bluuebunny/crossref_metadata_2025 huggingface dataset:
(67) Effect of Two Types of Fertilizers on the Growth and Development of Tissue-cultured Daylilies Transferred to the Greenhouse
Authors: Carter Johnny , Palmer Diondre , Chen Lianghong , Gulia Surinder
Published: February 2019

During Summer 2005, a study similar to that of Summer 2004 was conducted to determine the effect of two type of fertilizers on the growth and development of tissue-cultured daylilies transferred to the greenhouse. Peters 20–20–20 water-soluble fertilizer and a slow-release fertilizer were the two fertilizers evaluated. Peters 20–20–20 fertilizer was used at 0 (control), 50, 100, 200 mg/L rates. The slow-release fertilizer was used at 2.5 g per 10.2-cm pot. Each treatment was replicated four times in randomized complete-block design. After 6 weeks of growth, the results showed that when compared to the control, all treatments except for 200 mg/L caused a significant increase in root growth. Shoot growth was significantly increased by the 100 mg/L treatment, while the 200 mg/L and the slow-release treatments suppressed shoot growth. Similar to the growth of roots and shoots, the 100 mg/L treatment caused significant increase in fresh weight, while both the 200 mg/L and slow-release treatments caused a reduction. Results obtained for Summer 2005 were similar to that of Summer 2004. These results imply that the 100 mg/L Peters 20–20–20 fertilizers treatment is the best treatment for maximum growth and development of tissue-cultured daylilies transferred to the greenhouse.
(232) Production of an Intergeneric Hydrangeaceae Hybrid
Authors: Jones Keri D. , Reed Sandra M. , Rinehart Timothy
Published: February 2019

Dichroa febrifuga (Hydrangeaceae) is an evergreen shrub with metallic blue fruit that persists throughout winter. Phylogenetic studies have indicated that D. febrifuga is closely related to Hydrangea macrophylla. The objective of this study was to produce hybrids between these two ornamental species. Reciprocal crosses were made between D. febrifuga and both diploid and triploid cultivars of H. macrophylla. Two-thirds of the seed capsules produced from these hybridizations were allowed to mature on the plant, after which time seed were collected and sown in a greenhouse. Embryo rescue was used with the remaining seed capsules. Ovules were excised from ovaries about 9 weeks after pollination and plated on Gamborg's B-5 media with 2% sucrose. Both germination techniques resulted in vigorous seedlings. Hybridity was verified in plants obtained from ovule culture using simple sequence repeat (SSR) markers. Reciprocal hybrids were obtained using both diploid and triploid forms of H. macrophylla. This study confirms the close relationship between D. febrifuga and H. macrophylla and provides valuable material for future breeding efforts.
(233) Comparison of Inflorescence Morphology, Anthesis and Floral Sex Expression in Bottlebrush and Red Buckeye
Authors: Chanon Ann M. , Jourdan Pablo S. , Scheerens Joseph C.
Published: February 2019

As a prelude to interspecific hybridization, we compared the floral biology of bottlebrush buckeye (Aesculus parviflora) and red buckeye (A. pavia) by examining inflorescence morphology, pattern of floral anthesis, sex expression, and the effects of panicle decapitation on complete flower development. Inflorescences of both species (n = 1606) were randomly selected and analyzed for length, total number of flowers and complete flower number and location. The pattern of anthesis was observed in four genotypes using 10–30 inflorescences per plant. For each flower, its date of anthesis, position on both the rachis and cincinnus, and sex were recorded. For studies of panicle decapitation, sets of panicles were selected and one member was severed in half early in development in an attempt to increase the number of complete flowers. More than one-fourth of all panicles observed were completely staminate. For both species, the ratio of complete flowers to male flowers (C:M) within mixed panicles was about 5%. Complete flowers were observed in the basal portion of A. pavia inflorescences and in the apical portion of A. parviflora inflorescences. Anthesis progressed from base to tip over a period of 6–11 days. Complete flowers are present in A. pavia from the beginning of anthesis but do not appear in A. parviflora until the fifth day of anthesis. Staminate flowers are present throughout anthesis in both species. Severing panicles in half increased the potential for differentiating complete flowers. In conclusion, the frequency of complete flowers in both species was quite low, but could be increased by panicle decapitation to increase opportunities for controlled hybridization.
(235) `Raspberry Profusion' and `Lavender Mist': New Abelia Cultivars for the Landscape
Authors: Robacker Carol D. , Scheiber Sloane M.
Published: February 2019

Abelia ×grandiflora is a drought-tolerant, pest-resistant, flowering shrub that has long been used as a foundation plant. Interspecific hybridization has produced seedlings with an assortment of morphological traits, allowing for development of new cultivars with unique or improved qualities. `Raspberry Profusion' and `Lavender Mist', developed at the University of Georgia, are seedling selections of `Edward Goucher' × Abelia chinensis. `Raspberry Profusion' is a very heavy and very early bloomer. Panicles are large and showy with fragrant pink flowers and raspberry-colored sepals. Flowering begins in early May and becomes very heavy by early June. The bright-colored sepals remain on the plant throughout the summer. Summer foliage is a medium to dark green color. In a pot, `Raspberry Profusion' blooms early and heavily. `Lavender Mist' is a heavy bloomer, with clusters of fragrant lavender flowers beginning in mid-June, and continuing into autumn. Sepals are a straw-green color at the base, becoming rose at the tips. Summer foliage is gray-green. `Lavender Mist' performs well in a pot, forming a gray-green mound contrasting with the lavender blossoms scattered around the plant. Leaves on both cultivars are glossy, particularly from mid-summer through autumn. Both plants tend to be mostly deciduous in the winter. Laboratory evaluations of cold hardiness in Griffin, Ga., during Winter 2003–04 revealed a mid-winter hardiness of –18 °C to –21 °C for `Raspberry Profusion' and –15 °C to –17 °C for `Lavender Mist'. These plants develop into dense compact shrubs following pruning and establishment in the landscape.
(236) `Plum Surprise': A New Heat- and Drought-tolerant Evergreen Abelia
Authors: Robacker Carol D. , Scheiber Sloane M.
Published: February 2019

