bluuebunny/crossref_metadata_2025 huggingface dataset:
(154) Alternatives for Pest Management in a Tropical Organic Watermelon Production System
Authors: Wszelaki Annette L. , Brunner Bryan
Published: February 2019

While much research has been conducted in organic farming, little has focused on tropical systems. Tropical, versus temperate, systems present additional challenges for organic producers, including differences in soils, temperature, daylength, rainfall, and humidity. Pest management in tropical organic systems can be particularly demanding due to the year-round pest pressure and optimal environment for pest proliferation. Weed management is essential for the production of high-quality watermelons, but can be difficult when herbicides are not permitted. Weeds also serve as a source of inoculum for disease organisms and a habitat for insects, both beneficial and detrimental. Many products have been advertised for pest control in organic farming systems, most of which have not been adequately evaluated in independent, replicated trials. Here we investigated alternatives to pesticides for the control of weeds, insects, and diseases in `Crimson Sweet' watermelons. A split plot on a RCBD with four replications per treatment was used, with weed treatment (± paper-grass mulch) as the main plot and 12 insect and disease control alternatives as subplots. The alternatives for insect and disease control included traditional copper-based fungicides, biological control agents, potassium bicarbonate, hydrogen dioxide, milk, and commercial formulations of essential oils. Weed abundance (percentage cover), disease severity (percentage disease), and insect damage (percentage foliar damage) were evaluated weekly using a modified Horsfall-Barratt scale. Yield and quality were measured at harvest on five plants from each replication. While none of the products should be relied upon as the sole means of managing pests, those with efficacy could be integrated into organic management programs.
(174) Determination of Fatty Acid Composition in 120 Korean Native Rice Cultivars
Authors: Cho Kyoung-Shim , Kim Hyun-Ju , Lee Jae-Ho , Kang Jung-Hoon , Lee Young-Sang
Published: February 2019

Fatty acid is known as a physiologically active compound, and its composition in rice may affect human health in countries where rice is the major diet. The fatty acid composition in brown rice of 120 Korean native cultivars was determined by one-step extraction/methylation method and GC. The average composition of 9 detectable fatty acids in tested rice cultivars were as followings: myristic acid; 0.6%, palmitic acid; 21.2%, stearic acid; 1.8%, oleic acid; 36.5%, linoleic acid; 36.3%, linolenic acid; 1.7%, arachidic acid; 0.5%, behenic acid; 0.4%, and lignoceric acid; 0.9%. Major fatty acids were palmitic, oleic and linoleic acid, which composed around 94%. The rice cultivar with the highest linolenic acid was cv. Jonajo (2.1%), and cvs. Pochoenjangmebye and Sandudo showed the highest composition of palmitic (23.4%) and oleic acid (44.8%), respectively. Cultivar Pochuenjangmebye exhitibed the highest composition of saturated fatty acid (28.1%), while cvs. Sandudo and Modo showed the highest mono-unsaturated (44.8%) and poly-unsaturated (42.4%) fatty acid composition, respectively. The oleic acid showed negative correlation with palmitic and linoleic acid, while positive correlation between behenic and lignoceric acids was observed.
(176) Yield Data from 2005 and Instrumental and Sensory Evaluation of Tomato Fruits from Plants Grown in High Tunnels at Beltsville, Md., or Obtained from Commercial Sources
Authors: Krizek Donald , Saftner Robert , Park Eunhee , Abbott Judith , Camp Mary , Clark David
Published: February 2019

A study of tomato (Lycopersicon esculentum Mill.) production and quality in high tunnels was conducted. Seedlings of `Oregon Spring' and `Red Sun' were transplanted weekly to two high tunnels at Beltsville, Md., from 23 Mar. to 13 Apr. 2005. Data were recorded on the date of anthesis, leaf expansion, and marketable yields of tomato fruits for each cultivar and transplant group under UV-transmitting (+UV) and UV-blocking (–UV) covering materials. Instrumental and sensory quality characteristics of fruit obtained from `Oregon Spring' and `Red Sun' in the two high tunnels were compared with field- and hydroponic greenhouse-grown fruit obtained from a wholesale warehouse. `Oregon Spring' plants flowered in 16-17 days from transplanting vs. 25 days for `Red Sun'. `Red Sun' produced 3× as much leaf area as did `Oregon Spring'. The fresh weight of `Red Sun' tomatoes in the +UV and –UV high tunnel was 60% and 22% greater, respectively, than that of `Oregon Spring'. Intact fruit or extracts were used for measurements of firmness, titratable acidity (TA), soluble solids content (SSC), and aromatic volatile concentration. The SSC of high tunnel-grown tomatoes was higher than that of commercially grown fruit. Field-grown tomatoes had the highest firmness and hydroponically-grown tomatoes had the highest concentration of volatiles. `Red Sun' fruit from plants grown under –UV had a higher SSC than corresponding fruit grown under +UV. High tunnel-grown tomatoes had higher sensory scores for sweetness, flavor, and for acceptability of texture, taste and overall eating quality than commercially grown fruit. These results are the first to show that high tunnel-grown tomatoes generally have better consumer acceptance than those grown commercially.
(212) Influence of Mineral Nutrient Source in NFT System and Temperature on the Yield of Cos Lettuce `Cimmaron'
Authors: Egilla Jonathan N. , Nyirakabibi Isabelle
Published: February 2019

