bluuebunny/crossref_metadata_2025 huggingface dataset:
521 PB 483 RESISTANCE TO EASTERN FILBERT BLIGHT IN CORYLUS SPECIES AND INTERSPECIFIC HYBRIDS
Authors: Coyne Glare J. , Mehlenbacher Shawn A.
Published: February 2019

Eastern filbert blight (EFB) (Anisogramma anomala) is a serious disease of the European hazelnut (Coryls avellana). A single dominant gene for immunity to EFB from C. avellana `Gasaway' is being combined with good nut and kernel traits using a modified backcross approach. Additional sources of resistance would be highly desirable. Clones and seedlings of six other species (C. columa, C. comuta, C. heterophylla, C. sieboldiana, C. amencana, and C. jaquemontii] and a few interspecific hybrid selections were screened in the greenhouse to identify new sources of resistance. C. jacquemontii seedlings and C. columa clones were highly susceptible. C. comuta, C. hetemphylla, and C. sieboldiana clones were resistant, as were 86% of the C. americana seedlings tested. Five C. americana × C. avellana hybrids from New York were resistant under field conditions. One of four C. comuta × C. avellana and two of three C. hetemphylla × C. avellana hybrids were resistant.
524 PB 492 SEVERITY OF BOTRYTIS BLOSSOM BLIGHT DAMAGE ON BLUEBERRY CULTIVARS AND SELECTIONS
Authors: Finn Chad , Koskela Gina , Snead Joseph
Published: February 2019

Infestations of Botrytis blossom blight (Botrytis cinerea) can reduce yields in commercial blueberry fields in the Pacific Northwest. In 1993, environmental conditions during blueberry flowering were ideal for the development of Botrytis. Individual plants were evaluated in a replicated highbush blueberry culture/advanced selection trial (42 clones, 5 reps, 3 plants) in Aurora, Ore. Each plant was evaluated for damage due to Botrytis using a subjective scoring system (1= all flower clusters on plant appear blighted, 5= many blossoms blighted, 9= no blossoms blighted). Many clones showed very little injury. The following clones showed the greatest injury, in decreasing order of severity, NC 2678, `Bluechip', `Bounty', G-805, `Nelson', G-224, `Berkeley', `Sierra', and `Bluegold'. In addition, Botrytis damage was scored on the field collection of Vaccinium at the National Clonal Germplasm Repository. Data from this nonreplicated study will also be presented.
528 PB 522 WILD RIBES OF THE PACIFIC NORTHWEST
Authors: Messinger Wes , Liston Aaron , Hummer Kim
Published: February 2019

The Pacific Northwest boasts a remarkable diversity of wild currants and gooseberries (Ribes). Of nearly 150 species worldwide, 34 occur in the region. All but two infrageneric taxa are represented, including close relatives of the black currants, red currants, and cultivated gooseberries. High ecological diversity parallels this taxonomic diversity: a Ribes species occurs in nearly every terrestrial habitat, from sea level to above treeline, and from swamp to desert. This diversity is a valuable source of agronomically important genes for the plant breeder. In addition, wild Ribes represent a relatively unexplored source of ornamental shrubs. Habit and habitat of a number of species of interest are described and illustrated. An annotated list of species, subspecies, and varieties native to the Pacific Northwest is presented with discussion of taxonomic proximity to Cultivated varieties, range, natural habitat, and ornamental potential.
531 PB 005 PLANT POPULATION AFFECTS THE YIELD AND FRUIT SIZE OF `SUPERSTAR' MUSKMELON
Authors: Scott W.D. , Maynard E.T.
Published: February 2019

Muskmelons (Cucumis melo L. cv. Superstar) were grown at two between-row spacings (1.5 m or 2.1 m) and four in-row spacings (0.6, 0.9, 1.2, or 1.5 m), corresponding to populations from 3074 to 10763 plants ha-1, to determine the influence of row spacing and population on melon growth and yield. The study was conducted at two sites in 1993, one in northern and one in southern Indiana. Numbers of flowers and early season vine growth were not significantly different between treatments. In southern Indiana, the number of fruit harvested per plot increased as in-row spacing decreased; means ranged from 5.2 fruit plot-1 for 0.6 m in-row spacing, to 4.7 fruit for 0.9 m in-row spacing, 3.9 fruit for 1.2 m in-row spacing, and 3.3 fruit for 1.5 m in-row spacing. Harvests were significantly earlier for the 0.6 m in-row spacing. Mean melon weight was significantly greater for 1.5 m in-row spacing, averaging 4.1 kg, compared to 3.8, 3.7, and 3.7 kg for 0.6, 0.9, and 1.2 m in-row spacings, respectively. Between-row spacing did not affect number or weight of melons. There were no significant interactions between in-row and between-row spacings.
536 PB 020 CULTURAL METHODS AFFECTING BELL PEPPER PRODUCTION IN SOUTHEASTERN OKLAHOMA
Authors: Russo Vincent M.
Published: February 2019

Bell pepper yields can be improved if appropriate cultural methods are used. Cultural methods evaluated at the South Central Agricultural Research Laboratory are reviewed. Yields were best from plants grown on soil with deep `A' horizon and soil pH approaching neutral. Fertilizer applied at 1.2 or 1.5 fold the recommended rate did not improve yield. Planting by mid-May was superior to later plantings. Delaying harvest up to 2 weeks after the first fruit reached US # 1 grade improved marketable yield up to 1.8 fold over plants whose harvest was not delayed. This was because crown fruit increased in size and branch fruit attained marketable size. Knowledge of the cultural methods best suited for pepper in a geographical area should aid in increasing marketable yield.
540 PB 052 RESPONSE OF PEJIBAYE TO HERBICIDES AND BLACK POLYPROPYLENE MAT DURING ESTABLISHMENT IN HAWAII
Authors: DeFrank Joseph , Clement Charles R.
Published: February 2019

