because of their bright, colorful leaves. Improving leaf characteristics or generating new combinations of these characteristics has been one of the most important breeding objectives in caladium. A major leaf characteristic in caladium is leaf blotching, the presence of numerous irregularly shaped color areas between major veins on leaf blades. This pattern of coloration in combination with bright colors has resulted in the popularity of a number of caladium cultivars. In this study, controlled crosses were made among three blotched and six nonblotched caladium cultivars. Their progeny were analyzed to understand the mode of inheritance of leaf blotching and its genetic relationship with the color of main leaf veins. Progeny of selfing nonblotched or crossing nonblotched cultivars were all nonblotched; selfing blotched cultivars (Carolyn Whorton, White Christmas, and Florida Blizzard) or crossing ‘Florida Blizzard’ and ‘Carolyn Whorton’ resulted in a 3:1 ratio (blotched:nonblotched); and progeny from crosses between blotched and nonblotched cultivars segregated in a 1:1 ratio (blotched:nonblotched). These results indicate that leaf blotching is controlled by a single nuclear locus with two alleles (B and b). χ2 analysis of the joint segregation between leaf blotching and vein color (V) in five crosses showed that the blotching allele B is linked to the green vein allele Vg. ‘Carolyn Whorton’, ‘White Christmas’, and ‘Florida Blizzard’ are heterozygous for leaf blotching, and their genotype for leaf blotching and vein color (Vr, Vw, and Vg for red, white, and green veins, respectively) are Vrb//VgB, Vgb//VgB, and Vwb//VgB, respectively. This information will be valuable for planning crosses and breeding populations to develop new blotched caladium cultivars. The information gained in this study may be helpful for understanding the inheritance of similar traits in other aroids.
Growth and Photosynthetic Response of Pot-in-pot-grown Conifers to Substrate and Controlled-release Fertilizer
Authors: Klooster Wendy S. , Cregg Bert M. , Fernandez R. Thomas , Nzokou Pascal
Published: February 2019

Container production of landscape conifers, including pot-in-pot (PIP) production, is increasing relative to field production in the northern United States. Because much of the research on PIP has been performed in the southern United States, this study focused on characterizing the growth and physiological response of PIP-grown conifers to fertilizer and substrate to improve production for growers in northern climates. In May 2006, we potted 90 seedlings each of Abies fraseri, Picea glauca var. densata, P. pungens glauca, and Pinus strobus into 11.2-L containers. Substrate consisted of pine bark (B) and peatmoss (PM) in ratios of 90:10, 80:20 or 70:30 (vB:vPM). Trees were top-dressed with controlled-release fertilizer (15N–4P–10K) at rates of 0.25, 0.5, and 1.0 g of nitrogen per liter of container (g·L−1). After 2 years, growth response to substrate varied by species; however, all species grew as well or better in the 80:20 mix than in the other mixes. In response to fertilizer addition, adding 0.5 or 1 g N/L increased height growth compared with 0.25 g. Increasing the fertilizer rate from 0.5 g N/L to 1 g did not increase height growth. Foliar nitrogen increased with each fertilizer addition although height growth did not increase beyond 0.5 g·L−1, indicating possible luxury consumption. Furthermore, net photosynthesis rates of spruce trees declined with fertilization in the second year of the study, possibly as a result of increased water stress due to greater total leaf area per tree. Chlorophyll fluorescence was not consistently correlated with foliar nutrition. From a practical standpoint, results of the study indicate that 0.5 g N/L will provide adequate nutrition for these crops. A substrate mix of 80% bark:20% peatmoss produced maximal or near-maximal growth for all four species tested.
Gardening Consumer Segments Vary in Ecopractices
Authors: Behe Bridget K. , Campbell Benjamin , Dennis Jennifer , Hall Charles , Lopez Roberto , Yue Chengyan
Published: February 2019

