bluuebunny/crossref_metadata_2025 huggingface dataset:
(422) Application of X-Ray in Flower Seed Technology
Authors: Tay David , Tychonievich Joseph , Burns Stephanie
Published: February 2019

The Association of Official Seed Analysts adopted X-ray technology for testing agricultural and forest tree seeds in 1979. It has not been applied on flower seeds. To date, its use is still lacking, despite the relatively simple and nondestructive nature of the test. One of the reasons for the slow adoption is the lack of a simple X-ray unit that gives instant high resolution digital images. The Faxitron MX-20, a cabinet X-ray unit designed for high detail radiographic imaging of medical specimens, fulfills this need. The high magnification capacity of 1×, 1.5×, 2×, 3×, 4×, and 5×, and the low kilovoltage (kV) provide enhanced image performance with good quality contrast. The exposure time and X-ray tube kV can be selected to produce the best images. Its laser locator eases the positioning of a sample under examination accurately and the 2-× 4-inch field of view digital camera with 10 lp/mm resolution provides the instant high quality on-screen viewing of seed sample images. The most useful application at the Ornamental Plant Germplasm Center is not in seed testing as recommended for agricultural and tree seeds, but as a tool during seed cleaning to see in a matter of seconds whether empty, immature, insect-damaged, and broken seed have been removed. It has proven useful in Achillea, Alstroemeria, Aquilegia, Aruncus, Aster, Baptisia, Begonia, Campanula, Chrysanthemum, Coreopsis, Dianthus, Euphorbia, Geranium, Hemerocallis, Impatiens, Iris, Lilium, Lupin, Lysimachia, Narcissus, Pelargonium, Penstemon, Petunia, Phlox, Platycodon, Ranunculus, Rudbeckia, Salvia, Silene, Stokesia, Tagetes, Talinum, Verbena, Veronica, and Viola.
(426) Evaluation of Pregerminative Treatmentsin Soursop (Annona muricata L.) Seeds
Authors: Gonzalez Juan Manuel González , Gonzalez Salvador Guzman , Rosales Arnoldo Michel , Juarez Francisco Radillo , Tene Marcelino Bazan , Cervantes T. Fernando
Published: February 2019

The most common spread of this species is sexual or by seed. In normal conditions, the germination of the seeds of Anonaceae can increase with pregerminative treatments prior to sowing. The objective was to determine the best pregerminative treatment to increase germination of soursop seeds. This study was carried out under the the dry, tropic conditions of Tecomán, Colima, Mexico. The experimental design was completely random with 12 treatments: 1) dip in water for 24 hours; 2) dip in water for 24 hours + gibberellic acid (GA3) at 350 ppm; 3) dip in water for 24 hours + GA3 at 500 ppm; 4) dip in water for 24 hours + GA3 at 1000 ppm; 5) mechanical scarification; 6) dip in water for 24 hours + mechanical scarification; 7) mechanical scarification + GA3 at 350 ppm; 8) mechanical scarification + GA3 at 500 ppm; 9) mechanical scarification + GA3 at 1000 ppm; 10) GA3 at 350 ppm; 11) GA3 at 500 ppm; and 12) GA3 at 1000 ppm; and control. There were four repetitions with 10 seeds in each experimental unit. The evaluated variables were the percentage of germination and the number of days from planting to emergence. To record results, analysis of variance and Tukey's test averages were used. The major percentage of germination resulted from the seeds treated with soaking in water for 24 hours plus GA3 to 350 ppm, dip in water for 24 hours plus scarification and GA3 at 1000 ppm, and equalized statistically to the control. For the number of days from planting to emergence, the treatment with mechanical scarification + GA3 at 500 ppm was statistically better. The use of gibberellic acid with mechanical scarification diminishes the dormancy of soursop seeds, producing plants in a relatively short period.
(339) Preemergence Weed Control in Container-grown Herbaceous Perennials
Authors: Klett James E. , Staats David , Rogoyski Matt
Published: February 2019

During the 2004 season, preemergence herbicide was applied to 12 container-grown herbaceous perennials and woody plants and evaluated for weed control, phytotoxicity, and effect on plant growth. The herbicide and rates were: pendimethalin (Pendulum 2G) 908 g (label rate), 1816 g, and 3632 g/acre a.i. Herbicides were applied to lady's mantle (Alchemilla mollis), purple rock cress (Aubretia species), blue wild indigo (Baptisia australis), pink pussytoes (Antennaria dioica var. rosea), common sneezeweed (Helenium autumnale), redhot poker (Kniphofia uvaria), showy goldenrod (Solidago speciosa), heartleaf foamflower (Tiarella cordifolia), lavender (Lavendula angustifolia), blue flax (Linum perenne), catmint (Nepeta ×faassenii), and hen and chicks (Sempervivum tectorum). At 32 and 117 days after application, plants were evaluated for phytotoxicity. No phytotoxicity symptoms were apparent on any of the plants tested. Weed control was good in most cases with this herbicide but it did not control all weeds. Increasing the rates from 1× (label rate) did not significantly improve weed control.
(310) Peach Orchard Systems Management Trial: The First Six Years
Authors: Layne Desmond R. , Hitzler Eric J.
Published: February 2019

