bluuebunny/crossref_metadata_2025 huggingface dataset:
PHOTOSYNTHESIS AND RUBISCO IN STRAWBERRY SPECIES
Authors: Moon John W.
Published: February 2019

CO2 assimilation (20-25%) and carboxylation efficiency (30-35%) was greater (P < 0.01) in Fragaria chiloensis, clone RCP37 than F. ananassa cv. `Midway'. Both leaf thickness (P < 0.05) and internal mesophyll cell surface area (P < 0.01) was greater in RCP37 than `Midway'. No differences in Rubisco specific activity were observed between the 2 species, whereas Rubisco amount was 40% greater (P < 0.01) and leaf nitrogen per area was 30-35% greater in RCP37 compared to `Midway'. Potential for selection of clones with high photosynthesis by screening for soluble protein will be discussed.
EFFECT OF TWO-SPOTTED SPIDER MITE FEEDING ON GAS EXCHANGE AND CHLOROPHYLL CHARACTERISTICS OF RED RASPBERRY LEAVES
Authors: Cameron J. Scott , Hartley Carol A. , Shanks Carl H. , Garth Jeannie K. L.
Published: February 2019

At two-week intervals from 17 June to 15 July, three groups of `Meeker' red raspberry plants were infested with two-spotted spider mites (Tetranychus urticae) in a greenhouse. While populations on individual plants were allowed to develop freely, control plants were kept free of mites with a chemical miticide. Gas exchange measurements were made on 27 July prior to visible mite damage, and on 7 October after injury was apparent. The relationships between mite populations and leaf gas exchange and chlorophyll characteristics were described using a logarithmic function.

Physiological responses to mite feeding were observed prior to visible leaf injury. On both dates, CO2 assimilation rates decreased (p ≤ 0.001) with increasing mite numbers per leaflet. On 27 June, a significant relationship (R2 = 0.61***) was found between mite number and mesophyll conductance (gm). On 7 October, significant relationships (p ≤ 0.001) were also observed with gm, stomatal conductance (gs), and transpiration (E). Total chlorophyll content of leaves decreased with increasing mite populations, but chlorophyll a/b ratio and dry weight per leaf unit area were unchanged.
GA3 SPRAYS ALTER THE FATE OF LATERAL MERISTEMS OF `REDKIST' PEACH.
Authors: Ward Daniel L. , Taylor Bradley H.
Published: February 2019

G A3 sprays were applied to 10 primary scaffold limb replications with a handgun at three concentrations (25, 50, 100 mg/l), from May to September 1989. Flower bud thinning with G A3 applied in the year prior to bloom was examined for its effect on the developmental fate of lateral meristems. Limbs treated in late May had, on average, 45% more flower buds survive near-critical winter temperatures than did controls. During the period of greatest sensitivity to Flower Bud Density (FBD) reduction, GA3 treated limbs had vegetative bud densities (VBD) higher than control (on average 45% greater at 100 mg/l). On 9 June 100 mg/l reduced FBD by 78% compared to control and increased VBD by 57%, while on 6 July the same concentration. reduced FBD by 94% but VBD was increased by only 32%. These results appear to support the hypothesis that GA3 induced FBD reduction has more than one mode of action.
EFFECT OF GA3 ON THE TIME OF MATURITY, FIRMNESS, COLOR AND SIZE OF PEACH FRUIT.
Authors: Sher-Muhammad  , Taylor Bradley H.
Published: February 2019

