bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrogen Requirement of Prosopis velutina Seedlings
Authors: Hahne Kathryn S. , Schuch* Ursula K.
Published: February 2019

The objective of this study was to determine whether mesquite (Prosopis velutina) seedlings have a preference for the ammonia or nitrate form of nitrogen (N), and to determine the optimum rate of N to maximize growth and minimize N leaching when seedlings are grown in different substrates. Mesquite seedlings were fertigated with different ratios of NH4+: NO3- to determine effects on shoot and root growth and N-uptake efficiency. Nutrient solution containing 67% NH4+ : 33% NO3- resulted in greatest biomass after 120 days of fertigation. N leachate remained stable until 12 weeks after the onset of treatment, but increased significantly by week 16. Subsequently, mesquite seedlings were grown in sand or soilless media and were fertigated with a solution of 67 % NH4+: 33% NO3- at a rate of 25, 50, 100, or 200 mg·L-1 of N. After 60 days, plants in media produced 41% more leaves and total biomass compared to those in sand. Leaf number was greatest for plants grown at 200 mg·L-1 of N in both substrates. Root biomass of plants in media showed no response to increasing N concentrations while root biomass of seedlings in sand were similar for the three lower N concentrations and nearly doubled for the highest one. Shoot biomass of seedlings receiving 25, 50, or 100 mg·L-1 of N was similar, but more than doubled for plants fertigated with 200 mg·L-1 of N. N leachate losses were highest from seedlings growing in sand and receiving the two higher N fertigations, those in media had greatest N leachate loss when fertigated at 200 mg·L-1 of N. For balanced mesquite seedling growth and minimum N leaching losses, concentrations between 50 to 100 mg·L-1 of N are recommended. Implications of using a sand culture system vs. soilless growing substrate for nutrition studies will be discussed.
Spacing and Fertilizer Application Method Influence Container Plant Growth and Runoff
Authors: Million* Jeff B. , Yeager Thomas H. , Albano Joseph P.
Published: February 2019

The influence of production practices on runoff from container nurseries was investigated in Spring 2003 (March to July) and Fall 2003 (August to January). Viburnum odoratissimum (Ker-Gawl.) liners were planted in 3.8-L containers with a 2 pine bark: 1 sand: 1 Canadian peat substrate and placed on 1.5 m2-platforms at one of two plant spacing densities: 16 or 32 plants/m2 [spaced to 16 plants/m2 after 13 weeks (spring) or 14 weeks (fall)]. Overhead sprinkler irrigation was applied daily (1 cm) and runoff collected weekly. Osmocote 18 N-2.6 P-10 K was surface-applied to each container (15 g) in the spring and surface-applied or incorporated in the fall. Cumulative runoff averaged 1240 L·m-1; in spring (19 weeks) and 1050 L·m-1; in fall (20 weeks), which represented 72% and 66% of applied irrigation plus rainfall, respectively. The lower density spacing resulted in a 19% increase in cumulative runoff in spring (1340 vs. 1130 L·m-1) but had no effect in fall (970 vs. 890 L·m-1). Weighted average ECwa of runoff decreased 10% (0.436 vs. 0.485 dS·m-1) and 12% (0.420 vs. 0.476 dS·m-1) with the lower density spacing in spring and fall, respectively. ECwa in fall was not affected by fertilizer method. Plant size index [(height + width)/2] was reduced 22% in both spring (38.7 vs. 49.7 cm) and fall (26.9 vs. 34.4 cm) when plants were grown at the lower density spacing throughout production. This reduction in plant size was attributed to container heat stress. Plant size was unaffected by fertilizer application method (fall) but fertilizer incorporation resulted in greener plants than surface-applied fertilizer (60 vs. 53 SPAD readings).
BMP Development and Implementation Process for the Nursery Industry
Authors: Yeager* Thomas H. , Kuhl Kenneth A.
Published: February 2019

Nursery operations have strategically positioned themselves close to markets and many are now an agricultural entity surrounded by urban encroachment. The environmental pressures of society have mounted at unprecedented rates, resulting in additional regulations for nurseries. Development and implementation of Best Management Practices (BMPs) for the nursery industry allows nurseries to be proactive and not wait for regulations that might harm the industry. Univ. extension personnel with BMP subject matter expertise can play a pivotal role in assisting the industry with development and implementation of proactive BMPs. Important steps that have served as a model for BMP development and implementation include the following. Establish need—the industry leadership must explain to nursery personnel the reasons why BMPs are needed and elicit assistance with BMP development from university personnel. Committee guidance—the industry leadership establishes a steering committee of nursery personnel representing various interests of the industry to work with university and regulatory personnel to conceptualize BMPs and develop objectives. Consensus development—steering committee communicates their objectives to the nursery industry, explains the impacts, and provides a mechanism for feedback to achieve broad-based stakeholder participation. BMPs drafted - steering committee writes a draft BMP manual that is available for industry review. Industry-wide input—steering committee aggressively seeks input from the industry, implements as many suggestions as possible, and informs industry of BMP manual revisions. Educational programs—university extension personnel conduct training for nursery operators implementing BMPs and track the impact of BMPs on nurseries.
Development of an Ohio Liner Production System Using Retractable Roof Greenhouses
Authors: Stoven* Alison A. , Mathers Hannah M. , Struve Daniel K.
Published: February 2019

