Rachel P. Naegele

Genetic diversity, population structure, and resistance to Phytophthora capsici of a worldwide collection of eggplant germplasm

Eggplant (Solanum melongena L.) is an important solanaceous crop with high phenotypic diversity and moderate genotypic diversity. Ninety-nine genotypes of eggplant germplasm (species (S. melongena, S. incanum, S. linnaeanum and S. gilo), landraces and heirloom cultivars) from 32 countries and five continents were evaluated for genetic diversity, population structure, fruit shape, and disease resistance to Phytophthora fruit rot. Fruits from each line were measured for fruit shape and evaluated for resistance to two Phytophthora capsici isolates seven days post inoculation. Only one accession (PI 413784) was completely resistant to both isolates evaluated. Partial resistance to Phytophthora fruit rot was found in accessions from all four eggplant species evaluated in this study. Genetic diversity and population structure were assessed using 22 polymorphic simple sequence repeats (SSRs). The polymorphism information content (PIC) for the population was moderate (0.49) in the population. Genetic analyses using the program STRUCTURE indicated the existence of four genetic clusters within the eggplant collection. Population structure was detected when eggplant lines were grouped by species, continent of origin, country of origin, fruit shape and disease resistance.

Evaluation of a diverse, worldwide collection of wild, cultivated, and landrace pepper (Capsicum annuum) for resistance to Phytophthora fruit rot, genetic diversity, and population structure

Pepper is the third most important solanaceous crop in the United States and fourth most important worldwide. To identify sources of resistance for commercial breeding, 170 pepper genotypes from five continents and 45 countries were evaluated for Phytophthora fruit rot resistance using two isolates of Phytophthora capsici. Genetic diversity and population structure were assessed on a subset of 157 genotypes using 23 polymorphic simple sequence repeats. Partial resistance and isolate-specific interactions were identified in the population at both 3 and 5 days postinoculation (dpi). Plant introductions (PIs) 640833 and 566811 were the most resistant lines evaluated at 5 dpi to isolates 12889 and OP97, with mean lesion areas less than Criollo de Morelos. Genetic diversity was moderate (0.44) in the population. The program STRUCTURE inferred four genetic clusters with moderate to very great differentiation among clusters. Most lines evaluated were susceptible or moderately susceptible at 5 dpi, and no lines evaluated were completely resistant to Phytophthora fruit rot. Significant population structure was detected when pepper varieties were grouped by predefined categories of disease resistance, continent, and country of origin. Moderately resistant or resistant PIs to both isolates of P. capsici at 5 dpi were in genetic clusters one and two.

Evaluation of Eggplant Rootstocks and Pepper Varieties for Potential Resistance to Isolates of Phytophthora capsici from Michigan and New York

Phytophthora capsici is a soilborne pathogen of major economic importance in pepper, and of less importance in tomato and eggplant production. As soil fumigation becomes more expensive and limited, and fungicide insensitivity of P. capsici isolates becomes more prevalent, grafting is quickly becoming an industry-favored method to control soilborne diseases. Greenhouse experiments were performed to evaluate an eggplant cultivar (Classic), two eggplant lines (EG195, EG203), a pepper line (CM334), and three pepper cultivars (Paladin, Camelot, and Red Knight) for root rot resistance to 14 P. capsici isolates. The isolates showed various degrees of virulence between pepper and eggplant in both experiments. Both eggplant and one pepper lines showed moderate resistance to the most virulent isolates tested in experiment one. The partially resistant pepper cultivar, Paladin, was significantly more susceptible than CM334 and the eggplant lines, but was still resistant to most isolates. In the second experiment, the eggplant cultivar Classic and the susceptible pepper cultivar Red Knight were both susceptible to most isolates tested, while EG203 and EG195 were resistant to most isolates. The two eggplant breeding lines, EG195 and EG203, showed moderate resistance to all isolates tested in both experiments. This is the first reported evaluation of eggplant resistance to P. capsici. Further research is warranted to test eggplant lines EG195 and EG203 for resistance to a wide range of soilborne pests and to evaluate their usefulness as P. capsici-resistant rootstocks for peppers, tomatoes, and eggplants.