Abelia ×grandiflora is a hardy shrub in the landscape, surviving heat and drought with few pest problems. However, improved cultivars with better form, the ability to retain foliage during drought, and unique flowering and foliage characteristics are in demand. `Plum Surprise' is a new cultivar of Abelia that was developed at the University of Georgia in response to these needs. `Plum Surprise' is a seedling selection from the cross `Edward Goucher' × `Francis Mason'. It forms an unusual weeping, spreading mound with fine-textured foliage. In March and April, foliage is yellow-green with scattered red/purple leaves. In late spring, the foliage becomes emerald green, changing to a lighter green throughout the summer. New stem growth is red. The most striking features of `Plum Surprise' are the fall and winter foliage color and the evergreen habit of the cultivar. As autumn progresses, the outer shoots and leaves transform to red/purple or crimson, while the inner foliage is bright emerald green. Foliage is glossy in the winter, and a deep purple or burgundy color. `Plum Surprise' is a relatively light bloomer, with flowers scattered individually or in pairs. The flowers appear white, but on close examination have a purple blush with a pale yellow throat. `Plum Surprise' is noteworthy for its heat and drought tolerance. In both the summers of 2002 and 2005, when check cultivars had lost 50% to 80% of their foliage, `Plum Surprise' exhibited little leaf drop. `Plum Surprise' performs well in a pot under nursery conditions. The foliage cascades down over the pot, making an attractive appearance in both form and color.
(238) Ethylene Screening using 1-aminocyclopropane-1-carboxylic acid (ACC) in Both Nonmutagenized and Mutagenized Snapdragon Lines
Authors: Heffron Leslie , Blowers Alan , Uchneat Michael , Korban Schuyler
Published: February 2019

A tissue culture screen for ethylene tolerance using 1-aminocyclo-propane-1-carboxylic acid (ACC) was optimized for a snapdragon (Antirrhinum majus) inbred line, OAK564. Two experiments were conducted using various concentrations of ACC (ranging from 0 to 100 μM). Presence of 5 μM ACC in the tissue culture medium elucidated biological activity in snapdragon seeds. This screen was used to determine relative sensitivity to ethylene in 48 hybrid lines. Different levels of sensitivity to ethylene were observed among the various hybrid lines. Moreover, 40,000 mutagenized seeds from three M2 populations, derived from different levels of EMS (0.5%, 0.75%, and 1.0%) treatments, were screened for ethylene sensitivity. A total of 231 putative mutants were recovered spanning eight distinct phenotypes based on the `triple response' assay. Of these putative mutants, 16 mutants were selected for further analysis, including at least one and up to three lines from each of the eight phenotypic classes. Plants were established in the greenhouse, and allowed to grow to maturity to collect selfed seeds. These seeds were once again screened with 5 μM ACC to determine the level of ethylene sensitivity present within each of the eight phenotypic classes. Responses in the M3 populations varied from complete ethylene tolerance to ethylene sensitivity. Implications of these results on the recovery of ethylene tolerant mutants will be discussed.
(91) Yield Recovery of Commercial Citrus Trees Impacted by the 2004 and 2005 Florida Hurricanes
Authors: Salvatore James J. , Ritenour Mark A. , Scully Brian T. , Albrigo L. Gene
Published: February 2019

Up to three hurricanes (Charley, Frances, and Jeanne) passed over the same citrus-producing areas of Florida in August and September 2004. In October 2005, hurricane Wilma also passed over South Florida. We began evaluating citrus tree recovery in four commercial groves (red and white grapefruit, and `Murcott' tangerine) following the 2004 hurricanes to determine how quickly commercial groves recover following such catastrophic events. We previously reported that, among other things, even branches formed after the last 2004 hurricane matured sufficiently to flower the following spring, but to a lesser extent than older shoots. Here, we report hurricane effects on tree yield, fruit quality, and shelf life. Fruit loss was dramatic following the 2004 hurricanes (>90%). Fruit loss was also substantial following hurricane Wilma, with `Murcott' yields reduced 18% and grapefruit yields reduced 58%-65%. However, in comparison to 2003 pre-hurricane yields, yields following hurricane Wilma declined only 9% for `Murcott,' and 26%-40% for grapefruit. These yield reductions are less than the fruit lost due to the present year's hurricane. Therefore, the citrus trees studied demonstrated tremendous resilience and, if not for another hurricane the following year, would have likely exceeded pre-hurricane yields only 1 year after the devastating 2004 hurricanes. Effects of the hurricanes on harvested fruit quality and shelf life will also be discussed.
(303) Performance of a New, Low-cost Soil Moisture, Temperature, and Electrical Conductivity Sensor
Authors: Campbell Colin S. , Campbell Gaylon S. , Cobos Douglas R. , Teare Brody
Published: February 2019