G A3 sprays (50, 65, 100 mg/L) were applied to six single tree replications of mature `Redhaven' and `Cresthaven' trees on 23 June 1989 to measure their effect on fruit maturity and the relationship among its indices. There was little effect of GA3 on fruit diameter except on the final harvest when the treated trees had 6% larger fruits. Seventy-two percent of the total yield of `Redhaven' control trees was mature at the first picking while only 30% of total yield from treated trees was ready on the same date. GA3 had a similar effect on fruit maturation on `Cresthaven'. Fruit on treated `Redhaven' trees were on average 1.3 kg firmer than control. Furthermore, GA3 increased the firmness over control on the shaded and sunny side and the suture of the fruit and no interaction between the location of pressure test and GA3 treatments was observed. There was a slight reduction in yellow ground color of G A3 treated fruits. The effect of GA3 on the relationship between individual fruit color and firmness will be examined. The effects of 1990 GA3 sprays on peach maturity and quality will also be presented.
LEAF SPOT COLOR AND VENATION INHERITANCE AND PETIOLE STRENGTH VARIATION IN CALADIUM
Authors: Gager Charles F. , Wilfret Gary J.
Published: February 2019

The mode of leaf spot color, venation color and pattern inheritance and differences in the apparent strength of leaf petioles were investigated. Progeny from self pollinations of Caladium bicolor cv. Painter's Palette and two commercial cultivars (`Florida Cardinal' and `Aaron') were utilized in a pedigree and back cross breeding program to delineate and prove a proposed model for the mechanisms controlling spot and vein color inheritance as well as the inheritance of venation patterns. Differences in the apparent strength of leaf petioles in Caladium were observed in the field, Anatomical and mechanical analysis using a Kramer Shear Cell, showed significant differences among 12 experimental lines, The relative strength of the petioles were correlated to petiole pigmentation, with darker colored petioles being stronger and less prone to bending than lighter colored petioles.
CHARACTERIZATION, INHERITANCE AND PRACTICAL APPLICATION OF FUSED-VEIN TRAIT IN SQUASH, CUCURBITA PEPO L.
Authors: Loy J. Brent , Carle R. Bruce , Hutton Mark G.
Published: February 2019

A new leaf mutant, fused-vein, is described in Cucurbita pepo L. for use as a plant gene marker. Morphologically, the fused-vein trait is characterized by a partial fusion of the lateral leaf veins to the main central vein. Fusion begins at the distal point of the petiole and extends for 5 to 10 cm into the leaf blade, thereby delaying branching of the leaf veins and causing the dorsal leaf surface to appear puckered. The trait is expressed beginning at the fourth to sixth leaf stage and throughout vegetative growth. Preliminary inheritance data suggests a two gene, double recessive model. Data on segregation of the fused-vein trait in reciprocal F2 and backcross progenies will be obtained during the summer of 1990. This trait has been incorporated into hull-less seeded lines for use as a marker to identify rogue genotypes. Comparison of F5 sister lines with and without the fused-vein trait indicated that the trait does not affect fruit or seed yields.
BRANCH AUTONOMY AND BLANKING IN PISTACHIO
Authors: Weinbaum Steven A. , Muraoka T.T.
Published: February 2019

An average of >20% seedless (blank) fruit are produced annually in Pistacia vera cv. Kerman. The degree of blank production was reportedly not related to individual tree yields and, therefore, was not thought to be resource limited (Crane, J.C., 1973. HortSci. 8:388-390). In two crop years, we studied the variability in percentage blanking among individual shoots characterized by widely varying leaf area to fruit (L/F) ratios. L/F ratios were related inversely to the percentage of blank fruit produced. Thus, individual branches behaved somewhat autonomously with respect to blanking. Our data are consistent with the view that embryo development was resource-limited. Although `Kerman' exhibits the potentiality for parthenocarpic fruit set, the hissed distribution of seedless fruit within the tree presumably indicates that blanking is an example of stenospermocarpy. Blanking does not result primarily from inadequate pollination under typical field conditions.
XENIA AND METAXENIA: DEFINITIONS AND OTHER BOUNDARIES
Authors: Denney James O. , Martin George C.
Published: February 2019