A study was conducted to determine if similar quality shade tree liners could be produced using a retractable-roof greenhouse structure versus an outdoor environment. All plants were started in a heated greenhouse on campus in 250 XL-sized containers. The species included Eastern redbud, red oak (both grown from seed) and Autumn Blaze maple and Prairifire crabapple (both grown from rooted cuttings). On 15 Mar. 2003, half the plants remained in the heated greenhouse and the other half were moved to a Cravo retractable-roof structure and placed on heating mats set at 22 °C. In May, all of the plants (retractable and greenhouse) were upshifted into 3-gallon Spin-out® treated containers. Trees in each environment were fertilized with either Osmocote® (20 N, 2.2 P, 6.6 K), nine month release, applied broadcast at 45 g/pot, or with a 100 ppm-N water-soluable fertilizer (21 N, 3.1P, 5.9 K), applied at 0.1 g N/day. All trees received the same irrigation volume (1 L/day). All trees were grown according to nursery standards including bamboo staking, taping and regular pruning. Plants were arranged in a completely randomized design in each environment. The Cravo structure provided a more uniform environment with reduced air and soil temperature fluctuations versus the outdoor environment. Liners produced in the Cravo structure were taller, had greater caliper and root and shoot mass. Slow release fertilizer produced larger plants. Root dry weight for trees inside the Cravo environment increased nearly five times over the harvest dates of July to October with the maples having the largest root weight.
Ethylene-inducible Expression of ipt Gene Produces a Dramatic Increase in Fower Bud Count in Transgenic Plants
Authors: McAvoy* Richard J. , Khodakovskaya Mariya V. , Liu Hong , Li Yi
Published: February 2019

Cytokinins play an important role in regulating plant growth and development. The cytokinin gene, isopentenyl transferase (ipt), was placed under the control of the ACC oxidase promoter from the LEACO1 gene from Lycopersicon esculentum and introduced into Nicotiana tabacum (cv. Havana) and chrysanthemum (Dendranthema × grandiflorum `Iridon'). Transformants were confirmed by PCR reaction and Southern blot and analyzed for phenotypical changes under both greenhouse and growth chamber conditions. With both species, LEACO1-ipt transgenic plants displayed a wide range of vegetative and generative phenotypes. With plants growing in the vegetative state, some LEACO1-ipt transgenic lines appeared similar to the non-transgenic wild-type cultivars while other lines showed excessive lateral branch development and short internodes. With plants grown under generative conditions, several LEACO1-ipt transgenic lines showed a 2 to 10-fold increase in the number of flower buds relative to the wild-type cultivars. With chrysanthemum, dramatic increases in bud count were observed on transgenic lines that otherwise displayed a morphology similar to the non-transgenic lines. Analysis of ipt expression indicated a marked change in gene expression between the most extreme phenotypes observed in this study. LEACO1-ipt lines that express normal vegetative development but increased flower bud counts appear to have great potential for ornamental crop improvement.
Agrobacterium-mediated Transformation of Cotyledon Explants of Bottle Gourd (Lagenaria siceraria S.)
Authors: Han* Jeung-Sul , Kim Chang Kil
Published: February 2019

A procedure for producing transgenic bottle gourd plants by inoculating cotyledon explants with Agrobacterium tumefaciens strain AGL1 carrying a binary vector pCAMBIA3301, which contains glufosinate ammonium-resistant (bar) and the reporter (gus) genes, is describe. Infection was the most effective (highest infection frequency and index) when explants were co-cultivated with Agrobacterium for 6-8 days on co-cultivation medium supplemented with 0.001-0.1 mg/L L-a-(2-aminoethoxyvinyl) glycine (AVG). Transgenic plants were obtained with frequencies of about 0.2% when the explants were cultured on selection medium (MS medium supplemented with 3.0 mg/L BAP, 0.5 mg/L AgNO3, 500 mg/L cefotaxime, 2.0 mg/L DL-phosphinothricin, 0.3% sucrose and 0.8% Plant Agar. A histochemical gus assay, PCR and Southern blot analyses confirmed that transformation had occurred. Genetic analysis of T1 progenies showed that the transgenes were inherited in a Mendelian fashion. To our knowlege, this study represents the first report for Agrobacterium-mediated transformation in bottle gourd, rootstock for watermelon and other cucurbit crops in many countries.
Effects of GA3 on Poinsettia Over-retarded with Paclobutrazol
Authors: McDaniel* Amy D. , Wang Yin-Tung
Published: February 2019

A study was initiated to determine the effect of GA3 as a counter measure to restore the growth of over-retarded poinsettia. Euphorbia pulcherrima `Sonora Red' plants were treated once foliarly with paclobutrazol at 40 or 80 mg·L-1 one week following pinching. Four weeks later, plants receiving the 80 mg·L-1 rate were treated once foliarly with GA3 at 0, 10, 20, 30 or 40 mg·L-1. The effect of GA3 was visible within 3 days of application. GA3 between 10 and 40 mg·L-1 caused long internodes, excessive stem elongation, as well as small leaves and bracts, resulting in unmarketable plants. Plants receiving 10 mg·L-1 GA3 were nearly twice the height of the over-retarded plants (31 vs. 17 cm), with increasingly taller plants at higher concentrations, up to 30 mg·L-1. In a second experiment, single-stemed plants were treated with one foliar spray of 50 or 150 mg·L-1 paclobutrazol two weeks following the beginning of short days. After another 3 weeks, the overdosed plants were then foliarly treated once with 0, 3, 5, 10, or 15 mg·L-1 GA3. GA3 at all rates promoted stem elongation and resulted in large bracts and much increased inflorescence diameter. The 15 mg·L-1 GA3 rate resulted in undesirable long internodes on the upper stem. Plants that received 3, 5, or 10 mg·L-1 GA3 were of excellent quality, with their heights and inflorescence sizes similar to those of plants receiving 50 mg·L-1 paclobutrazol (26 cm). Parallel experiments using `Burgundy Cortez' had similar results.
Sucrose and Ethylene Biosynthesis/Perception Inhibitors Additively Enhance Postharvest Display Life of Cut Racemes of Lupinus havardii Wats.
Authors: Mackay* Wayne , Sankhla Narendra , Davis Tim
Published: February 2019

