bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Agrobacterium-mediated Transformation System in Pear Cultivars with Low-regeneration Frequency
Authors: Matsuda* Narumi , Isuzugawa Kanji , Gao Mei , Takashina Tadashi , Nishimura Koichi
Published: February 2019

The transformation of pears such as `Conference', `Doyenne du Comice' and `Passe-Crassane' has been attributed to the high regeneration frequency from leaf discs (71% to 97%; Leblay et al. 1991). However, it has been difficult to transfer desirable genes into cultivars with low-regeneration frequency such as `Silver bell' (35.4%) and `La France' (10.7%), which are the two major pear cultivars in Japan. In this study, we developed an Agrobacterium-mediated transformation system for `Silver bell' and `La France'. For `Silver bell', leaf discs derived from in vitro shoots were used as explants. The antibiotics for selection of transformants and elimination of Agrobacteria were investigated. In the most optimum condition, which is 30 mg·L-1 Kanamycin and 500 mg·L-1 Sulbenicillin, a 3.2 % transformation efficiency was obtained. However, no success was recorded in an effort to transform `La France' using leaf disc explants because of very poor regeneration frequency. Therefore, axillary shoot meristems were used as explants for transformation of `La France'. The conditions for antibiotic selection and elimination of Agrobacteria were also investigated. In 5 mg·L-1 Kanamycin and 375 mg·L-1 Carbenicillin, transformed shoots were produced at 4.8% efficiency. No chimera was observed in the transgenic shoots during a 2-year subculture period. Since the inoculated explants developed into multiple shoots during selection, it was thought that the problem of chimera might have been overcome. Therefore, this transformation method using axillary shoot meristem may be applicable to pear cultivars recalcitrant to regeneration from leaf disc. To the best of our knowledge, this is the first report of a transformation system in pear cultivars with low regeneration efficiency.
Enhanced Axillary Branching and Pigment Development of Double-Node Explants of Bigtooth Maple
Authors: Bowen-O'Connor* Clare A. , Hilaire Rolston St. , Hubsten-berger John , VanLeeuwen Dawn
Published: February 2019

Bigtooth maple (Acer grandidentatum Nutt.) is indigenous to the southwestern United States. This species is not widely used in managed landscapes but the plant holds promise as a useful ornamental tree. Micropropagation might provide additional sources of selected genotypes for the nursery industry, but tissue culture has not been used successfully to propagate this species. We cultured double-node explants from greenhouse-grown, 2-year old seedlings of bigtooth maples that originated from Utah, Texas and New Mexico. Seedling height ranged from 15-90 cm. The shoot region was divided into three equal zones designated as terminal, intermediate and basal. Explants were selected from each of those zones. Explants were established on Murashige-Skoog (MS), Linsmaier-Skoog (LS), Woody Plant Medium (WPM) and Driver-Kuniyuki (DKW) tissue culture media. Shoot proliferation, area of the plate covered by callus and foliar pigment development (hue as determined by Royal Horticultural Society Color charts) were monitored for 17 weeks. Media affected shoot proliferation (P = 0.0042) but the zone of origin (P = 0.6664) of the explant did not. Callus area showed no significant difference among the four media and three zones (P = 0.2091) and averaged 3.60 centimeters2. After four subcultures, each lasting 30 days, explants on DKW media produced 10 shoots per explant. This media might hold promise for the micropropagation of bigtooth maple. Twenty-nine percent of all explants expressed foliar pigmentation, which ranged from red-purple to orange-red. Whether foliar pigment development in tissue culture correlates with expressed pigmentation in nature warrants further investigation.
Screening Ornamental Plants for Their Ability to Accumulate Nitrogen and Phosphorus
Authors: Polomski* Robert F. , Taylor Milton D. , Klaine Stephen J. , Whitwell Ted
Published: February 2019

Commercial nurseries utilize large amounts of water and nutrients during the production cycle of container-grown plants. Excess water contaminated with N and P can impact the quality of surface water and groundwater. Earlier work by the authors found that constructed wetlands are highly efficient for removing N at water temperatures above 15 °C. However, PO4 removal was highly variable with uptake coinciding with periods of active plant growth and net export occurring during all other periods. Ornamental plants that remediate nutrients, especially phosphorus, would be very useful in designing constructed wetlands for commercial nurseries and greenhouses, rain gardens, and homeowner buffer strips. A greenhouse study was initiated in 2003 at Clemson Univ.'s Biosystems Research Complex to screen commercially available ornamental plants for their phytoremediation potential. Among others, these included the woody ornamental plants Cornus amomum, Myrica cerifera `Emperor', and Salix integra `Hakura Nishiki' and the semiaquatic herbaceous ornamental plants Canna `Bengal Tiger' and `King Humbert', Colocasia esculenta `Illustris', Rhynchospora colorata, Iris virginica `Full Eclipse, Pontederia cordata `Singapore Pink', and Thalia geniculata `Red Stem'. Plants were grown in pea gravel media kept saturated with one of five concentrations of Hoagland's Solution. Herbaceous and woody ornamental plants were harvested after 8 and 13 weeks, respectively. Water usage and biomass production were measured and nitrogen and phosphorus uptake was assessed. Experiments were replicated twice for each cultivar. Results indicate several species have the potential to be used in phytoremediation systems.
Early Growth Control of Plants by Seed Soaking in Growth Regulator Solutions
Authors: Magnitskiy* Stanislav , Pasian Claudio , Bennett Mark
Published: February 2019