In 1999, a trial was established at the Clemson University Musser Fruit Research Farm to investigate the effects of training system/tree density, rootstock, and irrigation/fertilization on tree growth, productivity and profitability. The replicated trial comprised three training systems/tree densities (open center–332 trees/ha; quad V–664 trees/ha; and perpendicular V–996 trees/ha). The two rootstocks used were Lovell and Guardian. Three irrigation/fertilization treatments included: natural rainfall only plus granular program; supplemental irrigation plus granular; and supplemental irrigation plus fertigation at a reduced nitrogen rate from the granular program. The scion was the popular midseason cultivar Redglobe. There were a total of 18 treatment combinations replicated 4 times with 5 trees per treatment plot. Soil moisture was determined by TDR and pan evaporation monitored by weather station. Seventy-two minirhizotron tubes were installed in 2002 to monitor fine root growth. During 1999–2001, drought conditions limited rainfall to 35% below the annual average. Spring freeze events in 2001 and 2004 reduced crop load disproportionately in shorter, open-center trees. As tree density within the tree row increased, trunk cross sectional area (TCA) decreased. Trees on Guardian rootstock had significantly greater TCA than Lovell each year. Trees that received supplemental irrigation had greater TCA than nonirrigated trees each year. By reducing N rate through fertigation, TCA was reduced. Cumulative yield was not affected by training system/tree density. Cumulative yield was not affected by rootstock. Cumulative yield was 7% greater by supplemental irrigation. Pruning, thinning and harvesting was easier in V-systems than for open center trees.
(312) Replant Apple Tree Performance, and Rhizotron Observations of Root Development, Distribution, and Survival for Three Rootstock Clones in a New York Orchard
Authors: Yao Shengrui , Merwin Ian A. , Brown Michael G.
Published: February 2019

Rhizotron observations enabled us to compare the performance of three apple (Malu ×domestica) rootstock clones following different pre-plant soil treatments in an apple replant study at Ithaca, NY. Trees were planted in Nov. 2001, with one minirhizotron tube per tree in three replicate plots of three rootstocks (M7, CG30, and CG6210), three pre-plant soil treatments (fumigation, compost amendment, and untreated controls), and two planting positions (within the old tree rows, or in the old grass lanes). Monthly root observations were conducted during the 2003 and 2004 growing seasons. There were substantially fewer new roots observed in the first bearing year (2004) than the previous nonbearing year (2003), for all three rootstocks. A root-growth peak in early July accounted for more than 50% of all new roots in 2003, but there was no midsummer root growth peak in 2004. Neither pre-plant soil treatments nor old row or grass-lane planting positions had much influence on root growth. The median lifespan for roots of CG6210 was twice as long as that of CG30 and M7 in 2004. Also, CG6210 had more roots below 30-cm depth, while M7 had more roots from 11–20 cm. Trees grafted on CG6210 were bigger and yielded more fruit in the third year after planting, compared with trees on CG30 and M7 rootstocks. Crop load severely inhibited new root development and changed root-growth dynamics during the first cropping year, with a surge in root growth after fruit harvest in Oct. 2004. Rootstock genotype was the dominant influence on root lifespan and distribution, compared with pre-plant soil fumigation, compost amendments, or replanting positions within the previous orchard rows or grass lanes.
(313) Climatic Effectson Four Low-chill Peach Cultivars in North Central and Central Florida
Authors: Wert Todd , Williamson Jeffrey G. , Rouse Robert E. , Miller E. Paul
Published: February 2019

Four low-chill peach cultivars were evaluated for vegetative and reproductive growth, fruit quality, and yield in north central and central Florida. Twenty-trees (five of each cultivar) were planted at each site in Feb. 2002. Prior to budbreak in the spring of 2004 and 2005, three shoots of average length and diameter were selected at a height of 1.5–2.0 m and the number of vegetative and flower buds was recorded for each shoot. Percentage of bloom was estimated, and the number of open flowers on selected shoots was measured weekly. Trees were harvested twice per week starting in mid-April in central Florida, and in late April in north central Florida. Total number and weight of marketable fruit was measured for each tree. Ten representative fruits were selected from each tree at each harvest. Fruit were measured for blush, weight, and size. Soluble solids, TAA, and pressure were determined for five fruit from each 10-fruit sample. Preliminary results indicate a higher mean number of blind nodes in central Florida and a higher mean number of flower buds in north central Florida. In central Florida, 90% bloom was about 4 days earlier than north central Florida. Fruit number and individual fruit size, weight, and marketable yield were higher in north central Florida than in central Florida. Fruit blush was higher in central Florida than in north central Florida and tended to increase as the season progressed. In north central Florida, blush decreased slightly throughout the season.
(315) Geneva® 935: A New Fire Blight Resistant, Semidwarfing Apple rootstock
Authors: Fazio Gennaro , Aldwinckle Herb S. , Robinson Terence L. , Cummins James
Published: February 2019

The Geneva® Apple Rootstock Breeding program, which was initiated in 1968 by Dr. James Cummins and Dr. Herb Aldwinckle of Cornell University and which has been continued as a joint breeding program with the U.S. Dept. of Agriculture Agricultural Research Service (USDA-ARS) since 1998, has released a new semi-dwarfing apple rootstock which is named Geneva® 935 or G.935. G.935 (a progeny from a 1976 cross of `Ottawa 3' × `Robusta 5') is a selection that has been widely tested at the New York State Agricultural Experiment Station in Geneva, N.Y., in commercial orchards in the United States and at research stations across the United States and Canada. G.935 is a semi-dwarfing rootstock that produces a tree slightly larger than M.26. G.935 is the most precocious and productive semi-dwarf rootstock we have released. It has had similar yield efficiency to M.9 along with excellent fruit size and wide crotch angles. It showed no symptoms of winter damage during the 1994 test winter in N.Y. G.935 is resistant to fire blight and Phytophthora; however. it is susceptible to infestations by woolly apple aphids. G.935 has shown tolerance to replant disease complex in several trials. It has good propagation characteristics in the stool bed and produces a large tree in the nursery. G.935 has better graft union strength than M.9, but will require a trellis or individual tree stake in the orchard to support the large crops when the tree is young. G.935 will be a possible replacement for M.26. Suggested orchards planting densities with this rootstock are 1,500-2,500 trees/ha. It has been released for propagation and sale by licensed nurseries. Liners will be available in the near future.
(316) Development of Rootstocks to Promote Early Bearing in Pawpaw
Authors: Pomper Kirk W. , Crabtree Sheri B.
Published: February 2019

