bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of Commercially Available True Potato Seed Hybrids Grown from Tubers
Authors: Love Stephen L. , Werner Bruce K. , Groza Horia I. , Thompson-Johns Asunta
Published: February 2019

Nine commercially available true potato seed (TPS) hybrids were compared to four standard clonal cultivars with respect to mean and uniformity of foliar characteristics and tuber traits important to the North American potato industry. The TPS hybrids were planted using second vegetative generation tubers derived originally from botanical seed. Ten plants from each plot were individually evaluated for plant height, vine maturity, early blight symptoms, and verticillium wilt symptoms. Following harvest, yield was determined and the tubers were rated or measured for appearance, shape, specific gravity, and french fry color. The TPS hybrids had mean values for all tuber and foliar traits, except plant height, that were not significantly different from those of one or more of the cultivars; generally, values for the hybrids fell amid those of the cultivars. Two of the hybrids were taller on average than any of the four cultivars. In contrast to the means, trait uniformity of the TPS hybrids was consistently less than for the cultivars. For all foliar traits, except plant height, the TPS hybrids were substantially less uniform than the standard cultivars. For specific gravity and french fry color, two important processing quality traits, the hybrids tended to be less uniform than the cultivars; however, the difference was much less pronounced than for the foliar traits. Four of the hybrids were not significantly less uniform than one or more of the cultivars for french fry color and seven were not less uniform for specific gravity. For many market uses, the TPS hybrids appeared to have the tuber yield and quality characteristics needed to compete with standard clonally propagated cultivars.
Vase Life of Some Cut Flowers Following Fumigation with Phosphine
Authors: Karunaratne Chinthaka , Moore Graham A. , Jones Rodney B. , Ryan Robert F.
Published: February 2019

Phosphine (PH3) is a potential alternative fumigant to methyl bromide for insect disinfestation of cut flowers. King protea (Protea cynaroides L.), tulip (Tulipa gesneriana `Apeldoorn'), kangaroo paw (Anigozanthos manglesii Hook.), and geraldton wax (Chamelaucium uncinatum `Purple Pride') were fumigated with PH3 at varying concentrations (100 to 8000 μL·L-1) for 2, 4, or 6 hours. Vase life was evaluated at 20 °C, 65% relative humidity, and constant illumination with a photosynthetically active radiation of 15 μmol·m-2·S-1. No significant change in vase life was observed for kangaroo paws after any of the PH3 fumigations. A 6-hour fumigation at 8000 μL·L-1 significantly reduced vase life in king protea, tulip, and geraldton wax flower. Geraldton wax flower and tulip were relatively sensitive to PH3, as they were damaged by 4000 μL·L-1 for 6 hours and 8000 μL·L-1 for 4 hours, respectively. Phosphine has potential as an insect disinfestation fumigant for king protea, tulip, and kangaroo paw at 4000 (μL·L-1 for 6 hours without affecting vase life or causing damage.
Use of Maturity Indices for Predicting Poststorage Firmness of `Fuji' Apples
Authors: Blankenship Sylvia M. , Parker Michael , Unrath C. Richard
Published: February 2019

`Fuji' apples (Malus domestica Borkh.) were harvested at three maturities for three consecutive seasons. Fruit firmness, soluble solids concentration, starch—iodine index (SI), and internal ethylene concentration were measured at harvest. Fruit were stored in 0 °C air storage for 8 months. Fruit firmness and other maturity indices were measured monthly during storage. Using a stepwise regression procedure, harvest maturity indices were used to predict firmness after air storage. When all maturity indices measured were represented in the model, R2 = 0.29, 0.34, and 0.26 at 4, 6, and 8 months, respectively. Use of only SI and fruit firmness in the model gave R2 values of 0.25, 0.29, and 0.24 for 4, 6, and 8 months, respectively. Although R2 values were low, they were highly significant. The model using fruit firmness and SI resulted in the best fit. Thus, an equation was developed using months of air storage, firmness, and SI at harvest. Actual firmness values correlated fairly well with predicted firmness values, usually within ≈5 N. On Washington apples, predicted values were 4.3 and 3.7 N too low compared to actual firmness values after 3 or 5 months' storage. In 1993, when predicted and actual firmness values were compared for Pennsylvania apples, predicted values ranged from 2.6 to 8.3 N too high after 3 months' storage, depending on harvest date. In 1994, Pennsylvania fruit stored 4 months had predicted values 0.5 N too high to 6.3 N too low, depending on harvest date. It may be possible to develop and refine models for an apple variety that would be applicable to several regions.
X Alpingera martinica (Zingiberaceae): An Intergeneric Hybrid between Alpinia purpurata and Etlingera elatior
Authors: Luc-Cayol F. , Fereol L.
Published: February 2019

Artificial intergeneric crosses between Alpinia purpurata and Etlingera elatior (Zingiberaceae) have produced hybrids. Data are presented with a Latin diagnosis and the name X Alpingera martinica F. Luc-Cayol proposed for these hybrids. The shape and color of the inflorescence of this hybrid species are an improvement relative to the ornamental value of the parents.
Segregation Distortion and Linkage of Mango Isozyme Loci
Authors: Aron Y. , Czosnek H. , Gazit S. , Degani C.
Published: February 2019