Over the years, by recurrent phenotypic selection, breeding and evaluation, we have developed blue, white, and pink flowered lines of Big Bend bluebonnet (L. havardii Wats.). The racemes, which differ in their sensitivity to ethylene, hold promise as a new specialty cut flower crop. The key determinants of postharvest longevity and performance of cut racemes are flower abscission and senescence. Our studies indicated that the addition of sucrose in the holding solution greatly enhanced the vase life, although the optimum sucrose concentration varied considerably in different lines. In blue flowered lines (e.g., `Texas Sapphire', Blue Select) sucrose concentration greater than 2% induced `osmotic wilting' followed by senescence of the standard petal (banner spot petal), while the petals in white flowered lines (e.g., `Texas Ice', White Select) did not show any wilting even in 4% to 6% sucrose. Ethylene perception inhibitors such as 1-MCP or STS completely suppressed the induction of flower abscission in racemes of all the bluebonnet lines. Ethylene biosynthesis inhibitors (e.g., ReTain, CO++), on the other hand, were relatively less effective than 1-MCP/STS. Both ethylene perception as well as biosynthesis inhibitors, in combination with sucrose, acted additively and further enhanced the postharvest performance by delaying flower abscission/senescence.
Influence of Plant Growth Regulators on Growth, Flowering and Corm Yield of Gladiolus (Gladiolus grandiflorus L.) cv. Oscar
Authors: Maurya* Rajendra P. , Nagda* Champa lal
Published: February 2019

In a field experiment, uniform sized corms of gladiolus (Gladiolus grandiflorus L. cv. Oscar) were planted in last week of October at a distance of 30 cm. between rows and 20 cm. between plants. The effect of GA (50, 100 ppm), Cycocel (500, 1000) and NAA (50, 100 ppm) on gladiolus plants. It was concluded that foliar application of 100 ppm GA3 at 45 days after corm planting has shown superiority in all vegetative, floral characters and corm & cormel yield viz., plant height (128.53 cm), number of leaves (8.57) per plant, spike length (108.33 cm), spike weight (128.87 g), number of florets (17.60) per spike, size of second florets (15.07 cm), number of spikes (1.67) per plant, size of largest corm (7.52 cm), number of corms (1.80) per plant, number of cormels (11.53) per plant and weight of corms (79.33 g) per plant. Whereas, a highest longevity of florets opening or survival on spike (20.33 days) was recorded in 1000 ppm Cycocel.
Effect of Vernalization and Growth Regulators on Flowering of Ornithogalum `Chesapeake Snowflake'
Authors: Wang Jin , Walter* Virginia R.
Published: February 2019

The effect of vernalization and two growth regulators Fascination™ and Pro-Gibb® on the growth, inflorescence development and flowering of Ornithogalum `Chesapeake Snowflake' was studied. Regardless of bulb size, chilling bulbs for 3 weeks at 10°C before planting accelerated flowering of the first inflorescence and shorten leaf length by 3-5cm as compared to non-chilled bulbs. Fascination™ 10% 100 μL and Pro-Gibb® 200 ppm accelerated flowering of first inflorescence by large bulbs (8- to 10-cm circumference) as compared to controls. PGR treatments appear to have no effect on small bulbs (3-5-cm circumference).
Balancing Act: Effects of Fertilizer and Uniconazole on Growth of Herbaceous Perennials
Authors: Scoggins* Holly L. , Latimer Joyce G.
Published: February 2019

Increasing fertilizer levels may reduce production time but can lead to excessive growth of herbaceous perennials, requiring the application of plant growth regulators (PGRs). This study investigated the effects of ascending fertilizer rates in conjunction with two rates of uniconazole and a control. Rooted liners of Artemisia arborescens L. `Powis Castle', Artemisia vulgaris L. `Oriental Limelight, Astilbe chinensis (Maxim.) Franch. `Pumila', Filipendula rubra (Hill) Robinson `Venusta' and Perovskia atriplicifolia Benth. were potted with controlled-release fertilizer (15N-3.9P-10K) incorporated at 2.4, 4.72, and 7.11 kg·m-3. A single foliar spray application of uniconazole was applied two weeks after transplanting at a volume of 210 mL·m-3 and two rates from 15 to 60 mg·L-1 plus a control (species-dependent). Plant height and width were measured at 2,4,6, and 8 weeks after treatment (WAT). No interactions between fertilizer rate and uniconazole were observed. Main effects varied by species. The application of uniconazole controlled height and width of Artemisia `Oriental Limelight' and Astilbe for the duration of the experiment. Height, width, and dry weight of Artemisia `Oriental Limelight' increased with ascending fertilizer rates while Astilbe was not affected. Growth of Filipendula and Artemisia `Powis Castle' was unresponsive to uniconazole, though dry weight was reduced for both at the lowest fertilizer rate. Uniconazole provided height control of Perovskia, but the effect did not persist beyond 6 WAT. Ascending fertilizer rates increased Perovskia dry weight but not height.
The Effective Pollination Period in Rabbiteye Blueberry
Authors: Brevis* Patricio A. , NeSmith D. Scott
Published: February 2019