Two-week-old seedlings of cos lettuce (Lactuca sativa L. var. longifolia) `Cimmaron' were transferred into NFT hydroponic troughs in July and Sept. 2005. The crop was grown either in a polyethylene or polycarbonate greenhouse. Mean July temperature and maximum relative humidity (RH) in the two greenhouses were 30.5 and 27.7 °C ± 0.32 °C; 81.3% and 84.7%, respectively. In September, the mean temperature and RH in the same greenhouses were 22.6 °C and 21.9 °C ± 0.30 °C; 95.6% and 99.2%, respectively. Lettuce crop grown with Peters Excel® [15N–5P2O5–15K2O; (Excel)], had higher fresh mass (FM) and dry mass (DM) compared with either Peat-lite®; [15N-16P2O5-17K2O; (Peat-lite)] or All-Purpose Hydroponic Fertilizer® [9N-4P2O5-15 K2O; (All-Purpose)], but lower DM/FM. At harvest, the crop had good market quality, regardless of mineral nutrient source (MNS). MNS significantly (P ≤ 0.05) influenced yield (FM and DM) in September, regardless of greenhouse type. However, in July only Peat-lite caused significant (P < 0.0252) increase in DM, under the higher temperature condition of greenhouse I. This trend suggests that good quality lettuce and sustained yield can be obtained with the soluble fertilizers Excel and Peat-lite, which are not formulated for hydroponic crop production. Furthermore, `Cimmaron' can produce satisfactory yield under relatively high temperature conditions. However, taste panel evaluation and nutrient content analysis of lettuce produced with these various fertilizers are necessary to determine consumer satisfaction.
(213) Establishing Minimum Critical Nutrient Standards for Herbaceous Perennials
Authors: Byrd Allison L. , Groover Velva A. , Scoggins Holly L.
Published: February 2019

Herbaceous perennials comprise one of the fastest-growing segments of floriculture crop production. Little information has been published regarding their mineral nutrition requirements, specifically nutrient foliar standards and nutrient deficiency symptoms. Our research documents visual symptoms of nutrient deficiencies in the chronological order in which they appear from incipient to advanced stages, and establishes foliar analysis standards by correlating nutrient levels with initial and advanced stages of symptoms for nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, copper, zinc, manganese, molybdenum, and boron. Rooted cuttings were grown for as many as 12 weeks in a hydroponic system with modified Hoagland's solution minus the element of interest, along with complete nutrient solution controls. Taxa selected for study were representative of commonly grown varieties and of differing families; Verbena canadensis `Homestead Purple' (clump verbena), Heliopsis helianthoides `Bressingham Doubloon' (false sunflower) and Veronica × `Goodness Grows' (speedwell). Days to incipient deficiency symptoms ranged from 5 to 60. Chronological order of appearance was consistent with Fe and Ca symptoms appearing within 10 days for all three taxa. Other deficiency symptoms varied both by taxa and in chronology. Root and shoot dry weights were closely and positively correlated with time to incipient deficiency.
Efficiency of Recurrent Selection by Marker and Phenotype for Multiple, Quantitative Yield Components in Four Cucumber Populations
Authors: Robbins Matthew D. , Staub Jack E.
Published: February 2019

Four cucumber (Cucumus sativus L.) inbred lines were intermated then bulked maternally to create four base populations denoted as cycle 0 (i.e., Pop.1 C0, Pop.2 C0, Pop.3 C0, Pop.4 C0). Each of these populations underwent phenotypic selection (PHE; open-field evaluations), selection by marker (MAS; genotyping at 20 marker loci), and random mating (RAN; no selection) for three cycles. The four traits under selection, multiple lateral branching (MLB), gynoecious sex expression (GYN), earliness (EAR), and fruit length to diameter ratio (L:D), are quantitatively inherited, controlled by relatively few (two to six) QTL per trait and are directly related to yield. Using the same C0 populations and selection scheme allowed a direct comparison of the effectiveness of MAS and PHE. Because each C0 population varied for any given trait, the response to MAS and PHE was not the same for each population. In general, C0 populations that were inferior for a trait either responded favorably to selection or remained constant, while those with superior trait values either did not change or decreased. Both MAS and PHE provided improvements in all traits under selection in at least one population, with the exception of MAS for EAR. MAS and PHE were equally effective at improving MLB and L:D, but PHE was generally more effective than MAS for GYN and EAR. When considering all traits, responses to PHE were superior in three of the four populations. The population for which MAS was superior, however, showed the only increase in yield (fruit per plant), which was not under direct selection. These results indicate that both MAS and PHE are useful for multi-trait improvement in cucumber, but their effectiveness depends on the traits and populations under selection.
Detection of Genetic Variation in Wild Populations of Three Allium Species using Amplified Fragment Length Polymorphisms (AFLP)
Authors: Phillips Nathan C. , Larson Steve R. , Drost Daniel T.
Published: February 2019

The genus Allium is distributed worldwide and includes about 80 North American species, with at least 13 occurring in Utah. Our study focuses on the population dynamics of three Allium species native to Utah; Allium acuminatum, A. brandegei, and A. passeyi. In conjunction with our studies of life history, growth characteristics, demographics, and habitat, we are interested in determining the levels of genetic variation in these species. This study examines amplified fragment length polymorphism (AFLP) within and among five Allium acuminatum, four A. brandegei, and three A. passeyi populations native to Utah. These species have contrasting abundance and distribution. The study populations were selected along an elevation gradient to represent within-species habitat differences. About 10–20 plants from each of the 12 populations were genotyped using six AFLP primer combinations, which detect DNA variation within and among all three species. These data will be used to compare levels of genetic variation and isolation among populations and species.
Relationships Among Reducing Sugar, Asparagine, and Chip Color in Wild Solanum Species
Authors: McCann Leah C. , Simon Philipp W.
Published: February 2019