Xenia and metaxenia are phenomena dealing with the effects that pollen from different sources have on certain characteristics exhibited by seeds and fruits in a variety of species. A review of dictionaries, textbooks, and the scientific literature reveals that there is widespread confusion with regard to the nature of these phenomena and how they are to be distinguished. This discussion will attempt to clarify the boundary between these related phenomena by examining both the origins of the terms and our present understanding of the metabolism and anatomy involved. From this perspective, we contend that xenia applies to pollen effects as exhibited in the syngamous parts of ovules, that is, the embryo and endosperm only. Metaxenia applies to such effects found in any structure beyond the embryo and endosperm, this is, in tissues which derive wholly from mother plant material. Metaxenia then encompasses effects found in seed parts such as the nucellus and testa as well as those found in carpels and accessory tissue.
MANIPULATION OF VEGETATIVE, GENERATIVE, AND MIXED SHOOT TYPES IN CITRUS
Authors: Davenport T. L. , Codallo M.
Published: February 2019

Fruit set in some species of citrus is greater on mixed shoots (leafy inflorescences) than on generative shoots (leafless inflorescences). Combination treatments involving water stress, cool winter night temperatures, and branch pruning were used to manipulate the number of shoots and ratios of the three shoot types in containerized `Tahiti' lime (Citrus latifolia Tan.) plants. Plants were water stressed in a greenhouse for five weeks, pruned after rewatering, transferred to the open environment, and observed three weeks later. Appropriate control plants were carried along with treated ones. Combination treatments of all three variables increased the number and ratio of mixed shoots four fold over the non-stressed, non-pruned controls. More shoots formed on non-pruned, water stressed plants than on controls. Both formed predominantly generative shoots. Shoots of pruned, non-stressed plants were predominantly vegetative. Non-pruned non-stressed plants were typical of those growing in the field exposed to cool winter nights.
PRODUCTION OF SOME FLOWERS IN HYDROPONICS AND SOILLESS MEDIA
Authors: Al-Mana Fahed A. , El-Kiey Tarik M.
Published: February 2019

Production of five commercial cut flowers in different culture media, namelyI nutrient film technique (NFT), soilless media (perlite and an equal mix of perlite and peatmoss), and soil mix (2 sand: 1 loam by volume), was investigated in controlled fiberglass-house. Two rose varieties (Rosa hybrida var. Baccara and Madina); carnation (Dianthus caryophyllus var. William Sim); Chrysanthemum morifolium var. Delta, and Dahlia hybrida var. variabilis were used. Plants were watered as they needed by the same nutrient solution used for NFT.

Generally, growth and yield of Baccara and Madina roses, Chrysanthemum and Dhalia plants were superior in NFT than in the other media. On the contrary, the growth and yield of carnation plants were significantly greater in conventional soil or perlite and peatmoss mix than in NFT or perlite.

Flower crops grown in NFT generally reached harvest stage 5-10 days earlier than those grown in the other media except carnation plants. There were variations in the accumulation of N, P, K mg, ca, and Fe in plant leaves among the various culture media.
HOLDING LEMON FRUIT AT 5 OR 15C BEFORE COLD TREATMENT REDUCES CHILLING INJURY
Authors: Houck Laurie G. , Jenner Joel F. , Bianchi Jan
Published: February 2019

An approved quarantine treatment for Tephritid fruit fly control of citrus fruit requires fruit be held at 0.0-2.2C for 10-22 days, depending on fruit fly species involved and actual temperature attained. However, this treatment causes chilling injury (CI) in California-Arizona desert lemons harvested in late summer or early autumn. We found that temperatures at which lemons are held before cold treatment affects the susceptibility of lemon fruit to CI. Commercially packed lemons obtained from Yuma, AZ packinghouses in Sept.-Nov. 1987 and 1988 were held at 1C for 3 or 6 weeks, or cured for one week at 5, 15 or 30C, or at 15C for one week, followed by 30C for one week, before receiving the 1C cold treatment. Lemons cured one week at 5 or 15C before the cold treatment developed at least 25-30% less CI during 4 weeks peat treatment storage at 10C than noncured fruit. The other curing treatments were not as effective for reducing CI.
PLANTS AND HUMAN CULTURE
Authors: Shoemaker Candice A.
Published: February 2019