Rabbiteye blueberries (Vaccinium ashei Reade) often exhibit poor fruit set under commercial field conditions. Problems of low fruit set have been attributed to short periods of flower receptivity in different fruit crops. This study seeks to establish the effective pollination period (EPP, defined as the number of days during which pollination is effective to produce a fruit) in rabbiteye blueberry. The cultivars Brightwell and Tifblue were chosen due to their known difference in fruit set and field performance. Flowers were hand pollinated 0, 2, 4, 6, and 8 days after anthesis (DAA) using self- and cross-pollen. Fruit set, seeds per berry, berry weight and days to ripening were recorded. Fruit set showed a polynomial trend across flower ages. `Brightwell' was highly receptive from the day of anthesis, whereas, `Tifblue' receptivity was low until 2 DAA. `Brightwell' and `Tifblue' flowers produced adequate fruit set (≥50%) over a period of 7 and 5 days, respectively. In `Tifblue', fruit set was limited by the low receptivity of newly opened flowers. The difference in EPP helps to explain the performance of these cultivars in the field. The rate of ripening increased with flower age in both cultivars. The number of seeds per berry was affected by flower age only in `Tifblue'. The effect of flower age on berry weight depended on the cultivar and the pollen source.
Natural and Artificial Chilling of Southern Highbush Blueberry
Authors: Marshall* Donna A. , Stringer Stephen J. , Spiers James M.
Published: February 2019

A study was initiated in November, 2002 to determine the effects of exposing two Southern Highbush blueberries (Vaccinium corybosum L) to artificial chilling hours on initiation of bud break and advancement of floral and vegetative bud maturity. Plants of `Jubilee' and `Misty' were divided into 2 groups in which one was left outdoors, allowing chilling to occur and accumulate naturally, while the other group was placed in a growth chamber set at a constant artificial temperature of 4 °C. Five plants of each cultivar were then placed into a heated greenhouse after 0, 200, 400, 600, or 800 hours of chilling (total hours of exposure to <5 °C) had accumulated for forcing of flower bud development. The progression of floral bud development of the terminal three buds on five tagged stems was observed at 7-10 day intervals for 30 days. At the end of the forcing period observations were also made on total percent vegetative and floral bud break. Prior to accumulating sufficient chilling requirements, chilling delivery method did not appear to influence the rate of floral bud development since none advanced past stage 3 regardless of chilling regime used. However after chilling requirements were met, flower buds of plants that were allowed to chill naturally developed more quickly than did those chilled by artificial means.
Preharvest Application of Methyl Jasmonate Increases Content of Antioxidant Compounds and Oxygen Absorbing Capacities in Raspberries
Authors: Wang* Shiow , Zheng Wei
Published: February 2019

The effects of preharvest methyl jasmonate (MJ) application on fruit quality, flavonoid content and antioxidant capacity (ORAC) in black raspberry cv. Jewel (Rubus occidentalis L) were studied under field conditions. Raspberries treated with 0.1 mm methyl jasmonate had 20% higher soluble solids content, 20% higher total sugars, 16% higher fructose, 34% higher glucose and 30% lower titratable acids, 31% lower malic acid and 17% lower citric acid than untreated fruit. El-lagic acid, quercetin 3-glucoside, kaempferol 3-glucoside, kaempferol 3-glucuronide, cyanidin 3-glucoside and cyaniding 3-rutinoside were found in raspberry fruit extract. Cyanidin 3-rutinoside was the most dominant anthocyanin and was the major contributor to antioxidant activity in Jewel raspberries. MJ treatments significantly enhanced the content of anthocyanins by 92%, total phenolics by 53%, flavonoids by 98% and the antioxidant capacities by 74% in the fruit. The ORAC value was positively correlated with anthocyanins and total phenolics. In this study, the correlation coefficient for ORAC (y) vs anthocyanins (x) was 0.977 (y = 0.056x + 27.874), and that for ORAC (y) vs. total phenolics (x) was 0.988.
Sensory and Instrumental Measurement of Texture of Fruits and Vegetables
Authors: Abbott* Judith A.
Published: February 2019

Demand for fresh fruits and vegetables is increasing worldwide in response to health concerns, wealth, and the desire for variety in the diet. However, consumption of produce is contingent on the ability of the industry to provide high quality fresh produce and on its convenience, as well as on consumer education and economics. Texture measurement is accepted by horticultural industries as a critical indicator of quality of fruits and vegetables. The fresh produce industry and, indirectly, consumers need methods for measuring produce texture to ensure the quality within a grade, and scientists need measurements to quantify the results of their treatments, whether treatments are genetic, chemical, or physical. The variety of attributes required to fully describe textural properties can only be fully measured by sensory evaluation by a panel of trained assessors. However, instrumental measurements are preferred over sensory evaluations for both commercial and research applications because instruments are more convenient, less expensive, and tend to provide consistent values when used by different people. Thus, instrumental measurements need to be developed that predict sensory evaluations of texture. Such instrumental measurements can then provide a common language among researchers, producers, packers, regulatory agencies, and customers. We compare sensory evaluations of specific critical textural attributes to instrumental force/deformation measurements on a wide variety of fruits and vegetables with relatively uniform bulk tissues, such as apples, bananas, carrots, jicama, melons, pears, potatoes, rutabagas, and several others.
Comparison to Polyphenol Contents and Anti-oxident Activity of Apple Fruits by Organic Cultivation
Authors: Kim* Wol-Soo , Jo Jung-An
Published: February 2019