The propagation of clonal rootstocks for the pawpaw [Asimina triloba (L.) Dunal] has been unsuccessful; therefore, nurseries currently graft cultivars onto rootstock derived from locally available seed of diverse genetic origin. Great variation in pawpaw scion growth and suckering is observed with this seedling rootstock and grafted trees are also slow to come into production, often producing fruit 5 to 6 years after planting. In an effort to develop superior seedling rootstocks for pawpaw cultivars, seedstock was evaluated from the cultivars PA-Golden (#1), Sunflower, Susquehanna, NC-1, K8-2, and commercially available seed (RVT). The objectives of the experiment were to determine if: 1) genotype and seed size influenced vigor of greenhouse-grown container seedlings; 2) graft compatibility and growth rate of scions would vary by rootstock; and 3) scion precocity was influenced by various seedling rootstocks in the field. Greenhouse experiments were conducted in 2002, 2003, and 2004, and each year all seedstocks had a high germination percentage (95%) and uniform size within each seedstock. Seed size was an important factor in determining vigor in container production. Seed of `Sunflower' was large (1.65 g/seed) and consistently produced vigorous seedlings that were able to be chipbudded within 6 months. Seed of the selection K8-2 was smallest (0.94 g/seed) and showed the least vigor. Bud take was similar for the scions `Sunflower' and `Susquehanna' on all rootstocks. Twenty-one weeks after budding, scions of `Sunflower' were about 30% larger than scions of `Susquehanna'; however, source of seedling rootstock did not affect growth of either cultivar. Field evaluations have begun with the two cultivars budded onto the six rootstocks.
(318) Influence of Orchard Site Parameters and Fruit Distribution within Canopy on Fruit Quality of `Fuji' Apple
Authors: Cmelik Zlatko , Tojnko Stanislav
Published: February 2019

Canopies of `Fuji' apple trees, grafted on M.9 rootstock, planted in 1998 on two orchard sites at 2.8 × 0.7 m and trained as super spindles, were subdivided in Spring 2003 into upper and lower parts. In each part, the number of fruits, yield per tree, external (fruit size classes, and fruit coloring), and internal (total sugar content, titratable acid content, and flesh firmness) fruit quality attributes were determined. The orchard site parameters affected growth, yield, and fruit quality in different ways. The less suitable orchard site had less growth, lower yield per tree, and a lower percentage of first class fruits, but most fruits had good color (86% in top and 75% in lower part of canopy). The favorable orchard site produced higher growth and yield, and a higher percentage of first class fruits, but fruits had poorer color. In the lower part of the canopy, fruits were of a good size, but had poor color. Fruits of the best quality were obtained from the top part of the tree.
(358) A GIS Approach to Managing the Invasive Species of Texas
Authors: Spencer William , Williams Justin
Published: February 2019

The state of Texas consists of roughly 4800 species of vascular plants. In 1970, it was estimated that 200 of these were introduced species. By 2003, the number of introduced species almost doubled to 350. Using the Atlas of the Vascular Plants of Texas, a database was compiled listing the invasive species in Texas and which of the 254 counties they inhabited. This database was then converted into a GIS platform that allowed us to analyze those data spatially. With these data, we were able to calculate the actual number of invasive species per county. In addition, these data were used to predict possible points of invasive species introduction, the rate of spread for certain problematic species, routes of migration, and to isolate counties under threat of possible infestation.
(38) Carbohydrate Content in Leaves of Three Poinsettia Cultivars (Euphorbia pulcherrima) Grown at Two Locations
Authors: Colinas-Leon Maria-Teresa , Alia-Tejacal Iran
Published: February 2019

In Mexico, poinsettia plants are grown under very different and changing environments, thus influencing their metabolism and changing the sugar content that is important in leaf and bract longevity. In the present study, the content of total soluble and reducing sugars and starch was evaluated in leaves of three cultivars, `Marmol', `Supjibi', and V-17 `Angelika', in two contrasting environments: Cuautla, Morelos [24.6 °C, 74% relative humidity (RH), lat. 18°49'N; 1300 msl], and Texcoco, Mexico (14.6 °C, 61.6% RH, lat. 19°31'N; 2310 msl). Plants were grown under greenhouse conditions in 6-inch pots; the substrate and cultural practices were similar in both locations. In Texcoco, plants were covered with black plastic for 12 hours at night to control growth and flowering initiation (15 Sept. to 12 Nov.). In Cuautla, this was not necessary. Leaf samples were taken 8 days after initial covering of plants in Texcoco (84 days after transplant) and 155 days after transplant, when plants were ready for sale. Total soluble sugars were reduced between 84 and 110 days after transplant in leaves of `Supjibi' and `V-17' cultivars independently of the location, while changes in `Marmol' were minimal between days 84 and 155. Significant statistical differences were found for leaf total soluble sugars between locations, being higher in Cuautla, Morelos. For reducing sugars, no differences were detected among cultivars and for the two locations.
(40) A Procedure for Quantitation of Fatty Acid Precursors in Relation to Capsaicinoid Accumulation in Pepper Fruits
Authors: Maruthavanan Janakiraman , Maness Niels , Chrz Donna
Published: February 2019