The inheritance of five polymorphic enzyme systems, aconitase (ACO), isocitrate dehydrogenase (IDH), phosphoglucose isomerase (PGI), phosphoglucomutase (PGM), and triosephosphate isomerase (TPI), was studied in selfed progenies of four mango (Mangifera indica L.) cultivars and selections. Only in `Haden' did the allozymes of all of the studied loci segregate in the expected Mendelian ratios. Distorted segregations were present in the other cultivars at some loci; three of the five analyzed in `Edward' showed distorted segregations, as did two of three loci in `13/1', and both loci in `21/6'. The distorted ratios in `Edward', a descendant of `Haden', did not appear to be associated with gametic selection because pollen viability in both of these cultivars was high. The five enzymic loci were not linked to one another in `Edward', `13/1', or `21/6'. In `Haden', however, Pgi-2 and Aco were linked, with a distance of about 19.4 map units.
Orchard Variation in Micropropagated Trees of `Redspur Delicious' Apple
Authors: Zimmerman Richard H.
Published: February 2019

Micropropagated trees of `Redspur Delicious' apple (Malus ×domestica Borkh.), planted as small, actively growing trees in May 1982, lacked uniformity in tree size, appearance, and flowering by the spring of 1986. Only four of the 18 trees had a typical spur-type growth habit; these four trees had 80% more spurs per meter of shoot, 8 to 10 times as many flowers the first year of flowering and 9.5-fold higher early fruit yields, but were 40% smaller after 14 years in the orchard and had 25% less cumulative fruit yield than the nonspur types. Shoots from the spur-type trees were recultured in 1988 and the resulting trees planted in an orchard in 1990. These latter trees were uniform in appearance and all had typical spur-type growth, with about 30% more spurs per meter of shoot growth than the spur-type trees from which they were propagated. Micropropagating spur-type apples from previously micropropagated trees that have maintained clonal fidelity may overcome the potential problem of clonal variation in orchard planted micropropagated trees.
The Effect of Day/Night Temperature on Pharbitis nil Chois, Flowering
Authors: Reese Cheryl L. , Erwin John E.
Published: February 2019

The interaction between day/night temperature (DT/NT) and irradiance during the photoperiod prior to the inductive night on Pharbitis nil (L.) cv. Violet flower induction was studied. Plants exposed to 12 or 18 °C NT did not flower regardless of DT. When NT was 24 or 30 °C, percent flowering plants increased progressively as DT increased from 12 to 30 °C. Percent flowering plants and total flower bud number per plant was greatest when seedlings were induced with a 24 or 30 °C DT/30 °C NT regime. DT/NT did not affect the node number to first flower. Irradiance did not affect flowering. Temperature effects on P. nil flowering could be described as a function of average daily temperature, where flowering increased as temperature rose from 22 to 30 °C.
Control of Pecan Aphids with an Organosilicone Surfactant
Authors: Wood Bruce W. , Tedders W. Louis , Taylor James
Published: February 2019

Aphids cause major annual economic losses to the U.S. pecan [Carya illinoinensis (Wangenh.) K. Koch] industry and are becoming harder to control with standard pesticides. An evaluation of efforts by certain growers to suppress aphid populations using air-blast sprays of 0.05% Silwet L-77, a non-ionic super-wetting organosilicone surfactant, indicated that: 1) reductions in blackmargined aphid [Monellia caryella (Fitch)] levels were mostly attributable to the air-blast spray effect rather than to the Silwet L-77 component; 2) a 0.05% solution of Silwet L-77 reduced net photosynthesis (A) of foliage by 5% for at least 14 days post-treatment; and 3) the efficacy of 0.05% Silwet L-77 sprays is not substantially increased by doubling the volume of spray per tree (1868 L·ha-1). However, higher Silwet L-77 concentrations were highly effective in killing aphids, although there was little or no residual activity. A response curve indicated that air-blast sprays of orchard trees with 0.30% (v/v) Silwet L-77 (at 934 L·ha-1) are capable of reducing yellow pecan aphid (Monelliopsis pecanis Bissell) populations by at least 84% while only reducing A by ≤10%. Chemical names used: silicone-polyether copolymer (Silwet L-77).
Hazelnut Production in Oregon
Authors: Olsen Jeff
Published: February 2019

Hazelnuts in Oregon are grown on 30,000 acres by ≈1000 orchardists in the Willamette Valley. Their annual production accounts for 3% to 5% of the world's hazelnut tonnage. The trees are grown in a single trunk system wrtb an average spacing of 20 feet between trees. Mechanical harvestihg is done in October. The industry employs an Integrated Pest Management approach, utilizing combinations of scouting, trapping, and biological control. The main insect pests are filbertworm, filbert leafroller, obliquebanded leafroller, and filbert aphids. The aphid parasite Trioxys pallidus was imported from Europe and successfully established in Oregon. Eastern Filbert Blight, Anisogramma anomala, a fungus disease, is the most serious disease problem in the industry. Annual applications of nitrogen to the soil and boron applied to the foliage are routine for Oregon's hazelnut growers. OSU research has quantified the importance of good light distribution in the tree canopy for increased nut production. OSU recommends a 5-year rotational pruning program. Some growers use mechanical hedging instead of hand pruning. OSU is home to the world's largest hazelnut breeding program. `Barcelona' is still the main, cultivar grown, while `Ennis' is the main in-shell variety. There is growing interest in planting varieties with a high percent kernel, such as `Casina', `Willamette', and `Lewis'.
Evaluation of Grape Rootstocks for Resistance to Phymatotrichum omnivorum
Authors: Kilby Michael W.
Published: February 2019

