bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement Opportunities for Growers of Ornamental Plants: A Survey of Landscape Architects
Authors: Garber M.P. , Bondari K.
Published: February 2019

A survey of landscape architects in Georgia was conducted to identify opportunities for nurseries to meet the needs of landscape architects and to improve the quality of installed landscapes. The primary opportunities identified for improvement for growers are to provide regular, frequent plant availability (32% of respondents); develop new plant varieties for specific needs (21%); supply plants that meet specified sizes (20%); recommend plant varieties for specific conditions (12%); provide picture of plants (9%); and make presentations to landscape architects (5%). Additional insight into how growers can help landscape architects achieve a higher quality installed landscape was gained from the question, `What is the most common complaint you experience regarding plant material installed?” Landscape architects indicated that plants below specified size (44%) and plants below specified quality (24%) were the two most common complaints.
Manipulating Primocane Architecture in Thornless Blackberry with Uniconazole, GA3, and BA
Authors: Malik Hermen , Archbold Douglas D.
Published: February 2019

The potential for plant growth regulator (PGR) manipulation of `Chester Thornless' blackberry (fibus spp.) primocane growth was evaluated. PGR treatments included combinations of soil-applied uniconazole at 1, 5, 25, and 125 mg/plant and GA, foliar-applied one or two times at 100 ppm 3 and 4 weeks after a 25-mg/plant uniconazole application. Also, GA and BA were applied at 100 ppm alone or in combination one, two, or three times. Increasing rates of uniconazole reduced primocane length, leaflet count, and leaf, cane, and root dry weights. GA, applications reduced primocane length and increased branch elongation but failed to reverse the effects of uniconazole at 25 mg/plant, except those on branch length, leaflet count, and primocane dry weight. Only applications of BA + GA, increased both branch production and elongation and dry weights of some component tissues, while BA alone generally had no effects. Chemical names used: (E)-1-(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol (uniconazole); N-(phenylmethyl)-1H-purin-6-amine (benzyladenine, BA); gibberellic acid (GA).
Residual Efficacy of Uniconazole and Daminozide on Potted `Bright Golden Anne' Chrysanthemum
Authors: Tayama Harry K. , Carver Stephen A.
Published: February 2019

Residual activity of a single uniconazole spray (15 mg a.i./liter), uniconazole drench (600 μg a.i./pot), and daminozide spray (5000 mg a.i./liter) were compared to an untreated control using the `Bright Golden Anne' chrysanthemum [Dendranthema grandiflorum (Ramat.) Kitamura]. Based on weekly internode growth, spray and drench treatments with daminozide and uniconazole remained active for 2 to 2.5 and 3 to 3.5 weeks, respectively. Chemical names used: butanedioic acid mono (2,2-dimethylhydrazide) (daminozide); (E)-1-(p-chlorophenyl)-4,4-diemethyl 1-2(1,2,4-triazol-2-yl)-l-penten-3-01 (uniconazole).
Inheritance of Tolerance to Mineral Element-induced Chlorosis in Rabbiteye Blueberry
Authors: Gupton Creighton L. , Spiers James M.
Published: February 2019

A study of leaf chlorosis in rabbiteye blueberries (Vaccinium ashei Reade) grown in soil containing 300 to 400 ppm diethylenetriaminepentaacetic acid (DTPA)-extracted Mn revealed no relationship between leaf Mn content and chlorosis. A second study was conducted to estimate heritability of the content of Mn, Fe, and certain other mineral elements that have been associated with leaf chlorosis and to determine the genetic relationships among shoot dry weight, visual rating, and the mineral elements in rabbiteye blueberry. Heritability estimates were high for all variables except Fe, suggesting that changes in Mn, Zn, Ca, Mg, or K contents could be expected from phenotypic recurrent selection. However, manipulation of mineral content probably would not ameliorate the Fe chlorosis. The high heritability of shoot dry weight and visual rating and the high genetic correlation between these variables suggest that plants resistant to mineral effects on Fe metabolism can be selected on the basis of visual rating.
Evaluation of Cold Hardiness of Blackberry Seedling Populations
Authors: Bourne Timothy F. , Moore J.N.
Published: February 2019

Twelve seedling blackberry (Rubus spp.) populations were tested over 2 years for cold hardiness of stem and bud tissues. Seedling populations resulted from a partial diallele of crosses made among nine parents representative of three categories of cold hardiness. Viability testing of xylem, phloem, and bud tissues was conducted following exposure to a temperature lethal to 50% of tested tissue. Significant population effects (P < 0.05) occurred for xylem and bud cold hardiness in 1988 and for xylem, phloem, and bud cold hardiness in 1989. Results were similar for the 2 years, although there was a greater discrimination between populations for xylem and phloem cold hardiness in the 2nd year. Seedling populations having `Darrow' as a parent showed less tissue damage than the other eight populations. The populations having `Brison' as one parent showed consistently poor hardiness with the exception of one resulting from a cross of `Brison' × `Darrow'. This population showed consistently good hardiness, indicating that dominance effects may play a role in cold hardiness of blackberries.
Sod Production on a Solid-waste Compost over Plastic
Authors: Cisar John L. , Snyder George H.
Published: February 2019