Pejibaye (Bactris gasipaes, Palmae) is being evaluated for heart of palm production in Hawaii. Yields and weed control were evaluated in response to: oryzalin (4.5 and 9.0 kg ai/ha), oxyfluorfen (0.6 and 1.2 kg ai/ha), paraquat (1.2 and 2.4 kg ai/ha) and woven black polypropylene mat. Four open-pollinated progenies from the Benjamin Constant population of the Putumayo landrace were used as replications. Paraquat was sprayed at 50 day intervals, while the preemergence herbicides were sprayed at 90 day intervals. Harvest started at 18 months after planting out, 17 months after treatment initiation. The polypropylene mat yielded the highest percent harvest (80%), followed by Oxyfluorfen (50%), paraquat (20%), oryzalin (12.5%). There were replication (genotype) effects that suggest varying tolerance to paraquat and oryzalin. Estimated palm heart yields (3731 plants/ha), corrected for % harvest, were highest with polypropylene mat (490 kg/ha), followed by oxyfluorfen 1.2 ai (425 kg/ha) and 0.6 ai (330 kg/ha). Paraquat severely inhibited growth of the suckers that assure future harvests. The performance rating of these weed control treatments was: mat = oxyfluorfen > oryzalin > paraquat.
541 PB 055 PRECOCIOUS RESPONSE OF PEJIBAYE TO LEGUME, GRASS AND BLACK POLYPROPYLENE GROUNDCOVERS DURING ESTABLISHMENT IN HAWAII
Authors: DeFrank  , Clement Charles R.
Published: February 2019

Pejibaye (Bactris gasipaes, Palmae) is being evaluated for palm heart production in Hawaii. Counts of parasitic nematodes and yields at 18 months and weed control were evaluated in response to: Arachis pintoi, Cassia rotundifolia cv. Wynn, Desmodium ovalifolium, Chloris gayana, and woven black polypropylene mat. Four open-pollinated progenies from the Benjamin Constant population of the Putumayo landrace were used as replications. Twenty five percent of the plants were harvested, with means of 5, 20, 15, 15, and 70%, respectively. Individual heart weights did not vary significantly among treatments (mean = 169 g). Actual yields were significantly different, with means of 31, 125, 92, 99, and 440 kg/ha, respectively. All vegetative ground covers competed with pejibaye for nutrients, which explains the harvest percentages and yields. D. ovalifolium and C. gayana provided acceptable weed control. A. pintoi provided good ground cover, but reduced weed control.
542 PB 058 RELATIVE GREENNESS READINGS OF DRY BEAN CULTIVARS
Authors: Lindgren Dale T. , Coyne Dermot , Nuland David , Clark Ralph B. , Schaaf Dan
Published: February 2019

Color (chlorosis) of eight dry bean cultivars was measured using a Chlorophyll Meter at 5 sites over 2 years in western Nebraska to determine color differences due to cultivars, site, year and iron treatments. There were significance differences between cultivars for color at all sites. However, cultivars were not consistent in color response to iron treatments across all sites. `Spinel' and `Othello' were classified as having darker green foliage while `Steuben Yellow Eye' and `Redkloud' were classified as having lighter green foliage. Correlations between foliage color and yield were greater on sites with higher pH. Selections can be made for bean lines which consistently have darker green foliage color. However, they are not always the highest yielding lines.
543 PB 081 THE EFFECTS OF SOIL TYPE, SULFUR FERTILITY, AND HARVEST DATE ON THE PUNGENCY OF TG1015Y ONIONS
Authors: Hamilton B.K. , Pike L.M.
Published: February 2019

A field study was conducted on TG1015Y onions (Allium cepa L.) grown in the Lower Rio Grande Valley of Texas. Treatments included two soil types (clay & loam), four harvest dates throughout the bulbing process, and two S rates [0 kg S/ha (standard) & 22.4 kg S/ha (high)]. Laboratory analysis included pyruvic acid concentration for pungency measurement, percent dry matter, and sucrose, glucose, and fructose concentrations. Harvest date influenced all variables tested. Percent dry matter generally decreased as bulbs matured (8.0 to 6.9% DM) with a slight increase at maturity (7.4% DM). Enzymatically developed pyruvic acid concentrations ranged from 3.13 to 4.03 μmole/g fresh wt. There was an upward trend of pyruvic acid over the bulbing process. Total sugars, measured by HPLC methods, tended to increase during bulb development (39.3 to 46.5 mg/g fresh wt.). However, sucrose decreased during the last two harvests causing a corresponding increase in glucose and fructose. The S treatment had no effect on any of the factors measured. The only influence by soil type was sugar concentration, with the loam field being higher in glucose.
546 PB 090 OPTIMIZING TOMATO YIELDS IN HIGH TUNNELS
Authors: Wells Otho S.
Published: February 2019

Tomato production in high tunnels is very intensive, although relatively low-input. However, optimal use of every square foot of growing space is critical to maximizing returns. Utilizing the basket-weave trellis system, `Ultrasweet' tomatoes were grown in 4 (replicated), 14-foot-wide high tunnels in 4 rows per tunnel at 3.5 ft between rows. In-row spacing of 12, 18, and 24 inches was combined with removal of sideshoots below the first flower cluster: one or three shoots at 18 and 24-inch spacing and none or one at 12-inch spacing. The highest marketable yield per plant was 22 lbs at 24 inches and three sideshoots, while the lowest yield per plant was 13.9 lbs at 12 inches and no sideshoots. The highest yield per sq ft was 4.2 lbs at 12 inches and no sideshoots, while the lowest yield per sq ft was 2.5 lbs at 24 inches and one sideshoot. The yield response to spacing and side-shoot removal was inverse for lbs per plant and lbs per sq ft. There was no difference in fruit size among any of the treatments. In a comparable experiment under field conditions, the highest yield per plant was 12.6 lbs at 24 inches and one sideshoot; and the highest yield per sq ft was 2 lbs at 12 inches and one sideshoot. The percentage of marketable fruit in the tunnels and in the field was 93.0 and 85.1, respectively.
548 PB 096 EFFECT OF METHANOL ON BIOMASS ACCUMULATION AND PHOTOSYNTHETIC EFFICIENCY OF VEGETABLE CROPS IN HAWAII
Authors: Valenzuela Hector R. , Kawabata Osamu , Yamamoto Harry
Published: February 2019