Plants are a part of many rituals and celebrations and they influence our language, art, and literature. At the First National Symposium on The Role of Horticulture in Human Well-Being and Social Development, a session on Plants and Human Culture was held. A review will be given of the seven oral presentations from this session and the discussion which followed. Some of the topics presented included the role of the corporate garden in the cultural activities of the community, the role of horticulture in holiday celebrations, the role of flowers in the bereavement process, and floral symbolism in paintings. Actions which horticulturists can take to promote horticulture within the cultural setting will be presented.
HORTICULTURAL THERAPY
Authors: Flagler Joel
Published: February 2019

It has been observed that the process of horticulture can help to heal physical, mental, and social disabilities. Professionally trained horticultural therapists prescribe and administer planting and gardening activities to provide benefits to people of all ages and abilities. Horticultural therapy programs are now commonplace in hospitals, geriatric centers, schools, rehabilitation facilities, community gardens and prisons. One common goal in all of these programs is to help heal, teach and retrain individuals through the use of plants.

As a result of repeated successes, horticulture is being widely accepted as an effective therapeutic tool. Research is underway to measure the effectiveness of horticultural therapy in clinical and correctional settings. Databases are being developed to document and substantiate the beneficial effects of horticulture on human well-being. With such research results we can better understand the value of horticultural therapy in the recovery and rehabilitation processes.
SUMMARY OF RESEARCH IMPLEMENTATION SESSION (April 21, 1990).
Authors: Adler Barry
Published: February 2019

Summary and discussion to include the keynote topic RESEARCH IMPLEMENTATION by Diane Relf; contributed papers -THE CHICAGO BOTANIC GARDEN: IT`S ROLE IN THE ECONOMIC AND SOCIAL GOALS OF CHICAGO, by Sue Burd Brogdon, NATIONAL SURVEY OF ATTITUDES TOWARD PLANTS AND GARDENING, by Bruce Butterfield* and Diane Relf, USING AN EXTENSION APPROACH TO IMPLEMENT RESEARCH RESULTS IN THE FLOWERING PLANT INDUSTRY, by Kevin Grueber, BEYOND ROMANTICISM: THE SIGNIFICANCE OF PLANTS AS FORM IN THE HISTORY OF ART, by Rhonda Roland Shearer, PEOPLE AND PLANTS: A CASE STUDY IN THE HOTEL INDUSTRY, by Michael Evans; and a brief review of posters.
MOLECULAR ANALYSIS OF HEAT STRESS PROTEINS IN HIGHER PLANTS
Authors: Vierling Elizabeth
Published: February 2019

When plants experience high temperature stress, they respond by synthesizing a discrete set of proteins called heat shock proteins (HSPs). This response is not unique to plants, but is observed in all other eukaryotes. It is now known that the HSPs are evolutionarily conserved proteins, and furthermore, that HSPs function not only during stress, but also during normal growth and development. My laboratory has characterized several of the major groups of HSPs in higher plants. We have cloned genes encoding plant HSP70 proteins and low molecular weight (LMW) HSPs (17-23 kDa). Using this information we have investigated the expression of HSPs both in the field, and under laboratory conditions which mimic field situations. We have determined the temperature limits for expression of HSPs in vegetative tissues, and have also found that HSPs are frequently produced in plant reproductive structures, even in the absence of stress. As a first step toward understanding HSP function, we have characterized the intracellular localization of HSPs. Results show that there are unique HSPs in the cytoplasm, chloroplast and endomembrane system. These ubiquitous proteins appear to play essential roles in many cellular processes.
PHYTOHORMONE ANALYSIS WHAT DO THE NUMBERS MEAN?
Authors: Cohen Jerry D. , Slovin Janet P.
Published: February 2019