Savvy marketers rely on the principles of customer segmentation and product targeting to more efficiently allocate scarce resources and effectively reach groups of consumers with similar likes, preferences, or demands. Our objective was to identify and profile consumer segments with regard to their gardening purchases to determine whether there were differences in their ecofriendly attitudes and behaviors such as recycling. Our underlying hypothesis was that different types of gardeners may exhibit more environmentally friendly behavior, predisposing them to be more receptive to product innovations specifically designed to be ecofriendly. Researchers collected plant purchases, recycling attitudes and behaviors, and preferences for ecofriendly containers from 763 consumers in Indiana, Michigan, Minnesota, and Texas. A cluster analysis based on plant purchases yielded three consumer segments: low use, woody plant buyers, and herbaceous plant buyers. There were some differences with regard to recycling behaviors among consumers in the three groups, including recycling aluminum drinking cans, newspapers, magazines, use of energy-saving bulbs, and composting yard waste. Generally, herbaceous plant buyers were most ecofriendly followed by woody plant buyers and low use. Given these differences, there appears to be some merit in the future to segment consumers by plant purchases versus others to target specific types of ecofriendly products to them.
Effects of Early Defoliation on Yield, Fruit Composition, and Harvest Season Cluster Rot Complex of Grapevines
Authors: Sabbatini Paolo , Howell G. Stanley
Published: February 2019

Viticulture in Michigan is limited by a cool and humid climate and as a result, there is a problem of harvest season cluster rot, especially in cultivars with compact cluster morphology. Economically important wine grape varieties in eastern North America possess varying susceptibility to harvest season cluster rot. Some important cultivars that are susceptible are Pinot gris, Pinot noir, Riesling (Vitis vinifera L.) as well as Seyval and Vignoles (French–American hybrids or interspecific hybrid cultivars). A common characteristic of these cultivars is the compactness of the berries held on the cluster rachis. The aim of this work was to determine whether a quantified amount of leaf removal or a temporary reduction in carbon assimilation at the beginning of bloom would reduce fruit set and cluster compactness. Vines subjected to removal of four or six basal leaves had an average fruit set reduction of ≈45% from a non-treated control. Cluster weight and berries per cluster were similarly reduced with a greater effect on the basal than the apical cluster of the shoot. Reduced fruit set was associated with a reduction in cluster compactness and harvest season rot. This was also reflected in yield and basic fruit chemistry parameters associated with the importance of basal leaves to the developing cluster. Multiple applications of stylet oil at different time intervals resulted in significant reduction in net photosynthesis (Pn). A single application had no significant impact on Pn, whereas multiple applications reduced leaf assimilation rates. However, this reduction in Pn did not reduce fruit set or improve cluster compactness. There was a strong negative effect of early leaf removal in Year 1 on vine performance in Year 2; this carryover effect increased shootless nodes per vine, reduced the number of clusters per shoot and per vine, and dramatically reduced fruit set and consequently yield per vine.
Non-deep Physiological Dormancy in Seeds of Two Polygonella Species with Horticultural Potential
Authors: Heather Alison E. , Pérez Hector E. , Wilson Sandra B.
Published: February 2019

The perennial nature, prolific white to pink racemes, and attractive foliage and form of october flower [Polygonella polygama (Vent.) Engelm. & A. Gray] and sandhill wireweed [Polygonella robusta (Small) G.L. Nesom & V.M. Bates] suggest that these wildflowers could have significant ornamental and landscape potential if an effective propagation method could be developed. However, a paucity of seed biology information exists for these species. Two- to 4-month-old seeds of both species were tested for viability using triphenyltetrazolium chloride (TZ) before germination experiments. Initial viability of seed lots was 77.4% ± 6.3% and 53.5% ± 6.8% for october flower and sandhill wireweed, respectively. Initial germination tests showed that both species had the highest number of germinated seeds in cool temperatures (22/11 °C day/night), but a portion of the seed population remained dormant. Germination of both species at simulated seasonal temperatures indicated that seeds require a warm, moist period (warm stratification) before germination starts at cooler temperatures. Germination of both species also increased when gibberellic acid (GA3) was applied at the highest rate of 1000 ppm. We conclude that seeds of both species exhibit non-deep physiological dormancy.