Phymatotrichum omnivorum (P.O.) is a soil-borne fungus ubiquitous to the alkaline soil of Texas, New Mexico, Arizona, and Mexico. This fungus causes serious economic loss to grapevines in Arizona, ranging from high to low desert environments. In order to determine the relative resistance to P.O., rootstocks of various species combinations were planted in a calcareous soil which had a history of P.O.; the primary Vitis species included in the trial were champini, candican, berlandieri, repestris, and vinifera. One-year-old rooted cuttings were planted in a randomized block design with one plant per plot with six replications. Common names of rootstocks planted included Freedom, Dogridge, Oppenheim 4 (SO4), Harmony, Champanel, and 5BB. The vinifera used as the control was `Sauvignon Blanc'. Vines were allowed to grow and die for two years. All of the rootstocks exhibited greater resistance to P.O. when compared to the vinifera control. The rootstock exhibiting the greatest resistance was Harmony, with a low of 18% mortality. Other rootstocks showed a loss of approximately 33% over the duration of the trial.
Effect of Media Volume on Water Uptake of Tomato
Authors: Albahou M.S. , Green J.L.
Published: February 2019

It has been shown that container medium volume affects plant growth and development in conventional production methods. The objective of this study was to investigate the effect of media volume on the growth and yield of the determinate tomato genotype `Pik Red' in the closed, insulated pallet system (CIPS). The CIPS contains media pouches with wicks extended down into a water reservoir. Three root media volumes were investigated: 3, 6, and 9 L (3L, 6L, and 9L). The root media were placed in pouches that varied in diameter but had constant depth. The surface area of the wicks in contact with the bottom of all pouch sizes remained constant at 110 cm2. It was hypothesized that increasing the volume of root media would allow sufficient water replenishment during the dark period to meet the plant's need the next day, and thus allow greater growth and fruit yield. Daily water uptake for each individual plant was measured by the principle of atmospheric pressure and water replacement technique. Media volume had no significant effect on water uptake during early stage of plant growth. After 45 days after planting (DAP), water uptake and plant growth were less in 3L media volume. Water uptake was similar in the 6L and 9L treatments between 45–60 DAP. Total water uptake from day 60 to 125 was greatest in the 9L, intermediate for 6L, and least in the 3L treatments. The water uptake from 1–60 DAP was reflected in the fresh shoot weight, and the water uptake was reflected in the fruit weight. Average fruit sizes and the total fruit weights for the 3L were 67.7% and 60.4% those of the 9L treatment, respectively. The 6L treatment fruit yield and fruit size were intermediate between the 3L and 9L.
HortBase: Providing a Foundation for Distance Education
Authors: Kjelgren Roger
Published: February 2019

Technology allows educators to convey information more flexibly and visually. How to access and make use of technological teaching tools is the challenge facing educators. HortBase provides the framework for educators to create and access educational chunks. How to make use of the information in HortBase in distance teaching is a three-step process. 1) Before assembling the teaching material, the educator must decide on who the target audience is and what information to convey. Audiences on campus have higher expectations of how they learn, as they are used to live teaching and guidance, and often do not have a clear idea of what they want to learn. Off-campus audiences have lower expectations and are more focused on the information they want. 2) The educator then decides how much of the information to convert into digital form individually and how much to draw from elsewhere. Pieces of digitized information can be created by scanning existing images into the computer or created on computer with authoring-illustrating programs. Once digitized, images can be manipulated to get the desired look. This is a very time-consuming step, so much effort can be saved by taking created “chunks” from HortBase. 3) Finally, what medium and tools to use must be decided. Course content can be presented with slide-show software that incorporates digitized slides, drawings, animations, and video footage with text. Lectures can then be output to videotape or broadcast over an analog rework. Alternatively, the digitized information can be incorporated into interactive packages for CD-ROM or the World Wide Web.
Integrated Pest Management on the Web and on CD-ROM: Two University of California Projects for Helping Farmers and Gardeners Solve Pest Problems
Authors: Flint Mary L. , Strand Joyce F.
Published: February 2019

Over the past decade, the University of California Statewide IPM Project has been extending pest management information electronically to farmers, pest management consultants, landscapers, and home gardeners. During this session we will demonstrate the Project's web site (http://www.ipm.ucdavis.edu) and a CD-ROM developed to assist horticulture advisors, Master Gardeners, retail nursery personnel, and others who help gardeners manage pest problems. We will discuss considerations in using these programs for extending information, keeping the programs up-to-date, and integrating them into educational programs. The CD-ROM covers 40 vegetables and tree fruits, allowing users to specify visual symptoms, describe a situation, or look at color photos, video images, or line drawings to help identify the problem. Twenty-five to 35 different pests are included for each crop, with thousands of photo images. An ornamentals module will be added in 1998. Once the problem is identified, the system provides screens to confirm pest identity, learn about biology and damage, and choose management practices. For instance, users can view several common natural enemies for a pest, look up the relative toxicity of pesticides, or get details on how to prune to avoid stressing a tree. Choices focus on methods to reduce pesticide use. The program is being developed with cooperators at Oregon State University and Washington State University, and with guidance of end users. The UC IPM web site includes information on biology and management of hundreds of insect, pathogen, weed, and nematode pests on 35 crops and in landscapes and gardens with thousands of color photos linked through hypertext. Other databases on the site include weather databases, pesticide use data, and phenology databases for pests.
Host Preference of Radopholus citrophilus from Hawaiian Anthurium among Selected Tropical Ornamentals
Authors: Goo M.Y.C. , Sipes B.S.
Published: February 2019