When stored at temperatures less than 10 °C, tubers of all cultivated potatoes exhibit cold-induced sweetening (CIS) during which starch degrades to sucrose, glucose, and fructose. Upon frying at high temperatures, the reducing sugars (Fru, Glu) interact with free amino acids via the non-enzymatic Maillard reaction to form dark-colored chips that are unacceptable to consumers. In addition, scientists recently discovered that the toxic chemical acrylamide is also produced during frying. Although storage at warmer temperatures reverses CIS and circumvents dark chip production, the probability of storage loss due to shrinkage and disease increases. Wild Solanum species form the backbone of many potato-breeding programs. In this study, we evaluated 36 different plant introductions (PI) including 20 different species, grown in Madison and Rhinelander, Wis., to identify germplasm resistant to CIS for genetic analysis. After storage for 2–3 months at 4 °C, tuber sugar and amino acid content were analyzed via HPLC and slices were fried to determine chip color. Sugar and chipping data support previous research indicating CIS resistance in S. okadae, S. raphanifolium, and S. phujera. Interestingly, some germplasm selections with high reducing sugar content produced light-colored chips, indicating exceptions to the typical correlation between reducing sugar content and chip color. Genetic bases to these exceptions are under evaluation.
The eXtension Consumer Horticulture Community of Practice
Authors: Durham Richard
Published: February 2019

A Community of Practice (CoP) for consumer horticulture has been formed as part of the eXtension system. The CoP was organized at the National Consumer Horticulture Forum held Nov. 2005 at the Minnesota Landscape Arboretum. The meeting was attended by representatives of 24 states from all four Extension geographical regions. The attendees discussed project priorities and began to build a framework for working together across state lines on eXtension-sponsored activities and other efforts. Initial plans from the meeting include constructing a National Consumer Horticulture FAQ database, developing online learning modules that can be used for Master Gardener training, and developing marketing tools to better identify consumer horticulture resources available through local as well as national Extension activities. This presentation will provide additional details regarding the Consumer Horticulture Forum, an update regarding consumer horticulture activities within eXtension, and an opportunity for members of ASHS to learn how they can get involved in eXtension. Information regarding eXtension CoPs (including Consumer Horticulture) is continually being updated on the eXtension CoP Web site (cop.extension.org) and information regarding the Consumer Horticulture Forum has been posted on the Consumer Horticulture CoP Community Home page (cop.extension.org/wiki/Consumer_Horticulture_Community).
Using SPAD-meter in Nitrogen Fertilization of Rosa chinensis Jacq. var. mutabilis
Authors: Zanin Giampaolo , Sambo Paolo
Published: February 2019

Rosa chinensis Jacq. var. mutabilis plants were grown in a greenhouse to determine whether a hand-held chlorophyll meter (SPAD-meter) is suitable for the plant N status assessment. Therefore, plants were fertilized with increasing levels of N, applied through urea form as top dressing. The doses were: 0, 0.15, 0.3, 0.45, 0.6, and 0.75 g of N per liter of substrate. Periodically during the growing season, plant height and width, fresh and dry weight of different plant organs at 10, 20, and 30 weeks after planting, and their total N, plant P, and K were measured. Furthermore, six times along the growing cycle, the amount of chlorophyll in leaves was estimated using a SPAD-meter and analytically measured by chlorophyll extraction with ethanol and reading through a spectrophotometer. In the same leaves, N concentration was also determined. Treatments with 0.45–0.6 g of N per liter of substrate gave the tallest and widest plant. Plant weight and flower production were also the highest with these doses. The concentration of organic N in plant organs increased along with the N availability in the substrate, which suggests that a “luxury consumption” took place. The SPAD values showed high correlation among chlorophyll and N concentrations. Values that ranged between 35–40 seemed to mean good nutrient status. A high correlation was also found among SPAD values and some of the productive characteristics, which indicates that a SPAD-meter is a suitable tool in the dynamic fertilization of rose.
Impact of Flower Removal and Light and Temperature Stresses on Acidification of Nutrient Solution by Geranium
Authors: Taylor Matthew D. , Nelson Paul V. , Frantz Jonathan M.
Published: February 2019

The cause of sudden substrate pH decline by geranium (Pelargonium ×hortorum Bailey) is unknown. Published reports indicate that this response can be influenced in other plants by temperature and light extremes. The first of five experiments compared plants with all flowers removed to plants that were allowed to flower. Experiment 2 compared plants grown at four light levels (105, 210, 450 and 1020 μmol·m–2·s–1). Experiment 3 compared plants grown at four temperatures (14/10, 18/14, 22/18 and 26/22 °C day/night). Experiment 4 was a repeat of Experiment 1 and Experiment 5 was a factorial combining the three highest light levels and the three highest temperature levels. Plants allowed to form flowers had a final substrate pH of 5.7 compared to 6.3 for plants where flowers were removed. With increasing increments of temperature, substrate pH declined from 6.8 to 4.6 and with increasing light intensity from 6.1 to 4.8. There was no effect of flower removal in Experiment 4. Light and temperature had no consistent effects in Experiment 5 throughout 46 days after planting, with most pH values remaining in the acceptable range of 5.6–6.1. By 60 days, temperature treatments began to segregate, with pH being highest in the low-temperature treatments and lowest, down to 5.5, in the highest-temperature treatments. High temperature stimulated geranium acidification in both experiments, with the effect more severe in the first experiment. The flowering and high light effects were not duplicated in the second trial. This indicates that an additional factor is involved in expression of the light, temperature, and flowering control of acidification.
Comparison between Protoplast Transformation and Co-transformation in `Hamlin' Sweet Orange [Citrus sinensis (L.) Osbeck]
Authors: Omar Ahmad A. , Song Wen-Yuan , Graham James H. , Grosser Jude W.
Published: February 2019