Knowledge of soil water, fertilizer, and temperature is important when growing plants in any type of growing media. Although instruments to measure these properties have been available for several years, they are often expensive, failure-prone, and require different calibration for individual soil types. Recently, a low-cost sensor (Trade name: ECH2O-TE) was released that measures volumetric water content, electrical conductivity (EC), and temperature. The objective of this study was to determine how the probe performed in various soil and soilless media, as well as various salinities. We found the probe performed very well over a wide range of soil types and salinities. From the data, it appears that a single calibration can be used for all mineral soils and organic potting soils. A second calibration equation may be required for substrates such as rockwool. The output of the probe was not affected by the salinity (EC) of the soil from 0.1 to greater than 10 dS/m and showed considerable improvement in temperature sensitivity compared to existing technology. These results suggest the sensor provides a low-cost, reliable, easier-to-use alternative to other sensors of its kind.
(227) Guava Callus Production In Vitro
Authors: Yang Guochen , Lu Zhongge (Cindy) , Niedziela Carl E.
Published: February 2019

This research was initiated to study different culture media and plant growth regulators for their influences on callus initiation and production, with a research goal of developing an efficient in vitro callus regeneration protocol for guava (Psidium guajava L.). Guava is an important tropical fruit species that is rich in vitamins and vitamin precursors, minerals, organic acids, and pectins. Seventy-nine phytochemicals provide guava with many unique properties and actions, including anti-microbial, astringent, bactericidal, cicatrizant, emmenagogue, hypoglycemic, laxative, nutritive, and spasmolytic. Different concentrations of various plant growth regulators (PGR), such as 6-benzyladenine (BA), kinetin, or 2,4-dichlorophenoxyacetic acid (2,4-D), and naphthaleneacetic acid (NAA) were added to basic Murashige and Skoog (MS) and woody plant medium (WPM) and tested for their influences. Differences in callus initiation and morphology were noticed between MS and WPM, and among PGR concentration treatments.
(231) Habitat-correlated Germination and Growth Characteristics in Intermountain Allium (Liliaceae)
Authors: Phillips Nathan C. , Drost Daniel T. , Varga Bill , Shultz Leila , Meyer Susan E.
Published: February 2019

Seed germination timing strategies and seedling growth characteristics in wild populations have evolved in response to their life history, ecology, and habitat. In this study, we examined the ecophysiological aspects of seed germination and growth in three Allium species native to the Intermountain West (A. acuminatum, A. brandegei, and A. passeyi). Three populations of each species were studied along an elevation gradient resulting in low, mid, and high elevation sites for each species. We investigated seed dormancy patterns within and among species and their relation to habitat. Seeds collected at the study sites were subjected to cold (3 °C) moist stratification in low light to simulate the natural winter environment under snow. Stratification periods ranged from 0 to 24 weeks. After stratification, seeds were placed in lighted growth chambers at 8 °C to simulate the natural spring environment. Germination was observed for 4 weeks. Germinated seeds were then grown at either 12 °C or 16 °C until leaf senescence. Destructive sampling occurred at 2, 4, and 8 weeks. Bulb mass and water content were also assessed after leaf senescence. In the germination experiment, all species responded favorably to cold moist stratification, suggesting physiological seed dormancy. Germination percentages among species varied greatly with 98% germination in A. acuminatum, but only 33% in A. brandegei. Seedling survival and growth varied among species and in response to growing temperature. Observed patterns in seed germination and growth are typical of survival strategies in other spring ephemerals. Seed dormancy traits and seedling growth characteristics in these species have evolved to allow optimal success for their specific habitat.
(39) Determination of the Optimum Species for Ohio Tree Liner Production in Retractable Roof Greenhouses
Authors: Case Luke , Mathers Hannah , Grosskurth Elizabeth
Published: February 2019

Many Ohio growers import liners from the West Coast due to the increased growing season on the West Coast. Lengthening the season in Ohio may provide a way for Ohio growers to produce liners of their own. Retractable roof greenhouses (RRG) are one possible way to extend the growing season in Ohio. Research done previously at The Ohio State University suggests that retractable roof greenhouses do in fact lengthen the growing season, and tree liners can be produced using RRG. The objectives of this study were: 1) to determine the optimal growing environment from three different environments; and 2) to determine the optimal species for tree liner production in Ohio. In Oct. 2004, 180 liners each of Cladrastis kentuckea, Quercus rubra, Stewartia pseudocamellia, Syringa reticulata, and Tilia cordata were upshifted to 3-gallon pots. In Mar. 2005, 90 of each species were transferred to either a flat roof retractable house (FRRG), peak roof retractable house (PRRG), or polyhouse. Growth was measured in Mar. (initial), June, Aug., and Oct. 2005 by taking leaf area, shoot and root dry weights, height, and caliper. There were no differences across species and dates between the environments for any of the parameters measured. Tilia showed the greatest increase in growth from June to October in all the parameters measured except leaf area. Cladrastis showed the greatest increase in leaf area from June to October. There were species by date interactions. Quercus had the greatest root weight in October. Syringa and Quercus were not significantly different from each other and had the highest shoot weights and leaf areas in October. Tilia, Quercus, and Syringa had the highest calipers in October.
(40) Evaluation of Freshly Chipped Pine Tree Substrate for Container-grown Lantana camera
Authors: Boyer Cheryl R. , Fain Glenn B. , Gilliam Charles H. , Torbert H. Allen , Gallagher Thomas V. , Sibley Jeff L.
Published: February 2019