The pungency in hot peppers [Capsicum annuum (L.) var. annuum] is mostly due to two capsaicinoids, capsaicin (CAP) and dihydrocapsaicin (DC), which are amide derivatives of vanillylamine and 8-methyl-6-nonenoic acid (E) or 8-methyl-nonanoic acid (A), respectively. During our investigation of the mechanism of capsaicinoid-specific metabolism in pepper fruit, we have developed a method to extract, purify, and quantitate these fatty acids from the free fatty acid pool in placental tissue. Fresh placenta was ground using a mortar and pestle and extracted with diethyl ether. Fatty acids were methanolysed and fatty acid methyl esters were quantitated using GC with capric acid as internal standard. Capsaicinoids accumulated in the same placenta were extracted with N,N-dimethylformamide (DMF) and quantitated using HPLC. The lipid fraction had to be separated from capsaicinoids, since capsaicinoids yielded about 10% of their respective fatty acids during methanolysis. An aminopropyl column was used to separate capsaicinoids from free fatty acids. Extraction recovery for both fatty acids was greater than 70%. This procedure is being used to quantitate fatty acid precursors for capsaicinoid biosynthesis in pepper placenta. We will demonstrate use of this procedure with pepper selections varying in CAP/DC ratio to evaluate the effect of metabolic precursors on capsaicinoid metabolism.
(43) Maturity Influences Lycopene Segregation during Filtration Processing of Red-fleshed Watermelons
Authors: Oikonomakos Ioannis P. , Maness Niels O. , Chrz Donna , McGlynn William , Perkins-Veazie Penelope
Published: February 2019

Lycopene from ground watermelon flesh can be segregated between filtrate and filter cake by coarse filtration. Low speed centrifugation of the filtrate can further segregate filtrate lycopene between an easily recoverable precipitated high lycopene pellet and a serum. Lycopene in watermelon flesh increases steadily during maturation and remains constant, or slightly decreases in overripe melons. This study was conducted to document the effect of melon maturity on lycopene segregation during filtration/centrifugal processing. Flesh of three seedless watermelon cultivars was ground and filtered through two layers of Miracloth. Filter cakes were rinsed with water and filtrates were centrifuged at 3500 g to precipitate lycopene. Centrifugal recovery of lycopene from filtrates was about the same for undermature and mature melons (50% to 70%), but was much lower for overripe melons (35% to 45%). This decline in recoverable lycopene from overripe melons could be negated if ground flesh was heated to 60 or 85 °C prior to filtration. Lycopene from preheated flesh segregated predominately into the filter cake for all three maturity groupings. The interaction between melon maturity and pre-filtration heating will be evaluated and integrated into a potential watermelon lycopene production system.
(189) Heirloom Tomato Cultivar Evaluations for the New Jersey Market
Authors: Kline Wesley , Nitzsche Peter
Published: February 2019

A 3-year study was established to evaluate a large number of heirloom tomato cultivars for horticultural characteristics and yield. The initial 2001 screening included 110 cultivars with fruit types from currant to beefsteak. The 110 cultivars were reduced to 12 (`Arkansas Traveler', `Box Car Willie', `Brandywine Red', `Carmello', `Cherokee Purple', `Costoluto Genovese', `Eva Purple Ball', `Hawaiian Pineapple', `Mortgage Lifter', `Prudens Purple', `Ramapo', and `Santa Clara Canner') based on yield, consumer preference and fruit characteristics and evaluated in 2004. The cultivars were arranged in a complete-block design with plots of eight plants replicated four times. Fruits were harvested 10 times from 15 July to 16 Sept., graded into marketable and cull, counted, and weighed. Internal and external fruit characteristics were evaluated at the seventh harvest from 10 randomly selected marketable fruit from three replications. Days to harvest from transplanting ranged from 61 to 82 days. For the early harvest (1–4), `Mortgage Lifter' (20.18 t·ha-1) and `Cherokee Purple' (19.23 t·ha-1) had significantly more marketable fruit than the other cultivars. By mid-season harvests (5–7), the cultivar Carmello (43.38 t·ha-1) yielded statistically more marketable fruit than all other cultivars. There were few differences among the cultivars for the late harvest (8-10) period. When all harvests were combined, `Carmello' (76.59 t·ha-1) had significantly higher yields than the other cultivars except `Mortgage Lifter' (74.72 t·ha-1). External and internal fruit characteristics varied among the various cultivars. All 12 cultivars would be acceptable in different market segments.
(191) Vegetative and Productive Components of Genotypes of Red Tomato (Lycopersicon esculentum Mill.) under Greenhouse Conditions
Authors: Juarez Francisco Radillo , Gonzalez Juan Manuel González , Tene Marcelino Bazan , Garcia Luis Fernando Velasco
Published: February 2019