Citrus canker disease caused by the bacterial pathogen Xanthomonas axonopodis pv. citri is becoming a worldwide problem. Xa21 gene is a member of the Xa21 gene family of rice, which provides broad spectrum Xanthomonas resistance in rice. `Hamlin' sweet orange [Citrus sinensis (L.) Osbeck) is one of the leading commercial cultivars in Florida because of its high yield potential and early maturity. `Hamlin' also has a high regeneration capacity from protoplasts and is often used in transformation experiments. Since the citrus canker pathogen is in the same genus, this gene may have potential to function against canker in citrus. The wild-type Xa21 gene contains an intron, and there are some questions whether dicot plants can process genes containing monocot introns (the cDNA is intron-free). Plasmids DNA, encoding the non-destructive selectable marker EGFP (Enhanced Green Fluorescent Protein) gene and the cDNA of the Xa21 gene were transformed or co-transformed into `Hamlin' orange protoplasts using polyethylene glycol. More than 200 transgenic embryoids were recovered. More than 400 transgenic plants were developed from 75 independent transgenic events. PCR analysis revealed the presence of the cDNA of the Xa21 and the GFP genes in the transgenic plants. Some of the plants have the GFP only. Southern analysis is showing integration of the cDNA into different sites ranges from one to five sites. Western analysis is showing the expression of the cDNA of the Xa21 gene in the transgenic citrus plants. This is the first time that a gene from rice has been stably integrated and expressed in citrus plants. Canker challenge assay is in progress.
OASIS: An Experiential Learning Class in Organic Production
Authors: Silva Erin , Falk Connie
Published: February 2019

New Mexico State University has designed a course in Organic Vegetable Production centered on a working CSA (Community Supported Agriculture) Farm. This project, named “OASIS” (Organic Agriculture Students Inspiring Sustainability), was funded by a 3-year USDA Hispanic Serving Institutions (HSI) grant from 2002–05. The project has multiple objectives, including: to provide students with a multi-disciplinary experiential educational opportunity; to investigate the feasibility of small-scale organic drip-irrigated farming in the Chihuahuan desert; to demonstrate the CSA model to the local community; and to trial vegetable varieties. The class is co-listed in the Department of Plant and Environmental Sciences and the Department of Agricultural Economics and Agricultural Business. Recently, the class was adopted in the Honors College and also became part of the General Education (G) program at NMSU. The course meets twice a week during two 2-h class periods. In-class time is divided between lectures, active learning projects, and work at the 0.26-ha field plot. The class content covered by the instructors includes organic regulations, history of CSAs and organic agriculture, evaluating the profitability of CSAs, the production of specific vegetable crops, planting and harvesting procedures, and postharvest requirements. Guest speakers are also part of the regular class structure and have discussed various topics such as beneficial insects, tillage, cover cropping, and weed management. The “living classroom” allows for these lectures to draw upon the experiences of students working on the farm. Although the course presents several challenges, the hands-on experience gained by the students is considered to be invaluable.
Effect of Volatile Ethanol Exposure on the Growth and Development of Three Radish Cultivars
Authors: Stutte Gary , Eraso Ignacio
Published: February 2019

NASA has intensively studied the use of plants to regenerate the atmosphere, purify water, and produce food within a bioregenerative life support system for many years. A unique aspect of growing plants in a controlled environment is chronic exposure to low levels of atmospheric volatiles. Alcohols are one of the most common classes of atmospheric contaminants currently detected onboard the International Space Station. A series of experiments were performed in specialized volatile organic compound analysis (VOCA) chambers in order to determine sensitivity of three Raphanus sativus L. to atmospheric exposures of ethanol. Three radish cultivars, Sora, Cherry Belle, and Cherry Bomb Hybrid II, were grown under continuous exposure to 0, 50, 100, 300, 500, or 1000 ppm ethanol for 21 days in the VOCA chambers with environmental setpoints of 23 °C, 75% relative humidity, and 18/6 photoperiod under T8 triphosphor fluorescent lamps at 300 μmol·m-2·s-1 PAR and 1200 μmol·mol-1 CO2. These concentrations corresponded to 5%, 10%, 30%, 50%, and 100% of the human exposure limits established by NASA and OSHA. Exposures to less than 10% of the legal exposure limit resulted in a 30% reduction in total biomass, 12% reduction in leaf area, and a 6% reduction in harvest index. Extreme stunting, chlorosis, and plant death were observed at only 50% of the exposure limit. All three cultivars were sensitive to ethanol exposure, with Cherry Bomb Hybrid II being slightly less sensitive than either Sora or Cherry Belle.
Reconfigurable LED Lighting System Development: Potential Energy Savings for CEA
Authors: Massa Gioia D. , Emmerich Jeffery C. , Morrow Robert C. , Bourget C. Michael , Mitchell Cary A.
Published: February 2019