The objective of this experiment was to determine the suitability of a compost obtained from a commercially available solid-waste processing plant for sod production when placed over a plastic barrier. Comparisons were made between compost-grown sod with and without fertilizer and between compost-grown sod and commercially grown sod. Six weeks after seeding or sprigging, both fertilized and nonfertilized compost-grown `Argentine' bahiagrass (Paspalum notatum Flugge), `Tifway' bermudagrass (Cynodon transvaalensis × C. dactylon), and `Floratam' St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze.] had discolored leaf blade tissue and poor growth. At 6 weeks, bahiagrass leaf tissue had a low N concentration, which suggested that the compost immobilized fertilizer N. Additionally, initial high salinity of the compost (2.85 dS·m-1) may have contributed to turf discoloration and lack of vigor. However, poor growth and discoloration were temporary. At 3 and 5 months, fertilized compost-grown turfgrasses had higher quality and coverage than nonfertilized sod. At 5 months, fertilized sod had sufficient coverage for harvest, whereas for conventional field production 9 to 24 months generally is required to produce a harvestable product. Compost-grown sod pieces had similar or higher tear resistance than commercially grown sod. One and 3 weeks after transplanting on a sand soil, compost-grown sod produced higher root weight and longer roots in the underlying soil than did commercially grown sod. The solid-waste compost used in this study offers a viable alternative material for producing sod that will benefit solid-waste recycling efforts.
Reduction of Phytotoxicity in Polyurethane Foam-containing Potting Media
Authors: Wees David , Donnelly Danielle
Published: February 2019

Leachates were produced by washing Hydra-fill, a polyurethane ester foam, with water. These leachates decreased radish (Raphanus sativus L.) and tomato (Lycopersicon esculenturn Mill.) seed germination and were phytotoxic to seedlings. Washing the foam for as little as 5 minutes (compared to not washing) before collecting the leachate significantly decreased the mean seed germination time by 0.6 to 1 day. Rinsing the foam with ethanol before collecting the leachate was detrimental to germination. When used as a potting medium component, the foam reduced radish shoot and root dry weights compared to potting media without foam. Washing the foam with tap water before use resulted in increased radish shoot and root dry weights. Hydra-fill generally reduced plant performance when included in potting media. However, radish grew well in fresh 25% Hydra-fill (raw or washed) mixed with loam.
Sodium Chloride Resistance in Selected Cultivars of Hedera helix
Authors: Headley David B. , Bassuk Nina , Mower Robert G.
Published: February 2019

Two experiments were conducted to determine the relative resistance of 33 selected cultivars of English ivy (Hedera helix L.) to soil- and shoot-applied NaCl. In the soil-applied NaCl experiment, ramets of the 33 cultivars were irrigated with a fertilizer + 0.25-N NaCl solution for 55 days. `Harrison', `Hibernica', `Thorndale', Wilson', and Woerner' exhibited the least amount of visible shoot damage. Dry weights of all cultivars were much lower in the salt treatment. In the shoot-applied NaCl experiment, plants were sprayed daily with a 0.25-n NaCl solution for 48 days. The young leaves and stems of all cultivars were severely injured by the salt spray, while the mature leaves and stems and the dormant buds were only slightly injured. Reduction in dry weight varied between cultivars. Two subsequent experiments focused on resistance to soil-applied NaCl. Ramets of the NaCl-resistant `Harrison', `Hibernica', and `Thorndale', and the NaCl-sensitive `Baltica', `Cathedral Wall', and Wingertsberg' were irrigated with a fertilizer + 0.25-N NaCl solution for 48 days. Whole-plant Cl content for all six cultivars was in the range of 30,000 ppm. Ramets of `Thorndale' and `Cathedral Wall' were irrigated with a fertilizer + 0.25-N NaCl solution for 30 days with replicate plants harvested at S-day intervals. `Cathedral Wall' accumulated more Cl at a faster rate than `Thorndale'. Mean whole-plant Cl concentration peaked at 97,000 ppm for `Cathedral Wall' and 40,000 ppm for `Thorndale'. Salt resistance may be partly based on slower uptake of Cl.
In Vitro Propagation of the Rare and Endangered Grevillea scapigera (Proteaceae)
Authors: Bunn Eric , Dixon Kingsley W.
Published: February 2019

Micropropagation, including adventitious shoot growth from leaf sections, was achieved for Grevillea scapigera (Proteaceae), a rare and endangered species from Western Australia. Shoot tips were initiated on filter paper supports with liquid WPM (Woody Plant Medium) and supplemented with 20 μm zeatin riboside and 2 μm GA3. Shoots were then incubated on WPM solidified with agar and supplemented with 5 μm kinetin and 0.5 μm BA, which produced an approximate 6-fold multiplication rate per month. Up to three adventitious shoots were induced from 0.7-cm2 leaf sections after 6 to 7 weeks on solid 1/2 MS (Murashige and Skoog) medium supplemented with 10 μm BA and 0.5 μm IBA. Shoots, 30 to 50 mm long, were rooted in vivo in a fogged glasshouse under 70% shade using a commerical rooting powder [IBA, 0.1% (w/w)] applied to the base of the shoots. Most (67%) of the shoots treated in this way rooted after 5 weeks. Established, rooted plants have been grown on under glasshouse conditions. Chemical names used: N6-[2-isopentenyl] adenine riboside (zeatin riboside); gibberellic acid (GA3); 6-furfurylaminopurine (kinetin); N-(phenylmethyl)-1H-purine-6-amine (BA); 1-H-indole-3-butyric acid (IBA).
An Expert System for Integrated Production Management in Muskmelon
Authors: Sullivan Glenn H. , Ooms William J. , Wilcox Gerald E. , Sanders Douglas C.
Published: February 2019

A management expert system that enables producers to fully assess the integrated resource requirements, management risks, and profit potential for growing muskmelon was developed. The expert system environment Guru was used as the development software.
Chrysanthemum Response to Timing of Paclobutrazol and Uniconazole Sprays
Authors: Gilbertz David A.
Published: February 2019