Fourteen tropical ornamental plants were evaluated for their host status to a population of Radopholus citrophilus isolated from anthurium. No nematodes were recovered from the roots of Aglaonema commutatum, Caryota mitis, Cycas revoluta, Dracaena deremensis, Neodypsis decaryii, Ravenea spp., or Spathiphyllum wallisii 5 months after inoculation, making these plants nonhosts. Low numbers of R. citrophilus were recovered from the roots of Phoenix roebellinii, Rhapis excelsa, and Howea forsteriana, suggesting that they were poor hosts to this nematode population. Anthurium trifidum, Chamaedorea neathebella, Chamaedorea seifrizii, and Calathea variegata were hosts for the nematode, allowing population increases of 2.47 to 29.92 times the inoculation density. C. seifrizii and C. variegata represent new hosts of R. citrophilus.
Evaluating Genetic Relationships of Geranium Using Arbitrary Signatures from Amplification Profiles
Authors: Starman Terri Woods , Abbitt Shane
Published: February 2019

Our objective was to distinguish between eight cultivars of two geranium species, Pelargonium ×hortorum L.H. Bailey (cutting and seed geranium) and Pelargonium peltatum (L.) L'Hér. ex Ait. (ivy geranium), and evaluate their genetic relationships using the nucleic acid scanning techniques of DNA amplification fingerprinting (DAF) and/or arbitrary signatures from amplification profiles (ASAP). Cultivars used in the study represented three commercial types: cutting, seed, and ivy geranium. Two seed geranium cultivars from each of the Dynamo and Orbit series were included. Cutting geranium cultivars were `Designer Lilac Chiffon' and `Starburst Red' and the ivy geraniums were `Bernardo Guiber' and `Vinco Guivin'. The ASAP amplification protocol used one of two arbitrary octamer primers, followed by reamplification with one of four different minihairpin primers. ASAP profiles were complex, with 66% of bands being polymorphic and useful in distinguishing between cultivars. Genetic relationships were evaluated by principal coordinate analysis and cluster analysis based on the Jaccard distance estimator. This analysis grouped cultivars by species according to commercial type, i.e., seed geraniums were in one large group, the cutting geraniums were grouped together, and the ivy geraniums were a separate branch.
Evaluation of New and Promising Apple Cultivars for New England
Authors: Greene Duane W.
Published: February 2019

Over 225 apple cultivars grown at the Horticultural Research Center in Belchertown have been evaluated for fruit quality and fruit characteristics. Methods used to determine fruit characteristics and organoleptic assessment will be presented. The postharvest potential of the most promising apples will be presented. Two apples ripen about the first of September and show promise for early market. `Sansa' is a medium-sized red apple that ripens about the first of September. It is a high-quality apple with characteristics similar to `Gala'. `Ginger Gold' is a large, firm, mild-flavored, russet-free, yellow apple. `Honeycrisp' is a red apple that ripens in mid-September, before `McIntosh'. It is a large, mild-flavored apple that is sometimes erratic in red color development. It maintains firmness and explosive crispness out of storage better than any other apple evaluated. `Golden Supreme' is an extremely attractive, russet-free `Golden Delicious' type ripening 7 to 10 days before `Golden Delicious'. When ripe it has a very aromatic, fruity flavor. It stores better than `Golden Delicious'. Other apples with merit that have commercial potential include: `Hampshire', `Shizuka', `Cameo', `Creston', `Coop 25', `Coop 29', and `Braeburn'. `Pink Lady' is a very late maturing, new cultivar that is being heavily planted in other areas. Although it does mature here, based upon starch rating, fruit size is small, the flesh is dry and very tart, and taste is only fair.
Reduction of Toxicity of Immature Composts
Authors: Hu Yifan , Barker Allen V.
Published: February 2019

Uses of immature composts are difficult due to wide C:N ratio, high NH4 content, and phytotoxins, such as phenols and low molecular weight organic acids. This research focused on toxicity from high NH4 content. A compost of biosolids and wood chips was used. The compost was treated with (NH4)2SO4 to 2000 mg N·kg-1 (dry weight) to simulate an immature compost. The same compost without any external NH4 was used as a mature compost. Different proportions (regimes) of compost and soil provided 1/3, 1/6, and 1/12 compost (by volume). Each regime received potassium treatment at 0 or 0.6 g K·kg-1 as KC1. A nitrate treatment, at the same N rate as NH4 in immature compost, was factored into both mature and immature composts. For the mature compost, adding K generally decreased tomato (Lycopersicon esculentum Mill.) growth (measured by shoot mass) regardless of regimes. Adding Ca(NO3)2 to mature compost greatly increased plant growth for the regimes of 1/6 and 1/12. When the regime was 1/3, this increase diminished. For the immature compost, adding nitrate restricted plant growth due to excessive amount of N, including already high amounts of NH4. This response was especially true for the 1/3 regime. Adding K to immature compost greatly increased plant growth for the regimes of 1/3 and 1/6; K suppressed plant growth at the regime of 1/12. The results indicated that using K properly can effectively reduce immature compost toxicity due to high amount of ammonium. E-mail barker@pssci.umass.edu
Heavy Metals and Seed Germination in Medicinal and Aromatic Plants
Authors: Jeliazkova Ekaterina A. , Jeliazkov Valtcho D. , Craker Lyle E. , Xing Baoshan
Published: February 2019