In world production of vegetables, the red tomato contributes 47% of the total production and occupies second place in world consumption. The objective of this research was to evaluate 13 genotypes of red tomato with high technology for horticultural production in the greenhouse. This study was realized in “Zamora” greenhouses in Quesería-Montitlán, Colima, Mexico. The evaluated materials were: `Sun', D-0289, D-2465, D-2467, D-2475, D-2503, D-2505, D-2512, D-2515, D-2534, D-2541, D-2552, D-7705, and, as control, the `Roman' variety. The tallest height was that of `Roman' plants, 2.46 m, vs. the height of the first cluster of fruits in D-2575 with 51 cm. With respect to largest number of fruits per cluster and total harvested, D-0289 stood out with four and 18 fruits per plant, respectively. In regard to fruit size, the genotypes D-0289 and D-2534 presented the largest equatorial and polar diameter, with 19.2 and 14.2 cm, respectively. For fruit weight, the genotypes `Sun' and D-0289 presented the largest weight with 160 and 151 g, respectively. We conclude that agronomic management influences production under technical systems. For vegetative and productive desirable characteristics, the genotypes `Roman', D-0289, and D-77055 were the more adaptable for production in the greenhouse.
(388) Media Type and Moisture Influence Growth and Development of Ginger (Zingiber officinalis) Propagules
Authors: Marsh Lurline , Cotton Corrie , Philip Elizabeth , Aighewi Isoken
Published: February 2019

Ginger(Zingiber officinalis) is a spice crop with a variety of medicinal uses. Potentially, it may be suitable for ethnic production following necessary studies to determine optimum cultural conditions. The propagation of ginger from rhizomes was investigated using three growth media, three media moisture levels, and two types of propagules. The media were poultry compost amended with peat and perlite in a volume ratio of 2:1:1, municipal yard waste compost, and the commercial mix Promix. The moisture levels of each medium were: no applied water, moderately watered (between wilting point and field capacity), and field capacity, which represented moisture tension levels of >–1.5, –0.08, and –0.03 MPa, respectively. Growth from single-node rhizome propagules and large pieces of 5.6 to 7.6 cm long with one or more nodes was determined over 90 days. The large propagules and the field capacity moisture regime produced the tallest shoots, and largest number of shoots and leaves per propagule, as well as the highest percentages of secondary rhizomes, root, and shoots per propagule. The yard waste and Promix were superior to poultry compost in the development of the propagules for all the traits measured. The large propagules produced earlier shoot emergence at field capacity than at the moderate moisture levels. Single-node propagules generally failed to emerge without applied moisture or when in poultry compost.
(389) Enhanced Growth in Acclimatization of In Vitro Plantlets of Wasabi japonica using Hydroponics
Authors: Lee Joo Hyun , Lee Yong-Beom , Lee Kyu Sook
Published: February 2019

Wasabi japonica plantlets were acclimatized in a hydroponic system to determine effective procedures. The plantlets were cultured on solid Murashige-Skoog medium with 3% sucrose. Shoots that formed roots were transplanted into hydroponic systems: 1) acclimatization in ebb-and-flow (EBB) for subirrigation (medium: granulated rockwool and coir); and 2) acclimatization in deep flow technique (DFT). The plantlets were acclimatized for 5 weeks under two irradiance treatments, 50 and 300 mmol·m-2·s-1. Photosynthetic capacity in high PPF was higher than that in low PPF during acclimatization. Electron transport rate from PS II (ETR) and biomass production increased significantly with increased light availability. The fresh weight, dry weight, and leaf area of plantlets in high PPF were higher than those in low PPF. In particular, the dry weight and ETR of the plantlets grown in high PPF increased more than twice as much as those in low PPF. At 50 mmol·m-2·s-1 PPF, growth indexes, such as number of leaves, leaf length, leaf width, leaf area, fresh weight, and dry weight, were higher in EBB (granulated rockwool) > EBB (coir culture) > DFT. At 300 mmol·m-2·s-1 PPF, those indexes were higher in DFT > EBB (granulated rockwool) > EBB (coir). The Wasabi japonica plantlets acclimatized in a hydroponic system also had a superior performance when they were transferred to the field.
(396) Growth of American Mayapple Rhizome Segments Affected by Time of Transplant
Authors: Cushman Kent , Maqbool Muhammad
Published: February 2019

American mayapple (Podophyllum peltatum) is being investigated as a domestic, renewable, and alternative source of podophyllotoxin, a precursor compound used in the manufacture of several drugs. Indian mayapple (P. emodi) is the current source of the compound. The objective of this study was to examine growth of transplanted rhizome segments of American mayapple at four transplant times during the year. Two-node rhizome segments were carefully dug with roots intact from naturally occurring wild populations near Holly Springs, Miss. Segments were dug in Oct. 2002, Dec. 2002, Feb. 2003, or June 2003. Within 1 day of each harvest, segments were transplanted into 1-gal pots containing a mixture of sandy soil and a finely ground pine bark mulch. Pots were then set in a raised bed, such that the soil surface within the pots was even with that of the plant bed. Pots and plant bed then received a 3-inch layer of pine bark mulch. Rhizome segments were harvested from pots four times during the year following the date of transplant. Rhizome and roots were separated according to new or old growth and then dried. Rhizome segments transplanted during October and December increased about 36% in dry mass during the 1-year period after transplant. This was significantly greater than an increase of 12% for segments transplanted during June. Segments transplanted during February performed intermediately, increasing by 22%. Our results show that rhizome segments of American mayapple performed better when transplanted during fall and winter compared to those transplanted during summer. Segments transplanted during spring performed intermediately.
(448) Arbuscular Mycorrhizal Fungi Enhance Tolerance of Rosa multiflora cv. Burr to Bicarbonate in Irrigation Water
Authors: Cartmill Andrew D. , Davies Fred T. , Alarcon Alejandro , Valdez-Aguilar Luis A.
Published: February 2019