Spray applications of 15 or 30 mg uniconazole or 30 or 60 mg paclobutrazol/liter (20 ml/1.5-liter pot) were sprayed 0, 2, or 4 weeks after pinching of Dendranthema × grandiflorum (Ramat.) Kitamura `Bright Golden Anne' plants. Plants were shorter the earlier growth regulators were applied. Plants were more responsive to uniconazole, requiring paclobutrazol at up to four times the uniconazole concentration to achieve the same height control. Time to flowering was also lengthened the earlier applications were made, up to 3 days compared to nontreated plants. Flower diameter was only minimally affected by the treatments. Chemical names used (2RS,3RS)-1-(4-chlorophenyl)-2-1,1-dimethylethyl)-(1H-1,2,4-triazol-1-yl)pentan-3-ol(-paclobutrazol);(E)-l(p-chlorophenyl) -4,4-dimethyl-2-(1,2,4-triazol-1-yl-1-penten-3-ol) (uniconazole).
Correlation between Early and Late Growth Characters in an Improved True Potato Seed Population
Authors: Golmirzaie A. , Serquen F.
Published: February 2019

A field experiment was conducted at two locations to determine the correlation between seedling and mature plant characters in a large potato (Solanum tuberosum) population developed for production from true potato seed. There was no significant correlation between seedling and reproductive characters, including earliness, at the two locations. Number of internodes and yield per plant were significantly correlated at Huancayo, and at San Ramon, root length and hypocotyl length had a significant correlation with the number of tubers per plant and yield per plant. Although significant, the latter correlations are not high enough to be used to predict the final behavior of genotypes by their seedling traits. Thus, it may be assumed that a certain independence between seedling and mature plant growth characters exists.
RFLPs Obtained from an rDNA Probe and Detected with Enhanced Chemiluminescence in Apples
Authors: Nybom Hilde , Gardiner Susan , Simon Charles J.
Published: February 2019

Individual-specific DNA fragment patterns were obtained by hybridization of endonuclease-digested apple (Malus ×domestica Borkh.) DNA with a probe (pAR72) derived from the rDNA spacer region of the `White Angel' crab apple. Fragment detection was carried out with a nonradioactive method, using a horseradish peroxidase-catalyzed luminol oxidation. Paternity could be inferred by comparison of the fragment pattern generated by a seedling with those derived from putative parents.
A System for Controlling Water Potential in Seed Germination Research
Authors: Allen Phil S. , White Donald B. , Russer Karl , Olson Dave
Published: February 2019

An inexpensive system for maintaining desired water potentials throughout seed germination was developed. During hydration, a water reservoir at the base of inclined petri dishes allowed continual saturation of filter paper on which seeds were placed. During dehydration, seeds were exposed to equilibrium vapor pressures above saturated salt solutions. Constant temperature, necessary to prevent condensation of water vapor, was achieved via a small (0.2 A) fan that furnished and circulated heat throughout an insulated chamber in which salt solutions were placed. By operating the chamber above ambient laboratory temperature, interior cooling was not required. The system allowed manipulation of the rate, degree, and frequency of dehydration episodes to which germinating seeds were exposed.
Conventional Selection versus Methods that Use Genotype × Environment Interaction in Sweet Corn Trials
Authors: Bachireddy V.R. , Payne R. , Chin K.L. , Kang M.S.
Published: February 2019

The analysis of variance of a data set made up of 30 sweet corn (Zea mays L.) hybrids evaluated over 5 years for marketable ears (dozens per hectare) indicated a significant genotype (hybrid) × year (GY) interaction. Three selection methods were compared: 1) a conventional method based on mean yield alone (YA), 2) Kang's ranksum (KRS) method, and 3) Kang's modified rank-sum (KMR) method. The number of hybrids selected on the basis of YA, KRS, and KMR was 13. The KRS selected the lowest number of unstable hybrids (three) compared with the YA and KMR, which selected eight and six unstable hybrids, respectively. The mean yields of the selected hybrids were 3034 dozen/ha for YA, 2945 dozen/ha for KRS, and 3019 dozen/ha for KMR. The mean yield of KRS-selected hybrids and KMR-selected hybrids was <2.9% and 0.5%, respectively, than that of YA-based selections. This yield reduction was regarded as insignificant considering the farmer would be able to choose more consistently performing hybrids on the basis of KRS than on the basis of KMR or YA. Heterogeneity due to environmental index is the mean of all genotypes in the jth year and X is the overall mean) was significant and was removed from the GY interaction. The removal of heterogeneity revealed that hybrids 77-2269, 116-Kandy Korn-EH, Golden Queen, 141-Sundance, Merit, and Stowell Evergreen were unstable because of a linear effect of the environmental index, and that hybrids 76-2681 and 806F-Truckers showed stable performance due to a linear effect of the environmental index.
Infusion of shrunken-2 Sweet Corn Seed with Organic Solvents: Effects on Germination and Vigor
Authors: Hung Patricia E. , Fritz Vincent A. , Waters Luther
Published: February 2019