Although fruits obtained by organic cultivation (OC) have been believed to be healthier than those by conventional cultivation (CC), but clear experimental evidences supporting the assumption are still lacking. Therefore this study was carried out to investigate the effects of OC on total polyphenol content and anti-oxidant activity in `Hongro' apples (Malus domestica). Anthocyanin content of fruit skin was increased in apples from OC. Soluble solid content and pH of apple juice was higher in the OC than in the CC, but total acidity in fruit juice showed reversed result. Also, chlorophyll content showed no difference between OC and CC. Total polyphenol compounds extracted with methanol, were higher in the OC than in the CC, and also higher in peel than in flesh. Also, anti-oxidant activity estimated by free radical scavenging effect showed significantly stronger under the OC than the CC.
Hormonal Concentration and Growth in Chili Plants Inoculated with Several Mycorrhizal Fungus, Evaluated in Different Steps
Authors: Roman-García Francisco , Yahuaca-Mendoza María Patricia , Farias-Larios Javier , López-Aguirre* J. Gerardo , Aguilar-Espinosa Sergio , del Rocío Flores-Bello María
Published: February 2019

The contribution of arbuscular endomycorrhizal fungus (AMF) on hormonal levels increase in chili plants, at different steps is currently unknown. In this experiment was evaluated the effect of Glomus sp. Zac-19, G. etunicatum and G. intraradices, inoculation mirasol and ancho cultivars, under greenhouse conditions. Plants were growing in pots containing 1 kg of substrate (3 sand: 1 soil ratio). The effect was measured on fresh fruit production and indolacetic acid, giberellin GA3 and 6-aminopurine concentration. Also plant parameters measured were: plant height, foliar area, stem diameter, root length, aerial fresh weight, total fresh weight, fruit weight and mycorrhizal colonization. All treatments were imposed using 16 replications in a full random design. Results shown that mycorrhizal colonization average of the three fungus was 44% in mirasol cultivar y 42% in ancho cultivar. Mycorrhizal colonization had an effect on growth and development in both cultivars, expressed in a greater height, leaf number, foliar area, total fresh weigh and fruit mass. Was registered an increase of 80% in the yield in inoculated plants respecting to control. Indolacetic acid and gibberellins concentration in shoots, were bigger in plants colonized by arbuscular mycorrhizal fungus (AMF) than in control. The 6-aminopurine levels in roots of colonized plants by AMF shown higher values. These results suggest that AM fungi modify the hormonal concentration and some growth factors in chili plants.
Enhanched Development and Flowering of Rudbeckia hirta in Far-red Amended Environments
Authors: Karlsson* Meriam , Werner Jeffrey
Published: February 2019

The importance of far-red in the spectral energy distribution was evaluated for the development of Rudbeckia hirta. In a high pressure sodium production system of 8 mol·m-2 per day during 16 hours, a limited number of incandescent lamps were added to provide 15 to 20 μmol·m-2 s-1. The red to far-red ratio decreased through the addition of incandescent lighting from |2.2 of high pressure sodium to 1.2. The dwarf R. hirta cultivars Toto Gold, Toto Lemon and Toto Rustic, suitable as container or bedding plants, were transplanted into 10-cm containers 1 month after seeding and the experiment was initiated 3 weeks later. At this time, the plants had 7 to 8 leaves and were 3 to 4 cm in height. Flowering time decreased with 10 to 14 days for the R. hirta cultivars in the incandescent amended environment compared to exclusively high pressure sodium irradiance. Overall plant height averaged 24 cm for `Toto Lemon', 26 cm for `Toto Rustic' and 28 cm for `Toto Gold'. All three cultivars grew |4 cm taller by adding incandescent light. Main branches of each plant averaged 4 with 14 developed flowers and flower buds independent of cultivar and light quality. Average flower diameter increased 0.5 cm in incandescent amended environments to 7.1 cm for `Toto Gold' and `Rustic' and 6.4 cm for `Toto Lemon'.
Plasticity in Leaf and Photosynthetic Characteristics of Ficus benjamina Ggrown under Different Lght Regimes
Authors: Wang Qibing , Chen* Jianjun
Published: February 2019

Ficus benjamina is considered to have a high degree of morphological and physiological plasticity in response to light levels. In this study, leaf area and thickness, specific leaf area (SLA), chlorophyll content, and photosynthetic characteristics of Ficus benjamina `Common'; grown in a shaded greenhouse under four maximum photosynthetic photon flux densities (PPFDs) of 150, 250, 450, or 650 μmol·m-2·s-1 were investigated. Results showed that plants grown under 450 and 650 PPFDs had higher SLA and leaf thickness but smaller leaf areas than those grown under 150 and 250 PPFDs. Total chlorophyll content per unit leaf area decreased as PPFDs increased. Net photosynthetic rates (Pn) increased from 2.7 μmol·m-2·s-1 under 150 PPFD to 5.7 μmol·m-2·s-1 under 450 PPFD, then slightly decreased to 5.5 μmol·m-2·s-1 under 650 PPFD. The highest net photosynthetic rate was not associated with higher intercellular CO2 concentrations (Ci) and stomatal conductance (gs) as plants grown under 250 PPFD had the highest (Ci) (259 ppm) and gs (0.1 mol·m-2·s-1), which suggests that photosynthetic enzymes could play a increasing role under 450 PPFD. Plant quality, however, was not necessarily correlated with the Pn because only those grown under 250 PPFD had appropriate heights, large and dark green leaves, and well-spread branches, and thus were graded higher than plants grown under the other PPFDs. This study shows that fine-tuning production light level is important for high quality Ficus benjamina production.
Characterization of Postharvest Disorders and the Effect of Shipping on Shelf Life of 22 Vegetative Annual Cultivars
Authors: Beach* Shannon E. , Starman Terri W.
Published: February 2019