Electrical cost, primarily for lighting, is one of the largest factors inhibiting the development of “warehouse-based” controlled environment agriculture (CEA). In a jointly sponsored collaboration, we have developed a reconfigurable LED lighting array aimed at reducing the electrical energy needed to grow crops in controlled environments. The lighting system uses LED “engines” that can operate at variable power and that emit radiation only at wavelengths with high photosynthetic activity. These light engines are mounted on supports that can be arranged either as individual intracanopy “lightsicles” or in an overhead plane of lights. Heat is removed from the light engines using air flow through the hollow LED strip mounts, allowing the strips to be placed in close proximity to leaves. Different lighting configurations depend on the growth habit of the crops of interest, with intracanopy lighting designed for planophile crops that close their canopy, and close overhead lighting intended for erectophile and rosette crops. Tests have been performed with cowpea, a planophile dry bean crop, growing with intracanopy LED lighting compared to overhead LED lighting. When crops are grown using intracanopy lighting, more biomass is produced, and a higher index of biomass per kW-h is obtained than when overhead LEDs are used. In addition, the oldest leaves on intracanopy-grown plants are retained throughout stand development, while plants lit from overhead drop inner-canopy leaves due to mutual shading after the leaf canopy closes. Research is underway to increase the energy efficiency and automation of this lighting system. This work was supported in part by NASA: NAG5-12686.
Application of 1-MCP for Quality Preservation of Tomato (Lycopersicon esculentum) Seedlings during Long-distance Transportation
Authors: Kubota Chieri , Kroggel Mark
Published: February 2019

Increasing numbers of vegetable growers purchase their seedlings from specialized transplant producers. However, early yield reduction due to abnormal first fruit truss development was often observed after long-distance transportation of seedlings. 1-Methylcyclopropene (1-MCP), an inhibitor of ethylene-mediated reactions, is widely used for postharvest management. If ethylene accumulated in trailers causes such abnormal first truss fruit development, application of 1-MCP to seedlings may prevent such problems. To test this hypothesis, `Durinta' tomato seedlings with visible flower buds were placed in chambers for 4 days under one of the following conditions: 1) conventional transportation air temperature of 18 °C without 1-MCP, 2) 18 °C with 1-MCP, 3) 12 °C without 1-MCP, and 4) nonstored control. The target initial 1-MCP concentration was 1 μmol·mol-1 inside the chamber, and the concentration was estimated to reach 0.2 μmol·mol-1 after 96 h. Three weeks after transplanting, 81.3% of first trusses on the plants treated at 18 °C without 1-MCP exhibited an abnormal, delayed fruit development. Both 1-MCP application and 12 °C air temperature successfully reduced the symptom to 4.7% and 3.1%, respectively; not significantly different from the nonstored control (1.6%). The average first truss yield was the lowest for 18 °C without 1-MCP (223 g per truss), followed by 18 °C with 1-MCP (582 g), and was the greatest (609–637 g) for 12 °C without 1-MCP or the control. Ethylene accumulation was the primary cause of the delayed fruit development causing yield reduction. Application of 1-MCP during transportation was shown to prevent such undesirable yield loss, although lowering temperature was the most effective under the present experimental conditions.
Measurements of Ambient Ozone Concentrations Show Elevated Levels within Commercial Greenhouses
Authors: Wetzstein Hazel Y. , Law S. Edward
Published: February 2019

Ozone is a highly oxidizing phytotoxic air pollutant, whose effects are documented to adversely affect crop growth and productivity. In contrast to the large body of published work investigating the effects of atmospheric ozone on outdoor agronomic and forestry crops, relatively few studies have addressed the effects of ozone exposure on greenhouse-grown crops. Outdoor concentrations of ozone can commonly attain concentrations in the 50–150 ppb range, which are known to detrimentally impact plant growth. The objective of this study was to characterize ozone exposure in commercial greenhouses as a prelude to the determination of dose–response effects on specific greenhouse crops and the development of ozone abatement methods, if appropriate. This study documented the levels and diurnal fluctuations in atmospheric ozone concentrations over two annual June–October “ozone seasons.” Measurements were taken every 10 min. for both indoor and outdoor ozone concentration, solar radiation, and temperature. Unexpectedly, indoor ozone concentrations often exhibited elevated levels that were 25% to 35% higher than outdoor concentrations, even in well-ventilated houses. These findings suggest that additional ozone production may occur within the greenhouse environment. Evaluations of causative factors and ozone effects on commercial crop production are warranted.
The Use of Cyclanilide to Promote Lateral Branching in Container-grown Whips
Authors: Sternberg Petra , Struve Daniel K.
Published: February 2019

In nursery production, increased branching is desirable, especially when growing stock that will be marketed at smaller sizes. Typically, branching is increased by pruning, which reduces growth potential. As an alternative to mechanical pruning, a chemical branching agent, Cyclanilide, has been evaluated for its ability to increase branching in container-grown whip production systems. Cyclanilide sprays of 0, 50, 100, and 200 mg·L-1 were applied to elongating shoots of Acer ×freemanii `Jeffsred', Cercis canadensis, Diospyros virginiana, Eucommia ulmoides, Malus ×`Prairie Fire', Malus ×`Harvest Gold', and Quercus rubra whips. Branching was increased in all taxa except Eucommia at concentrations >100 mg·L-1, without significantly reducing plant dry weight. For Diospyros, branching was increased when combined with pruning before Cyclanilide application.
Effect of AVG and MCP on Volatile Production of `Gala' Apple
Authors: Sigal-Escalada Valeria , Archbold Douglas D.
Published: February 2019