Sweet corn (Zea mays L. var. rugosa Bonaf.) seed carrying the mutant endosperm gene shrunken-2 (sh2) are very susceptible to seed rot and pre- and post-emergence damping off. Experiments were conducted to determine if selected organic solvents were suitable carriers for fungicide infusion of sh2 sweet corn seed for improved germination and stand establishment. Seed of `Florida Staysweet' and `Crisp-n-Sweet 710' were immersed in acetone, cyclohexane, decahydronaphthalene (Decalin), dimethylsulfoxide (DMSO), ethanol, or xylene for 5 seconds, 0.25, 0.50, 1.0, 2.0, 4.0, or 8.0 hours, air-dried, and subjected to a cold-stress test. Total germination and percentage of normal seedlings in both cultivars were significantly decreased after 8 hours of immersion in acetone. Average seedling dry weight, however, did not decrease. DMSO was highly toxic to both cultivars. Ethanol increased seed mortality with increasing immersion times. Cyclohexane, Decalin, and xylene caused erratic responses in all measured variables as immersion time increased. In a second experiment, the effects of immersion time up to 4 hours in acetone on germination and vigor of 11 sh2 cultivars were compared. There was no correlation between cultivar germination or vigor and immersion in acetone. Results indicate acetone could be used to infuse fungicides into the seed of some sh2 cultivars without compromising seed germination or vigor. However, each sh2 cultivar must be screened individually to determine if it is a suitable candidate for organic solvent infusion of fungicides.
CHILLING INJURY OF TROPICAL HORTICULTURAL COMMODITIES
Authors: Wang Chien Yi
Published: February 2019

Chilling injury inhibits the growth and development of tropical plants and shortens the postharvest life of tropical horticultural commodities. This presentation will emphasize the postharvest aspects of chilling injury. While most tropical commodities are sensitive to temperatures below 10 to 15C, specific critical temperatures may vary with the species, stage of development, and type of tissue. Likewise, symptoms of chilling injury also vary with different commodities. Reduction of chilling injury can be achieved either by increasing the tolerance to chilling in sensitive tissues or by delaying the development of chilling injury symptoms. Some methods involve the manipulation and modification of the storage environment, whereas other techniques involve direct treatment to the commodities. Specific examples of the alleviation of chilling injury in various tropical commodities will be discussed.
A CLOSED, INSULATED PALLET PRODUCTION SYSTEM
Authors: Green James L. , Robbins James A. , Briggs Bruce A.
Published: February 2019

A closed, insulated, pallet production system (CIPPS) has been designed to meet current challenges: 1) Elimination of production related pollution. 2) Reduction and conservation of resources. 3) Improvement of working conditions. 4) Alternatives to pesticides. 5) Prevention of temperature extremes and rapid temperature fluctuations in the plant environment. Biological feasibility of CIPPS was established in research on pathogen epidemiology, water and fertilize efficiency, plant growth and development in CIPPS. Water and fertilizer ion movement-removal in the closed system was plant-driven in response to growth and transpiration; water and fertilizer use in CIPS was 10% of that applied to open containers. Growth of 28 plant species ranging from herbaceous annuals to woody perennials was greater in CIPPS than in control, individual containers. Phytophthora cinnamomi did not spread from inoculated to noninoculated plants within CIPPS. Inoculation with nonpathogenic bacteria increased plant growth (gfw) in CIPPS but not in open plant containers.
THE USE OF TREESHELTERS IN NURSERY PRODUCTION
Authors: Burger David W. , Harris Richard W. , Svihra Pavel
Published: February 2019

Treeshelters are translucent, polypropylene tubes that have been used in England for 10 years to improve the transplantation success and early growth of trees in the landscape. The focus of the presented research will be on the use of treeshelters in producing plants in the container nursery. The results from outdoor nursery and greenhouse, solution culture experiments will be presented. Treeshelters increase the temperature, relative humidity, and carbon dioxide concentration around those plants growing in them. Photosynthetically active radiation (PAR) inside shelters is reduced 40-60% depending on treeshelter color. Plants growing in treeshelters show increases in height and in the ratio between total fresh weight and total dry weight. However, plants growing in treeshelters also show decreases in leaf, stem, and root fresh and dry weights and leaf area. The potential benefits and current challenges surrounding the use of treeshelters will be discussed.
NITROGEN USE IN AN ASPARAGUS/LIVING MULCH CROPPING SYSTEM
Authors: Paine Laura , Newenhouse Astrid , Harrison Helen
Published: February 2019

Seedlings of Syn 4-56 hybrid asparagus were planted in May, 1990 on loamy sand in the irrigated Central Sands region of Wisconsin. Treatments were unsuppressed living mulches of perennial ryegrass, Dutch white clover, a mixture of ryegrass and clover and cultivated bare ground. Ammonium nitrate was banded at rates of 90, 45, and 0 kg/ha across all treatments. Measurements of weed populations, asparagus growth, and soil and tissue nitrogen levels were made in 1990 and 1991. Soil nitrate and ammonium levels were measured in 30 cm increments to a depth of 90cm. In 1990, asparagus fern growth was greater in the bare ground controls than in any of the mulch treatment plots. In 1991, asparagus growth in the clover-based mulches was greater than that in the ryegrass mulch, although also still less than that of the bare ground control. Total accumulated nitrogen in clover-based mulch plots at the end of each season was more than twice the level of that of either the grass mulch or the cultivated plots. Percent nitrogen in asparagus tissue varied with mulch treatment: in 1991, the %N was higher in the asparagus tissue grown with clover than either that grown with the grass or on bare ground. Weed control in all mulch plots was good; in clover plots it was nearly 100%.
DRIP/TRICKLE FERTILIZING EGGPLANT
Authors: Paterson James W.
Published: February 2019