Methanol sprays reportedly increased yields of several crops in Arizona by 50 to 100 percent (Nonomura and Benson PNAS 89:9794(1992). Reports from other parts of the country have shown conflicting results with regards to the effect of methanol sprays on yields of horticultural crops. Several greenhouse and growth chamber (controlled temperature. day length, and photosynthetic photon flux) experiments were conducted to evaluate the effect of methanol sprays on the growth and productivity of several vegetable crops in Hawaii. Treatment spray solutions consisted of 20-25% methanol, 0.5% low biuret urea. 0.001% chelated iron, and 0.02% surfactant. Control sprays only contained urea, chelated iron, and surfactant. Each experiment consisted of at least 5 weekly methanol sprays. Flowering cabbage, Brassica campestris var. parachinensis, had greater biomass production when sprayed with methanol in the late summer months. Similar results were obtained with choi sum in a 2 by 2 factorial experiment with methanol and water stress treatments. However, choi sum did not respond to methanol treatments in follow-up greenhouse trials. perhaps attributable to the shorter and Overcast days experienced in the fall and winter. Okra, chili pepper, and eggplant showed no response to methanol sprays. Okra showed a trend toward increase yields in response to methanol sprays, but differences were not significant. Follow-up studies in the greenhouse and in the field, which include evaluation of photosynthetic efficiency through chlorophyll fluorescence determinations will be presented.
552 PB 340 DORMANCY DEVELOPMENT AND STRESS TOLERANCE IN `BRAEBURN' AND `FUJI' APPLE NURSERY STOCK
Authors: Castagnoli Steven P. , Fuchigami Leslie H. , Chen Tony H. H. , Zhen Liping
Published: February 2019

Studies were performed on the development of dormancy, cold hardiness, and desiccation tolerance, and the effect of manual defoliation timing on performance of `Fuji' and `Braeburn' apple nursery stock. Dormancy development, response to defoliation, and desiccation tolerance of apple differed from those reported for other temperate woody plant species. Dormancy development in `Fuji' was approximately two weeks ahead of `Braeburn', and was strongly regulated by temperature. Photoperiod had no influence on dormancy development of `Fuji'. Desiccation tolerance of both varieties was greatest just prior to the onset of dormancy and early dormancy. This pattern in the seasonal development of tolerance to desiccation is not typical of temperate woody plant species. Early defoliation was detrimental to performance of `Braeburn', but had little effect on `Fuji'. Early defoliation promoted earlier spring budbreak in `Fuji'. Development of freezing tolerance in both apple varieties was typical of other woody plants, and coincided with the onset of dormancy. Maximum hardiness was achieved after the requirements for dormancy were completely satisfied.
555 PB 368 GROWTH AND ION CONTENT OF INTERGENERIC BC1 CITRUS × PONCIRUS PROGENY IN RESPONSE TO A 9-MONTH SALINIZATION PERIOD
Authors: Tozlu Ilhami , Guy Charles L. , Cai Ouinvin , Moore Gloria A.
Published: February 2019

There is wide variation in Citrus and related genera in tolerance to cold and salt stress. While Poncirus trifoliata (L.) Raf. is an important rootstock for cold regions, it is salt sensitive. C. grandis (L.) Osb., on the other hand, is cold sensitive, but is relatively salt hardy. We are attempting to map genes (quantitative trait loci, QTLs) influencing salt and cold tolerance in Cirrus, using a BC1 population from [C. grandis × (C. grandis × P. trifoliata)]. As a first step, 2 year old containerized replicates of individual BC1 progeny plants have been salinized with 30 mM NaCl over a 9 month period under greenhouse conditions. Growth response under saline conditions, as evaluated by plant height and node number, varied significantly between individual progeny. Concentrations of 11 macro- and micro-elements, including Na and Cl, in leaf and root tissues were also determined. Ultimately, this data will be analyzed in conjunction with our current linkage map of this population, which consists of more than 200 marker genes, in order to map QTLs for salt tolerance.
556 PB 371 EFFECTS OF SUBLETHAL HEAT STRESS 0N ENDODOPMANCY AND ECODORMANCY OF PEACH AND HYBRID POPLAR
Authors: Wisniewski Michael , Sauter Jörg , Stepien Valerie , Fuchigami Les
Published: February 2019

Sublethal heat stress has been shown to decrease or eliminate deep supercooling of flower buds in woody plants and to release plants from endodormancy. Experiments were conducted to characterize the effect of heat stress on endodormancy and ecodormancy in peach (cv Loring) and two hybrid poplars. Protein synthesis (de novo) and patterns of protein expression were also monitored. In order to determine optimum treatment temperatures, shoots, collected September-March, were exposed to a range of temperatures (35-60 C) under wet or dry conditions for 1-6 h. Shoots were then placed in the greenhouse and cumulative budbreak was monitored over 4 weeks. Samples of bud and bark tissues were collected during and up to 72 h after heat treatment for SDS-PAGE analysis. Data indicate: 1) twigs must be immersed in water for the heat treatments to be effective; 2) heat treatments resulted in a release from endodormancy and a decrease in thermal units needed for budbreak during ecodormancy; 3) 40 C for 2-4 h was optimum in fall and late winter whereas 45 C was the optimum temperature to induce budbreak in midwinter; 4) optimum temperature for peach floral buds (37.5 C/2h) was lower than for vegetative buds (40 C/4h), and 5) heat treatments also decreased cold hardiness. Protein synthesis decreased significantly following heat treatment but was significantly greater than controls (room temp) 24-48 h after heat treatment.
561 PB 406 THE EFFECTS OF COLD TEMPERATURES ON THE SURVIVABILITY AND POST-STRESS PERFORMANCE OF CONTAINER-GROWN NURSERY STOCK
Authors: Dwyer Jennifer L. , Peterson N. Curtis , Howell G. Stanley
Published: February 2019