Regulation of excessive vegetative growth is of importance in both field and bedding plant production. The goal of the study was to evaluate the effect of preplant seed soaking in growth regulators on the growth control of floricultural (verbena, salvia, pansy, marigold, celosia) and agronomic (cucumber, dill) crops. Seeds were soaked in water solutions of growth regulators of different concentrations ranging according to the crop from 50 to 1000 mg·L-1 for paclobutrazol, 1 to 10 mg·L-1 for uniconazole, 10 to 200 mg·L-1 for ancymidol, 100 to 5000 mg·L-1 for chlormequate chloride and dried at 20 °C for 24 h prior to sowing into plugs. In the first experiment, seeds of verbena, salvia, pansy, and dill soaked for 5 minutes in 50 mg·L-1 paclobutrazol solutions produced seedlings that were up to 43, 18, 30, and 22% shorter than the controls, respectively. Increased paclobutrazol concentrations and soaking time generally corresponded to a greater reduction of plant height, as well as delays and reduction in seedling emergence of all crops, except cucumber. In the second experiment, growth of marigold plugs from seeds soaked in 5 mg·L-1 uniconazole or 60 mg·L-1 ancymidol solutions during 45 min was associated with 23% or 6% plant height reduction, respectively. Soaking of marigold seeds in the solutions of chlormequate chloride did not significantly affect seedling growth. Increasing time of seed soaking in growth regulator solutions did not influence emergence of marigold seedlings. The height of celosia seedlings was only slightly reduced by soaking seeds in the solutions of all studied growth regulators. Results indicate that seed treatments with growth regulators might be useful in growth control of selected bedding plants.
Fungicidal Seed Treatments and Formonetin Affect Arbuscular-Mycorrhizal Fungi Colonization of Muskmelon
Authors: Burrows* Rhoda L. , Ahmed Ismail
Published: February 2019

Fungicides applied as soil drenches affect arbuscular-mycorrhizal (AM) fungal colonization of plant roots to different degrees, depending on the chemical used. However, the effect of fungicides applied as seed treatments has been less studied, and is of particular interest to growers who want to encourage beneficial mutualisms while protecting seedlings against pathogens. We tested the effects of four common seed treatments, Apron (mefenoxam), Thiram, Raxil (tebuconzaole), and Captan on colonization of `Superstar' muskmelon roots by the AM fungus Glomus intraradices in the greenhouse. By 30 days after planting, colonization was very high (>90% root length) for all treatments, with relatively minor (<10%) differences in percent length root with AM hyphae. The Apron seed treatment had the highest percent root length with hyphae, but the lowest amount of vesicles, while roots from Raxil and Captan-treated seeds had the lowest hyphal colonization and highest vesicle formation. Myconate ®, a commercial formulation of formononetin, an isoflavone previously shown to increase AM colonization, significantly increased the percent colonization of roots from the Raxil treatment, but not other treatments. Myconate also increased vesicle numbers in all but the Captan treatments, but not significantly.
Genotypic Variability in Staminate Flower and Pollen Grain Production of Diploid Watermelons [Citrullus lanatus (Thunb.) Matsum. & Nakai]
Authors: Stanghellini Mike , Schultheis* Jonathan R.
Published: February 2019

In 1999 and 2000, a total of 28 diploid watermelon cultigens (released cultivars and advanced breeding lines) were evaluated for staminate flower and pollen grain production to assess their potential to serve as pollenizers (pollen source plants) in triploid watermelon production systems. Male reproductive output (staminate flower and pollen production) was quantified during the peak flowering and fruit setting phase of the cultigens under field conditions. The number of staminate flowers produced per plant per day, number of pollen grains produced per flower, and total number of pollen grains produced per plant per day (staminate flowers per plant x pollen grains produced per flower) differed greatly between cultigens (for all tests, P < 0.01). Staminate flower production by cultigens differed by year (P < 0.0003) and days-within-years (P = 0.0094), but pollen production between years by cultigens was stable (P = 0.3845). Total male reproductive output ranged from 134,206 pollen grains per plant per day for `Jamboree' to 321,905 pollen grains per plant per day for `Summer Flavor 500'. These studies demonstrate the genotypic variability in watermelon male reproductive output potential, and may assist growers in selecting an optimal diploid pollenizer for triploid watermelon production.
Translocation and Distribution of C14 Photosynthates in Watermelon and Tomato
Authors: Lee* Sang Gyu , Lee Chiwon W.
Published: February 2019

The pattern of translocation and distribution of C14 labeled photo-assimilates in watermelon and tomato grown in the greenhouse and field was characterized. Each of the mature leaves of the plant at active fruit development stage was exposed to 14CO2 (20 μCi radio activity) for 40 min and the leaves, stems, fruit, and roots were harvested 3, 6, 9, or 12 hours after treatment. One half of the plants were grown under natural light and the other half in the dark during the experimental period. The activity of C14 in the dry tissues of the leaves, stems, fruits, and roots was determined, using a liquid scintillation analyzer. Both watermelon and tomato plants grown in the greenhouse and field contained C14 in all tissue types 3 hr after treatment, regardless of exposure to light or dark during the experimental period. Watermelon and tomato, respectively, transferred 22% to 61% and 9% to 26% C14 from the source leaf in 3 hours. Fruit tissues served as the strongest sink, with the highest percentages of C14 transfer in watermelon (99%) and tomato (90%) in plants grown in the field. The rate of C14 translocation was highest when plants were kept in the dark after 14CO2 feeding. In general, total translocation of C14 compounds from the source leaf was higher in watermelon than in tomato plants. For both watermelon and tomato, most field-grown plants showed a higher rate of C14 translocation as compared to greenhouse grown plants for a given period of time.
Effect of Colored Plastic Mulch on Soil Temperature and Yield of Eastern Muskmelon in Indiana
Authors: Gunter* Christopher , Lam Frankie
Published: February 2019