The literature is full of different techniques and approaches to the isolation, purification and quantitative analysis of plant hormones. From this body of literature it is possible to deduce that 1) a lot of investigators are interested in how much of these compounds are in plants and 2) that the techniques for phytohormone analysis are still largely “under development”. This talk will discuss different approaches to hormone analysis, suitability of each approach, and criteria for the evaluation of techniques and results. The goal will be to highlight points that are important to obtaining reliable analytical information and knowing what to do when problems occur. Nevertheless, having reliable numbers is frequently only the first step in understanding hormonal systems involved in plant development, It is often the case that the expected results are not what is found in experiments involving plant hormone quantitation. We will consider experimental design, tissue localization, developmental stages, sampling and extraction procedures, and the limits of what to expect when “dogma confronts reality”. Work reported was supported by grants from the National Science Foundation DCB-8917378, USDA-CRGO 89-3721-4734, US-Israel BARD US-1362-87, and by funds from the USDA Argicultural Research Service,
IMPROVEMENT OF NEW GUINEA IMPATIENS BY INTERSPECIFIC HYBRIDIZATION
Authors: Stephens Loren C. , Fruth Robin L.
Published: February 2019

New Guinea Impatiens cultivars, I. hawkeri Bull., are susceptible to hot, windy conditions throughout much of the Midwest and Western U.S. Certain Indonesian Impatiens from Java (I. platypetala Lindl.) and Celebes (I. aurantiaca Teysm.) are much more heat-tolerant. Interspecific hybrids involving Java and Celebes Impatiens with the New Guinea species have been produced, but lack of fertility has been a persistent problem, unless amphidiploids are produced. Because selection is difficult in amphidiploid populations, other methods of recovering fertility have been investigated. Some interspecific hybrid fertility has been obtained from crossing Impatiens `Tangeglow' with a Java × New Guinea hybrid. Evidence will be presented on the role of the Celebes genome in female fertility, and the role of unreduced pollen in the Java × New Guinea hybrid. Approaches to understanding and overcoming sterility in Impatiens interspecific hybrids will be discussed.
MINIMIZING ENVIRONMENTAL STRESS IN FIELD ESTABLISHMENT OF VEGETABLE CROPS
Authors: Hartz T.K.
Published: February 2019

Overcoming environmental stresses during seedling establishment is crucial to successful vegetable production. In the irrigated production areas of the West stress is most often related to unfavorable temperature, soil or water salinity, or poor soil structure; it is frequently difficult to separate the effects of these stresses since they may all be present to some significant degree. Growers use a variety of techniques to ameliorate these conditions. Advances in seed priming and coating have improved seedling establishment under unfavorable temperatures, particularly for lettuce. The use of sprinkler irrigation for stand establishment has become a widespread practice; sprinkling moderates soil temperature, minimizes salinity in the zone of germination, and reduces soil crusting. By modifying bed configuration growers have been able to increase soil temperature to stimulate germination. Modifying furrow irrigation patterns can create zones of lower salinity. Various chemical treatments have proven effective in reducing soil crusting. The use of transplants is expanding for many crops, both as a means to circumvent seedling establishment problems as well as a technique to obtain earliness.
NATIVE SEEDS/SEARCH: BRIDGING IN SITU AND EX SITU CONSERVATION OF NATIVE SOUTHWESTERN CROPS
Authors: Nabhan Gary Paul , Drees Mahina , Dahl Kevin
Published: February 2019

The binational Southwest remains rich in native crop land races and crop wild relatives, despite numerous pressures favoring genetic erosion. Native Seeds/SEARCH is promoting in situ conservation in traditional Indian fields and nearby wild habitats, but also maintains a gene bank as a back-up, to allow future reintroductions. Seeds are distributed to Native American communities for free, and their value is reinforced through a variety of educational materials and presentations. Our regional focus allows us to serve as an effective bridge between in situ and ex situ conservationists, between Indian and international organizations, and between tribes. Methods, ethics and accomplishments to date will be highlighted.
REDUCING WATER USE DURING CUT FOLIAGE PRODUCTION
Authors: Stamps Robert H.
Published: February 2019