The effectiveness of varying rates and timing of applied primary plant nutrients as a completely soluble N-P-K fertilizer through a drip/trickle low volume irrigation system was studied during 1991 on eggplant (Solanum melongena cv. Harris Special Hibush). Before the drip irrigation tubing and black plastic mulch were laid on a coastal plain sandy loam soil, plots were treated with 0, 22, 45, and 67 kg ha-1 of nitrogen (N), phosphate (P2O5) and potash (K20). The higher rates of preplant fertilization did have a significant beneficial effect on total seasonal yields of quality eggplants. The preplant treatments also had an influence on mid and late season production. As the frequency of drip/trickle applied primary plant nutrients increased up to 6 seasonal applications, the total quality fruit production substantially increased. Frequency of applications also had an influence on seasonal yields. Applying increased rates of the primary plant nutrients at a low seasonal frequency of 3 applications had little influence on increasing total quality yields of eggplants. Individual quality fruit was significantly heavier from plants which received 5 to 6 applications of the soluble N-P-K fertilizer than from plants which received no fertilizer through the drip/trickle irrigation system for the season.
CROP ROTATION AND NITROGEN RATE INFLUENCE PROCESSING TOMATO QUALITY
Authors: Seliga John , Shattuck Vernon , Johnston Russel
Published: February 2019

A study was conducted from 1989 to 1991 to examine the effects of continuous tomato cropping, short-term crop rotation and, nitrogen fertilization rates on processing tomato quality. Research was conducted at two sites in southwestern Ontario, Leamington and Dresden, in split-plot experimental design. The rotations included tomato (Lycopersicon esculentum) - winter wheat (Triticum aestivum) (underseeded with red clover (Trifolium pratense), tomato-winter wheat-soybean (Glycine max), tomato-alfalfa (Medicago sativa), and tomato-rye (Secale cereale). Nitrogen fertilization rates of 0, 45, 90 and 135 kg/ha were used. Processing tomato cv. Heniz 9230 and Nabisco Brands Ltd. 7107 were assessed for colour, % soluble solids and total solids, and blossom end rot [BER]. In most instances, continuous tomato [C-T] had significantly poorer colour, soluble solids, and total solids than fruit from the various crop rotations. High nitrogen rates for C-T at Leamington, resulted in improved soluble solids and total solids, but had no significant effect on colour. A lower incidence of BER consistently occurred with low rates of nitrogen. Our results indicate that short-term crop rotation and nitrogen management in processing tomatoes can enhance fruit quality when compared to C-T.
RAPD MARKER DIVERSITY AMONG PAKISTANI APRICOTS
Authors: Gogorcena Y. , Parfitt D.E.
Published: February 2019

A number of 10 base primers were screened to identify RAPD polymorphisms among a population of semi wild apricot genotypes that had been collected by Maxine Thompson in 1988. 30 families collected from trees at 6 locations were analyzed. DNA from leaf tissue of 180 plants, ca. 6 genotypes per family, were isolated and tested against 20 primers. Seven primers were identified that produced consistent results with relatively few (thus, scoreable) and consistent bands. DNA was isolated using the cTAB method and the effects of additional CsCl centrifugation isolation were tested. No differences were found. Reaction conditions were tested to ensure consistent results. Considerable RAPD polymorphism was observed in this population. Parsimony analysis is being conducted to assess the relative variation among and within populations and to determine whether collection location had a more significant effect on DNA variation than other factors such as outcrossing or level of heterogeneity within populations.
SAMPLING VARIANCE FOR MOLECULAR MARKER DATA WITH RESPECT TO GENETIC DISTANCE
Authors: Tiväng Jan , Nienhuis Jim , Smith O.S
Published: February 2019

The sampling method was applied to a data-set generated by RFLP molecular marker analysis, representing 37 Zea maize cultivars. A total of 251 enzyme probe-combinations were used yielding a total of 1,205 scores per genotype. Genetic distance was calculated among all 37 entries from subsets of arbitrary and increasing sample size. Each score entry in the subset was selected at random from all possible scores with replacement following each selection. The variance for genetic distance was calculated among all subsets of equal size for all possible cultivar pairs. The pooled pair variance was plotted and compared to random simulation models. Additional comparisons were made contrasting closely vs. distantly related cultivars.
INFLUENCE OF DRY-BACK TEMPERATURES AFTER SOLID MATRIX PRIMING ON SUBSEQUENT SEED PERFORMANCE
Authors: Parera Carlos A. , Cantliffe Daniel J.
Published: February 2019

The effects of the dry-back temperature on sh2 sweet corn seeds primed via solid matrix priming combined with sodium hypochlorite (SMPsh) were studied. Seeds of two sh2 sweet corn cultivars: Crisp N'Sweet 711 (CNS-711) and How Sweet It Is (HSII) were primed via SMPsh. After the treatment, the seeds were dried-back from 50-54% to 6-7% moisture content at 20, 30 or 40C and 25% RH. The rate of dehydration was significantly lower in CNS-711 compared to HSII at all dry-back temperatures. In both cultivars, seed respiration after 4, 16, and 32h of imbibition was greater in those dried at 30 and 40C compared to 20C or non-primed seed. Enzyme activity (glutamic acid decarboxylase activity) was decreased in HSII seeds dried at 20C. There were no differences among treatments in CNS-711. Leakage conductivity was significantly less when the seeds were dried-back at 30C or 40C compared to 20C or nonprimed seeds. Laboratory germination and seedling fresh weight were greater in seeds dried-back at 30C compared the others temperatures or non-primed seeds. The low rate of desiccation at 20C (30h and 8h in CNS-711 and HSII, respectively) may not suppress germination events after priming, thus damaging the embryo during dry-back. This work demonstrated the importance of dry-back temperature to the efficacy of SMPsh seed treatment in sh2 corn.
SEEDLING DEVELOPMENT OF SWEET CORN WITH LOW TEMPERATURE AND POTASSIUM
Authors: Coons Janice , Tsengwa Nombasa
Published: February 2019