A study was conducted at Auburn University to evaluate freshly chipped pine trees as an alternative substrate in container nursery crops. Two substrates were tested alone and in combination with aged pine bark (PB), peat (P), and composted poultry litter (PL). A 6:1 (v:v) PB: sand control treatment was also included. The two substrates were both composed of small caliper (2 to 10 cm) Pinus taeda processed in a chipper (including needles) (AUC); however, one substrate was additionally processed through a hammermill with a 0.95-cm screen (AUHM). Treatments included were 100% AUC, 3:1 (v/v) AUC:PB, 3:1 (v/v) AUC:P, 3:1 (v/v) AUC:PL, 1:1 (v/v) AUC:PB, 1:1 (v/v) AUC: P, 1:1 (v/v) AUC:PL, and the same treatments for the AUHM substrate. There were a total of 15 treatments with six replications per treatment. Each substrate was amended with 0.45 kg·m-3 gypsum, 6.35 kg·m-3 Polyon 17–6–12 (17N–2.6P–10K) and 0.68 kg·m-3 MicroMax. Trade gallon (2.8-L) containers were filled with respective substrates and planted with Lantana camera `New Gold' on 20 July 2005. AUC and AUHM treatments amended with either PL or P resulted in Lantana with growth indices similar to PB:sand (6:1). In general, plants tended to be larger when amended on a 1:1 basis with either PL or P, but were similar statistically to those amended 3:1. For example, plants grown with AUHM:P 1:1 or AUHM:PL 1:1 were 7.3% and 8.8% larger, respectively, than plants grown in the same medium at 3:1. The lowest growth indices tended to occur with AUC and AUHM alone or amended with pine bark. Lantana root growth followed a similar trend to growth indices in that greatest coverage of the rootball surface occurred with AUC or AUHM treatments amended with PL or P.
(41) Growth of Japanese Holly in Pine Chips and Pine Bark as Influenced by Fertilizer Rate
Authors: Jackson Brian E. , Wright Robert D. , Browder Jake F.
Published: February 2019

Many industrial and agricultural wastes have been evaluated for use as alternative container substrate components. Recently, a new material produced from ground pine logs (Pinus taeda L.) has been utilized as a substitute for peat moss and pine bark (PB). On 17 Aug. 2005, japanese holly (Ilex crenata `Compacta' Thunb.) plants were potted in milled PB (Pinus taeda L.) and debarked ground pine chips (PC). Pine chips were ground with a hammermill to pass through a 6.35-mm screen. Osmocote Plus 15–9–12 (15N–4P–10K) was incorporated in both PB and PC substrates at the rates of 3.5, 5.9, 8.3, and 10.6 kg·m-3. Plants were greenhouse grown until 22 Nov. 2005. Substrate solution nutrient content and pH were determined for all treatments in each substrate. Shoots were dried, weighted, and tissue analyzed for N, P, K, Ca, Mg, S, Fe, Cu, Mn, and Zn. Shoot weights were higher in plants grown in PB than PC at the 3.5 and 5.9 kg·m-3 fertilizer rates. At the 8.3 kg·m-3 rate, shoot dry weight was about the same for each substrate, but at the 10.6 kg·m-3 rate, growth was higher for plants grown in PC than in PB. Substrate EC increased with increasing fertilizer rates and with the exception of Cu, was higher in PB substrates at all fertilizer rates. Plant tissue levels generally increased as fertilizer rate increased in both substrates but were higher in plants grown in PB than PC with the exception of Cu. Therefore, higher rates of fertilizer are required to produce optimal plant growth in PC compared to PB.
(272) An Alternative Method for Estimating Heritability in Facultative Apomictic Guayule
Authors: Veatch-Blohm Maren E. , Ray Dennis T. , Teetor Valerie H.
Published: February 2019

Guayule (Parthenium argentatum Gray) has been difficult to improve through classical plant breeding because of its facultative apomictic reproductive system. Attempts have been made to increase rubber concentration and yield by examining traits correlated with rubber production and their heritabilities. We propose a new way of estimating heritability in guayule that more accurately accounts for the contributions of apomictic and sexual reproduction. At two years of growth, there was a significant relationship between the parents and the progeny for all traits measured, except for rubber and guayulin B concentrations. Due to the facultative apomictic nature of guayule reproduction, heritabilities are more accurately presented as a range of values between the narrow and broad sense heritabilities. Since guayule is more apomictic than sexual, most heritabilities will be closer to the broad sense values. To increase resin and rubber yield in the progeny, selection should focus on height and width in the parents because height and width are highly correlated with rubber yield, with the highest heritabilities (0.65 to 1.00 and 0.97 to 1.0, respectively) of the traits measured.
(273) Orchid Seed Storage for Germplasm Preservation
Authors: Mweetwa Alice , Tay David , Welbaum Gregory
Published: February 2019