Phytoremediation has been suggested as a solution to heavy metal—polluted soils, but the choices of suitable plant species for phytoremediation have been limited. Medicinal and aromatic plants appear to be excellent selections for these plantings, since these plants are grown for economically valuable secondary products (essential oils), not for food or feed. Preliminary research indicates that heavy metals are not accumulated in essential oils, permitting the oil to be used commercially. Productivity of some, but not all aromatic plants was reduced, however, by the heavy metals. The objective of our experiment was to distinguish the mechanism of heavy metal tolerance of plants using germinating seeds of medicinal and aromatic plant species. Seeds from medicinal and aromatic plants were germinated in solutions with selected levels of heavy metals (cadmium at 6 and 10 (μg·L-1; copper at 60 and 150 μg·L-1; lead at 100 and 500 μg·L-1; zinc at 400 and 800 μg·L-1) and in distilled water. Tests on Anethum graveolens L., Carum carvi L., Cuminum cyminum L., Foeniculum vulgare Mill., Pimpinella anisum L., Ocimum basilicum L., and the hyperaccumulator species Brassica juncea L. and Alyssum bertolonii established that different plant species reacted in different ways to the heavy metals. For example, cadmium did not decrease seed germination of Alyssum, O. basilicum, and B. juncea compared with germination in water but did decrease germination of C. cyminum. Lead did not affect germination of A. bertolonii and B. juncea as compared with water but did negatively affect germination of P. anisum, F. vulgare, and C. cyminum. Except for B. juncea, F. vulgare, and C. cyminum, copper had a negative effect on germination. Zinc decreased germination in all tested species except B. juncea.
ReTain Effects on Fruit Size, Maturity, and Storage Quality of' Jonagold' Apples
Authors: Watkins Chris B. , Beaudry Randolph M. , Robinson Terence L. , Lakso Alan N.
Published: February 2019

ReTain™, a commercial plant growth regulator containing aminoethoxyvinylglycine, an inhibitor of ethylene production, was applied 4 weeks before normal harvest to `Jonagold' trees and the effects on fruit maturity and quality at harvest, and quality after air and controlled atmosphere storage was investigated. When fruit were harvested from 3 to 6 weeks after treatment, fruit ripening was inhibited as indicated by lower internal ethylene concentrations, delayed starch hydrolysis, and lower levels of skin greasiness. A number of factors indicated that other aspects of fruit metabolism were affected by the compound. Treated fruit were softer than nontreated fruit at the first harvest, and the benefits of ReTain on firmness appeared only at the later harvests. Also, at each harvest date, average fruit weight of ReTain-treated fruit was lower than nontreated fruit. We have investigated the possibility the ReTain and/or the accompanying surfactant, Silwet, inhibited leaf photosynthesis, thereby leading to altered carbon metabolism. Trees were unsprayed, or sprayed with surfactant, and ReTain plus surfactant. No treatment effects on photosynthesis were detected. However, leaf photosynthesis rates were generally low and quite variable. Measurements of fruit diameter confirmed that the increase in fruit volume following treatment was ≈2% less on the ReTain plus surfactant-treated fruit than nontreated fruit. The increase in fruit volume for the Silwet treatment was ≈1.5% less than in untreated fruit. The data indicates a rapid change in fruit volume as fruit changed in color. Inhibition of ethylene by ReTain may be an important factor influencing fruit size.
Strawberry Waiting-bed Plants: A Valid Alternative to Increase Early and Total Yields in Subtropical Regions
Authors: Kirschbaum Daniel S. , Honorato Javier , Cantliffe Daniel J.
Published: February 2019

Strawberry (Fragaria xananassa Duch.) production in subtropical areas is characterized by a low late-fall and early winter fruit yield, a time when the value of the crop is the highest of the season. Under this context, the objective of the present study was to evaluate the feasibility of waiting-bed plants for late fall and early winter production in order to increase early and total fruit yields in the Argentine sub-tropic. Plants of the cultivar `Chandler' produced in a waiting-bed (WB), at high-latitude (HL), high-altitude (HA), or low-altitude (LA) were compared at two locations in Tucuman, NW Argentina: Famailla (1995, experiment 1; 1996, experiment 2) and Lules (1995, experiment 3). Total production from WB plants was 41% higher than from HA plants in experiment 1. Total production from WB plants was 83 % and 53 % greater than from HL plants and LA plants, respectively, in experiment 2. Early season fruit production was greater in WB (241%) than HL plants in experiment 2. In experiment 3, early fruit production from WB plants was greater than HL, HA, and LA, by 573, 177, and 158%, respectively. The number of marketable fruit from WB plants was larger than in the other treatments (139-231%). WB percentages of marketable fruit were above 90%. The results suggest that WB plants could be considered as an alternative to HL, HA, and LA plants to improve strawberry production and yield distribution in South American subtropical regions.
Evaluation of Disease Resistance among 57 Varieties of Zinnia elegans
Authors: Gombert Linda , Hamilton Susan , Windham Mark
Published: February 2019

Fifty-seven of the most widely grown, commercially popular varieties of Zinnia elegans were evaluated for disease susceptibility under uniform field conditions. Plants were started from seed and transplanted into cell-packs to be grown on as bedding plants. They were later transplanted into the field and observed for development and progression of the diseases alternaria blight (Alternaria zinniae), powdery mildew (Erisyphe cichoracearum), and bacterial leaf and flower spot (Xanthomonas campestris pv. zinniae). Evaluations were performed throughout the growing season in order to rate each variety on its susceptibility to disease based upon severity of infection as well as portion of plant affected. Results will be presented on disease susceptibility and resistance of the 57 varieties evaluated.
Selection of Cold-hardy Rootstocks
Authors: Peterson Mary , Hoover Emily
Published: February 2019