Vegetative annuals are increasing in popularity among greenhouse growers and consumers but little is known about their postharvest shelf life. Twenty-two cultivars from ten species of vegetative annuals were grown to marketability with optimum greenhouse culture. Plants were then subjected to one of three shipping durations (0, 1, or 2 days) in simulated shipping i.e., a growth chamber at 26.7 ± 0.3 °C, 0 μmol·m-2·s-1, and 50% relative humidity. The plants were then moved to simulated postharvest environment i.e., growth room at 21.1 ± 1.3 °C and 6 μmol·m-2·s-1 to evaluate shelf life. Flower number and plant quality rating were measured weekly in addition to observations of plant appearances. Some of the postharvest disorders noted on several species and cultivars were stem die back, leaf chlorosis, stem elongation, bud abortion, flower drop, and flower fading. The majority of the cultivars maintained their quality one-week postharvest although flower drop was common. After the first week of shelf life, decline in vegetative and reproductive tissues were noted in most plants. Cultivars from nine species: Argyranthemum frutescens (L.) Sch. Bip, Bracteantha bracteata (Vent.) Anderb. & Haegi, Calibrachoa hybrid Lave Lex, Diascia ×hybrida, Lantana camara L., Nemesia ×hybrida, Petunia ×hybrida, Sutera hybrida, and Sutera cordata showed decreased flower number and/or quality rating due to shipping duration, with increased shipping duration causing accelerated postharvest disorders. The only species unaffected by shipping duration was Angelonia angustifolia Benth.
Characterizing the Vernalization Response of Campanula `Birch Hybrid' to Temperatures Between -2.5 to 20 °C
Authors: Padhye* Sonali , Cameron Arthur
Published: February 2019

Campanula `Birch Hybrid' has an obligate vernalization requirement, though little is known about the vernalization response as a function of temperature and duration. The objective of this study was to characterize the qualitative and quantitative effects of exposure to -2.5 to 20 °C on C. `Birch Hybrid' flowering. Plugs were bulked at 20 °C for 4 weeks and then transferred to -2.5, 0, 2.5, 5, 7.5, 10, 12.5, 15, 17.5 or 20 °C for 0, 3, 5, 7, 9, or 12 weeks. Plugs were then potted and grown at 20 °C under 16-h photoperiod. Nine plants were used per treatment. Date of first open flower and the number of open flowers and flowering nodes 7 d later were recorded. No plants flowered after 0 or 3-week treatments. One plant held at 20 °C flowered and no plants flowered after exposure to 17.5 °C. After 5 weeks at 0 to 7.5 °C, 100% of plants flowered with the fastest flowering after 2.5 to 7.5 °C. The number of flowering nodes and open flowers were similar for plants held at -2.5 to 10 °C for 5 weeks. All plants flowered following 7 weeks at -2.5 to 12.5 °C, though flowering was quickest after exposure to 2.5 to 7.5 °C. After 7 weeks, plants held at -2.5 to 10 °C produced similar number of flowering nodes and open flowers. Following 9 weeks, all plants at -2.5 to 12.5 °C flowered and 2.5 to 7.5 °C treated plants flowered first. The number of flowering nodes was uniform across -2.5 to 12.5 °C and the highest number of flowers was produced at 12.5 °C. All plants held at -2.5 °C died after 12 weeks. After 12 weeks, all plants flowered following 0 to 15 °C. However, following 15 °C, plants produced fewer flowers and flowering nodes. Overall, the optimal vernalization response was between 0 to 7.5 °C.
Photosynthesis and Growth of Single-node Cutting Rose `Red Velvet' and `Vital' by Nutritional Control in a Plant Factory
Authors: Yeo* Kyung-Hwan , Son Jung-Min , Lee Yong-Beom
Published: February 2019

Plant factory is a new plant production system that enables high quality, year-round, and planned production by controlling the environment. However, the recirculation of the nutrient solution leads to several problems because of unstable condition by nutrient uptake. The concentrations of nutrients in the recirculating solution should be kept at the required levels, since an optimum nutrition is determined by the specific concentrations of an element and mutual ratio to other nutrients in the root zone. Consequently, the nutrient solution is required adjustments based on regular analysis of the drain water and relationships among nutrient uptake, growth stage, and environmental factors for plant quality. This study was conducted to examine the effect of mineral nutritional control by five different methods on growth and photosynthesis of single-stemmed rose `Red velvet' and `Vital' in a plant factory. The nutritional control of nutrient solution was as following: the control of electrical conductivity (EC), N, P, and K elements (NPK), macro elements (M), macro and micro elements (MM) to target ranges in root environment, and the supplement of nutrient solution (S). The growth of single-node cutting rose `Vital' and `Red velvet' was higher in the M and MM than that of other control systems. Although M and MM system showed no significant difference, the photosynthetic rate, stomatal conductance, and transpiration rate were higher than those with other systems. The maximal efficiency of photochemistry (Fv/Fm) was higher in the M and MM control system, which showed the highest root activity. These results could be attributable for modelling the mineral nutritional control system, which reduces the use of fertilizers and increases the productivity of single-stemmed rose.
Preliminary Study of the Impact of an After School Gardening and Nutrition Program on Children's Nutrition Knowledge, Fruit and Vegetable Preference, and Self-efficacy of Gardening and Eating Fruits and Vegetables
Authors: Poston* Suzanne A. , Shoemaker Candice A.
Published: February 2019