Indiana ranks seventh in the nation for watermelon production and fifth in the nation in muskmelon production. Both of these crops are intensively managed and cultivation using plastic mulches is the industry standard in the area. The purpose of this study was to determine the effect of plastic mulches of various colors and breakdown properties on the yield and earliness of eastern muskmelons in southwestern Indiana in 2002 and 2003. In 2002, eight colors were used, black, clear, brown, green, olive, grey, blue, and red. In 2003, five colors were used, grey, black, blue, clear, and olive. A bare ground treatment was also included in 2003. Temperature information was also collected both above and below these plastics in attempt to relate that back to performance of the crop. In 2002, green and clear mulches produced more melon numbers and higher melon weights compared to other mulch colors, however this was not significantly different than the black control mulch. In 2003, olive mulch produced significantly higher melon number and weight than clear mulches. In 2003, early-breakdown clear mulches, designed to last only until canopy fill, produced significantly lower yields than early-breakdown black mulch. This appears to be due primarily to weed production initiated early under the clear mulch and subsequent weed growth after mulch was broken down. The effect of plastic mulch type and earliness to crop maturity is also explored.
Leaf Carbohydrate Concentration Affects Development of Phenolic Compounds in Grape Berries
Authors: Heuvel* Justine E. Vanden , Robidoux Jessica L. , Neto Catherine C.
Published: February 2019

Carbon supply reduction was used to investigate the relationship between total non-structural carbohydrate (TNSC) concentration in the vegetative tissue and the production of phenolic compounds in the fruit of grapevines. Potted, greenhouse-grown DeChaunac vines were partially defoliated on one of three dates (berry set, veraison, or 7 days pre-harvest) during the growing season. Light environment of the fruit clusters was not affected by defoliation. Seven days following defoliation, half of the vines were destructively harvested for carbohydrate analysis, while the remaining vines were kept for fruit analysis at maturity. Defoliation of vines at berry set and veraison significantly reduced TNSC concentration in the leaf tissue. Partial defoliation of vines at berry set reduced total flavonols by 24%, total anthocyanins by 33%, and total phenolics by 13% in the fruit compared to the control vines. At veraison, partial defoliation of vines reduced total flavonols by 8%, anthocyanins by 43%, and did not affect total phenolics. While flavonol and total phenolic content was not affected by defoliation 7 days prior to harvest, total anthocyanins were increased by 39%, although leaf TNSC concentration was not affected. Concentration of total flavonols and anthocyanins were positively correlated with TNSC in the leaves (r = 0.53 and r = 0.73, respectively) while total phenolic content was not correlated with TNSC. These results indicate that development of anthocyanins and flavonols in fruit is linked to carbohydrate availability from vegetative tissues during berry set and veraison.
Correlation Among the Nitrogen, Chlorophyll (SPAD Value) and Photosynthetic Reactions on the Leaves of One-year-old Shoots by Training Angles in `Fuji' Apple Trees
Authors: Han* Hyun-Hee , Kim Yong-Koo , Lee Jae-Young
Published: February 2019

The nitrogen contents of leaves were the same on the first measurement of 9 May 2003 and the date was immediately prior date to application of different training angles to the one-year-old shoots grown during the previous year. However, the nitrogen content began to be different according to training angles as early as 8 days after the training of one-year-old branches. The 90° branch showed higher nitrogen content on the eighth date from the training application against 120° or non-trained slanting branch. The 90° branch continuously demonstrated larger nitrogen contents on 23 May and 2 June against non-trained branch. While, the 120° branch began to show the tendency of larger nitrogen content compared with slanting branches from 23rd May which was 2 weeks from training, and this difference continued up to 2 June 2003. The chlorophyll (SPAD value) of the leaves trained to 120° and 90° were the same at the time of initial training was applied on 9t May 2003, but a significant reduction of the chlorophyll (SPAD value) was found as early as eighth date from the first training date and this difference was reduced to be the same on the date of 2 weeks after the initial training date, but the chlorophyll (SPAD value) became different again on 2 June 2003. Correlations between chlorophyll contents (SPAD value) and photosynthetic rates influenced by training angles were highly positive in 90° training and in 120-degree training than non-training. Additionally, the correlations between the specific leaf weight and chlorophyll contents (SPAD value) were highly positive in 120° training than in 90° training or non-training.
Increased Water Use Efficiency with a Surfactant
Authors: Sloan* John , Mackay Wayne
Published: February 2019