Genetic Diversity, Population Structure, and Heritability of Fruit Traits in Capsicum annuum.

Cultivated pepper (Capsicum annuum) is a phenotypically diverse species grown throughout the world. Wild and landrace peppers are typically small-fruited and pungent, but contain many important traits such as insect and disease resistance. Cultivated peppers vary dramatically in size, shape, pungency, and color, and often lack resistance traits. Fruit characteristics (e.g. shape and pericarp thickness) are major determinants for cultivar selection, and their association with disease susceptibility can reduce breeding efficacy. This study evaluated a diverse collection of peppers for mature fruit phenotypic traits, correlation among fruit traits and Phytophthora fruit rot resistance, genetic diversity, population structure, and trait broad sense heritability. Significant differences within all fruit phenotype categories were detected among pepper lines. Fruit from Europe had the thickest pericarp, and fruit from Ecuador had the thinnest. For fruit shape index, fruit from Africa had the highest index, while fruit from Europe had the lowest. Five genetic clusters were detected in the pepper population and were significantly associated with fruit thickness, end shape, and fruit shape index. The genetic differentiation between clusters ranged from little to very great differentiation when grouped by the predefined categories. Broad sense heritability for fruit traits ranged from 0.56 (shoulder height) to 0.98 (pericarp thickness). When correlations among fruit phenotypes and fruit disease were evaluated, fruit shape index was negatively correlated with pericarp thickness, and positively correlated with fruit perimeter. Pepper fruit pericarp, perimeter, and width had a slight positive correlation with Phytophthora fruit rot, whereas fruit shape index had a slight negative correlation.

Genetic Resources of Cucumber

The Cucurbitaceae is a monophyletic family without any close relatives. It includes important vegetables such as cucumber, melon, watermelon, squash, pumpkin, and gourd. Within Cucurbitaceae, the genus Cucumis includes cultivated species C. sativus (cucumber) and C. melo (melon), as well as wild species including C. hystrix, C. callosus, and C. sativus L. var. hardwickii. More than 50 species have been identified in Cucumis with high levels of phenotypic and genetic diversity found in centers of diversity in Africa, Asia, and India. Primary and secondary centers of diversity can serve as useful sources of variation, and have been widely used to incorporate traits such as disease resistance into cultivated materials. During domestication, cucumber and melon underwent severe bottlenecks, which resulted in low genetic variation despite high phenotypic diversity. Since its domestication, approximately 3000 years ago, cucumber has undergone significant morphological changes from its small-fruited, black spined, seedy progenitor. More than 150 single gene traits have been described in C. sativus, including powdery mildew and virus resistance, sex expression, leaf morphology, and parthenocarpy, and molecular markers continue to be rapidly developed.

Regional and Temporal Population Structure of Pseudoperonospora cubensis in Michigan and Ontario

Cucurbit downy mildew (CDM), caused by the oomycete pathogen Pseudoperonospora cubensis, is a devastating disease that affects cucurbit species worldwide. This obligate, wind-dispersed pathogen does not overwinter in Michigan or other northern regions and new isolates can enter the state throughout the growing season. To evaluate the regional and temporal population structure of P. cubensis, sporangia from CDM lesions were collected from cucurbit foliage grown in Michigan and Ontario field locations in 2011. Population structure and genetic diversity were assessed in 257 isolates using nine simple sequence repeat markers. Genetic diversity was high for isolates from Michigan and Canada (0.6627 and 0.6131, respectively). Five genetic clusters were detected and changes in population structure varied by site and sampling date within a growing season. The Michigan and Canada populations were significantly differentiated, and a unique genetic cluster was detected in Michigan.