Five supersweet cultivars of corn (Zea mays L. var. rugosa) were planted in fields and growth chambers to compare potassium effects on seedling development at low temperatures. In fields, seeds were planted at Urbana, IL, in 1991 when soil temperatures were 15C(April) and 23C(June). Potassium chloride(KCl) was banded at 0, 45 or 90 kg KCl/ha. After 32 days `Illini Gold', `Florida Staysweet', and `Crisp'n`Sweet' were more developed than `Honey'n`Pearl' and `How Sweet It Is' as indicated by emergence, height, leaf area and number, and weight in April. However for June, cultivar differences were observed only for emergence. KCl had no effect on any cultivars. In chambers, seeds were planted in trays(6×22×30 cm) of vermiculite mixed with 0, 5 or 10 g KCl/tray at 17 and 26C. After 15 days, cultivar responses at both temperatures were similar to those at the April field planting except at 26C where none differed for emergence. KCl only affected seedlings at 26C when 10 g/tray slowed development. Thus more differences were found between cultivars at lower than higher temperatures, and potassium did not improve seedling development at low temperatures.
FAST, EFFECTIVE HANDS-ON ASSESSMENT OF STUDENTS IN HORTICULTURE CLASSES
Authors: Preece John E.
Published: February 2019

In an effort to improve higher education, most states now require non-graded assessment of students enrolled in publicly funded universities. Assessment may be across the curriculum or within a major at graduation, yearly, or during individual courses or lectures. I have used two assessment techniques in my classroom that are effective and require a minimum of time. These techniques encourage student participation in class and allow for non-graded anonymous assessment in a manner that the students take very seriously. During the first class of the term students are handed filing cards and given 5 minutes to write their course objectives. By comparing their objectives with mine, I am able to react to student interests and needs in a constructive manner. At the end of one out of three lectures per week, students are given 1-2 minutes to write the “muddiest point” of the day's lecture. This enables the instructor to determine which points need further clarification. Discussion will focus on these techniques and their implications for learning horticulture at both the graduate and undergraduate levels.
READ THE LABEL, A PESTICIDE SAFETY VIDEO TAPE
Authors: Lerner B. Rosie
Published: February 2019

The general public is in need of education regarding the responsible use of pesticides in home gardens. A 1990 California survey indicated that many individuals never read product labels and do not follow safety precautions when applying pesticides. A 1991 EPA study found that the most frequently detected pesticide in well water was a breakdown product of DCPA, a commonly used herbicide on home lawns. A 1988-89 National Gardening Survey found that 39% of US households purchased pesticide products. Excerpts of a video tape titled “Read the Label”, which specifically targets the home gardening audience, will be presented. Because the subject of pesticide safety may be of little intrinsic interest to gardeners, actors were hired to lend a bit of light humor. Highlights feature Gordon Guardian, the Gardening Angel, who comes to Earth to guide Beth Homeowner through the proper selection, use. hazards, storage, and disposal of pesticides. Production methods, funding and budgeting of the video will also be discussed.
OLIVE FREEZE DAMAGE IN CALIFORNIA
Authors: Denney James O. , Martin George C.
Published: February 2019

Record low temperatures were experienced in California during the last 10 days of December, 1990. Olive trees in both the Sacramento and San Joaquin Valleys suffered damage from the freeze. The lowest minimum recorded in these areas was -11.6C at Willows (Glenn Co.). Types of damage included death of succulent growing tips, defoliation, bark split, and bark and xylem discoloration. Tree death to the ground was uncommon. Defoliation continued throughout the growing season, and many leaves that persisted became chlorotic. Major outbreaks of olive knot disease caused by Pseudomonas savastanoi were seen in damaged trees, especially in `Manzanillo.' Anatomical studies showed evidence of ice nucleation events in the phloem, xylem, and leaves, but the cambium was usually left intact. Refoliation and healing of bark splits progressed rapidly once growth resumed in the spring, except in cases of olive knot infestation. Cultural practices that predisposed trees to freeze damage were those leading to late-season vegetative growth, namely fall pruning and late or excessive irrigation or fertilization. `Manzanillo' is the least cold-hardy of California cultivars and the most susceptible to olive knot. `Barouni' is the most hardy.
EXPRESSION AND PURIFICATION OF THE IPT GENE
Authors: Barbour Sandra L. , Schaff D.A. , Smigocki A.C. , Frett J.J.
Published: February 2019

The ipt gene of Agrobacterium tumefaciens T-DNA encodes for isopentenyl transferase, which is an enzyme active in cytokinin biosynthesis. While it is known that cytokinins are associated with in vitro promotion of cell division and stimulation of shoot production, little is known about their mode of action. As the first step in localizing cytokinin synthesis, we present a cloning and expression strategy for the ipt gene. The source of the ipt gene was Agrobacterium tumefaciens octopine Ti plasmid 15955. The ipt gene was amplified by the polymerase chain reaction (PCR) and cloned into pMal-c2 (New England Biolabs, Beverly, MA). This construct was transformed into E. coli and the ipt gene was expressed as a fusion protein. The protein was purified by affinity chromatography to serve as an antigen for polyclonal antibody production. These antibodies will be used to localize isopentenyl transferase in plant tissue.
USE OF RAPD TECHNOLOGY IN CUCUMBER
Authors: Staub Jack , Poetter Karl , Fruth Robin
Published: February 2019