The nursery industry continues to develop improved methods for successfully overwintering container-grown nursery stock. Experiments were conducted using several different species of woody ornamentals ranging from species known to be cold hardy to cold tender. Eighteen species were subjected to temperatures ranging from 20F to -20F and observed for post-stress performance and viability. Rates and timing of acclimation, mid-winter hardiness, and deacclimation of seven species were determined by examining the shoots for injury after subjecting them to controlled freezer conditions. The roots of the same seven species were exposed to three different overwintering systems: in a polyhouse, pot-to-pot above the ground, and pot-in-pot below the ground. Cold hardiness of root and shoot systems and the effects of warming temperatures on shoots were determined as well as the post-stress performance of each species. Results of this research will be presented.
562 PB 409 THE EFFECT OF PHOTOPERIOD ON THE COLD HARDINESS AND CARBOHYDRATE CONTENT OF TWO CULTIVARS OF SOUTHERN MAGNOLIA
Authors: Haynes C.L. , Dirr M.A. , Severson R.
Published: February 2019

The cold hardiness of Magnolia grandiflora `Claudia Wannamaker' and `Little Gem' was determined under 8, 12 and 16 hour daylengths. Temperature was maintained at 25C day and 20C night. In addition, specific and total carbohydrates of both cultivars were analyzed. Cold hardiness and carbohydrate content were tested at the beginning (0 week), middle (5 week), and end (9 week) of the study. As expected, both southern magnolia cultivars were more cold hardy after 9 weeks at 8 hour daylengths with -9C cold hardiness estimates, as compared to 12 and 16 hour daylengths. The 12 and 16 hour daylengths resulted in similar cold hardiness estimates of -6C after 9 weeks. Additional cold hardiness and carbohydrate information will be presented.
564 PB 415 A COMPARISON OF COLD HARDINESS AMONG LAGERSTROEMIA INDICA × FAURIEI CULTIVARS GROWN IN ZONES 7 AND 8 USING DIFFERENTIAL THERMAL ANALYSIS
Authors: Edwards April D. , Newman Steven E. , Matta Frank B. , Laiche Adolph J.
Published: February 2019

During recent freezes in the mid-south, crape myrtles have suffered severe freeze damage. Some increased levels of cold hardiness have been observed in the National Arboretum crape myrtle releases, but the degree of tolerance has not been documented. The relative cold hardiness of five hybrid crape myrtle cultivars `Muskogee', `Natchez', `Osage', `Tuskegee' and `Yuma' was determined using differential thermal analysis. Stem samples were collected from established trees at two locations, Poplarville, Zone 8 and Starkville, Zone 7 once per month from October through April. Freezing point suppression was determined from five samples from each cultivar and location. Observed exotherms ranged from -7C to -13C.
572 PB 041 SEED COAT STRUCTURE RELATED TO GERMINATION IN EASTERN REDBUD (CERCIS CANADENSIS L.)
Authors: Jones Rodney O. , Geneve Robert L.
Published: February 2019

Seed coat anatomy in the hilar region was examined in dry, imbibed and germinating seeds of Eastern redbud. A discontinuous area was observed between macrosclereid cells in the palisade layer of the seed coat which formed a hilar slit. A symmetrical cap was formed during germination as the seed coat separated along the hilar slit and was hinged by the macrosclereids in the area of the seed coat opposite to the hilar slit. The discontinuity observed in the palisade layer was the remnant of the area traversed by the vascular trace between the funiculus and the seed coat of the developing ovule. There were no apparent anatomical differences in the hilar region of the seed coat between dormant and non-dormant imbibed seeds. However, the thickened layer of mesophyll cells of the seed coat in this region and the capacity of the endospetm to stretch along with the elongating radicle may contribute to maintaining dormancy in redbud seeds.
575 PB 050 EFFICIENT PLANT REGENERATION FROM LEAF AND PETIOLE EXPLANTS IN RED RASPBERRY
Authors: Cohen Cynthia , Mathews H. , Dewey V. , Bestwick R.
Published: February 2019

Raspberry has very cultivar specific requirements for proliferation. Plant regeneration rates from isolated explants are inconsistent and vary widely among cultivars. As a step towards developing a viable transgenic system in red raspberry (Rubus idaeus L.) we first developed an efficient and consistent protocol for plant regeneration from isolated explants. A modified MS medium with cytokinin BA gave vigorous shoots with an average proliferation rate of 3-5 depending on the cultivar. These vigorous shoot proliferants served as an ideal explant source for plant regeneration experiments. The average rate of shoot regeneration from leaf explants was 72, 32, 68. and 72% for cvs. Canby, Chilliwack, Meeker and Heritage respectively. In addition to leaf, petiole explants were equally good sources for inducing shoot organogenesis. In all the above-mentioned cultivars, 44-57% of the petiole explants gave rise lo healthy and vigorous shoot regenerants in culture. The regenerated shoots were induced lo root on a rooting medium and were successfully transplanted to the greenhouse. This regeneration system was successfully applied in our laboratory for developing gene transfer system in red raspberry (see abstract by Mathews, et al).
577 PB 056 PLANT REGENERATION FROM CULTURED SOMATIC TISSUES OF HAZELNUT
Authors: Yu Xiaoline , Reed Barbara M.
Published: February 2019