Heritability and Genetic Variance Components Associated with Citrulline, Arginine, and Lycopene Content in Diverse Watermelon Cultigens

Citrulline, arginine, and lycopene are naturally occurring compounds found in watermelon, Citrullus lanatus (Thumb)Matsum&Nakai, with beneficial effects on plant growth and human health. This study evaluated seven commercial cultivars and one breeding line for citrulline, arginine, and lycopene content in mature fruit grown at two locations in North Carolina. Correlations among these compounds and fruit quality traits (percent soluble solids and flesh pH) were evaluated. Watermelon cultigens evaluated were chosen for their fruit trait diversity. ‘Yellow Doll’ and NC-517 possessed the highest citrulline and combined concentration of citrulline and arginine of all cultigens evaluated. Lycopene content was highest in ‘Dixielee’, followed by ‘Sugar Baby’, and ‘Allsweet’, each of which have different shades of red flesh color. Location and its interaction with genotype had no significant effect on arginine or lycopene concentration. Broad-sense heritability was estimated for each trait. Arginine content (89%) and lycopene content (99%) had very high heritability. Citrulline content (41%), percent soluble solids (46%), and flesh pH (61%) had moderate heritability. Lycopene was positively correlated with flesh pH (r = 0.517) and negatively correlated with percent soluble solids (r = L0.344). Arginine content had a weak negative correlation with flesh pH (r = L0.343) and was not correlated with percent soluble solids. Watermelon [Citrullus lanatus (Thumb.) Matsum & Nakai] is an important crop grown worldwide. The United States is the sixth largest producer in the world, with an industry value of more than

Characterization, Virulence, Epidemiology, and Management of Anthracnose in Celery