Fruit yield in cucumber is limited by the nature of its fruiting habit. Manipulation of plant architecture is one way of increasing yield potential in cucumber. We are incorporating a multiple lateral (ML), sequential fruiting habit into a determinate (de) background. Misclassification of mature plants occurs because the de character is difficult to identify in a ML/de background. It would be valuable to develop an inexpensive laboratory test which would allow accurate classification of ML/de plant types. To develop such a test, we have begun the use of a new DNA marker system, random amplified polymorphic DNA (RAPD). We performed a series of experiments designed to test the reproducibility and predictability of RAPDs. Data indicated that RAPD patterns were not significantly affected by tissue age, infection with powdery mildew or bacterial wilt, or presence of fruit. F1 RAPD polymorphisms segregated in predicted 3:1 ratios. A survey of 6 ML lines and 1 de line with 400 primers identified 4 polymorphisms shared by all ML lines and diagnostic for the de line. No association was found between any of these markers and the de character.
INFLUENCE OF SEED TREATMENTS ON GERMINATION OF Aleurites fordii
Authors: Tidmore Drew
Published: February 2019

The tung-oil tree (Aleurites fordii) was planted extensively in the southeastern United States in the 40's and 50's for their high quality oil used in jet engines and paint. Elimination of import tariffs destroyed the US industry. There is a possibility of a resurgence in popularity of this species as an ornamental because of its large leaves, spring flowers, and dense growth. If nurseries begin growing tung-oil trees they must have more information on the most efficient means of seed germination. One hundred percent of the seeds with intact shells germinated in 9 weeks if they received either 24 hr stratification or 24 hr. soak. Eighty-three percent of the untreated intact seeds germinated in the same period. Shell removal sped up germination as evidenced by 27% germination in 5 weeks. However the process left seeds susceptible since only 36% had germinated in 9 weeks.
MATURATION AND STORAGE OF FUJI APPLES (Malus domestica Borkh)
Authors: Fan Xuetong , Mattheis J.P. , Patterson M.E. , Fellman J.K.
Published: February 2019

Several strains of Fuji apples were harvested weekly from September through October in 1990 and 1991, and evaluated for maturation and quality after 1 and 7 days at 20 °C following harvest and storage in atmospheres of 0.5%, 1.0%, 2.0% O2 and air. Results showed that Fuji apples have very low ethylene production rates and little firmness loss during maturation. A change in the postharvest respiration pattern preceded the increase ethylene synthesis. Oxygen concentration during storage directly affected apple respiration rate after removal from storage. Ethylene production rates and internal ethylene concentrations indicated that the apples were still in the preclimacteric stage after 7 to 9 months storage at 0.5%, 1.0%, or 2% O2. Fuji apples develop watercore and tend to have a particular type of corebrowing during maturation on the tree, or during and after storage. The cause is unknown.
EFFECT OF CONTROLLED-RELEASE AND CONSTANT LIQUID FERTILIZATION ON LEACHATE AND PLANT QUALITY
Authors: Dole John M. , Cole Janet C. , Smith Randall M.
Published: February 2019

Poinsettias (Euphorbia pulcherrima 'Gutbier V-14 Glory'), chrysanthemums (Dendranthema grandiflora 'Tara') and geraniums (Pelargonium xhortorum 'Orbit') were grown using various ratios of controlled release:constant liquid fertilization as a percentage of recommended rates (%CRF:%CLF). While plants grown under the 100:0 CRF:CLF regime produced significantly less nitrates, phosphates and total soluble salts in the leachate than 0:100 or 50:50 CRF:CLF, quality rating, plant diameter, and leaf, bract and flower dry weight of poinsettias and chrysanthemums were reduced. Geraniums grown under 100:0, 50:50 or 0:100 CRF:CLF regimes were similar in quality rating, height, diameter, dry weights and days to anthesis. Poinsettias and chrysanthemums grown under 50:50 CRF:CLF were similar in height, days to anthesis, plant diameter, flower and stem dry weights and quality rating but produced less nitrates, phosphates and total soluble salts in the leachate than plants grown under 0:100 CRF:CLF. However, chrysanthemums grown under 50:50 CRF:CLF had lower leaf and root dry weights and poinsettias had lower leaf and bract dry weights than under 0:100 CRF:CLF regime.
GROWTH OF MULCHED GERANIUMS USING RECYCLED TOP- AND SUB-IRRIGATION.
Authors: Khoury N.S. , Holcomb E.J. , White J.W. , Rand M.
Published: February 2019

Recycled subirrigation systems are a possible solution to grower concerns over water use, ground water pollution, and regulations concerning these. The objectives of this experiment were to examine the differences between top- and subirrigated plants, with different fertilizer regimes and with mulches.

Six treatments of `Crimson Fire' and `Victoria' CVI geraniums were grown in 11 cm. pots. Treatments were: top irrigation, 100% N supplied with 20-10-20 soluble fertilizer; subirrigation, 100% N supplied with 20-10-20 soluble fertilizer; subirrigation, N supplied in equal portions of 20-10-20 soluble fertilizer and CRF, gel mulch; subirrigation, N supplied with CRF, gel mulch; subirrigation, N supplied in equal portions of 20-10-20 soluble fertilizer and CRF, wool mulch; subirrigation, all N supplied with CRF, wool mulch.