Sustainable horticultural production will increasingly have to rely on economically feasible and environmentally sound solutions to problems associated with high levels of bicarbonate (HCO -3) and associated high pH in irrigation water. The ability of arbuscular mycorrhizal fungi (AMF; GlomusZAC-19) to enhance plant tolerance to HCO3- was tested on the growth, physiology and nutrient uptake of Rosamultiflora Thunb. ex J. Murr. cv. Burr (rose). Arbuscular mycorrhizal colonized and noninoculated (non-AMF) plants were treated with 0, 2.5, 5, and 10 mm HCO -3. Increasing HCO -3 concentration and associated high pH and electrical conductivity (EC) reduced plant growth, leaf elemental uptake and acid phosphatase activity (ACP), while increasing alkaline phosphatase activity (ALP). Inoculation with AMF enhanced plant tolerance to HCO -3 as indicated by greater plant growth, leaf elemental uptake (N, P, K, Ca, Fe, Zn, Al, Bo), leaf chlorophyll content, higher mycorrhizal inoculation effect (MIE), lower root iron reductase activity, and generally lower wall-bound ACP (at 2.5 mm HCO3-), and higher soluble ALP (at 10 mm HCO3-). While AMF colonization (arbuscules, vesicles, and hyphae formation) was reduced by increasing HCO -3 concentration, colonization still occurred at high HCO -3. At 2.5 mm HCO3-, AMF plant growth was comparable to plants at 0 mm HCO3-, further indicating the beneficial effect of AMF for alleviation of HCO3- stress.
(452) Growth Responses of Salvia greggii and Dalea frutescens to Drought Stress
Authors: Niu Genhua , Rodriguez Denise S.
Published: February 2019

Salvia greggii (salvia) and Dalea frutescens (dalea) are two popular shrubs. However, little information is available on their drought tolerance. The objectives of this study were to investigate the effect of various degrees of water stress on growth and to characterize the dynamics of water relations to root substrate water content for developing best irrigation management. Salvia and dalea plants in 12-L plastic containers were grown in a greenhouse and pruned to one node at the base of the soft shoots for salvia or at the same height for dalea prior to the start of the experiment. There were three irrigation regimens: plants were irrigated daily (control), or irrigation was withheld until moderate or severe water stress signs exhibited. After several weeks of intermittent cyclic dry-down irrigation regimens, total shoot number per container was reduced by 40% to 50% for salvia and 35% to 40% for dalea. Average shoot length was reduced by 35% to 45% for salvia and 50% to 65% for dalea in moderate and severe stressed treatments compared to the control. Drought stress resulted in less shoot elongation and fewer new shoots in both species. To examine the relationship between plant water status and substrate water content, a dry down test was performed on five well-watered plants by withholding irrigation until midday water potential dropped to below –4 MPa. As substrate water contents in both species reached 8%, the predawn water potentials did not recover from the midday water potential of the previous day, indicating there was no available water in the substrate for roots to take up. The drought tolerance of these two species needs further study using various growing media.
(319) Mycorrhizal Symbiosis and Response of Sorghum Plants to Combined Drought and Salt Stresses
Authors: Augé Robert , Cho Keunho , Stutz Jean , Toler Heather
Published: February 2019

Colonization of roots by arbuscular mycorrhizal (AM) fungi can increase host resistance to drought stress, although the effect is unpredictable. Since AM symbiosis also frequently increases host resistance to salt stress, and since drought and salt stress are often linked in drying soils, we speculated that the AM influence on plant drought response may be linked to AM influence on salt stress. We tested the hypothesis that AM-induced effects on drought responses would be more pronounced when plants of comparable size are exposed to drought in salinized soils. In two greenhouse experiments, several water relations characteristics were measured in sorghum plants colonized by Glomus intraradices, Gigaspora margarita, or a mixture of AM species during a sustained drought following exposure to salt treatments (NaCl stress, osmotic stress, or soil leaching). The presence of excess salt in soils widened the difference in drought responses between AM and non-AM plants in just two instances: days needed for plants to reach stomatal closure, and promotion of stomatal conductance. In other instances, the addition of salt tended to nullify an AM-induced change in drought response; e.g., an AM effect on the decline in leaf or soil water potential required to cause stomatal closure disappeared when soils were salinized. Our findings confirm that AM fungi can alter host response to drought but do not lend much support to the idea that AM-induced salt resistance might help explain why AM plants can be more resilient to drought stress than their non-AM counterparts.
(324) Irrigation Effects on Fine Root Dynamics in Peach (Prunus persica)
Authors: Wells Christina , Layne Desmond
Published: February 2019

We are using a minirhizotron camera system to observe fine root dynamics beneath irrigated and nonirrigated peach trees. Our long term goals are: 1) to relate the timing of fine root production to tree phenology, soil water content, and soil temperature; and 2) to determine how fine root architecture and demography differ between trees with and without supplemental irrigation. In early 2002, minirhizotrons were constructed and installed beneath each of 72 open-center, 4-year-old `Redglobe' peach trees at the Musser Fruit Research Farm near Clemson University. Beginning in May 2002, videotaped images from each minirhizotron were collected at 2-week intervals; notes on tree phenology were also recorded biweekly. Videotapes were digitized in the lab, and information on root length, diameter, appearance and longevity was extracted from the images. Soil temperature and volumetric water content were measured in the orchard throughout the growing season. In the 2 years following minirhizotron installation, irrigated trees allocated a significantly greater percentage of their fine root length to the upper soil layers and exhibited less root branching than nonirrigated trees. Fine roots produced by irrigated trees lived significantly longer: irrigated trees had a median root life span of 165 days, while nonirrigated trees had a median root life span of only 115 days (P< 0.001; proportional hazards regression). Fine roots from irrigated trees remained in the physiologically active “white” state for an average of 10 days longer than roots from nonirrigated trees (P< 0.001). Data from 2002–03 indicate that the trees produce new root flushes at least three times during the year, with a significant flush occurring immediately after harvest.
(7) Molecular Phylogenetic Analysis of Genes of the Carotenoid Pathway in Cucurbita
Authors: Rivera-Hernández Marilyn , Wessel-Beaver Linda , Chaparro José X.
Published: February 2019