430million and an annual production of 2 million metric tons (FAO, 2012; NASS, 2014). Watermelons are grown throughout the United States, with production mainly in the southern states (Wehner, 2008). Recently, watermelon has gained national attention as a good source of antioxidants (lycopene), arginine, and the arginine precursor, citrulline (Hong et al., 2015; Kaore and Kaore, 2014; Wang et al., 2014). Lycopene is a red-pigmented carotenoid with powerful antioxidant properties that serves as an intermediate for the biosynthesis of other carotenoids (DiMascio et al., 1989; Sandmann, 1994; Tomes et al., 1963). In redfleshed watermelon, lycopene accounts for 70% to 90% of the total carotenoids; the remaining carotenoids include phytofluene, phytoene, b-carotene, lutein, nerosporene, and z-carotene (Gross, 1987; Tomes et al., 1963). In orange-fleshed watermelon, prolycopene, phytoene, and z-carotene are the major carotenoids, whereas in canary yellow and salmon yellow-fleshed watermelons, neoxanthin is the major carotenoid (Bang et al., 2010; Tadmor et al., 2004). Studies have shown that the content of lycopene and carotenoids increases rapidly and accumulates 10–12 d after pollination in diploid watermelons and continues to accumulate as the fruit mature (Lv et al., 2015). Lycopene concentration varied widely in the watermelon cultigens tested, ranging from 36 to 120 mg·kg of fresh weight and can vary among production environments (Leskovar et al., 2004; Perkins-Veazie et al., 2001, 2006). The lycopene content has generally not been measured in most commercial cultivars. In humans, lycopene scavenges singlet oxygen and peroxy radicals, and deactivates excited molecules or DNA chain breaking agents (Stahl et al., 1997). Several epidemiology studies found that lycopene reduced cancer cell growth and induced cell death in malignant leukemia, endometrial, mammary, lung, and prostate cancer cells (Amir et al., 1999; Collins et al., 2006; Kotake-Nara et al., 2001; Muller et al., 2002). Arab and Steck (2000) and Matos et al., (2000) reported that lycopene attached to low-density lipoproteins in blood plasma and protected against lipid peroxidation and foam cell production, both of which are implicated in the initiation of atherosclerosis. In other epidemiological studies, Steinmetz and Potter (1996) and Strandhagen et al. (2000) found that a diet consisting of fruits and vegetables rich in lycopene could protect against stroke and cardiovascular diseases, whereas Tarazona-Diaz et al. (2013) determined that watermelon juice containing lycopene and citrulline could improve athlete recovery and performance. Besides lycopene, watermelons produce L-arginine (arginine) and its precursor Lcitrulline (citrulline) in fruit and foliage (Akashi et al., 2001; Davis et al., 2011). In related Citrullus species, studies have shown that citrulline content increases in the foliage during drought stress and may improve plant tolerance to stress (Akashi et al., 2001; Wang et al., 2014). Similarly in melon, foliage citrulline content is an important indicator for drought stress (Kusvuran et al., 2013). In developing watermelon fruit, citrulline content is low, reaching peak levels just before maturity, and declining as fruit ages (Fish, 2014). In fruit, the value of citrulline accumulation as a stress tolerance is unknown. In mammals, arginine plays an essential role in the nitric oxide pathway, contributing to improved immune processes and cardiovascular health. In rats, consumption of watermelon extracts with high citrulline resulted in improved lipid profiles, lower inflammation, and higher antioxidant capacity (Hong et al., 2015). In mice, hypothermia recovery and vascular endothelium function were improved in subjects administered a 1% dose of citrulline (Kobayashi et al., 2014). Free arginine, administered through supplements, can result in side effects such as nausea and gastrointestinal discomfort, prompting physicians to seek alternative forms of arginine (Collins et al., 2007; Hong et al., 2015). In humans, the arginine precursor, citrulline, is converted into arginine via argininosuccinate synthase (Collins et al., 2007). In watermelon, citrulline has not been associated with fruit phenotypic traits such as flesh color (red, orange, salmon yellow, or white) (Davis et al., 2011). Previously, citrulline content was evaluated in 56 watermelon cultigens (cultivars, breeding lines, and PI accessions) at two locations in Texas and Oklahoma (Davis et al., 2011). Citrulline concentration varied greatly among cultigens. The highest citrulline concentrations were found in ‘Tom Watson’, PI 306364 Received for publication 26 Sept. 2016. Accepted for publication 23 Nov. 2016. We would like to thank Tammy L. Ellington for assistance and support with field and laboratory experiments provided at North Carolina State University, Raleigh, NC. Corresponding author. E-mail: tcwehner@gmail. com. 936 HORTSCIENCE VOL. 52(7) JULY 2017 (Northern Africa) and ‘Jubilee’, whereas the lowest citrulline concentrations were found in PI 164992 (Turkey), Low Sugar 177, and Low Sugar 194. These data suggest that citrulline has likely not been indirectly selected by breeders during cultivar development. Both unadapted lines and commercial cultigens may have useful variation in citrulline content. The variation in arginine content has not been directly evaluated in watermelon to date. Watermelon breeding has resulted in a diversity of fruit sizes, rind color, rind patterns, and flesh color. Most cultivars have soluble solids content ( Brix) between 8% and 15% and acidity (flesh pH) of 5.18–5.60 (Corey and Schlimme, 1988). Studies have shown that variation in citrulline and lycopene exist within cultivated watermelons, but wild relatives and heirloom cultivars can also serve as good sources of trait variation for genetic improvement (Wehner, 2008). Many of these wild and weedy relatives have undesirable characteristics such as high or low flesh pH or low sugar content. Estimates of heritability and correlations among traits can help in the selection of breeding strategies and selection of parent material. Few studies to date have looked at the heritability and correlation of health compounds such as lycopene, arginine, and citrulline with fruit quality traits such as percent soluble solids and flesh acidity. The objectives of this study were to a) evaluate a diverse set of watermelon cultigens for lycopene, citrulline, and arginine content; b) determine the heritability of those traits; and c) measure the correlation of health compound concentrations with fruit acidity and soluble solids content. Materials and Methods Germplasm and field design. Eight diploid watermelon cultigens were evaluated for lycopene, citrulline, arginine, flesh acidity, and percent soluble solids content using fieldgrown fruit (Table 1). Cultigens were chosen to represent a range of sizes, shapes, rind patterns, and flesh colors (including canary yellow, salmon yellow, coral red, and scarlet red) (Table 1). Seeds for each genotype were sown in 72-cell polyethylene flats filled with an artificial soilless growing medium (4P Fafard soilless mix; Conrad Fafard Inc., Agawam, MA) in a greenhouse at the Horticultural Field Laboratory at North Carolina State University, Raleigh, NC. The flats were moistened to capacity after seeding, and held in the greenhouse at 25–30 C until full seedling emergence. The transplants were moved to cold frames for 1 week of acclimation before transplanting into the field at the two-true-leaf stage. The plants were transplanted into raised beds covered with black polyethylene mulch and grown according to the recommendations in the North Carolina Extension Service and Southeastern US Vegetable Crops handbook (Holmes and Kemble, 2009; Sanders, 2004). The treatment unit for each plot was a 3.7m-long plot on rowswith 3.1m from center to center. Soils were a sandy clay loam at the Cunningham station near Kinston and sandy loam at the Horticultural Crops Research Station near Clinton, NC. Missing or damaged transplants were replaced 1 week after the initial transplanting. The experiment was a randomized complete block design with three replications, two locations, and eight cultigens. Fruit from each plot were harvested at maturity according to the number of days to maturity,