Soils exhibit a degree of hydrophobicity and can repel water rather than absorb it. Surfactants lower the surface tension of water which may increase its infiltration into the soil and adsorption to soil solids. The objective of this study was to determine if water treated with a surfactant would increase conserve soil moisture and decrease the amount of water needed to sustain healthy plant growth. Clay and sandy loam soils were placed in 15-cm greenhouse pots. Impatiens seedlings were transplanted into each pot. All pots were fertilized equally and the Impatiens flowers were allowed to grow for 8 weeks. Then the pots were treated with tap water or tap water mixed with a commercial surfactant at one times (1×) or two times (2×) the recommended rate. After applying the water treatments, pots received no additional water. Each pot was weighed twice per day and the plants were observed for signs of wilting. Upon initial signs of wilting, each plant was rated on a scale of 1 to 3 with 1 = no wilting, 2 = leaves starting to droop, and 3 = wilting leaves and stems. Addition of the surfactant at the 1× and 2× rates slowed the loss of water from both the sandy loam and the clay soils. The effects of the surfactant were apparent within 3 to 5 days in the sandy loam soil and 6 to 10 days in the clay soil. The benefits of reduced water loss from soil were manifested by reduced wilting in Impatiens plants in soils treated with 1× and 2× the recommended rate of surfactant. In the clay soil, use of the surfactant increased the amount of time before Impatiens plants began to wilt. It appears that adding a surfactant to irrigation water can conserve soil moisture and extend the time between water applications.
Irrigation Cutback a Reliable Tool for Soluble Solids Improvement in Processing Tomato
Authors: Hartz* T.K. , Johnstone P.R. , LeStrange M. , Nunez J.J. , Miyao E.M.
Published: February 2019

Soluble solids concentration (SSC) is a major quality factor for tomatoes (Lycopersicon esculentum Mill.) grown for processing. The effects of early irrigation cutback were investigated in a series of drip-irrigated field trials in California from 2000-03. Irrigation cutback was initiated from 4-7 weeks preharvest, with irrigation volume reduced to 30% to 70% of reference evapotranspiration. Early irrigation cutback was compared to full irrigation until cutoff 2-3 weeks preharvest. SSC was monitored from the initiation of deficit irrigation until harvest, with breaker-stage fruit sampled at approximately 10-day intervals; additionally, early-maturing fruits were tagged on the plant at breaker stage and retrieved at harvest for SSC analysis. Fruit yield, overall SSC, and brix yield (Mg·ha-1 fruit solids) were evaluated at commercial maturity. Fruit SSC increased in response to soil moisture stress, with late-maturing fruit as much as 2.0 °Brix higher than fruit maturing before significant moisture stress. However, once a fruit reached the breaker stage of maturity, its SSC did not increase regardless of subsequent soil moisture stress. Across field trials, yield decline resulting from early irrigation cutback was matched by a corresponding increase in overall SSC, resulting in equivalent brix yield in all test fields. We conclude that the early irrigation cutback provides a flexible tool for SSC management and that °Brix monitoring of breaker-stage fruit can augment soil moisture monitoring to tune irrigation management to field-specific conditions.
Irrigation Timing Effects on Cabbage (Brassica oleracea, L. Capitata Group) Head Traits and Sugar Concentrations
Authors: Radovich* T.J.K. , Kleinhenz M.D. , Streeter J.G. , Bennett M.A.
Published: February 2019

Cabbage (cv. Bravo) was grown in 2002 and 2003 at The Ohio State Univ., Ohio Agricultural Research and development Center in Wooster, Ohio. The four irrigation treatments, arranged in a RCB design, were: 1) irrigation throughout development [no stress (NS)], 2) irrigation only during head development [frame stress (FS)], 3) irrigation only during frame development [head stress (HS)], and 4) no irrigation [frame and head stress (FHS)]. Irrigation timing relative to crop stage significantly affected all head characteristics except density, with the greatest differences between cabbage receiving irrigation during head development (NS, FS) and cabbage not irrigated during head development (FHS, HS). On average, heads from NS and FS plots were heavier (38%), larger (15%), less pointed and had less volume occupied by the core than heads from HS and FHS plots. Combined head fructose and glucose concentrations were significantly greater in cabbage receiving irrigation during head development than in cabbage not irrigated during head development (47% vs. 41% dwt, respectively). Sucrose concentrations were significantly greater in cabbage not irrigated during head development than cabbage receiving irrigation during head development (8% vs. 6% dwt, respectively). The higher ratio of sucrose: fructose+glucose observed in HS and FHS relative to NS and FS treatments was interpreted as an osmo-regulatory response with potential implications for cabbage flavor. Overall, it was concluded that physiological responses elicited in cabbage by differential irrigation can affect important head traits, and that targeted applications of water during specific stages of crop development may be utilized to maximize water use efficiency and crop quality.
Nitrogen and Phosphorus Discharge during Spring Regeneration of Constructed Wetlands at a Commercial Nursery
Authors: Taylor* Milton D. , Klaine Stephen J. , Whitwell Ted
Published: February 2019

Mitigation of offsite movement of nutrients in nursery runoff is a serious concern for commercial nurseries with container-grown plants. Wight Nurseries, Cairo, Ga. has operated 3.77 ha of planted constructed wetlands since 1996 to remediate nutrients from runoff. The wetlands receive drainage from a 48.6 ha nursery production area. Monitoring by nursery staff had suggested net export of nitrogen and phosphorus may occur during spring regeneration. Intensive monitoring was conducted between early March and mid-May 2003. There was no net export of nitrogen during the study. Nitrite nitrogen removal remained at 100% in the 1st stage wetland throughout March but declined in April to 89.6% as loading increased 5-fold. However, the 2nd stage wetland removed 100% of the remaining nitrite. Nitrate removal in the 1st stage wetland was high through early April (97.6%) but low in 2nd stage wetlands (16%) until loading increased 10-fold when efficiency rose to 94.9%. Nitrate removal by the 1st stage declined during mid-April but 2nd stage efficiency remained above 95%. For phosphorus, there was net export during March from both stages. However, during April, the wetlands removed phosphorus although loading tripled during the month. In May, net export of phosphorus from the wetlands recommenced with peak 1st stage export of 130% and 2nd stage uptake declining until mid-May when export began again. Neither water temperature nor rainfall appeared correlated with wetland efficiency. While phosphorus was exported by the wetlands during parts of the study, neither nitrate nor nitrite was exported as spring progressed and decomposition of last year's growth accelerated.
Genetically Modified Herbicide-tolerant Chile Pepper Does Not Differ From Non-GM Chile Pepper (Capsicum annuum L. cv. `Subicho') For Horticultural Characteristics.
Authors: Cho* Myeong Cheoul , Kwon* Taek-Ryoun , Ryu* Tae-Hun , Chae* Young , Cheong* Seung-Ryong , Mok* Il-Gin
Published: February 2019