Orchids are important ornamental, food, and medicinal plants. Orchid germplasm preservation is important because some species are endangered due to loss of habitat and human predation. Very few of the world's genebanks are involved in orchid preservation. Orchid germplasm preservation is a priority for the USDA Ornamental Plant Germplasm Center in Columbus, Ohio. Brassia and Phalaenopsis seeds were harvested at different stages of development and stored at –196 °C (liquid nitrogen), –80, –18, 4, and 25 °C for 6, 12, 18, and 24 months to determine the optimum conditions for long-term seed storage. Phalaenopsis and Brassia seeds adjusted to 45.5% RH over chromium dichromate were able to survive 10-d storage. Seeds frozen in liquid nitrogen for 30 min were able to germinate and produce protocorms 19 d after sowing, just a day longer than control seeds. Liquid nitrogen storage also improved germination of some Phalaenopsis seed lots from 0 (control) to 38%. Storing Phalaenopsis seeds at –80 and 4 °C also improved germination similarly, suggesting dormancy was broken by low-temperature seed treatments. On the other hand, seeds stored at 25 °C did not germinate. Preliminary results suggest that orchid seeds tolerate freezing even in liquid nitrogen and that cryopreservation may be a viable long-term strategy for orchid germplasm preservation.
(95) Fruit Characteristics, Phenolic Compound, and Antioxidant Activity of Asian Pear Fruit from an Organically Cultivated Orchard
Authors: Kim Wol-Soo , Jo Jung-An
Published: February 2019

Pear (Pyrus pyrifolia) fruits of `Whangkeumbae' were produced from the organic orchard at Yongam, southwestern Korea, which was managed by spraying with chitin incubated solution (CIS) 15 times from petal fall stage, mid-April to late August, to control pests and diseases during the growing season. The CIS contained about 50 kinds of chitin digestive and/or effective microorganisms and other organic/inorganic biologically active substances by incubating the mixtures at 30 °C for 7 days. The soil had standard levels of chemical and physical properties in Korea, as well as 3.0% to 4.0% organic matter. The organic fruits showed higher soluble solid contents, and fruit firmness was increased in comparison to conventional fruits. The organic fruit skin changed in color from yellow to brown, and black spot occurred; however, there was no difference in flesh tissues in terms of colors and textures. The phenolic compounds were significantly increased in organic fruits and leaves, with especially higher levels for fruit skin than for flesh tissues. Free radical levels dropped sharply in organic fruit, but slowly in conventional fruits. The results showed that the organic pear fruits have higher levels of antioxidant activity, and also showed the phenomena related to the change in fruit skin color from yellow to brown.
(96) Sensory Evaluation of Alternative Pear Varieties for the U.S. West Coast
Authors: Elkins Rachel B. , Turner Janet D. , Castagnoli Steve , Seavert Clark F. , Mitcham Elizabeth J. , Biasi William V. , Colonna Ann
Published: February 2019

Assessing consumer acceptance is an important aspect of cultivar evaluation. Since 2002, about 2700 consumers have participated in pear preference surveys. Surveys were conducted on multiple dates and at multiple venues from 2002 to 2005 in Oregon and northern California. Survey participants were asked to indicate their preference for pears based on size, appearance, taste, and overall preference. They were also asked to indicate what attributes they liked or disliked about their favorite and least favorite varieties and to indicate their level of purchase intent. Each survey consisted of four to six cultivars, including at least one standard commercial comparison; i.e., Bartlett, Bosc, or Anjou. Data was analyzed (RCBD; Friedman Analysis of Rank or ANOVA/Tukey's HSD) at the OSU Food Innovation Center Experiment Station using Compusense® five v.4.6 software (Guelph, Ont., Canada). Results indicated several alternative possibilities for both summer and winter sales. Among the most preferred cultivars (variable between states) were Anjou (commercial standard winter pear), Bartlett (commercial standard summer pear and most-consumed cultivar), Blake's Pride, Cinnamon, Concorde, and 71655-014. Other major findings were preference for large pears for adults and small for children, overall liking based on sweetness and flavor rather than skin color, and general lack of knowledge of many commercial pear cultivars. Sensory evaluation surveys will be continued in 2006 in California, with focus on differential harvest times for selected preferred cultivars. Consumer preference data is being combined with production and postharvest quality data in order to provide the pear industry a comprehensive data set on potential alternative cultivars.
(103) Effects of Dormant Application Timing in `Bartlett' Pear
Authors: Glozer Kitren , Ingels Charles
Published: February 2019

Pear growers in California's Sacramento River Delta and, to some extent, other pear-growing areas in California, use dormant oils for pest control and dormant bud growth stimulation. It is generally believed that well-timed applications can advance flowering, improve uniformity of flowering and fruit ripening, and improve vegetative budbreak. Traditionally, dormant oils have been applied in late December to mid-January, based on experience and calendar date. However, bud development and full bloom dates may differ from year to year, with variable weather cycles and chill accumulation experienced by the plant. In the 2004–05 dormant season, some dormant oil applications timed at intervals calculated by chill portions (defined by the Dynamic Model) advanced and compressed the bloom period. Fruit size (diameter and weight) and total estimated yield were improved by dormant oil treatments applied within a certain range of chill portion accumulation without reduction in total number of fruit per tree, while the percentage of undersized fruit was decreased by 65% to 83% when compared to the untreated control. The use of chill portions and the Dynamic Model to time applications of dormant oil appears to benefit fruit quality. Although chill was not limiting in the trial dormant season, there may be benefit even in years when chill accumulation is adequate.
(160) Seasonal Variations of Nutrient Status in Soil and Leaves, Soil Properties, and Tree Growth under Different Organic Apple Groundcover Management Production Systems
Authors: Choi Hyun-Sug , Rom Curt R. , Gu Mengmeng , McAfee Jason
Published: February 2019