As the area devoted to cut foliage production has increased and residential development has encroached upon these agricultural areas, conflicts between growers and homeowners have increased. Withdrawals of water for cold protection produce severe reductions of local artesian levels which render domestic wells inoperative and lowered lake levels have made some boat docks useless. Overhead sprinkler irrigation has been used for irrigation and cold protection of cut foliage crops since the 1960's. Using water application rates of about 0.84 cm·hr-1 growers were able to reliably supply product on a year-round basis. Water management district developed regulations mandate that certain water saving methods be implemented prior to the issuance or renewal of consumptive use permits and limit water application rates for cold protection to 0.56 cm·hr-1 under certain circumstances. Research on irrigation scheduling and various cold protection strategies have and are being conducted to allow further reductions in water use during the production of cut foliage crops.
Yellow Cotyledon: A Seedling Disorder of Broccoli
Authors: Mayberry Keith S. , Bradford Kent J. , Rubatzky Vincent E.
Published: February 2019

A seedling disorder of broccoli (Brassica oleraceae L. var. italica) characterized by chlorotic cotyledons and delayed seedling growth is described. This disorder, termed “yellow cotyledon”, has been observed in field plantings under high temperatures with some broccoli seed lots. Yellow-cotyledon disorder can be observed in laboratory germination tests if they are conducted under illumination, where unaffected seedlings will develop green cotyledons. Little relationship was found between overall seed vigor and the expression of yellow cotyledon by use of early germination counts and accelerated aging tests, although the most severely affected seed lots had been stored for several years. Field trials in 2 years showed that although seedlings with yellow-cotyledon disorder developed into normal plants, maturity was delayed and total yields were reduced.
Chemical Desiccation of Onions for Set Production
Authors: Masiunas John B.
Published: February 2019

Experiments determined the effectiveness of the bipyridinium herbicides paraquat and diquat and of the diphenyl ether herbicide lactofen to desiccate onion (Allium cepa L.) shoots without affecting bulb quality and storage life. Paraquat, applied once, desiccated 80% of onion shoots within 3 days. Diquat desiccated ≈ 60% of onion shoots within 10 days of treatment. Lactofen caused slight necrosis but did not adequately desiccate onion shoots. Diquat and paraquat reduced sprouting of `Red Wethersfield' more than of `White Portugal'. Chemical names used: 6,7-dihydrodipyrido[l,2 2',1'-c] pyrazinediium ion (diquat); (±)2-ethoxy-l-methyl-2-oxoethy1 5-[2chloro-4-(trifluoromethyl)phenoxyl] -2-nitrobenzoate (lactofen); 1,1'-dimethyl-4,4'-bipyridinium ion (paraquat).
Centipedegrass Response to Plant Growth Regulators
Authors: Fry Jack D.
Published: February 2019

A field study was conducted in southern Louisiana to screen several plant growth regulators (PGRs) for efficacy in suppressing centipedegrass [Eremochloa ophiuroides (Munro) Hack.] vegetative growth and seedhead production. PGRs were applied in three sequential treatments in 1988 and included ethephon, glyphosate, mefluidide, paclobutrazol, sethoxydim, and sulfometuron methyl. Ethephon (5.0 kg·ha-1) suppressed mean centipedegrass vegetative growth by 15% with no turf injury. Mefluidide (0.6 kg·ha-1) and ethephon reduced mean seedhead number by 55% and 61%, respectively. Glyphosate (0.6 kg·ha-1) suppressed vegetative and reproductive growth, but caused unacceptable phytotoxicity and reduced centipedegrass cover and quality during Spring 1989. Use of ethephon or mefluidide to reduce trimming requirements or mower operation in hazardous areas may be an effective means of inhibiting centipedegrass growth. Chemical names used: N -(phosphonomethyl) glycine (glyphosate); N -[2,4-dimethyl-5-[[(trifluromethyl) sulfonyl]amino] phenyl]acetimide (mefluidide); 2-[1-(ethoxyimino)butyl] -5[2-(ethylthio) propyl]-3-hydroxy-2-cycIohexen-l-one (sethoxy-dim); 2-[[[[(4,6-dimethyl-2 -pyrimidinyl) amino] carbonyl]amino] sulfonyl]benzoic acid (sulfometuron methyl); (2-chloroethyl) phosphoric acid (ethephon); (±)-(R*R*)β-[(4-chlorophenyl)methyl]-α-(l,l-dimethylethyl) -1 H -l,2,4-triazole-l-ethanol (paclobutrazol).
Phytotoxic Reaction of Hawaiian Cut Flowers and Foliage to Hydrogen Cyanide Fumigation
Authors: Hansen James D. , Chan Harvey T. , Hara Arnold H. , Tenbrink Victoria L.
Published: February 2019