Adventitious shoots were regenerated from stem segments or leaf discs of hazelnut (Corylus species) in vitro shoot cultures. Five to 10% of stem segments of `Nonpareil' regenerated adventitious shoots on modified MS medium and NCGR-COR medium supplemented with 200 mg·1-1 glutamine and combination of 1 or 5 μM thidiazuron (TDZ) and 0.1 μM naphthaleneacetic acid (NAA). Callus derived from stem segments of `Nonpareil', `Tonda Gentile Romana', and `Willamette' and leaf discs of `Dundee' cultured on medium with TDZ and NAA also produced shoots (buds) after transfer to NCGR-COR medium or modified MS medium with benzyladenine (BA) and indole-3-butyric acid (IBA). Adventitious roots were produced from leaf discs and stem segments on medium with NAA alone or with high levels of IBA or NAA combined with low levels of BA. Regenerated shoots of `Nonpareil' and `Willamette' were multiplied, rooted, and acclimatized in the greenhouse. This provides a starting point for improving the plant regeneration frequency to a level useful for genetic manipulation.
580 FB 085 STIMULATION OF EMBRYOGENESIS BY ANTIBIOTICS FROM AMERICAN ELM COTYLEDONS
Authors: Shi Nian-Oing , Cheng Zong-Ming
Published: February 2019

Some antibiotics mimic plant hormones on cell growth and plant regeneration. Cefotaxime and carbenicillin were tested in American elm for induction of embryogenesis from cotyledonary explants, which normally show organogenesis. Cotyledons from 1-week-old in vitro germinated seedlings were placed on a shoot regeneration medium (a modified MS medium containing 15 μ M BA, B5 vitamins and 0.3% gelrite) with various levels of cefotaxime and carbenicillin. One hundred percent of explants showed embryogenesis in the medium supplemented with 125 μg/ml cefotaxime; 75% explants regenerated somatic embryos in medium with 500 μg/mg carbenicillin; and only 50% explants produced somatic embryos in the medium with both of these antibiotics. In control medium without antibiotics, 100% explants regenerated shoots, instead of somatic embryos. Further studies are necessary to determine the nature of these antibiotics on shifting developmental pathways and their stimulatory effect on embryogenesis from American elm cotyledons.
581 PB 088 Shoot Proliferation and plant Formation from Neem (Azadirachta indica Juss.) with Thidiazuron
Authors: Mohamed-Yasseen Yasseen
Published: February 2019

Neem is considered to be one of the most promising plants for producing pesticides, pharmaceutical, as well as many commonplace materials. A protocol for shoot formation from nodal and stem explants is described. Stem nodes and stem segments were obtained from mature tree and cultured in Murashige and Skoog medium (MS) supplemented with 0.5 μM thidiazuron (TDZ), and 0.5 uM naphthaleneacetic acid (NAA). Stem node explants produced multiple shoots which were separated and cultured on MS supplemented with 0.01, 0.03, 0.5, or 0.9 uM TDZ with 0.5 uM NAA. Stem explants produced callus which regenerated shoots upon transfer to a fresh medium. Formed shoots produced roots in proliferation medium or rooted in MS supplemented with 3.3 uN indolebutyric acid, and were transferred to soil. Number of produced shoots increased with increasing TDZ concentration but shoot and root length decreased.
584 PB 097 MICROPROPAGATION AND REGENERATION OF AN ELITE ASIAN WHITE BIRCH SELECTION
Authors: Schnurr Jeffrey P. , Cheng Zongming
Published: February 2019

A selection of Betula platyphylla, from an open pollinated population, was made for upright growth habit, cold hardiness, and a dark green canopy. A micropropagation system was developed to overcome the difficulty with conventional propagation techniques. Shoot-tip cultures were best established in 3/4 strength MS medium supplemented with 0.1 μM thiadiazuron. After 5 weeks in culture, shoots were transferred to woody plant medium (WPM) with 4.4 μM BA. The highest proliferation rate occurred at 24 C on WPM, solidified with agar, and supplemented with 2.2 μM BA. Shoots rooted in vitro and ex vitro and have been established in the field. A regeneration system has also been developed using leaves from aseptic cultures. The optimum conditions for shoot regeneration include a 2-week dark treatment before exposure to a 16-h day/8-h night cycle. Large, healthy leaf explants cultured on WPM with 20 μM BA regenerated shoots at the highest frequency. Regenerated shoots, when transferred to the micropropagation system, proliferate successfully. Currently, a transformation system for this selection is being developed.
590 PB 138 LOW-TEMPERATURE STRESSED-INDUCED FLOWERING OF THE `WASHINGTON' NAVEL ORANGE (CITRUS SINENSIS L. OSBECK) WAS INCREASED BY APPLICATION OF PUTRESCINE OR SPERMIDINE TO THE FOLIAGE
Authors: Ali Anwar G. , Lovatt Carol J.
Published: February 2019

The ability of arginine (50 mM), putrescine (10 and 20 mM), and spermidine (10 and 20 mM) to enhance low temperature stressed-induced flowering of 5-year-old container-grown `Washington' navel orange trees was evaluated. The metabolites were applied to the foliage at the end of the 4-week low-temperature treatment of 8-h days at 10°C and 16-h nights at 7°C; the trees were then moved to warmer conditions.

All treatments had a positive effect on floral intensity. Putrescine (20 mM) and spermidine (10 mM) significantly increased (P = 0.05) total flower number and both the number and proportion of leafless inflorescences per tree. However, the number of floral shoots per tree, as well as the number of leafy inflorescences and number of vegetative shoots were not significantly influenced by the metabolites.