Seasonal variations of nutrient concentrations in soil and apple leaves, soil properties, weed density, and tree performance were observed for response to four groundcover managements systems: 1) mowed control; 2) plastic woven landscape fabric; 3) wood chip mulch; and 4) shredded commercial paper mulch. Soil sampled below the wood chip and shredded paper mulch treatments had higher NO3-N concentrations during the season. Soil below the shredded paper mulch had greater soil Ca, Na, and Zn than other treatments. Soil sampled below wood chip mulch had higher Mg and B. Leaf K was greater for trees grown with bark chip mulch than the other treatments. Overall, the seasonal patterns of N, P, and K decreased and had similar patterns as previously reported conventionally grown orchards. The leaf Ca and Mg increased during the season for all treatments. The concentration of other microelements had patterns similar among all treatments. Seasonal soil pH decreased during the season and was affected by treatments. During the season, water infiltration was faster into the soil covered with shredded paper mulch. The organic matter was greater in soil under the wood chip mulch at the 15-cm soil depth. Very little weed invasion occurred in the landscape fabric through August. Trees grown with shredded paper and wood chip mulch treatments had greater trunk cross-sectional area compared to trees grown under landscape fabric after 5 years; however, the latter treatment resulted in greater tree height, tree canopy spread, and fruit yield.
(216) Beach Sand Hydrophobicidity Induced as a Result of the Presence of Beach Vitex
Authors: Cousins Matthew , Gresham Charles A. , Riley Melissa B. , Whitwell Ted
Published: February 2019

Beach Vitex (Vitex rotundifolia Lf.) was introduced to coastal Carolina areas in the 1980s. Since its introduction, it has become a major invasive plant problem. Beach Vitex rapidly dominates the vegetation and eliminates many native plant species on primary and secondary coastal dunes. It grows rapidly and reproduces vegetatively by rooting at the nodes. Thousands of fruits, containing one to four seeds each, are produced annually and assist in the plant's spread. Beach sand in areas dominated by Beach Vitex was found to possess hydrophobic qualities, while sand collected from areas not populated by Beach Vitex readily allowed water infiltration. GC-MS analysis of hydrophobic sand extracts showed four peaks that were absent from extracts of non-hydrophobic sand. These peaks were also present in chromatograms of water extracts of Beach Vitex fruits and leaves. Comparison of GC-MS spectra with compounds previously identified in Beach Vitex indicated that one compound was a diterpene (likely ferruginol or abietatrien-3ß-ol). The second compound is likely a flavonoid (possibly casticin, artemetin, or vitexicarpin). Two additional compounds are present at low levels and are possibly phenylnaphthalene compounds. These four compounds appear to be synthesized and incorporated into surface tissues of Beach Vitex leaves and fruits and are transferred to sand during rain events and decomposition. Further studies of Beach Vitex plant parts and beach sands are being conducted to further elucidate the possibility that these chemicals are involved in the intriguing property of sand hydrophobicity. This property may aide Beach Vitex in its competition with plants possessing less expansive root systems.
(218) Phytotoxicity of Several Herbicides in Pitahaya Grown under Plant Nursery Conditions
Authors: Michel-Rosales Arnoldo , Farias-Larios Javier , Osuna-Castro Juan Alberto , Peña-Beltrán Elpidio , González-González Juan Manuel , Garibay-Bautista Héctor Javier
Published: February 2019

At present, pitahaya (Hylocereus undatus Britt and Rose), a nonconventional crop and cactus native from Mexico, is considered very promising because of its high adaptability and tolerance to extreme agricultural conditions of tropical regions (poor soils, drought, and elevated temperatures), where they are cultivated. In addition, pitahaya fruit is well-accepted and identified as a nutraceutical food that lowers cholesterol and glucose levels in blood and might prevent stomach and colon cancers. However, little or no scientific information on chemical control alternatives of weeds in pitahaya commercial plantings have been generated. In this work, the phytotoxicity degree of seven commercial herbicides (metribuzin, glyphosate, glyphosate trimesium, paraqut, paraquat+diuron, atrazine, and halosulfuron methyl) in pitahaya plants grown under plant nursery conditions was assessed. A completely randomized design with 12 replications was used. The experimental unit was a flowerpot with a 5-month-old plants. The phytotoxicity degree was evaluated at 3, 7, 14, and 21 days after application using the scale proposed by EWRS. The herbicides that caused injury to the plants were paraqua+diuron (79%) and paraquat (77%), respectively. Metribuzin, halosulfuron-methyl, and atrazine did not cause any injury to the plants.
(219) Organic Watermelon Production Systems: Varieties and Weed Control
Authors: Webber Charles L. , Davis Angela R. , Shrefler James W. , Perkins-Veazie Penelope , Russo Vincent M. , Edelson Jonathan V.
Published: February 2019

The increasing perception by consumers that organic food tastes better and is healthier continues to expand the demand for organically produced crops. The objective of these experiments was to investigate the impact of different weed control systems on yields of watermelon (Citrullus lanatus var. lanatus) varieties grown organically. Six watermelon varieties were transplanted at two locations (Lane and Center Point, Okla.). The six varieties included three seeded varieties (`Early Moonbeam', `Sugar Baby', and `Allsweet') and three seedless varieties (`Triple Crown', `Triple Prize', and `Triple Star'). The weed control system at Lane utilized black plastic mulch on the crop row, while the area between rows was cultivated to control weeds. The no-till organic system at Center Point used a mowed rye and vetch cover crop, hand weeding, and vinegar (5% acetic acid) for weed control. When averaged across watermelon varieties, Lane produced significantly more fruit per plant (4.2 vs. 2.3 fruit/plant), greater marketable yields (16.0 vs. 8.4 kg/plants), and higher average marketable weight per fruit (6.1 vs. 4.0 kg) than at Center Point. When comparing locations, four of six varieties had significantly greater number of fruit per plant and higher marketable yields at Lane than at Center Point. Except for `Early Moonbeam', all other varieties produced significantly heavier fruit at Lane than at Center Point. In contrast, the Center Point location produced a greater percentage of marketable fruit for all varieties except `Allsweet'. Fruit quality (lycopene and °Brix) was as good or greater when harvested from the weedier Center Point location.
(275) Genetic Relationship of Fruiting-mei (Prunus mume Sieb. et Zucc.) Cultivars Evaluated by AFLP and SNP Markers
Authors: Fang Jinggui , Twito Tal , Zhang Zhen , Chao Chih Cheng T.
Published: February 2019