Cold-hardy candidates from the Univ. of Minnesota Vitis collection were evaluated for potential use as commercial rootstocks for the production of cold-tender grapes in conditions typical of the eastern and midwestern United States. The 53 genotypes studied were selected from the collection based on past field performance and cold-hardy parentage. These were compared with standard commercial rootstocks for these regions—C3309 and SO4—for characteristics typically evaluated in rootstock production: rooting ability, vigor, phylloxera resistance, disease resistance, first season root development, suitability of rootstock wood, ease of grafting and callusing, and growth of scion bud. In addition, indications of onset of dormancy were monitored to identify those genotypes with potential to influence scion dormancy regime for the purpose of increasing scion cold-hardiness.
Yield and Quality Evaluation of Zucchini and Yellow Squash Varieties
Authors: Infante M.L. , Garrison S.A. , Mangano S.A. , Probasco P.R.
Published: February 2019

In Summer 1997, zucchini (ZC) and yellow squash (YS) varieties were evaluated for yield and aesthetic qualities at the Rutgers Agricultural Research and Extension Center in Bridgeton, N.J. Only green ZC varieties and straightneck YS varieties were tested These types are commercially acceptable to fresh markets in New Jersey. Trials included 15 ZC and 11 YS varieties from seven participating seed companies. Experimental design included two sites arranged in a randomized complete-block design with three replications. Site 1 included the ZC varieties and Site 2 included YS varieties. Squash plants were grown on raised beds with black plastic mulch and drip irrigation. Squash was hand seeded on 30 May and harvests began on 7 July. Pesticides and fertilizers were applied according to the 1997 Rutgers Commercial Vegetable Recommendations Gluide. Plots were harvested, graded, weighed, and yield data recorded three times weekly; 12 harvests (over 4 weeks) for ZC and 15 harvests (over 15 weeks) for YS. Of the 15 ZC varieties, five expressed exceptional quality and highest yields: `Spineless Beauty', `Zucchini Elite', `Select', `XPHT-1776', `XPHT-1777'. Statistics showed that yields for these five varieties and two other ZC varieties were significantly higher than other ZC varieties trialed. There were no statistically significant yield differences among the 11 YS varieties evaluated. Fruit color from ZC and YS was subjectively rated to classify fruit into three categories: Dark Green, Medium Green, Light Green for ZC and Golden, Pale Yellow, and Yellow-Green for YS.
Heritability of Postharvest Longevity of Antirrhinum majus
Authors: Schroeder Kenneth R. , Stimart Dennis P.
Published: February 2019

Breeding for postharvest longevity of cut flowers has not been done to any great extent in spite of the potential benefits from reduced chemical preservative usage and increased popularity of cuts due to longer vaselife. Some studies have reported broad-sense heritabilities for postharvest longevity of 36% to 46% and narrow-sense heritabilities of 0% to 38%. Postharvest longevity of cut flowers of Antirrhinum majus L. (snapdragon) inbreds range from 2 to 16 d with the F1 hybrids intermediate at 8.1 d when evaluated in deionized water. It would appear postharvest longevity of snapdragon cut flowers should be a selectable trait. In an effort to determine narrow-sense heritability for postharvest longevity of snapdragon cut flowers, a generation means analysis was established using single-seed descent S4 generation inbreds with postharvest longevities of 2 and 15 d. Plants were grown in greenhouses at the Univ. of Wisconsin, Madison, in August and harvested in Nov. 1997 for postharvest evaluation. Experimental design was a randomized complete block with 2 environments and 3 replications. Nonsegregating generations (P1, P2, and F1) consisted of 10 plants per replication, backcrosses 30 plants per replication, and the F2 with 60 plants per replication. Data will be presented on narrow-sense heritability of postharvest longevity of snapdragon cut flowers.
Nitrogen Fertilization of Basil
Authors: Rangappa M. , Bhardwaj H.L.
Published: February 2019

Sweet basil (Ocimum basilicum) is an important culinary herb in Virginia and other areas. The objective of this study, conducted during 1997, was to determine optimal N rate for fresh and dry matter yield. Seed of Broad Leaf sweet basil were direct-seeded on 18 June in rows 0.75 m apart in a RCBD design with 8 replications. Four N rates (0, 25, 50, and 75 kg N/ha) were used. Calcium nitrate (15.5% N) was used as the fertilizer source. All plants from 1-m row length from middle row of each plot were harvested by hand on 23 Sept. and fresh weights were recorded. The plant material was dried at 70°C for 48 h to record dry weights. The moisture content at harvest was calculated from fresh and dry weights. The fresh yields following 0, 25, 50, and 75 kg N/ha were 3.7, 5.4, 6.4, and 6.8 kg/m2, respectively. The yield difference between two highest N rates was not significant, however, both these rates had significantly higher yield than the two lowest rates. Similar results were also obtained for dry matter yields. The highest N rate of 75 kg N/ha resulted in significantly higher dry matter yield (1.3 kg/m2) as compared to the other three rates. The lowest dry matter yield was obtained after the control treatment (0.6 kg/m2). An opposite relationship between N rate and moisture content was observed when the highest moisture content resulted from control and 50 kg N/ha treatments. These results indicate that optimum N rate for sweet basil in Virginia is 50 to 75 kg/ha.
Characterization of the Reproductive Mode in Guayule In Vitro
Authors: Keys Roy N. , Ray Dennis T. , Dierig David A.
Published: February 2019