Cucumber Cultivars for Container Gardening and the Value of Field Trials for Predicting Cucumber Performance in Containers

Leaf curling and petiole twisting of celery (Apium graveolens) were observed in several commercial fields in five Michigan counties in 2010 through 2012, causing significant crop damage and loss. Prior to this time, the pathogen Colletotrichum acutatum species complex had not been previously associated with celery in Michigan. In this study, the pathogens genotype and phenotype were characterized, the influence of environmental conditions determined, and fungicides tested. Pathogen identification was based on conidial morphology and molecular identification using species-specific primers. Intersimple-sequence repeat (ISSR) banding patterns were similar between C. acutatum isolates from celery (n = 51) and blueberry (n = 1) but different from C. dematium and C. gloeosporioides. Four ISSR primers resulted in 4% polymorphism when tested on isolates from celery. Pathogenicity and virulence of C. acutatum sensu lato isolated from celery (n = 81), tomato (n = 2), and blueberry (n = 1) were evaluated in greenhouse experiments, which revealed differences in virulence among isolates but no significant differences specific to collection year, county, or field. In dew chambers and growth chambers, high temperatures (≥25°C) or long leaf wetness duration (>24 h) increased disease incidence. Twelve fungicides were tested in field studies over two growing seasons to determine their efficacy against celery anthracnose. The fungicides azoxystrobin, pyraclostrobin, mancozeb, and chlorothalonil reduced disease by 27 to 50% compared with the untreated control when disease pressure was moderate.

QTL mapping of fruit rot resistance to the plant pathogen Phytophthora capsici in a recombinant inbred line Capsicum annuum population.