Two age appropriate curricula for third through fifth graders, Professor Popcorn (PP) and Junior Master Gardener: Health and Nutrition from the Garden (JMG), were compared for their effectiveness in teaching nutrition knowledge, improving fruit and vegetable preference, and improving self-efficacy in gardening and eating fruits and vegetables as part of an after school learning program. Eighteen third through fifth graders participated in an eight lesson summer program (11 in PP, 7 in JMG), and eleven fourth graders participated in JMG during the fall. Knowledge, preference and self-efficacy measures were obtained at baseline and at the end of the program. There were no significant differences in these variables between the participants in PP and JMG at end-program. One interesting finding, however, was the change in gardening self-efficacy of the summer JMG group compared to the fall JMG group. Gardening self-efficacy of the summer JMG group increased (P = 0.063) while that of the fall JMG group decreased (P = 0.012) from baseline to end-program. Further investigations examining the role seasons have in the outcome of a garden-enhanced nutrition program and the activities of gardening occurring at different times throughout the growing season are suggested. In addition, further research should examine the amount of classroom time versus gardening time that is needed to make a garden-enhanced nutrition program more effective in an after school learning program.
Tracking Horticultural Impact of Master Gardeners
Authors: Sciarappa* William J. , Zahorsky Diane C. , Obal Richard G. , Quinn Vivian A.
Published: February 2019

The Master Gardener program in Monmouth County began in 1999. In order to justify the initiation of such a time and resource intensive program for Rutgers Univ., detailed records of participant activities throughout the county were compiled. The educational program consists of several components related to horticultural science. These classroom topics are basic horticulture, environmental factors for plant growth, soils and fertilizers, plant propagation, vegetable gardening, integrated pest management, turfgrass systems and practical horticultural techniques. Since 1999, 145 graduates have passed through the program and contributed a total of 35,274 volunteer hours. The key horticultural program segments that result in direct return on this substantial investment include: 1) horticultural helpline—answering home gardening questions; 2) horticultural help—promoting gardening programs in schools, parks, etc; 3) Community outreach—lectures and demonstrations, hort therapy; 4) horticultural research at university extension and education farms; and 5) laboratory assistance - plant and pest identification, test measurements. The calculated value of such volunteer help at $15.43 per hour leads to a horticultural contribution of $544,277 over 5 years. It is important to realize that many key programs would not have even been initiated without the ability to quickly assemble large numbers of skilled volunteers on a part-time basis. The training program and hands-on experience made these Master Gardeners capable of detailed data collection from ornamental and agricultural plant studies. This impact expands and synergizes the plant science programs of the professional staff on both a county and statewide basis.
Evaluation of Master Gardeners of Greater Kansas City
Authors: Kumar* Lala A. , Schwarz Jan
Published: February 2019

The Master Gardener Program sponsored by the Univ. of Missouri provides the metropolitan Kansas City area with information, demonstrations and programs designed to educate the general public about gardening topics and suggests solutions to current or anticipated problems. The main objectives of this evaluation were to identify the satisfaction level of clients (public) and the Master Gardeners from the program, demographics of Master Gardeners, how the program has changed the quality of life of the Master Gardeners and to identify any constraints. An evaluation committee consisting a social scientist, horticulturist and Master Gardeners were formed to develop the process and tools necessary for a comprehensive evaluation. It was decided that each facet of the program should have its own separate evaluation. The committee met several times to develop evaluation tools (survey questionnaires), to gather information from clients and the Master Gardeners. The results indicate a high level of satisfaction from clients and the Master Gardeners. The program had made positive changes in lives of Master Gardeners. The results provide guidance in decision making for further implementation such as it was found that the program should give a strong emphasis on providing new or advance horticultural information to Master Gardeners through continuing education.
Temperate Fuits Production in the Tropics: A Review on Apples in Kenya
Authors: Njuguna* Joseph K. , Wamocho Leonard S. , Morelock Teddy E.
Published: February 2019

Temperate zone fruit crops undergo bud dormancy which can be described as a mechanism for avoiding the exposure of tender flowers and leaves to low winter temperatures. In Kenya, apple growing is mostly hampered by inadequate chilling that causes the plants to have prolonged dormancy leading to poor flowering and consequently low yield. Although the chilling requirements are obligatory, under subtropical and especially tropical conditions avoidance is possible. To achieve this, it is necessary to select cultivars with low chilling requirements. This has proven effective in Zimbabwe with cultivar Matsu which is grown without a need for artificial breaking of dormancy. In Kenya like Zimbabwe, low chilling requiring cultivars such as Anna have been grown successfully. However, for cultivars with high chilling requirements, there is need to apply artificial techniques/methods to enhance bud break. Some of the cultural techniques used are: defoliation after harvesting and bending of the shoots holizontally. Defoliation after harvesting has particularly been used successfully in the island of Java in Indonesia and it enables two crops to be grown per year. Root chilling of rootstock has also been found to enhance bud break of the shoot. In addition, chemicals like KNO3, mineral oil and thiourea (TU) have been found to be effective in breaking bud dormancy in Kenya. This paper is reviewing the challenges encountered in growing apples in the tropics and Kenya in particular and the progress that has made in addressing them.
Resistant Rootstocks, Preplant Compost Amendments, Soil Fumigation, and Row Repositioning for Managing Apple Replant Disease
Authors: Leinfelder Michelle M. , Merwin Ian A. , Fazio Gennaro , Robinson* Terence
Published: February 2019