Genetically modified herbicide-tolerant (GMHT) and non-GM chile pepper plants (Capsicum annuum L. cv. `Subicho') were grown in an isolated GMO field to evaluate horticultural characteristics. Phosphinotricin acetyltransferase (bar gene), which has a function of herbicide-resistance in plant, was introduced into chile pepper plants using the protocol of Agrobacterium-mediated transformation. Thirty nine characteristics were evaluated, consisting of 14 qualitative, 18 quantitative and 7 other characters. The evaluations were achieved by visual assessment for qualitative characteristics and numerical measurement for quantitative ones. The GMHT and non-GM plants did not differ in the 39 characteristics tested. Pollen viability and germination rate were not significant different between the GMHT plants and the non-GM plants. These results indicated that genetic transformation of bar gene into the chile pepper did not affect those horticultural characteristics and pollen viability.
Resistance to Leafminers in Lettuce
Authors: Mou* Beiquan , Liu Yong-Biao
Published: February 2019

Leafminer (Liriomyza spp.) is a major insect pest of many important agricultural crops including lettuce (Lactuca sativa L.). The goals of this study were to evaluate lettuce genotypes for resistance to leafminers and to estimate the heritabilities of leafminer-resistant traits in the field, to examine the association among different resistant traits, and to study the mechanism of leafminer resistance in lettuce. Seventy-eight lettuce accessions and 232 F2 plants of crosses were evaluated for leafminer stings and the production of pupae and flies in the field in 2001 and 2002, and resistant genotypes were subjected to no-choice test. Wild species (Lactuca serriola L., L. saligna L., and L. virosa L.) had significantly fewer stings than cultivated lettuces. Among cultivated lettuces, sting densities were lowest on leaf lettuce and highest on romaine types. The sting results from the field were highly correlated with the results from insect cages (r = 0.770 and 0.756 for 2001 and 2002 tests, respectively), suggesting that a cage test can be used to screen for resistance in the field. Broad-sense heritability estimates for stings per unit leaf area in the field were 81.6% and 67.4% for 2001 and 2002 tests, respectively. The number of pupae produced per plant or per leaf was moderately correlated with sting density but was not correlated with leaf weight. Results suggest that both antixenosis and antibiosis exist in lettuce germplasm and resistant genotypes from choice tests remain resistant under no-choice conditions. These findings suggest that genetic improvement of cultivated lettuce for leafminer resistance is feasible.
Hybridizing Collard and Cabbage to Make Collard Cultivars
Authors: Farnham* Mark , Ruttencutter Glen , Smith Powell , Keinath Anthony
Published: February 2019

Collard (Brassica oleracea L., Acephala Group) is a uniquely American cole crop adapted to the southeastern United States, and several lines of evidence indicate its closest relative is heading cabbage (B. oleracea, Capitata Group). These two cole crops have been grown in close proximity in the Southeast from colonial times. Today, the number of commercially available collard cultivars is limited, and the most popular ones are susceptible to diseases like fusarium yellows, something that numerous cultivars of cabbage are highly resistant to. We postulated that hybrids between cabbage and collard would look more like collard because heading of cabbage is recessive to the nonheading nature of collard, and that such hybrids might be directly used as collard cultivars that express disease resistance from cabbage. Cytoplasmic male-sterile (cms) cabbage inbreds were crossed with different male-fertile collard inbreds using bees in cages to produce hybrid seed. Resulting cabbage-collard hybrids were compared to conventional collard and cabbage cultivars in three replicated field trials in South Carolina. In all trials, collard-cabbage hybrids exhibited similar size and stature as conventional collard, and throughout most of the growing season the hybrids remained nonheading. In addition, the collard-cabbage hybrids were much more uniform than open-pollinated collard cultivars. Among the cabbage-collard hybrids there was significant variation with some more collard-like than others. Results indicate that select collard-cabbage hybrids could out perform certain conventional collards and serve as potential new collard cultivars
Response of Zonal and Ivy Geraniums to Root Medium pH
Authors: Kaufmann* Pauline H. , Hammer P. Allen
Published: February 2019