`Crimson Fire': fresh weight was not significantly different between top- and subirrigation; fresh weight at the same fertilizer level was not significantly different with either a gel or a rockwool mulch; all CRF resulted in the lowest fresh weights. `Victoria': top irrigated fresh weight was significantly higher compared to subirrigated. Gel mulched plants resulted in significantly lower fresh weights than wool mulched plants. All CRF resulted in the lowest fresh weights.
EFFECTS OF CONTROLLED-RELEASE AND LIQUID FERTILIZATION ON LEATHERLEAF FERN AND NITROGEN LEACHING
Authors: Stamps Robert H.
Published: February 2019

Established leatherleaf fern was grown for one year in a glasshouse in intact soil columns (Astatula fine sand, 21 × 61 cm) contained in drainage lysimeters. Columns were fertilized at rates of 224, 448, or 672 kg N ha-1 yr-1 using controlled-release (CR) fertilizer, either 360-day (360CR) or 180-day (180CR) term, or weekly applications of liquid (L) fertilizer. Water use, yield (number of harvestable fronds) and average frond weight increased linearly with increasing fertilization rate and more fronds were produced using L than CR fertilizers. Frond color measurements paralleled yield results. During cool weather when vase life is greatest, fronds from L fertilizer lysimeters lasted longer than fronds from CR treated plots. During warmer weather, treatments had no effect on vase life. Nitrate nitrogen (NO3-N) leaching increased with fertilization rate and exceeded 10 ppm in leachate from the L and 180CR treatments at all application rates. NO3-N in leachate from 360CR lysimeters never exceeded 8 ppm at any application rate.
INTERSPECIFIC HYBRIDIZATION OF IMPATIENS
Authors: Cleland Maryke A. , Jones Cynthia , Brand Mark H.
Published: February 2019

An interspecific hybridization program involving five species of Impatiens was initiated to delineate incompatibility barriers. With the exception of one cross, no viable hybrid seed was recovered. Fluorescence microscopy revealed foreign pollen tubes to reach ovules in all crosses, although not all ovules were approached. A histological study involving I. auricoma Baill. and I. walleriana Hook f. ensued to confirm the presence of hybrid embryos. Developing I. walleriana × I. auricoma and reciprocal hybrid embryos were compared to self embryos. Development of hybrid embryos was delayed as early as five days post-pollination. I. walleriana × I. auricoma embryos continued to develop for 8 days post-pollination, but did not reach a size greater than a 5-day self embryo. Excessive endosperm was observed in the hybrid. I. auricoma × I. walleriana embryos continued to enlarge up to ovary abortion but did not reach a size greater than a 7-day self embryo and little to no endosperm developed. Disintegration of ovules included disorganization and collapse of the endosperm, and vacuolization and loss of turgidity of the embryo.
CHARACTERIZATION OF ISOZYME DIVERSITY WITHIN AND AMONG PURPLE LOOSESTRIFE POPULATIONS (LYTHRUM SPP.).
Authors: Darmo E. , Strefeler M.S.
Published: February 2019

Purple loosestrife populations have developed into a highly aggressive and invasive weed in several Northern states (MN, NY, NJ etc.). How these populations arose is a key question in developing control strategies. Therefore, we initiated a study to elucidate the origin and genetic structure of invasive populations using isozyme analysis. The germplasm examined included invasive populations found in MN, NY, NJ, WI and MD, populations of Lythrum alatum, populations of L. virgatum and 22 cultivars of L. salicaria, the suspected progenitor of the invasive populations.

Unique isozyme patterns for most cultivars was observed and these were consistently indicative of that clone over repeated sampling. Clones of putative “salicaria” origin could not be distinguish from those of putative “virgatum” origin.Significant isozyme polymorphism was observed within and among the 26 Lythrum populations. Indicating that isozymes can be an important tool in studies on the structure and evolution of invasive loosestrife populations.

To date, our isozyme analysis indicates that L. salicaria and L. virgatum are not distinct species. It appears that the decision by the MN Department of Agriculture to add all horticultural lines to the noxious weeds list regardless of origin was a prudent decision.
KARYOMORPHOLOGICAL STUDIES ON HIPPEASTRUM SPECIES
Authors: Vahidy Ahsan A. , Shafiq Farzana A.
Published: February 2019

Chromosome morphology of locally available cultivars of Hippeastrum (Basionym: Amaryllis) was studied from the root tips of 60 bulbs. Optimum contraction with good resolution of chromosomes was obtained when a mixture of 0.0lg colchicine, 0.005g 8-hydroxyquinoline and 5 drops of DMSO in 20ml of distilled water was used as pretreatment. A count of 2n=22 was confirmed in all the bulbs except ten in which the diploid chromosome number was 55. Chromosomes of 2n=22 cytotype were very long to medium, while those in 2n=55 cytotype were long to small. Very long chromosomes were submetacentric, long chromosomes substantially heterobrachial or acrocentric, and medium to short chromosomes mainly metacentric. Karyotyping revealed nonhomology in different chromosomes which may be due to aneuploidy. The results are documented by photomicrographs and karyograms.
A MOISTURE CAPTURE SYSTEM FOR REDUCING SUPPLEMENTAL WATER REQUIREMENTS FOR CANTALOUPE PRODUCTION IN SEMI-ARID REGIONS.
Authors: Bender David A. , Dainello Frank J.
Published: February 2019

Trenched beds covered with plastic mulch was used to capture and retain precipitation for dryland cantaloupe production. Two trenches were formed in the fall in raised beds. Plastic mulch was laid over the beds and slitted at ca. 1 meter intervals over the trenches. Soil was placed over the slits, conforming the plastic to the shape of the trenches and channeling precipitation into the beds. Cantaloupes were seeded in the spring and grown with no supplemental irrigation. Planting moisture was significantly greater under the capture system than in unmulched beds. Seedling emergence time was reduced from 18 to 6 days and vine growth in the first 6 weeks was almost doubled. Total and marketable yields were doubled and fruit size significantly increased when water was limiting. Elevated soil temperatures under the mulch enhanced plant growth and yield even when moisture was not limiting. Combining a moisture capture system with supplemental irrigation could allow commercial production of cucurbit crops under limited water conditions in semi-arid areas.