We are testing control tactics for apple replant disease (ARD) complex, a worldwide problem for fruit growers that is attributed to various biotic and abiotic soil factors. In Nov. 2001, “Empire” apple trees on five rootstocks (M.26, M.7, G.16, CG.6210, and G.30) were planted into four preplant soil treatments—commercial compost at 492 kg/ha soil-incorporated and 492 kg·ha-1 surface-applied), soil fumigation with Telone C-17 (400 L·ha-1 of 1,3-dichloropropene + chloropicrin injected at 30 cm depth five weeks prior to replanting), compost plus fumigant combination, and untreated controls—at an old orchard site in Ithaca, N.Y. Trees were replanted in rows perpendicular to, and either in or out of, previous orchard rows. Irrigation was applied as needed, and N-P-K fertilizer was applied in 2001 to all non-compost treatments to compensate for nutrients in the compost treatment. After two growing seasons, the rootstock factor has contributed most to tree-growth differences. CG.6210 rootstock supported greater growth in trunk diameter, central leader height, and lateral shoot growth (P < 0.05), regardless of preplant soil treatments and replant position. Trees on M.26 grew least over a two year period. Replant growth was greater in old grass lanes than in old tree rows, despite higher root-lesion nematode populations in previous grass lanes. Growth responses to preplant soil fumigation were negligible. Preplant compost did not increase tree growth during year one, but did increase lateral branch growth in year two. Results thus far suggest that replanting apple trees out of the old tree-row locations, and using ARD tolerant rootstocks such as CG.6210, may be more effective than soil fumigation for control of ARD in some old orchard sites.
Alternative Orchard Floor Management Practices for Improving Soil Quality and Optimizing Nitrogen Uptake Efficiency
Authors: Azarenko Anita N. , Chozinski Annie , McDonald* Sarah F. , Forge Thomas A. , Righetti Timothy
Published: February 2019

Information about the use of alternative management practices (AOFMP) in perennial systems to manage soil biota and influence the uptake of nutrients is limited. The objectives of this study are to evaluate AOFMP on soil quality, focussing on soil biology, and on nitrogen uptake efficiency. Research plots are located in Lewis-Brown Farm (LB), Corvallis, OR (`Fuji' apple trees) and Mid-Columbia Ag. Research & Extension Cent. (HR), Hood River, OR (`Red Delicious' apple trees). Main plot treatments were weed control methods: herbicide or cultivation. Sub plot treatments were soil amendments: no amendment, bark mulch (BM), compost, and green vetch/barley mulch (VB). A split-plot completely randomized design with 3 replications was used. Depleted NH3 SO4 was applied to single-tree replicates at bud break in 2001, 2002, and 2003. Compost amended plots contained more fungivorous nematodes than other treatments, although this difference was not significant at LB. At both sites there was a significant interaction between main and sub plot treatments in the number of bacterivores. At LB, the interaction between main and sub plot treatments affected the number of enrichment opportunists and the F-ratio was affected by amendment. At HR, the structural index was also affected by amendment. Compost resulted in the most diverse populations. Soil respiration rates in compost and BM plots were consistently higher than in unamended and VB treated plots. Soil P, pH, and organic matter content were increased by compost amendment and bulk density was decreased. At HR mid-season leaves, fruit, and first year growth from compost treated plots contained the least nitrogen derived from fertilizer, followed by bark mulch. The highest nitrogen derived from fertilizer was in unamended plots.
Cropload Affects Fruit Quality of Honeycrisp Apple
Authors: Robinson* Terence L. , Watkins Christopher B.
Published: February 2019

In 2001 and 2002, we imposed a wide range of croploads (0-15 fruits/cm2 of TCA) on 4- and 5-year-old Honeycrisp/M.9 trees by manual hand thinning soon after bloom to define appropriate croploads that give adequate repeat bloom and also the best fruit quality. At harvest each year we evaluated fruit ripening and quality. Samples were stored for 5 months in air at 38 °F and 33 °F and evaluated for fruit firmness and storage disorders. Cropload was negatively correlated with tree growth, return bloom, fruit size, fruit red color, fruit sugar content, fruit starch content, fruit firmness, fruit acidity, fruit bitter pit, fruit senescent breakdown, fruit rot and fruit superficial scald, but was positively correlated with leaf blotch symptoms, fruit internal ethylene concentration at harvest, and fruit soggy breakdown. There was a strong effect of cropload on fruit size up to a cropload 7, beyond which there was only a small additional effect. Although there was considerable variation in return bloom, a relatively low cropload was required to obtain adequate return bloom. Fruit red color was reduced only slightly up to a cropload of 8 beyond which it was reduced dramatically. The reduced fruit color and sugar content at high croploads could indicate a delay in maturity of but, fruits from high croploads were also softer, had less starch and greater internal ethylene. It that excessive croploads advance maturity. Overall, croploads greater than 10 resulted in no bloom the next year, and poor fruit size, color and flavor, but these fruits tended to have the least storage disorders. Moderate croploads (7-8) resulted in disappointing return bloom and mediocre fruit quality. For optimum quality and annual cropping, relatively low croploads of 4-5 were necessary.