Squash and pumpkins (Cucurbita sp.) are important contributors of beta-carotene to the diet. Consumers of tropical pumpkin and butternut squash (both C. moschata Duchesne) prefer a deep orange mesocarp color. Color intensity is related to carotene content. Among the five domesticated Cucurbita species, C. moschata and C. argyrosperma Huber have a close relationship. In crosses between these two species, fertile F1 plants can be easily obtained when using C. argyrosperma as the female parent. This research studied the relationship between and within C. moschata and C. argyrosperma by sequencing three genes in the carotenoid biosynthesis pathway and generating gene trees. Genotypes used in the study differed in flesh color from very pale yellow to dark orange. In some cases, haplotypes were associated with a particular mesocarp color. Further study of these types of associations may improve our understanding of color development in Cucurbita. The frequency of single nucleotide polymorphisms (SNPs) in the sequenced fragments was low. There were more SNPs and more heterozygotes among C. moschata accessions than among C. argyrosperma accessions. Haplotypes of the outgroups (C. ficifolia C.D. Bouché and C. maxima Duchesne) were always distinct from C. moschata and C. argyrosperma. These later species had both distinct haplotypes and shared haplotypes. Haplotypes shared among species tended to be maintained in the same branch of the phylogenetic tree, suggesting either gene flow between the species or a common ancestral gene. Both explanations suggest a close genetic and evolutionary relationship between C. moschata and C. argyrosperma.
(9) Compositional Characterization of a Garlic Germplasm Collection
Authors: Cantwell Marita , Hong Gyunghoon , Voss Ron
Published: February 2019

A USDA germplasm collection of garlic (Alliumsativum) and related species (A. ophioscorodon, A. longicuspis) has been evaluated for horticultural characteristics and composition under California production conditions for several years. In 2004, 198 of the 217 accessions in the collection were evaluated. Bulbs were manually harvested late June to early July, cured about 3 weeks shaded at ambient temperatures, and the outer whorl of cloves manually peeled. Bulb and clove weights and percentage of dry matter were determined. Freeze-dried garlic powder was analyzed for alliin (precursor of flavor and health compounds) concentrations by HPLC. Thiosulfinates (mostly allicin, responsible for flavor and pungency) were determined by a spectrophotometric assay. Among the accessions evaluated in 2004, the percentage of dry matter ranged from 32.8% to 44.9%. Alliin content varied from 8.9 to 29.7 mg·g-1, and thiosulfinate concentrations ranged from 32.7 to 114.0 μmol·g-1. For comparison, the widely grown varieties California Early and California Late averaged 39.5% and 40.8% dry matter, 18.6 and 20.6 mg·g-1 alliin, and 68.1 and 78.8 μm·g-1 thiosulfinates.
(10) Four Genes Controlling Watermelon Fruit and Seed Traits
Authors: Gusmini Gabriele , Wehner Todd C.
Published: February 2019

Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] is a diverse crop, with much variability for fruit and seed traits. This study measured the inheritance of scarlet red flesh color, egusi seed type, yellow belly (ground spot) rind pattern, and intermittent stripes on the rind. Scarlet red is a dark red flesh color found in `Dixielee' and `Red-N-Sweet'. Egusi seed is an unusual mutant having a fleshy pericarp adherent to the seed coat found in PI 490383 and PI 560006. Yellow belly is found in `Black Diamond, Yellow Belly'. Intermittent stripes are found in `Navajo Sweet', which has narrow dark stripes that are irregular or nearly absent across the fruit. In order to study the inheritance of these traits, six generations, including parents, crosses, and backcrosses (Pa, Pb, F1, F2, BC1Pa, BC1Pb), were produced in each of seven crosses. Phenotypic data were recorded in the field, and analyzed with the Chi-square method for the segregation of Mendelian genes. Scarlet red color in `Dixielee' was allelic to scarlet red color in `Red-N-Sweet'. Four new genes were identified and named, in conformance with gene nomenclature rules for Cucurbitaceae: Scr for scarlet red, eg for egusi seed, Yb for yellow belly, and ins for intermittent stripes. Thus, we have added four new genes to the 52 morphological and disease resistance genes already published.
(85) Establishment of Seeded Bermudagrass following Preplant Application of Transition Herbicides
Authors: Brewer Shawn , Maurer Michael
Published: February 2019