The genetic relationship among 50 fruiting-mei (Prunus mume Sieb. et Zucc.) cultivars from China and Japan was investigated using 767 amplified fragment length polymorphism (AFLP) and 103 single nucleotide polymorphism (SNP) markers. The polymorphism among the cultivars was 69.77% based on EcoR I + Mse I AFLP primer pairs. The sequence alignment of 11 group sequences derived from 50 samples yielded 103 SNPs with a total length of 3683-bp genomic sequences. Among these SNPs, 73 were heterozygous in the loci of different cultivars. The SNP distribution were: 58% transition, 40% transversion, and 2% InDels. There was also one tri-nucleotide deletion. Both AFLP and SNP allowed the evaluation of genetic diversity of these 50 fruiting-mei cultivars; however, the two derived cladograms have some differences: 1) all the cultivars formed two sub-clusters (1A and 1B) within cladogram based on AFLP polymorphisms, and there were three sub-clusters (2A, 2B and 2C) formed in the cladogram based on SNP polymorphisms; and 2) most cultivars from G-F, Y-H-S regions and Japan are grouped in cluster 1A and 18 (78.26%) out of 23 cultivars from J-Z origin are grouped in cluster 1B in the cladogram generated based on AFLP polymorphisms. The results show cultivars from Japan are clustered within cultivars from China and supports the hypothesis that fruitingmei in Japan was introduced from China in the past. Cultivars from J-Z region of China have higher genetic similarities. Cultivars from G-F and Y-S-H regions have lower genetic similarities and suggest more germplasm exchanges in the past.
(50) Evaluating Low Light Level Effects on Chlorophyll Content and Commercial Quality in Several Species of Bambuseae
Authors: Simmons Harry G. , Menakanit Alisara , Wannakrairoj Surawit , Kasemsap Poonpipope
Published: February 2019

Bamboo has increasingly become a popular exterior ornamental plant because of its durability, versatility, and evergreen qualities in conditions of extreme temperature and moisture variations. Use as an interior foliage plant has been limited due to the difficulty of finding species adaptable to lower light levels. Nineteen species from seven genera (Bambusa, Cephalostachyum, Dendrocalamus, Gigantochloa, Schizostachyum, Thyrsostachys, and Vietnamosasa) were evaluated. Fifteen plants from each species were potted in like conditions (50% leaf mold; 50% topsoil; 5 g of 14–14–14 controlled-release fertilizer) and grown under a maximum daily photosynthetic photon flux density (PPFD) range between 1200 to 2000 μmol·m-2·s-1 for 6 weeks. Chlorophyll content of leaves was measured. The commercial quality of leaves, culms, and general appearance was also recorded. Light was then limited to a maximum PPFD of 150 to 300 μmol m-2s-1 for 6 weeks and all measurements were again recorded. Five species had significant increases in chlorophyll content after the 6-week period of reduced light levels. Species with a larger maturity size had a greater mortality percentage as well as lower quality leaf and overall appearance when grown under reduced light levels. Culm quality remained constant in 18 of the 19 species after the 6-week period. Vietnamosasa ciliata showed the greatest increase in chlorophyll levels as well as highest commercial quality of leaf and overall appearance.
(51) Intermountain West Native and Adapted Grass Species and Their Management for Turfgrass Applications
Authors: Dougher Tracy , Day Toby , Johnson Paul , Kopp Kelly , Majerus Mark
Published: February 2019

The ongoing drought in the Intermountain West has brought a great deal of attention to water conservation over the past several years. During that time, turfgrass irrigation has been targeted as a source for large potential water savings. Some communities promote downsizing turfgrass areas as the best water conservation measure. In reality, turfgrass controls erosion, reduces evaporation from a site, and provides a safe surface for human activities. One alternative to elimination would be wider use of low water-use-grasses appropriate to the area. However, many questions arise regarding the choice of such grasses and their management. Our research addresses these questions. Plots have been established at Montana State University, Bozeman; Utah State University, Logan; and USDA-NRCS Plant Materials Center, Bridger, Mo. The grasses considered include 12 single species and 12 mixed species stands of `Cody' buffalograss, `Foothills' Canada bluegrass, `Bad River' blue grama, sheep fescue, sandberg bluegrass, muttongrass, and wheatgrasses `Sodar' streambank, `Road Crest' crested, `Rosana' western, and `Critana' thickspike with Kentucky bluegrass and tall fescue as controls. Line source irrigation allowed the plots to be evaluated at a number of levels of irrigation. Experimental measurements on the plots included growth response as determined by clipping yield and quality ratings, and species composition. Fescues and wheatgrasses retained their color, texture, and density throughout the growing season, regardless of moisture level. Warm-season grasses performed well in June, July, and August only, and worked poorly in mixtures as the green cool-season grasses could not mask the brown dormant leaves in cooler weather.
(52) Evaluation of California Native Grasses for Revegetation Sod
Authors: Stott Lance , Rew Lisa , Dougher Tracy
Published: February 2019