The results suggest that polyamines are important to the development of flowers, but not leaves, along the axis of the inflorescence.
593 PB 167 EFFECTS OF REDUCED RATES OF NITROGEN ON GROWTH AND MINERAL NUTRITION OF YOUNG `PINEAPPLE' ORANGE TREES
Authors: Alva A.K. , Tucker D.P.H.
Published: February 2019

Recent trends in increased nitrate contamination of groundwater in parts of Central Florida have prompted this study to evaluate the potential for reducing the rates of nitrate (N) fertilizer to citrus. `Pineapple' orange trees on Swingle citrumelo rootstock growing on Candler fine sand were selected for the study. Fertilizer blends were applied using N as: (1) soluble ammonium nitrate and calcium nitrate in 4 applications per year and (2) controlled-release sources (Meister, Osmocote, Escote in one application per year and IBDU and Neutralene in 2 applications per year). Nitrogen rates varied 18-154, 36-308, and 57-454 g/tree/year during the first, second and third year after planting, respectively. Tree growth and leaf mineral concentrations (during the first 3 years) and fruit size and juice quality (second and third years) were not adversely affected by application of reduced N rates. Fruit yield (third year) was lower in the trees which received ≤ 114 g N/tree/year than in those which received higher rates of N.
599 PB 205 THE INFLUENCE OF COASTAL BERMUDAGRASS AND CHEMICAL MOWING ON THE GROWTH, DEVELOPMENT, AND WATER UTILIZATION OF YOUNG PECAN TREES AS MEASURED IN NON-WEIGHING LYSIMETERS
Authors: Worthington Josiah W.
Published: February 2019

Budded, bare root, `Wichita' pecan trees were planted and grown in inexpensive, 2m X.75m, non-weighing lysimeters for three growing seasons. Metered water was applied automatically through microirrigation systems as called for by switching tensiometers. Soil moisture tension was not allowed to exceed 25 Kpa. All tree/sod combinations received 336 kg N per hectare from 1-1-1 ratio commercial fertilizer.

Water use, tree growth, and nutrient status of trees grown under the following orchard floor management practices were measured: 1)Unmowed coastal bermudagrass. 2)Mechanically mowed bermudagrass, 3)Chemically mowed bermudagrass, and 4)Bare soil.

Water use by trees with chemical or mechanically mowed sod were intermediate in water use between unmowed and fallow soil treatments. In spite of the fact that water was never limiting for any treatment, fallow trees grew significantly larger than trees in any of the sodded treatments. A significantly lower level of foliar potassium was noted in trees growing in sod systems.
602 PB 214 GROWTH AND PRODUCTION OF ALMOND TREES AS AFFECTED BY PEACH AND PEACH-ALMOND HYBRID ROOTSTOCKS
Authors: Micke Warren C. , Freeman Mark W. , Yeager James T.
Published: February 2019

A replicated rootstock trial for almond was established in 1986 in the central San Joaquin Valley, a major almond growing area for this most widely planted tree crop in California. `Nonpareil', the major cultivar in California, was used for this trial with `Fritz' grown as the pollenizing cultivar. Two standard rootstocks for almond, `Nemaguard' and `Lovell' peach, were compared to two newer peach-almond hybrid rootstocks, `Bright's' and `Hansen'. After eight years both hybrid rootstocks produced significantly larger trees than the peach rootstocks, based on trunk cross-sectional area. Trees on hybrid rootstocks frequently produced greater yields than those on peach rootstocks; although, differences were not always significant. However, there were generally no significant differences in production per trunk cross-sectional area (yield efficiency). Thus, increased production by trees on hybrid rootstock was the result of larger tree size and not an inherent increase in productive efficiency of the tree itself. Since trees on hybrid rootstock should be planted further apart than those on peach, production per hectare should not be significantly increased, at least under good growing conditions as represented in this trial.
606 PB 246 Effect of planting density on root length distribution and mineral content in Y-shaped self rooted `Flordaprince' peach trees
Authors: Caruso T. , Marra F.P. , Motisi A. , Giovannini D.
Published: February 2019

Length and distribution of the roots of 2-year old cv. `Flordaprince' peach trees grown under polyethylene greenhouse were studied over a two year period. The self-rooted, micropropagated trees were spaced 4.9 m between the row and 70, 52 and 42 cm. along the row to obtain a density of 3000, 4000 and 5000 trees/ha respectively. Orchard was clean cultivated, mulched along the row with black plastic fabric 1 m wide, and drip fertigated. Soon after harvest, for each density, the root system of one tree was totally excavated and root length, distribution, dry weight and nutrients content were determined. Total root length per tree was negatively related to planting density in two-year old trees (470, 380 and 320 m/tree respectively for 3000, 4000 and 5000 trees/ha). The shallowest root systems were found at 5000 trees/ha density and their length was unchanged from year to year. Root length density, ranging from 220 to 250 m/m), was only slightly affected by spacing in the two years. The roots were evenly distributed between the two sides of the rows.
614 PB 290 FLOWER BUD POSITION DETERMINES BLOOM AND FRUIT CHARACTERISTICS IN `ROME BEAUTY' APPLE
Authors: Lee Randy R. , Fellman John K. , Fallahi Esmaeil
Published: February 2019

The influence of flower bud position on bloom, fruit quality, and fruit maturity was investigated on `Rome Beauty' apple (Malus domestica Borkh.). Limbs on trees containing spur terminal flower buds and lateral flower buds were tagged and the number of blossoms counted every three days until bloom ended. At harvest, fruit from each bud type were selected and seed number, fresh weight, fruit quality characteristics, and onset of ethylene production were measured. Spur terminal flower buds began blooming earlier, blossomed for a longer period of time, and produced more blossoms than lateral flower buds. Fruit from spur terminal flower buds had more seeds, were heavier, and contained more starch than lateral bud fruit. Lateral bud fruit had higher pressure values, due to smaller size, and higher soluble solids, due to consumption of starch reserves. Fruit color and titratable acidity were not significantly different regardless of bud position. Spur terminal fruit started producing ethylene eight days later than lateral bud fruit, indicating they were maturing less quickly. Cultivars such as `Fuji', `Gala', and `Braeburn' display similar growth and fruiting habits.
615 PB 293 BAGGING APPLE TREE LEADERS INCREASES LATERAL SHOOT DEVELOPMENT
Authors: Stasiak Matt J. , Roper Teryl R
Published: February 2019