Guayule (Parthenium argentatum Gray, Asteraceae) is a latex-producing perennial desert shrub that is potentially of economic importance as an industrial crop for the desert Southwest. It is known to possess complex reproductive modes. Diploids are predominantly sexual and self-incompatible, while polyploids show a range of apomictic potential and self-compatibility. This paper describes the development of a relatively rapid and simple technique for characterizing reproductive modes of breeding lines of P. argentatum. Initial field experiments were based on an auxin test used successfully to characterize reproductive mode in the Poaceae. The application of 2,4-dichlorophenoxyacetic acid inhibited embryo formation in P. argentatum, but this was not the case with other auxins tested. Results of field experiments were ambiguous because: 1) the floral structure of P. argentatum is such that auxins might not have penetrated to the ovules, and 2) there was potential self-fertilization by pollen released within isolation bags. Therefore, in vitro culture of flower heads was tested because it provided much better control of environmental conditions, growth regulator application, and pollen release. Auxin alone, or in combination with gibberellic acid or kinetin, inhibited parthenogenesis in vitro. Embryo production did not vary using two substantially different nutrient media. In vitro flower head culture using a (Nitsch and Nitsch) liquid nutrient medium without growth regulators, enabled characterization of the reproductive mode of seven breeding lines, ranging from predominantly sexual to predominantly apomictic. The results of this technique were substantiated using RAPD analyzes of progeny arrays from controlled crosses.
Effects of Ethylene Scrubber and Light on Yellowing of Geranium Transplants
Authors: Cheng Guiwen W. , Sargent Steven A. , Huber Donald J.
Published: February 2019

The yellowing of geranium transplants under simulated non-refrigerated transit conditions was investigated with ± KMnO4-based ethylene scrubber or supplemental light. The transplants were stored in the dark at 20 °C in glass jars or cartons, some of which were treated with ± ethylene scrubber (8 g) and/or ± light. Transplants (8) were removed daily for measurement of leaf yellowing intensity (= percentage of the sum of the products of yellowing rate and leaf number within the rate over the potential maximal sum, where rate 0 equals no yellowing; 1, discrete margin yellowing; 3, yellowing along margin; 4, uniform yellowing). Yellowing was evident after 1 day storage (3 days postharvest). The yellowing of `Pinto Red' geranium transplants stored in cartons progressed similarly ± ethylene scrubber (≈99% yellowing intensity on day 5). In jars, the scrubber delayed the yellowing of `Pinto Red' from 83% to 75% by the end of the 5-day test period. In a separate test of `Pinto Salmon' in jars, yellowing was delayed from 68% without scrubber to 30% with scrubber. Weak incandescent light plus scrubber substantially reduced yellowing in `Pinto Pink'(43%) compared with dark, – scrubber (96%) after 6 day storage. Under fluorescent light, yellowing in `Pinto Pink' was ≈20%. The results showed that the absence of light was the key stress factor causing yellowing in geranium transplants. Yellowing retardation by ethylene scrubber was observed only in a closed system and the effect was variety dependent.
Performance of Three Species of Salad-type Plants Grown under Narrow-spectrum Light-emitting Diodes (LEDs) in a Controlled Environment
Authors: Goins G.D. , Yorio N.C. , Kagie H.R. , Wheeler R.M.
Published: February 2019

Light-emitting diodes (LEDs) are a promising light source for growing crop plants in spaceflight systems because of their superior safety, durability, small mass and volume, wavelength specificity, and long life. To address the usefulness of LEDs as a plant lighting source, radish (Raphanus sativus L. cv. Cherriette), lettuce (Lactuca sativa L. cv. Waldmann's Green), and spinach (Spinacea oleracea L. cv. Nordic IV) were grown using nutrient film technique hydroponics under cool-white fluorescent (CWF) lamps, red LEDs (peak emission 660 nm), and red LEDs + 30 μmol·m–2·s–1 supplemental blue fluorescent (BF) light (400–500 nm). Each lighting treatment was maintained in a separate controlled-environment chamber with total photosynthetic photon flux (PPF) maintained near 300 μmol·m–2·s–1 and a photoperiod of 18-h light/06-h dark. Results showed significant reductions in total dry mass (TDM) accumulation for radish plants grown under red LEDs + 30 μmol·m–2·s–1 BF or red LEDs only as compared to CWF-grown plants. Although TDM tended to decrease with decreasing BF for lettuce, treatment differences were not significant. TDM for spinach plants was significantly less under red LEDs compared to CWF or red LEDs + 30 μmol·m–2·s–1 BF. Interestingly, single-leaf photosynthesis and leaf conductance were not significantly different for any treatment, regardless of species. The data suggest a species-specific response for the amount of blue necessary for normal plant growth.
Electronic Nose: A Non-destructive Technology to Screen Tomato Fruit with Internal Bruising
Authors: Moretti Celso L. , Sargent Steven A. , Puschmann Rolf
Published: February 2019