Our goal was to determine how aminoethoxyvinylglycine (AVG) and 1-methylcyclopropene (MCP) interact to influence postharvest storability and volatile production of `Gala' apple. In 2004 and 2005, AVG was applied to `Gala' apple trees 4 weeks before harvest. After harvest, control and AVG-treated fruit were treated for 20 h at 30 °C with MCP, and fruit were ripened at ambient temperature immediately after harvest, after MCP treatment, or after storage at 4 °C for 6 and 12 weeks. For both seasons, control fruit reached the highest internal ethylene concentration (IEC) during ripening at ambient temperature immediately after harvest. After storage, control fruit had very low IEC in 2004, but the highest in 2005. In general, the combined treatment repressed ethylene production the most for all harvest dates and lengths of storage. AVG plus MCP-treated fruit consistently had the highest flesh firmness (FF) but also had the lowest total volatile production (TVP) by flesh or peel after 6 and 12 weeks in cold storage following both harvest dates. The activity of alcohol acyltransferase was affected by the treatments, but could not explain all the variation found in TVP. TVP was lower for flesh than peel of control and treated fruit, but feeding alcohol substrates to the fruit resulted in a significant increase in TVP, regardless of tissue type or treatment. The results indicate that the combination of AVG plus MCP maintained apple fruit FF in cold storage better than the treatments used alone, but also substantially reduced TVP. Substrate availability seemed to be the most limiting factor affecting TVP by flesh and peel of `Gala' apples treated with AVG plus MCP.
Physical Properties of Whole Fresh-ground Parboiled Rice Hulls for Use as a Horticultural Root Substrate
Authors: Buck Johann S. , Evans Michael R. , Sambo Paolo
Published: February 2019

Horticultural root substrates are designed to provide the optimal physical properties for plant growth. These properties include bulk density (g·cm-3), air-filled pore space (% v/v), total pore space (% v/v), water-filled pore space (% v/v), water-holding capacity (% v/v and w/w), and wettability. Whole, fresh parboiled rice hulls were ground to produce four grades with varying particle size distributions. Particle sizes for the four grades ranged from <0.25 to >2.80 mm. Additionally, discrete particle sizes of <0.25, 0.50, 1.00, 2.00, 2.80, and >2.80 mm were produced. For all grade distributions and particle point sizes, physical properties were determined and contrasted against Canadian sphagnum peat. As the proportion of smaller particle sizes in the distributions increased or as the particle point sizes decreased, total pore space (% v/v) and air-filled pore space (% v/v) decreased, while, bulk density (g·cm-3) and water-holding capacity (% v/v and w/w) increased. Additionally, as the proportion of particle sizes from <0.25–0.50 mm increased, the wettabilty of the whole fresh parboiled rice hull material decreased. Particle sizes ranging from 1.00–2.80 mm possessed the physical properties most suitable for plant growth in containerized greenhouse crop production and were most similar to peat.
Growth of Geranium Plants in Soilless Media Containing Sphagnum Peat and Anaerobic Digestion-Derived Biosolids
Authors: Compton Michael , Zauche Timothy
Published: February 2019

Anaerobic digestion-derived biosolids (ADB) has the potential to become a complete or partial substitute for sphagnum peat in the greenhouse and nursery industry. Bedding plant production being one of the largest segments of the floriculture industry may possess the greatest application for this new organic addendum to soilless media. An experiment was conducted in which geraniums (Pelargonium ×hortorum `Red Elite') were grown in potting mixes formulated with vermiculite and perlite plus various concentrations and combination of anaerobic digestion-derived biosolids (ADB) and sphagnum peat to determine if ADB could be used as a partial or complete replacement for sphagnum peat in soilless horticultural growing media. Plants were grown during June and July 2003–05 in the greenhouse at 75 ± 5 °F and normal light and photoperiod. Plant growth was assessed by measuring the dry weight of stem tissue. Plants were harvested when at least 50% of the total number of plants produced at least one inflorescence. Floriferousness was measured by counting the number of visible inflorescences per plant. Dry weight of plants grown in media containing ADB was greater than those grown in media containing sphagnum peat as the sole organic addendum. Plants grown in media containing ADB were also more floriferous. This study demonstrates that ADB has great potential for use as an organic addendum to horticultural growing media as a partial or complete replacement for sphagnum peat. Use of anaerobic digester-derived biosolids in horticultural growing media is a protected intellectual property and available for license through the WiSys Technology Foundation.
Nutrient Ranges in Pelargonium ×hortorum and Pelargonium Species
Authors: Frantz Jonathan , Pitchay Dharmalingam , Tay David , Ehrenberger Jennifer , Gray John , Heckathorn Scott , Leisner Scott
Published: February 2019