In 2002 the USDA reported potted geraniums accounted for $150 million in wholesale value, more than any other bedding or garden plant surveyed. Despite the importance of the geranium in floriculture production, little published research data is available pertaining to the media pH requirements of zonal and ivy geraniums. Current recommendations suggest zonal geraniums be grown at pH 5.7-6.6 and ivy geraniums at pH 5.0-6.2. The wide range in root medium pH recommendations for both zonal and ivy geraniums and the lack of research data prompted this research. Also, the basis for recommending a lower medium pH for ivy geraniums could not be found in published literature. The research objectives were to investigate the effect of medium pH on plant growth and to determine more precise recommendations for both species. The growth of 3 cultivars each of zonal and ivy geraniums growing in 8 medium pH treatments were evaluated. Limestone and hydrated lime were incorporated at increasing rates into a 1:1:1 peat, perlite and bark mix to achieve a medium pH ranging from pH 4.0-7.5. Plants were harvested at weeks 3, 6, and 11 and plant dry weight and media pH were determined. Leaf luminance, chroma and hue were evaluated at week 10. Plant dry weight was greatest at pH 6.55 or higher for both zonal and ivy geraniums at week 11. Leaves of plants grown at pH 6.55 or higher had significantly lower luminance and chroma and greater hue in all cultivars, corresponding to leaves that were darker, less vivid, and deeper green in color. This study shows a root medium pH greater than pH 6.5 results in greatest plant dry weight accumulation and quality of leaf color for both zonal and ivy geraniums. This study also shows ivy geraniums can be grown at the same media pH as zonal geraniums.
Productivity of Two Limonium Species Irrigated with Saline Wastewaters
Authors: Grieve Catherine M. , Carter* Christy T. , Poss James A.
Published: February 2019

Saline wastewaters may provide a valuable water source for the irrigation of selected floriculture crops as demand for quality water increases. A completely randomized design with 3 replications was used to test the effects of salinity on productivity and mineral accumulation on each of two Limonium species grown in greenhouse sand tanks. Three-week-old seedlings (n = 15) of Limonium perezii `Blue Seas' and L. sinuatum `American Beauty' were exposed to 7 salinity treatments (2.5 (control), 7, 11, 15, 20, 25, and 30 dS·m-1) prepared to simulate saline drainage waters of the San Joaquin Valley (SJV) in California. After 10 weeks, vegetative material from five plants from each tank was harvested to assess mineral composition (total-S, total-P, Ca2+, Mg2+, Na+, K+, and Cl-), for each variety. Ion selectivity coefficients were calculated by dividing the ratio of specific ions in the plant by those found in the medium. Stem length and weight, and flower stem numbers were determined at harvest. Salt tolerance thresholds based on stem length for L. perezii and L. sinuatum were 2.5 and 7.0 dS·m-1, respectively. Maximum growth of both species declined as salinity increased, but both species were able to complete their life cycles at 30 dS m-1. L. sinuatum had higher leaf concentrations of Na+, K+, Mg2+, Cl-, and total-P than L. perezii. K+ was preferentially accumulated with regard to Na+ by both species, but was significantly higher in L. sinuatum. Limonium perezii and L. sinuatum can be rated as sensitive and moderately salt tolerant plants, respectively.
Effect of Tank Mixing Pesticides in Controlling Western Flower Thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae)
Authors: Warnock* Daniel , Cloyd Raymond
Published: February 2019

Greenhouse managers tank mix pesticides to broaden the spectrum of pest control, and reduce pesticide and labor costs. However, the effect of tank mixing an assortment of pesticides on efficacy to control pests has not been documented. This study assessed how tank mixing commercially available insecticides and miticides in two-, three-, and four-way combinations impacts the control of western flower thrips (WFT), Frankliniella occidentalis in greenhouse experiments and a laboratory bioassay. The pesticides screened were spinosad, abamectin, bifenazate, azadirachtin, and imidacloprid. Each pesticide was applied at the label-recommended rate. In the greenhouse experiments, transvaal daisy (Gerbera jamesonii) and lisianthus (Eustoma grandiflorum) flowers were inoculated with 25 adult WFT, and then flowers were sprayed with the designated treatments. After 72 hours, flowers were emasculated to assess the numbers of live and dead WFT. In the laboratory bioassay, chrysanthemum (Dendranthema grandiflora) leaf disks, treated with each pesticide and all tank mixes, were exposed to 15 adult WFT. The numbers of live and dead WFT were assessed after 48 hours. For all three experiments, no antagonistic tank mixes were identified. All treatments with spinosad, including the individual application and tank mixes, resulted in high mortality of WFT based on the numbers of live and dead WFT recovered. Our data suggest that tank mixes of spinosad with the other pesticides tested do not affect the efficacy of spinosad in controlling WFT. This information is important to greenhouse managers who want to tank mix pesticides and still control WFT in addition to the other plant-feeding arthropods found in greenhouses.
Evaluation of Growth Parameters of Anthurium andreanum Plants Grown in Mixes with Municipal Solid Waste Compost
Authors: Del Carmen Libran* Maria , Rivera Dania , Gonzalez Lizzette
Published: February 2019

In Puerto Rico, the ornamental crop production is one of the most important agricultural enterprises. The growing media most used to grow ornamentals contains peat moss which is very expensive and everyday results less available. There is a need to conduct studies to evaluate alternate organic components. In Puerto Rico, the Municipal solid waste compost (MSW) has been considered as a possible component for a growing mix to grow plants. Results from chemical properties studies of the MSW compost shows that it is a source of nutrients for plants. A raw MSW is a contaminat to the environment, but once is composted does not represent a hazard to humans or environment. The objective of this research was to evaluate the growth responses of Anthurium plants grown in mixes containing different proportions of MSW with a commercial type of mix containing peat moss. Plant of Rosa cultivar Anthura Co. were grown under six treatments containing proportions of MSW: Peatlite mix (0:100,15:85,25:75,50:50,75:25, and 100:0). Data of growth parameters such as number of leaves, leaf area index, clorophyll content, number of flowers, adn fresh and dry weight was gathered and analyzed. Results did show not significant differences in all treatments on number of leaves and leaves area. Clorophyll content was similar on treatment 0:100,15:85 and 25:75 of MSW: Peatlite mix. Fresh and dry weight (g) were lower in all treatments except on 0:100, which got the highest weight. These results shown that MSW could be considered to be a component of a soiless mix to grow ornamentals in order to reduce cost production and environmental impact.
Anthocyanins From the Flowers of Prunus mume Sieb. et Zucc.
Authors: Zhao Changling , Guo Weiming , Chen Junyu , Jiang* Zhongchun
Published: February 2019