Cucumber (Cucumis sativus L.) is one of the most popular vegetable crops grown in U.S. home and urban gardens. The objectives of this study were to identify cultivars and planting densities for high yield of container-grown cucumbers. Additional objectives were to determine the value of field trials for predicting cucumber performance in containers and to evaluate different plant types (dwarf-determinate vs. tallindeterminate, gynoecious vs. monoecious, pickling vs. slicing) for container use and disease severity across cultivars. Fourteen cultivars and breeding lines were tested at three planting densities in two seasons for yield, quality, and disease resistance in field and patio trials. Significant differences were detected for seasons, cultivars, and densities. Yields were highest in the spring season compared with the summer season, and the best performance was obtained using three plants per 12 L container. There was a high correlation between patio and field trials, allowing extension specialists to recommend cucumber cultivars with high yield, high quality, and disease resistance based on field trial data. Home gardeners who want space-saving, high-yielding cucumbers with tender skin should consider a dwarf-determinate, pickling type that is monoecious. With monoecious type, no pollenizer is needed, and the harvest will be spread over more weeks than would be for gynoecious types. Cucumber (C. sativus L.) is a popular vegetable originating in India (Harlan, 1975), but grown throughout the world for centuries. The main types of cucumbers grown are American pickling, American slicing,Middle Eastern (Beit Alpha), European greenhouse (parthenocarpic), Asian slicer, and Oriental trellis. Cucumber types differ in fruit length, diameter, skin color, color uniformity, skin thickness, and skin surface texture based on their primary use (Wehner, 1989). Most cucumber cultivars have long vines and are grown flat on the ground or on trellis supports (oriental and greenhouse types). Pickling and slicing cucumbers are the two main types grown for commercial markets and home gardens in the United States; annual per capita consumption of fresh and processed cucumber was 2.9 and 2.2 kg, respectively in 2005 (USDA, 2005). In 2014, per capita consumption of fresh cucumbers was 3.1 kg (Statista GmbH, 2017). Although cucumbers require a large growing area, vines can be trained vertically on a trellis to minimize space. Alternatively, gardeners may choose to grow dwarf, determinate, or compact cucumber cultivars that have shorter vines for patio containers or small garden spaces. These cultivars are sometimes categorized as compact or bush types based on their short internodes. Plant breeders make use of the determinate (de) gene for the dwarf habit because the bush (bu) and compact (cp) genes are associated with poor growth or abnormal seeds. Cucumber cultivars with dwarf growth habit include ‘Bush Whopper II’, ‘Picklebush’, and ‘Bush Champion’. Cucumber plants can produce a combination of three types of flowers: staminate (male), pistillate (female), and perfect (male and female). Based on the type of flowers present, cucumbers are monoecious (staminate and pistillate flowers), androecious (staminate flowers only), gynoecious (pistillate flowers only), hermaphroditic (perfect flowers only), or andromonoecious (staminate and perfect flowers). Cucumber plants are normally monoecious, but most current commercial cultivars are gynoecious hybrid blends (88% gynoecious plus 12% monoecious pollenizer) or parthenocarpic (pistillate flowers only, and fruit set without pollination). Gynoecious and parthenocarpic cultivars usually have earlier and more concentrated yield, whereas monoecious cultivars will produce fruit over a longer period of time. An earlier and concentrated production period is preferred by commercial growers and processors, but may not be ideal for home gardeners. In a study conducted by Wehner and Miller (1985), three versions of the hybrid ‘Meridian 76’ (gynoecious · gynoecious, gynoecious · monoecious, and monoecious · monoecious) were similar in overall yield among the hybrids. The gynoecious hybrids provided an advantage in early yield (higher yield at first harvest), but had more grade No. 2 and cull fruit than the monoecious hybrid, possibly because of the high number of pistillate flowers pollinated and grown in a tight sequence. Urban and container gardening are two of the fastest growing gardening trends in the United States (Crandall and Crandall, 1996; Mason et al., 2008). Urban gardening can occur at the individual or community level, stimulating economic development, creating green space, and providing a source of fresh vegetables, fruits, and flowers for local communities. Urban gardens have a beneficial effect on communities, and cities are starting to include these spaces in city planning (Colasanti et al., 2012; Freeman et al., 2012; Hunter and Brown, 2012). In addition to community