Inadequate branch production on apple trees can result in reduced bearing surface and problems with tree training. We sought to increase the number of lateral shoots by enclosing the one year old portion of the central leader of two year old `Jonamac', `Red Jonagold', and `Scarlet Gala', apple trees two weeks prior to bud emergence. The bags were then removed when the longest shoots in the bag were approximately 2.5 cm long. After leaf fall the number and length of shoots in the bagged sections were measured. The number of lateral shoots >5 cm in length produced on the bagged sections of the leaders was increased by 3.7. Total lateral growth on the central leader increased by 149 cm per tree. Trunk cross-sectional area, tree height, or production of lateral shoots >5 cm were not affected by bagging. Differences between clear and orange bags were not significant. Bagging appeared to be an efficient means to induce trees to produce lateral branches. The greatest benefit would be to varieties like `Jonamac' and `Red Jonagold' which averaged only 1.7 laterals without bags.
616 PB 296 GROWTH RESPONSES OF VERTICAL APPLE SHOOTS BENT WITH BRANCH BENDER' OR A HAND-TOOL
Authors: Gaus Alvan , Rogoyski Matthew
Published: February 2019

The main objective of this research was to compare the growth responses of l-year-old, vertical, apple shoots to bending with a simple hand-tool (HT) or bending with the commercially available Branch Bender® (BB). Single, vigorous, vertical shoots of `Red Chief Delicious (RCD), `Valnur' Jonathan (VJ), and Granny Smith were either bent with the BB or were bent by spirally wrapping the shoot around a 2.5 cm diameter plastic-rod, HT 2 times. Each variety had nine single-tree blocks with a control, BB, and HT as treatments. Measurements were taken on the number of clusters formed, length of subsequent terminal growth, number of shoots and spurs formed, and shoot cross-sectional area. No differences were found in RCD between the BB and the HT on all parameters; however, terminal growth was less with the BB than the control. With VJ, first year shoot cross-sectional area for the BB was less than for the HT. Cluster formation on both 1 and 2-year-old wood was greater with the BB than the control but not with the HT. No differences were found with Granny Smith.
620 PB 328 MATHEMATICAL MODELLING OF INTERTREE SHADING IN HEDGEROW AND NON-INTERSECTING CANOPY ORCHARD SYSTEMS AND ITS IMPLICATIONS ON OPTIMAL ORCHARD DESIGN
Authors: Burcaw Jeffrey W. , Wood Bruce W. , Pool Michael W.
Published: February 2019

The authors have developed a mathematical model designed for shade-intolerant tree crops which describes the amount of intertree shading in an orchard. These data are used to formulate an optimal orchard design based on shading reduction in orchards for any tree crop during any developmental window at any global location for either continuous canopy hedgerows or non-intersecting canopies for several different orchard geometries. Variables include tree shape, orchard geometry intertree spacing, row orientation, time and day of year, and geographical coordinates. Optimal orchard designs are based upon the total amount of unshaded canopy surface per unit area which each orchard configuration confers. Results indicate extensive variability of intertree shading between hedgerow and non-intersecting canopies to be largely a function of latitude, regardless of other variables.
621 PB 331 A FRUIT TREE COOLING CONTROL SYSTEM SIMULATOR
Authors: Rogoyski Matthew , Gaus Alvan , McNew Byron , Broner Israel , Mourney Thomas
Published: February 2019

A simulator of a control system for evaporative cooling of crop canopies was developed. This development, prior to implementation of an irrigation/cooling system, allowed for experimentation before committing resources to the field system. The project provided insight into problems of modeling interaction between biological, mechanical, and digital systems and demonstrated how specialists from diverse areas can solve these problems. The object orientation methodology and the C++ programming language were tools for development of this simulator. A communication mechanism was devised to facilitate interactions between software entities representing both concrete and abstract objects corresponding to the problem domain. The object-oriented approach to the system development allowed for better communication between team members, irrespective of their background in software engineering. The modular and polymorphic nature of the object-oriented code made it possible to plan for code reuse in future projects. Simulator development using the object-oriented paradigm was found to be preferable over the procedural model used by team members in other projects in the past.
625 PB 451 RESPONSE OF TOMATOES AND BEANS, GROWN IN ROTATION, TO THREE YEARS OF COVER CROP AND NITROGEN TREATMENTS
Authors: Davis Jeanine M.
Published: February 2019

In 1991, a four year study was initiated in which staked tomatoes and snap beans are rotated annually and grown with three cover crop treatments (wheat, crimson clover, and bareground) and three N rates (0, 60, and 120 kg N/ha) in a RCB with four replications. Crop growth, yield, nutrient status, N cycling, and pest populations are being studied. The first year there was no response to cover crop. The next two years, crimson clover reduced bean yields due, in part, to high levels of disease. Mexican bean beetle populations were also highest with clover and increased with increasing N rate. In 1992, wheat increased tomato fruit crack, but there was no effect on yields. In 1993, wheat reduced early season tomato yields but had no effect on total season yields. Aphid populations were highest on tomatoes grown with crimson clover. The study reveals that cover crop systems are dynamic and long-term studies are required before dependable grower recommendations can be made. This study is part of the Tri-State Vegetable Project, a cooperative research project with N.C., S.C. and Ga.
627 PB 457 RELAY-INTERPLANTING COVER CROPS IN SWEET CORN
Authors: TenPas Tom , Luna John
Published: February 2019

The effect on corn yield of interplanting two different cover crops, Trifolium repens, and Lolium perens into sweet corn, Zea mays, at 4 different times from corn planting was examined. Sweet corn was planted in 30 inch rows, and the cover crop was planted 0, 7, 14, and 21 days afterwards. The study was designed as a complete randomized block experiment with 4 replications. Weed management practices included pre-emergent herbicides and cultivation only treatments.