Mei (Prunus mume Sieb. et Zucc.) flower is one of the candidates for the national flower of the People's Republic of China. Several major anthocyanins from the flowers of P. mume Sieb. et Zucc. were isolated with MeOH-HOAc-water (10:1:9, v/v), and purified by paper chromatography and subsequent column chromatography. Specific chemical reactions, chromatographic and spectroscopic analyses indicated that the anthocyanins in `Nanjing Hongxu' (Nanjing red-bearded) were cyanidin 3-O-(6'-O-α-rhamnopyranosyl-β-glucopyranoside) and cyanidin 3-O-(6'-O-galloyl-3'-O-β-glucopyranosyl-β-glucopyranoside). Anthocyanins in `Nanjing Hong' (Nanjing red) were cyanidin 3-O-(6'-O-α-rhamnopyranosyl-β-glucopyranoside), cyanidin 3-O-(6'-O-galloyl-β-glucopyranoside) and cyanidin 3-O-(6'-O-E-feruloyl-βglucopyranoside). In addition to contributing to the blue flower color, the anthocyanins may improve the ability of the two cultivars to survive at low temperatures.
Response of Sweetpotato Nodal Cultures to Low Temperature Stress
Authors: Weathington* Tianna W. , Potluri DeviPrasad V.
Published: February 2019

Axillary bud cultures of sweetpotato Ipomoea batatus L. [cultivars comensal and salyboro] were propagated in vitro. Nodal cultures of these were grown at different temperatures ranging from 10 °C to 30 °C at 5 °C intervals from the time of axillary bud transfer to 10 weeks of growth in a controlled growth chamber. After 10 weeks of growth, morphological and physiological parameters were measured including shoot height, number of nodes and branches, levels of proline, soluble carbohydrate and protein. There was not much difference in the cultures grown at 25 and 30 °C but temperatures lower than 25 °C were inhibitory to both cultivars, though the effects were more pronounced in salyboro than comensal. Salyboro grew slower and exhibited leaf discoloration, weak stems, and poor root growth. Proline levels increased in both cultivars and the increase was higher in shoot than root due to low temperature stress. Soluble carbohydrates and proteins increased in comensal, maintaining the carbohydrate protein ratio, but decreased in salyboro. The results suggest that the cultivar comensal may tolerate cooler temperatures and the cultivar salyboro is susceptible to them.
Variation in Ploidy Levels and Reproductive Pathways Among Flowering Crabapples
Authors: Ranney* Thomas , Eaker Thomas
Published: February 2019

Information on ploidy levels is extremely valuable for use in plant breeding programs. Fertility, crossability, and heritability of traits are all influenced by ploidy levels. Knowledge of reproductive pathways, including occurrence of apomixes, pseudogamy, and formation of unreduced gametes can also be important information for developing breeding strategies. Although ploidy level can be determined by counting chromosomes, flow cytometry provides a reliable and much faster means for determination of nuclear DNA content and associated ploidy level. Measurement of ploidy levels of seeds (embryo and endosperm) can also provide useful insights into reproductive pathways. The objective of this study was to determine the approximate genome size, estimated ploidy level, and range of reproductive pathways of a diverse collection of flowering crapbapples (Malus spp.). Genome sizes were calculated as nuclear DNA content for unreduced tissue (2C). Results from the taxa included in our survey showed DNA contents ranging from 1.52 to 1.82 for diploids, 2.40 to 2.62 for triploids, and 3.36 to 3.74 pg/2C for tetraploids. Based on these ranges, we identified 43 diploid, 10 triploid, and 4 tetraploid crabapple taxa in this collection. Results from open pollinated seeds and seedlings demonstrated a variety of reproductive pathways including apomixes and unreduced gametes. This research provides information on ploidy levels and reproductive pathways of flowering crabapples and will allow for more systematic and efficient progress in the development of improved cultivars.
Determining the Contribution of Tomato Carotenoids to Plasma Antioxidant Status: A Study of Potential Applications for Breeding Tomatoes with Increased Health Benefits
Authors: Mes* Peter J. , Myers James R. , Frei Balz
Published: February 2019

A nutritional study was initiated to determine which carotenoids found in tomato result in decreased lipid oxidation ex vivo. To compare the carotenoids in a human diet without the use of purified supplements, tomatoes expressing nonfunctional enzymes in the carotenoid pathway were used. Tomato lines carrying the genes t, B, ogc, Del, or r were grown to produce fruit containing with high levels of prolycopene, beta-carotene, lycopene, or delta-carotene respectively, or low total carotenoids in r. Juices were processed from these lines and used in a dietary intervention study. Plasma samples were drawn before and after consumption of each juice. These samples were subjected to a battery of tests to analyze the contribution of carotenoids to the total lipid antioxidant status. Results of these tests are discussed.
Current Fertilizer Input for Pot Gerbera Production Can Be Reduced by More than 50%
Authors: Zheng* Youbin , Graham Thomas , Richard Stefan , Dixon Mike
Published: February 2019