gardens, container gardens provide a convenient alternative for the home-production of vegetables, fruits, and flowers. As the number of people living in apartments, condominiums, and townhouses increases, so does the number of potential container gardeners. Despite the popularity of container gardening, information is limited on cultivars and optimal production methods for container-grown vegetable production. Internet resources are plentiful, but might not be based on scientific research. Universities continuously update their extension bulletins and services, but without home gardening studies they have been unable to make research-based recommendations. One such bulletin recommended the use of cultivar H-19 littleleaf, a tall, multibranched inbred with late maturity (Hopkins et al., 2008). This pure-line cultivar does have multiple branching and high yield, but its concentrated set makes it less appealing for many home gardeners. ‘Bush Champion’ is another popular cultivar recommended by extension specialists. In older (pre 2005) resources, many of the recommended cultivars have growth habits unsuited to container production or are no longer available. Also, the cultural practices in the literature are often vague and recommend various cultivars, container sizes, media types, fertilizer, and water regimes. One would hope that they were based on local production requirements. In addition to limited information on production practices, plant diseases can be a hindrance for urban gardeners. Because of space constraints, home gardeners often use higher Received for publication 20 Mar. 2017. Accepted for publication 16 Nov. 2017. We gratefully acknowledge the technical assistance of Tammy L. Ellington. Corresponding author. E-mail: tcwehner@gmail. com. 16 HORTSCIENCE VOL. 53(1) JANUARY 2018 plant densities than university or commercial recommendations. Increased plant densities promote disease development. With the available chemical control options, there is a need for high yielding, dwarf, and resistant cultivars for urban gardens. Heirloom cultivars often lack disease resistance, and commercial cultivars with resistance may be unavailable. Two common diseases of cucumber are powdery mildew (PM) and downy mildew (DM) (Adams and QuesadaOcampo, 2015; Ojiambo et al., 2015). These diseases often appear in midto late summer and affect the leaves of the plant. Powdery mildew, caused by Podosphaera xanthii, produces chlorotic spots on the upper leaf surface with an eventual white ‘‘powdery’’ appearance as the disease progresses. Downy mildew, caused by Pseudoperonospora cubensis, causes angular chlorotic lesions on the upper leaf surface (Ojiambo et al., 2015). Both pathogens can significantly reduce yield and fruit quality in fieldor container-grown plants. In urban gardening, container size is also an important factor. Cucumber roots grow 30–60 cm deep in field soil (Sanders, 1997). Inadequately sized containers result in small plants and may reduce fruit quality and yield. In addition, small containers can dry out rapidly, resulting in poor nutrient uptake, stressed plants, and reduced yield. Large containers are often preferred, but can be difficult to move and require a large amount of potting media. Various container sizes are recommended in extension publications from U.S. universities, including a 20–40 L container with one to two plants each (Crandall and Crandall, 1996), an 8–20 L container or hanging basket (Harrison, 1996), a container with one plant per 4 L of soil volume (Bass, 1999), a larger container for vining crops (including tall-indeterminate cucumber) than crops with bush habit with 16–20 L of potting medium per plant (Demboski et al., 2001) and 12–20 L per plant (Hopkins et al., 2008; Whiting et al., 2014). The objectives of this study were to 1) determine the optimal cucumber cultivars of several types (dwarf vs. tall, gynoecious vs. monoecious, pickling vs. slicing) and planting density for use in containers and 2) evaluate field trials as a predictor of cultivar performance in containers. Materials and Methods Experiments were conducted at the Horticultural Crops Research Station in Clinton, NC, during the spring (May–July) and summer (August–September) seasons in a single year. Twelve commercial cultivars were evaluated based on NC extension recommendations for field and for container production representing different plant types (monoecious, gynoecious, tall, dwarf, pickling, and slicing) (Table 1). One container garden cultivar, M 27 · NC-25, which had not been released at the time of planting, was also included. Greenhouse and trellis cucumbers were excluded from this trial. Greenhouse cucumbers should be grown in structures that exclude insects as they have bitterfree foliage and parthenocarpic fruit, and both types must be supported to prevent a large proportion of their fruit from curving (common with fruit longer than 300 mm). For container evaluations, 12 L pots were filled with a soille