Zonal geranium (Pelargonium ×hortorum) and scented geranium (Pelargonium sp.) together are among the top-selling floriculture plants in the United States today, with several hundred cultivars and species available each year. With such diversity in appearances, growth habits, and developmental traits, we hypothesize a correspondingly wide range of nutritional uptake and partitioning characteristics. Mature leaves from 55 cultivars or breeding lines of zonal geranium and 60 species of Pelargonium sp. were sampled from paired plants twice throughout the year from the Ornamental Plant Germplasm Center. Their tissue was analyzed for essential macro- and micronutrients using ICP-OES. Generally, macronutrients varied by a factor of 3–5, whereas micronutrients varied by up to 100-fold. The micronutrient boron was a notable exception with variation across the samples of only about a factor of 5. With this information, attempts will be made to correlate tissue nutrient concentrations with genetic source (cultivars and breeding lines) and environmental conditions from the origin of the different Pelargonium species from South Africa. This work illustrates the challenges in associating specific sufficiency or deficiency values for nutrient concentrations in tissue of plants based on only a few cultivars, species, or locations.
Costs and Returns of Producing Outdoor Cut Flowers
Authors: Brumfield Robin
Published: February 2019

Field–grown cut flower production, in general, is a low–overhead business. This is both good news and bad news. Good—because it doesn't require a lot of capital to get started in this business. Bad—because competition can develop rapidly, sometimes from marginal producers for whom profitability is a low priority. Thus, it is important for producers to know the costs of growing each product so that they can make profitable production and marketing decisions. A cost accounting program was developed to help producers calculate the cost of each crop. In addition, a series of benchmark budgets were developed for specialty cut flowers. These budgets are on the Rutgers University Farm Management Website (http://aesop.rutgers.edu/~farmmgmt).
Performance of Bell Pepper Cultivars in a Commercial Field Infested with Phytophthora capsici
Authors: Babadoost Mohammad
Published: February 2019

Phytophthora blight, caused by Phytophthora capsici, is a widespread problem of many vegetables including bell peppers. Four bell pepper cultivars marketed as resistant/tolerant to P. capsici include `Paladin' (resistant), `Alliance' (tolerant), `Aristotle X3R' (tolerant), and `Revolution' (tolerant). These cultivars, along with four other widely grown cultivars (`Commandant', `King Arthur', `Legionnaire', and `Red Knight X3R') and a susceptible control (`California Wonder'), were evaluated for their performance in a commercial field highly infested with P. capsici. `Paladin' had the lowest incidence of Phytophthora blight and the greatest yield compared to all other cultivars. `Alliance', `Aristotle X3R', and `Revolution' (the tolerant cultivars) also had lower Phytophthora blight incidence and greater yields compared to the other five cultivars evaluated. Results indicated that in fields that historically have high incidence of Phytophthora blight, `Paladin' could be a reliable choice for commercial production.
Optical Tools, a Suitable Means to Reduce Nitrogen Use in Fertigated Tomato Crop
Authors: Gianquinto Giorgio , Sambo Paolo , Orsini Francesco , Sciortino Marco , Forte Valente
Published: February 2019

Technology provides new tools for agriculture to be able to optimize fertilization. Optical instruments are becoming valid tools for farmers in making decisions about fertilization, even though they need to be calibrated for specific crops. Chlorophyll meters and multispectral radiometers have been tested on rice, corn, and wheat and afterwards on vegetables, in timing fertilization. Today, threshold lines that are able to detect crop N status in tomato crops are available. These thresholds, obtained in experiments carried out at Padova University, were validated in three open-field experiments. The first experiment was carried out in 2004 at the University experimental farm on tomato cv. Perfect Peel. The second and third experiments were conducted in a commercial farm at Codigoro (Ferrara) in 2004–2005. Tomato cultivars used were `UGX 822' and `Precocix' in 2004, in 2005 `Jet' was also used. In all trials, a “standard fertilization” management was compared with fertigation guided using SPAD and/or Cropscan. Optical tools were used to manage fertigation adopting both “threshold method” and “reference plot method”. In general “guided fertigation” resulted in less nitrogen application (N supply reduced between 18% and 45%), especially when “threshold method” was adopted. Yields were comparable to “standard fertilization” treatments, showing a better efficiency of “guided fertigation”. In some cases, guiding fertigation by means of optical instruments allowed higher fruit fresh weight, although dry matter content and °Brix were not influenced. Guided fertigation reduced also the number of damaged fruit and the percentage of nonmarketable product.
Optimum Fruit Size and Yield to Maximize Crop Value of Gala Apple
Authors: Robinson Terence
Published: February 2019

Field thinning studies were conducted in two orchards at Geneva and Milton, N.Y., over 3 years (2003–05) using mature Gala/M.9 trees. A range of final croploads was achieved with various chemical thinning treatments, including, benzyladenine combined with carbaryl, or napthaleneacetic acid combined with carbaryl. The most-aggressive thinning treatments in the year with high rainfall achieved an average fruit size of 190–200 g; however, the yield was reduced considerably, resulting in a reduced farm gate crop value compared to less-aggressive thinning. In a dry year, the fruit sizes were smaller even with aggressive thinning. The optimum yield for maximum crop value varied for each orchard block for each year. The optimum croploads varied less than the optimum yield, since cropload normalizes the tree size between blocks. Optimum fruit size to maximize crop value varied narrowly between 155–170 g (113–100 count size) across blocks and years. This was true despite a substantial price difference between large, 80-count fruits and the moderate-size 113-count fruits. If lower prices received for processed apples were used in the analysis, then the optimum yield was significantly higher than with fresh fruit prices. In New York State, it appears that achieving 80-count fruit requires too large of a reduction in yield, which causes a reduction in crop value.
Progress in Selection for Cold-hardiness, Adaptation, and Quality in Vaccinium ashei and Vaccinium ashei/V. constablaei Derivatives and the Potential for Northern-adapted Rabbiteye Cultivars
Authors: Ehlenfeldt Mark , Rowland Lisa
Published: February 2019