Transition of perennial ryegrass from bermudagrass athletic fields in the spring delays the establishment of bermudagrass when the establishment period is limited. The objective of this field study was to determine the effects of transition herbicides on the establishment of seeded bermudagrass. Treatments consisted of an untreated control, foramsulfuron, rimsulfuron, trifloxysulfuron sodium, metsulfuron methyl methyl, isoxaban, and oxadiazon at low- and high-labeled rates for transitioning perennial ryegrass. `Riviera' bermudagrass [Cynodon dactylon (L.) Pers.] seed was seeded immediately after treatment and 2 weeks after treatment. Turfgrass coverage was evaluated visually and by digital analysis. Although differences between methods of turfgrass coverage evaluation varied, the differences between treat-ments were similar. There was no significant differences in turfgrass establishment between foramsulfuron, rimsulfuron, trifloxysulfuron sodium, metsulfuron methyl methyl, and the control for either seeding date or rate. Turfgrass coverage was significantly less for isoxaban and no turfgrass was established in the oxadiazon treatments. Initial results of this research indicate that bermudagrass seed can be seeded immediately following the application of foramsulfuron, rimsulfuron, trifloxysulfuron sodium, and metsulfuron methyl methyl.
(86) Seed Germination and Seedling Survival of Alnus maritima (Seaside Alder) in Three Soils in Northern Utah
Authors: Kratsch Heidi A.
Published: February 2019

Alnusmaritima may have potential for use in home and commercial landscapes in northern Utah. This fast-growing, fall-blooming shrub is cold-hardy to USDA hardiness zone 3b and tolerant of nutrient-poor soils and full sun. Because this taxon is native to low-elevation wetlands, I seek to determine its response to the high desert soils and climate of northern Utah. My specific objective was to test germination and survival of plants from seed sowed in three diverse soil types typical of the Wasatch front in north-central Utah. Seeds were rinsed with distilled water and cold-stratified in darkness for 16 weeks between wet filter paper in sealed petri dishes. Stratified seeds were sowed in flats filled with soil from each of three sites at the Utah Botanical Center in Kaysville and held in a greenhouse. Seeds planted in flats filled with soilless germination mix served as controls. Flats with 60 seeds were experimental units, and each medium was replicated three times. Soils ranged from silty loam to loam, nitrate-N was 3.2 to 5.4 mg·kg-1, and there was 1.4% to 2.9% organic matter. Germination rates were highest in the soilless mix (50%). Of the three soil types, the highest germination rates (24%) occurred in a loamy soil high in organic matter (2.9%). Rates were similar (12.5% and 13%) in the other two soils. Seeds of A. maritima can germinate in soils typical of urban landscapes in northern Utah, so both the potential for invasiveness and the performance of plants in the landscape of northern Utah are being evaluated.
(88) The Expressway Partnership: Greening Chicago's Highways
Authors: Shirazi A.M. , Dunn C.P.
Published: February 2019

The Expressway Partnership (a project of the Chicagoland Chamber of Commerce's Gateway Green Committee) is an urban landscape project that promises to change the face of the city's expressways. The Morton Arboretum's Urban Horticulture Research Lab., with the support of ComEd (Excelon Corp.), since 2001 has been selecting, planting, and evaluating various cultivars of trees, shrubs, and ground covers in a search for the most suitable and sustainable plantings for the expressway environment. About 470 trees and shrubs were planted plus more than 10,000 groundcovers. In May 2002 these plants were visually evaluated and ranked from 1–5 with one being in excellent condition and 5 being dead. The control plants planted at Urban Horticulture Research Nursery at the Morton Arboretum had 100% survival. The survival rates for groundcovers were: Euonymusfortunei (Virginia Creeper) and Hemerocallis×daylily (day lily) had 80% to 90% survival rates, respectively. Pachysandra terminalis (Japanese spurge) plants died due to either de-icing salt sensitivity, or poor weed control. Syringa pekinensis (Peking lilac), as well as four Syringa cultivars, `President Grevy', `Summer Charm', `Charles Joly', and `James Mcfarlane', had a 100% survival rate. Survival rates for other plants were: Malus sargentii (Sargent crabapple) 93%; Robinapseudoacacia (black locust) ∼93%; Malus cultivars ∼75%; and Pinusbanksiana (jack pine) 75%. Cornussericea (red-osier dogwood) covered with 3 inches of mulch had a significantly better survival rate (90% to 100%) than the mulch treatment (60% to 80%). The growth and performance of other trees and shrubs will be also reported. This research will ensure sustainable and esthetic urban expressway plantings, while enhancing Chicago's stature as a significant urban landmark.
(89) A New Granular Herbicide for Container, Landscape, and Field-grown Ornamentals
Authors: Smith Randy , Lickfeldt Darin , Loughner Dan , Melichar Mike , Breuninger James
Published: February 2019

In 2003 and 2004, a new herbicide containing three active ingredients was evaluated for efficacy on important weed species and the tolerance of popular ornamental plant species. Currently available ornamental herbicides differ greatly in the weeds they control and tolerance of ornamental plants grown in production nurseries. This new granular product, trade name Showcase, also known by its experimental number, GF-1162, contains 2% trifluralin, 0.25% isoxaben, and 0.25% oxyfluorfen. With preemergent applications applied to pots artificially infested with weed seed, GF-1162 demonstrated exceptional control of many difficult to control species, such as spurge, groundsel, bittercress, oxalis, and crabgrass. When applied preemergence at 150 lb/acre, GF-1162 was as efficacious as current standards. At 200 lb/acre, weed control was exceptional, exceeding all products included in the trials. Ornamental tolerance to GF-1162 was comparable to that of Snapshot TG, with the exception of whorled plants. On whorled plants, such as daylily and hosta, where granular products can be retained on leaf surfaces, products containing oxyfluorfen must be applied with special precautions to immediately shake or wash granules from leaf surfaces. Even when whorled plants were injured by GF-1162, they did eventually recover. GF-1162 received a federal registration in 2004 and state registrations may be complete as early as Spring 2005, at which time this new herbicide would be made available to ornamental nurseries and lawn care companies as an alternative to current herbicide options.