Pot gerbera (Gerbera jamesonii Var. `Shogun') plants were subirrigated with one of four nutrient solutions (10, 25, 50, and 100% of full strength) in order to determine whether currently used commercial nutrient solution concentrations can be reduced without negative impact on crop production. Nutrient concentration levels did not affect leaf area, flower number and appearance, and plant total dry weight. There were no significant differences in leaf chlorophyll content between the plants that received the 50 and 100% strength nutrient solutions. It is concluded that nutrient solution concentrations typically used in commercial greenhouse, for pot gerbera production, can be safely reduced by at least 50% without adversely affecting crop production. Nutrients accumulated in the top section of the growth substrate under all treatment levels; however, no phytotoxic effect was observed. Fertilizer inputs were reduced in the 50%, 25%, and 10% treatments by 54%, 75%, and 90% respectively. After 4 weeks recirculating, the quality of the nutrient solutions was still within acceptable limits.
Evaluating Silica Uptake in Bedding Plants
Authors: Frantz* Jonathan M. , Pitchay Dharmalingam S. , Locke James C. , Krause Charles
Published: February 2019

Silica (Si) is not considered to be an essential plant nutrient because without it, most plants can be grown from seed to seed without its presence. However, many investigations have shown a positive growth effect if Si is present, including increased dry weight, increased yield, enhanced pollination, and most commonly, increased disease resistance, which leads to its official designation as a beneficial nutrient. Surprisingly, some effects, such as reduced incidence of micronutrient toxicity, appear to occur even if Si is not taken up in appreciable amounts. The literature results must be interpreted with care, however, because many of the benefits can be obtained with the counterion of the Si supplied to the plant. Determining a potential benefit from Si could be a large benefit to greenhouse plant producers because more production is using soilless media that are devoid of Si. Therefore, Si must be supplied either as a foliar spray or nutrient solution amendment. We investigated adding Si to New Guinea Impatiens (Impatiens hawkeri Bull), marigold (Tagetes erecta), pansy (Viola wittrockiana), spreading petunia (Petunia hybridia), geranium (Pelargonium spp.), and orchid (Phalaenopsis spp.). Using SEM, energy dispersive X-ray analysis, and ICP analysis, Si content and location was determined. This information and other growth characteristics will be used as a first step in determining the likelihood of using Si as a beneficial element in greenhouse fertilizer solutions for higher quality bedding plants with fewer agrochemical inputs.
Anion Species in Fertilizers Affect Growth and Development in Bedding Plants
Authors: Pitchay* Dharmalingam S. , Frantz Jonathan M. , Locke James C.
Published: February 2019

Currently, formulation of inorganic fertilizers is based on cation amounts such as NH4, K, Mg, Ca, Fe, MN Cu, and Zn, whereas anion species and amounts are viewed, with few exceptions, as necessary fillers. The delivery of cations in the nutrient solution is associated with an anion such as Cl, SO4, NO3, PO4 or CO3. These anions at higher concentrations can result in different growth responses by altering the rhizosphere pH, soluble salts, and influencing the uptake of both cations and anions. The impact of these anions has not been extensively studied in the formulation of inorganic fertilizers. Several experiments assessed the effect of SO4 and Cl on root and shoot growth and development of bedding plants represented by petunia, impatiens, and vinca. In all treatments, plant height, shoot and root dry weight, and flower number decreased with an increase in Cl concentration. Root morphology was marked by fewer total roots and shorter primary and secondary roots when grown with Cl anions compared to the plants grown with SO4 anions. This indicates that anions have a larger role in determining optimum fertilizer formulation than previously believed. This information provides an additional tool in formulating fertilizers for greenhouse bedding plant production.
Managing Nitrogen, Potassium, and Boron in New Guinea Impatiens: Is More Better?
Authors: Pitchay* Dharmalingam S. , Frantz Jonathan M. , Locke Jonathan M. , Krause Charles
Published: February 2019

Growers tend to over fertilize their plants as a way to minimize the likelihood of encountering nutrient deficiencies that would reduce the quality of their plants. Much of the nutrition literature focuses on the nutritional extremes namely of toxicity and deficiency. Once plants get to this stage, little can be done to correct the problem. Characteristics of plant performance in super-optimal conditions, yet below toxic levels, is less well known, and needs to be developed to help growers identify problems in their production practices before they impact sales. New Guinea Impatiens were grown over a wide range of N, K, and B levels, from 15% to 400% full strength Hoagland's solution for each nutrient after establishing transplanted rooted cuttings in a peat: perlite soilless media. Plants were grown for four weeks during treatment, during which time the flowers were pinched. After only 2 weeks of treatment, plants with 200% and 400% N were significantly shorter than control plants and plants with 15% N. Reflectance measurements and photographs were made twice a week. At the end of the four weeks, plant tissue was analyzed for form of N, root development and structure, and leaf area. Tissue samples were also analyzed with SEM and energy dispersive X-ray analysis to determine changes in nutrient location and tissue structure. This data provides insight into the nutrition economy of plants in general, tests the use of reflectance spectrometry as a method of detecting super-optimal fertilizer concentrations, and will help growers optimize their fertilization requirements to reduce production costs yet maintain high plant quality.