Tomato (Lycopersicon esculentum Mill) fruit, cv. Solar Set, were harvested at the mature-green stage and gassed with 100 mg·kg–1 of ethylene at 20 °C. At the breaker stage, fruit were held by vacuum to avoid fruit rotation and dropped from a 40 cm height on a metallic, solid, smooth surface. Following impact, fruit were stored at 20 °C and 85% to 95% relative humidity until table-ripe stage. Bruised and unbruised fruit were then placed individually inside the electronic nose-sampling vessel and the 12 conducting polymer sensors were lowered into the vessel and exposed to the volatile given off by the fruit. Data were analyzed employing multivariate discriminant analysis (MVDA), which maximizes the variance between treatments. The degree of dissimilarity was defined using the Mahalanobis distance and posterior probabilities were calculated to accurate re-classification of cases. The differences found between bruised and unbruised fruit were highly significant (P < 0.0041). The Mahalanobis distance between groupings (28.19 units) was a dramatic indicative of the differences between the two treatments. The re-classification of bruised and unbruised fruit using a single linear discriminant function was highly accurate, being 1.0 for both bruised and unbruised fruit. The electronic nose proved to be a useful tool to nondestructively identify and classify tomato fruit exposed to harmful postharvest practices such as mechanical injuries. However, there are still some factors that must be investigated, including system stability and the development of specific sensors for specific commodities.
The Plumeria Germplasm Collection of the University of Hawaii
Authors: Criley Richard A.
Published: February 2019

Founded in the mid-1960s to serve as a repository for the diverse plumeria (Family: Apocynaceae) varieties found in Hawaii, the collection has been moved twice and now occupies an area of 0.8 ha. Since the retirement of the plant breeder who initiated the collection, no active breeding program is in place, but the collection is augmented by donation of plumeria cuttings thought by their discoverers to have exceptional merit. The plant material is evaluated for habit of growth, susceptibility to rust, and for flower qualities including productivity, color, size, petal overlap, fragrance, and keeping quality. Recent accessions include several compact, evergreen plumerias with pink and yellow flowers showing both Plumeria obtusa and P. rubra parentage. Several plumeria cultivars developed in Texas have demonstrated positive qualties in the more favorable growing conditons of Hawaii. Several Hawaii accessions to be registered with the Plumeria Society of America in 1998 will be described and illustrated in this presentation.
Comparison of Mother Stalk Culture and Clear-cut Harvesting for Spring Production and Forcing in Late Summer
Authors: Dufault Robert J.
Published: February 2019

Short lifespan is a major problem with asparagus grown in coastal South Carolina. The Taiwanese system of mother stalk culture may enhance asparagus longevity and yield. The objective was to determine if mother stalk culture improves survival and yields in the spring harvests or late summer forcing compared to conventional spring clear-cut harvesting or to non-conventional forced clear-cut summer harvesting. `Jersey Giant' asparagus was harvested for 3 years (1993–1996) using: 1) SCC–spring clear-cut (normal emergence in February in this location), 2) SMSuM–spring mother stalk followed by summer mother stalk (mow fern in August and establish new mothers), 3) SM–spring mother stalk only, 4) SuCC-summer clear-cut only (mow fern in August and harvest), and 5) SuM–summer mother stalk only. All mother stalk plots produced 40 mother stalks per 12 m of row length before harvesting. All plots were harvested for 8 weeks. Traditional SCC yielded poorly for a 3-year total of 1,651 kg/ha with a 94% stand reduction after 3 years. SM yielded only 793 kg/ha for all years with a 98% stand loss. SMSuM yielded 1985 kg/ha total for 3 years with an 81% stand loss. SuCC yielded 4073 kg/ha for 3 years with 43% stand loss. SuM yields and stand loss were similar to SuCC. Stand loss in an unharvested controls was 34%. Mother stalk culture did not improve longevity any time. Spring harvesting systems failed because by mid summer, aged fern depleted crown carbohydrates and repeated yearly, this eventually killed the plants. Summer forcing removed aged fern just about the time the fern became inefficient and new efficient fern produced sugars for root storage well into the fall, making recovery successful and sustaining plant longevity compared to traditional spring harvesting.
Potassium Fertilization Affects Yield and Leaf Mineral Concentration of Slicing Cucumber
Authors: Smith Carrie L. , Hochmuth George J.
Published: February 2019

Successful fertilization of a crop depends on knowing the crop nutrient requirement (CNR) for production of maximum economic yield and on using soil tests that are properly calibrated and correlated with crop response. During Summer 1997, `Lightning' cucumber was grown with white-on-black polyethylene mulch, methyl bromide fumigation, and drip irrigation on beds with 1.2-m centers. Two rows of cucumbers were planted per bed with an in-row spacing of 30.5 cm. Treatments were 0, 40, 85, 170, 340 kg·ha–1 K on a soil testing “low” in potassium (Mehlich 1 extractable K = 24.3 mg·kg–1 soil). Treatments were applied 20% preplant and the remainder injected through drip irrigation in five equal amounts as determined by treatment. The most recently matured leaf was sampled at first flower, full bloom, and first harvest for determination of K concentration. Leaf K concentration at first flower showed a quadratic response with a maximum of 54 g·kg–1 at 445 kg·ha–1 K. At full bloom and first harvest sampling, leaf K concentration showed a linear response over the range of 0 to 340 kg·ha–1 K. Leaf K was deficient for plants receiving 0 and 40 kg·ha–1 K at the full bloom sampling. Early yields (harvests 1+2) of U.S. number 1 and total marketable fruits increased linearly over the treatment range. Season total yield of U.S. fancy and total marketable fruits increased quadratically with maxima of 43 MT·ha–1 and 67 MT·ha–1 at K rates of 270 kg·ha–1 and 300 kg·ha–1, respectively, while U.S. number 1 yield increased linearly.