In recent years, the U.S. Department of Agriculture has generated V. ashei and V. constablaei derivatives to provide late-flowering, earlyripening rabbiteye germplasm for the southern U.S.; however, this germplasm has also performed well in New Jersey, and could potentially provide northern-adapted rabbiteye types. When combined, these germplasms complement each other in many respects. Crosses with varying percentages of V. constablaei germplasm ranging from 100% to 0%, in 25% increments, were evaluated for mid-winter cold-hardiness using a detached twig assay. Hybrids with 50% or more V. constablaei germplasm were hardy to –25° C or lower. Further backcrosses to V. ashei resulted in dramatic segregation for hardiness, but still yielded some progeny as hardy as typical northern highbush. Assays of rabbiteye cultivars have been recently completed to enhance the ability to generate cold-hardy hybrids. Recombination and selection have begun to yield hybrids improved for critical commercial characteristics, and further rapid progress is expected.
The Transition of the California Processing Industry from Direct-seeding to Transplanting
Authors: Murray Mike
Published: February 2019

The California processing tomato industry continues to utilize transplants as a primary method of obtaining final plant stands. About 75% of the anticipated 2006 acreage will be transpanted, up from 0% a scant 20 years ago. This trend is being driven by increasing hybrid seed costs, the desire to utilize the land for multiple crops per year, potential water savings, and enhanced weed management options. The history of this transition will be traced, identifying positive and negative impacts of reliance on transplants. An economic evaluation suggests that stand establishment using transplants costs at least $250 per acre more than direct-seeding. A cost-benefit analysis is considered. The movement to transplants has reduced seed sales and many hybrid seed variety prices are tripling in 2006, as seed companies attempt to recoup R&D costs with declining markets. This “differential seed pricing,” and its implications, are discussed in detail.
Yield and Isoflavone Content of Edamame Varieties at Different Planting Dates and Densities
Authors: Stewart Allison E. , Carpenter Debra J. , Pantalone Vincent R. , Sams Carl E.
Published: February 2019

Consumer interest in Edamame (edible soybean) is increasing due to reported health benefits associated with diets high in soy. The purpose of this study was to compare four varieties of edible soybean grown at four plant spacings on three planting dates. The lines were grown at the Plateau Research and Education Center in Crossville, Tenn. They were analyzed for horticultural traits and isoflavone content. All lines were at the R6 stage. Fresh weight of pods, weight of 200 pods per plot, the number of seeds per 200 pods, and the weight of 100 seeds were recorded from two-row plots (6.10 m x 1.52 m). A significant (P < 0.001) difference was found for fresh weight among planting dates. The May planting had the highest mean fresh weight (3118 g/plot), followed by the June (3068 g/plot) and July (2131 g/plot) dates. The weight per 100 seeds was significantly different (P < 0.001) for planting date and genotype. May seed weight was highest at 49 g, followed by June at 45 g, and July at 42 g per 100 seeds. `Gardensoy-43' was the highest-yielding variety, with a mean of 3253 g/plot. It was followed by `TN00-60' and `TN03-349', with mean fresh weights of 2730 and 2723 g/plot, respectively. The line `TN5601T' had the lowest mean fresh weight of 2389 g/plot. Both fresh weight (P < 0.001) and weight per 100 seeds (P < 0.05) were significantly different among plant spacings. Twenty-six plants per meter within rows yielded the highest total fresh weight per plot (3071 g), but had the lowest mean weight per 100 seeds (43 g). Spacing three plants per meter within rows resulted in the highest weight per 100 seeds (48 g), but the lowest fresh weight per plot (2122 g). Isoflavone content will be measured for each variety, planting date, and spacing.
Effects of Postharvest Storage and UV-C Irradiation on the Phenolic Content and Antioxidant Capacity of Cranberries
Authors: Kalt Wilhelmina , Rimando Agnes M. , Elliot Michele , Forney Charles F.
Published: February 2019

Recent interest in the human health-promoting properties of fruit phenolics, and especially fruit flavonoids, has stimulated research on how these secondary metabolites may be affected by pre- and postharvest horticultural factors. Resveratrol, although a minor phenolic in many fruit, possesses potent bioactivities, and is therefore of particular interest. To study the effects of postharvest storage and UV-C irradiation on selected phenolic components and antioxidant capacity of cranberry (Vaccinium macrocarpon), fruit of cv. Pilgrim, Stevens, and Bergman, were irradiated with UV-C at levels between 0 and 2.0 KJ·m-2, followed by storage at 9 °C for 7 and 17 d. Total phenolic content did not change during storage. However, resveratrol content was higher and antioxidant capacity (ORAC) was lower at 7 days of storage compared to 17 days. There was no main effect of UV-C on total phenolics, anthocyanins, resveratrol, or ORAC. However, there was an interaction between storage time and UV-C irradiation. Anthocyanin content was lower at 7 days, and higher at 17 days, at UV dosages of 1.0 or 2.0 KJ·m-2. Resveratrol content was higher in UV-C irradiated fruit at 7 days, while at 17 days there was no difference between UV-treated and untreated fruit.