No significant yield differences in corn yields were detected (alpha=.05). Most of the plots had very little weed competition, including those with no herbicide treatment. Earlier planted cover crops were better established at time of corn harvest. Additional work is needed to examine this practice in conditions of greater weed competion.
629 PB 481 RESPONSE OF VEGETABLES, N SOURCES AND FALL COVER CROPS ON YIELDS, N ACCUMULATION AND SOIL INORGANIC N
Authors: Anderson Wilbur C. , Kuo Shiou
Published: February 2019

Broccoli, potatoes, cucumbers and green peas were fertilized respectively with 241, 168, 168 and 28 kg N ha-1. The N accumulation was equivalent to the fertilizer application rates for the broccoli, potatoes and cucumbers while the peas accumulated 321 kg N ha-1. Vegetable yields were not affected by previous cereal rye cover crops when compared to the fallow control. Cover crops following broccoli accumulated the least and peas the most N. Inorganic N in the top 30 cm at harvest were significantly different between vegetables, but not in the 30-60 cm depth.

Chicken manure and ammonium nitrate as N sources were compared. Broccoli was the test crop and was fertilized with both sources at 241 kg N ha-1. Broccoli yields and N accumulation were different between sources of N and between N and no-N treatments. Inorganic N leaching was greatest with ammonium nitrate fertilization and chicken manure was similar to the no-N fertilizer treatment.
631 PB 487 ROOT ARCHITECTURAL RESPONSE OF BELL PEPPER TO SOIL AMENDMENTS
Authors: Snyder Robert H. , Lynch Jonathan P. , Kaufman Donald , Schettini Terry
Published: February 2019

Sustainable agricultural systems favor high organic amendments over chemical fertilizers for maintaining long-term soil fertility. To study root responses bell pepper was grown in soil treated with dairy compost, raw dairy manure, and a chemical fertilizer mix at Rodale Institute Research Center, Kutztown, Pa. Root crowns were excavated at 2-week intervals and total length determined from root subsamples by computer-based image analysis. Roots from compost amended plots displayed a simple branching pattern; a first order branch with short second order branches. Fertilizer stimulated a complex branching; short, thickened first and second order branches that supported long and thin third and fourth order roots. An intermediate form in the raw dairy plots yielded both simple and complex branching forms. All forms were dynamic within each treatment over time. Crown length averaged 250-300 m across treatments 6 weeks after transplanting. Raw dairy and fertilizer treatments decreased slightly in length by week 10, while compost remained constant. After heavy rainfall crown length increased to 400 m for compost and raw dairy, and to 750 m for the fertilizer treatment by week 13. Length for the fertilizer treatment dropped nearly 200 m by week 14. though an increase of 100-200 m occurred for compost and raw dairy treated roots respectively.
633 PB 493 EFFECT-OF COMPOSTED SEWAGE SLUDGE ON VEGETABLE PRODUCITON
Authors: Orzolek Michael D. , Murphy John H.
Published: February 2019

A long term study was initiated in 1993 to evaluate the effect of composted sewage sludge on growth, yield, and quality of different vegetables. The composted sewage sludge consisting of 40% hardwood sawdust and 60% clean municipal wastewater sludge was obtained from the University Area Joint Authority (UAJA) in State College, PA. The composted sewage sludge is currently sold by UAJA as a fertilizer amendment under the name CornposT. Two rates of the ComposT product (11 and 22 dry T/A) were compared to a granular fertilizer application of 800 lbs/A of 10-10-10. The low rate of ComposT also received half of the fertilizer rate. After incorporation of the amendments into a Hagerstown clay loam soil, lettuce, tomato, muskmelon, cabbage and pepper were transplanted in the field in a Randomized Block Design with 3 replications. ComposT application did not reduce yield or quality of cabbage, lettuce tomato,and muskmelon; in fact, yields were generally higher with the application of composted sewage sludge. The application of ComposT did not reduce the macro or micro nutrient concentration of leaf tissue below optimum levels nor did it result in any phytotoxic effects in plant growth. In addition, the application of ComposT did not increase the heavy metal (Cd, Ni, Pb) concentration in leaf tissue or increase the risk of microbial contamination in the edible portion of the vegetables.
634 PB 514 POTENTIALS OF SUNN-HEMP AS GREEN MANURE IN VEGETABLE PRODUCTION IN GUAM
Authors: Marutani Mari
Published: February 2019

Sunn-hemp, Crotalaria juncea L. cv. Tropic Sun was developed in Hawaii in 1982 and recently introduced to the island of Guam by USDA Soil Conservation Service as a potential green manure crop. An evaluation of various legumes at three different soil regimes revealed that sunn-hemp produced greater biomass than other plants. In the study of the effects of sunn-hemp in subsequent vegetable production, slightly greater canopy was observed for potato, Solanum tuberosum cv. Kennebec, with green manuring with sunn-hemp than without. Yield of head cabbage, Brassica oleracea var. capita cv. KK Cross, was higher with green manuring (1085.5g/head) than without (725.4g/plant). Competition between indigenous rhizobia and introduced inoculant seems to exist at some locations. Major constraints in using sunn-hemp as green manure on the island are its limited seed sources and requirements of additional labor. Education and promotion of using this legume in a long term soil-improving system is needed.