The California Department of Transportation (Caltrans) has used hydroseeding, imprinting, and drill seeding methods to revegetate highway construction sites, with varying degrees of success. Ecological concerns, particularly in areas with high erosion potential, have led Caltrans to search for more-reliable plant establishment methods. One possibility is native sod, which should reduce erosion potential, and, the species would also be better suited to local environments, require less maintenance, and pose no invasive threat to adjacent ecosystems. In addition, the use of native sod may also reduce or prevent weed establishment. Our project aims to evaluate different native grass species mixes to determine the best species combinations for sod. We selected 21 species of native grasses in order to determine their suitability for sod production in six Californian ecoregions. Grasses were grown in six growth chambers that mimic the climate of the six ecoregions. Mixtures of varying species included either one rhizomatous species with three bunch grasses, one rhizomatous species and five bunch grasses, two rhizomatous species with three bunch grasses, or two rhizomatous species with five bunch grasses for each ecoregion. The mixtures were grown and tested for yield, species composition, and percentage of cover over time. At the end of the 6-month production time, a final harvest evaluated root depth and biomass as well as sod strength. Rhizomatous grasses, if planted with Bromus sp., were quickly overwhelmed. At the first harvest ground coverage was between 10% and 15% for all species mixes. Ground coverage increased over the production cycle, but maximum ground coverage remained less than 80% overall.
(109) The Kentucky State University Pawpaw Regional Variety Trial: 1998–2005 Overview
Authors: Crabtree Sheri B. , Pomper Kirk W. , Layne Desmond R. , Peterson R. Neal
Published: February 2019

The pawpaw [Asimina triloba (L.) Dunal] is a tree fruit native to the eastern United States with potential as an alternative crop for small farmers. The Pawpaw Regional Variety Trial (PRVT) was established in 1993 by Kentucky State University (KSU) and the PawPaw Foundation (PPF) and includes 28 cultivars and advanced selections planted at 12 sites. The PRVT was established at the KSU Research Farm in Frankfort, Ky., in 1998. Data has been collected on the KSU-PRVT annually since its inception. The first fruit were produced in 1999, with Middletown, Mitchell, Overleese, and Sunflower being the most precocious varieties. A frost occurred in early April 2000, decimating the crop, with only eight fruit being produced across the orchard. In 2001, 12% of the trees produced fruit, with PA-Golden having the best early production. In 2002, 68% of trees in the PRVT fruited, producing a total of 3,500 fruit. Selections with the largest fruit (over 200 g) were Susquehanna, 5-5, 4-2, and 1-7-2. In 2003, a spring frost destroyed most of the flowers and developing fruit. Only 32 out of the 224 trees in the PRVT retained fruit, a total of only 131 fruit in the entire orchard. In 2004, the PRVT produced about 25,000 fruit across the entire orchard. Selections 4-2 and 7-90 produced the largest fruit, over 200 g. Shenandoah, 10-35, and 8-20 were the highest-yielding clones, all producing over 15 kg of fruit per tree. In 2005, spring frosts and a severe summer drought diminished fruit set and retention in the PRVT, with the orchard producing 8,900 fruit. Selections 4-2, 5-5, and Susquehanna produced the largest fruit, all weighing over 200 g. The highest yielding selections were 10-35, PA-Golden, and 1-7-2, all producing over 8 kg of fruit per tree.
(110) Suppression Subtractive Hybridization (SSH) Analysis for Detecting Genes Involved in Condensed Tannin Accumulation in Persimmon Fruit
Authors: Yonemori Keizo , Yoshida Junya , Ikegami Ayako , Sato Akihiko , Yamada Masahiko , Kitajima Akira
Published: February 2019

Pollination-constant and non-astringent (PCNA)-type persimmon has probably originated from astringent (non-PCNA)-type as a mutant that terminates condensed tannin accumulation at an early stage of fruit development. This trait is confirmed to be recessive and is controlled by a single locus. Since PCNA-type fruit stops tannin accumulation at an early stage, comparison of the gene expressions between PCNA- and non-PCNA-type will reveal the genes conferring condensed tannin accumulation in persimmon fruit. We performed suppression subtractive hybridization (SSH) analysis for detecting differentially expressed genes in non-PCNA-type fruit using BC1 offspring from a cross between PCNA `Fuyu' and non-PCNA “275-13” (F1 progeny derived from non-PCNA `Aizumishirazu' × PCNA `Taishu'). Fruits from seven individuals of PCNA or non-PCNA offspring in BC1 were sampled at early two stages of fruit development and total RNA was extracted by hot borate method from each fruit of different stage. Then, RNA was pooled as PCNA or non-PCNA bulk at two stages and cDNA was synthesized from each bulk for SSH analysis. A total of 5000 clones expressed differentially in non-PCNA-type fruit were picked from SSH library of two stages and 198 positive clones confirmed by differential screening were sequenced. The homologous sequences for the genes involved in flavonoid biosynthesis (CHS, CHI, F3H, F3'5'H, DFR, UFGT, and ANS) were obtained from the clones. The genes that are not considered to be involved in flavonoid biosynthesis so far (SCPL and DHQ) were also detected with high frequencies. We will discuss the role of these genes for condensed tannin accumulation in persimmon fruit.