Phytotoxicity from hydrogen cyanide (HCN) fumigation was measured in several varieties of Hawaiian cut flowers and foliage (Zingiberaceae, Heliconia, Orchidaceae, Marantaceae, Lycopodiaceae, Agavaceae, Proteaceae) as a potential disinfestation treatment. Concentrations tested were 2500, 3700, 4600, and 5500 ppm HCN for 30 min. All foliage and most heliconia were undamaged at fumigation levels of 5500 ppm HCN; most protea and `Midori' anthuriums were uninjured at 4600 pm HCN; red and pink ginger were uninjured at 3700 ppm HCN; and all pincushion protea showed phytotoxicity to HCN. Red ginger was quickly damaged when exposed to sunlight immediately after treatment at 2500 ppm HCN. No injury was observed in simulated shipment tests of red ginger and `Ozaki' anthuriums fumigated at 2500 ppm HCN. Wet, red ginger flowers longer than 6 cm were damaged at 2500 ppm HCN, whereas shorter flowers were uninjured. Wet `Ozaki' anthuriums showed phytotoxicity only at 4600 ppm HCN. Wet, treated lycopodium and bamboo orchid foliage was not injured. The number of marketable days and shelf life of the treated plant material were estimated from the visual ratings.
Pear in Vitro Propagation Using a Double-phase Culture System
Authors: Rodriguez R. , Díaz-Sala C. , Cuozzo L. , Ancora G.
Published: February 2019

Proliferation of Pyrus communis L. cv. Abate Fetel, Precoce Morettini, and Guyot was accomplished with a yield of 10 to 15 new shoots per explant. The in vitro procedure is based on the use of 6.7 μm BAP as an overlay on a modified MS medium. Rooting without callus formation was achieved by immersing the basal end in 5 μm IBA solution for 1 min. The possible inhibition of proliferation and plantlet regeneration by GA3 and IBA is discussed. Chemical names used: 6-benzylaminopurine (BAP); indole-3-butyric acid (IBA); gibberellic acid (GA3).
Survival and Shoot Formation in Vitro of Pear Winter Buds Cryopreserved in Liquid Nitrogen
Authors: Oka Seibi , Yakuwa Harumi , Sate Kimio , Niino Takao
Published: February 2019

Vegetative buds of pear (Pyrus serotina Rehder, cv. Senryo) associated with shoot tissue were frozen stepwise to – 40C, immersed in liquid N, and thawed either at 37C in water or at 0C in air. Survival and shoot formation on thawed material was higher when preliminary cooling lasted 12 to 48 h rather than 0.5 to 2 h. The proper thawing temperature depended on the degree of cooling before cryopreservation. A few whole plants were recovered from the cryopreserved buds.
Evaluation of Strawberry Cultivars for Ellagic Acid Content
Authors: Maas John L. , Wang Shiow Y. , Galletta Gene J.
Published: February 2019

Ellagic acid in tissue extracts of green and red-ripe strawberries (Fragaria × ananassa Duch.) was detected and quantified by HPLC. Ellagic acid content of green fruit pulp ranged from 1.32 to 8.43 mg·g-1 of tissue dry weight (mean 3.36 mg·g-l) and in achenes of green fruit from 1.32 to 20.73 mg·g-1 (mean 7.24). Ellagic acid content of red fruit pulp at one location for 35 cultivars and selections ranged from 0.43 to 4.64 mg·g-1 of dry weight (mean 1.55) and from 0.43 to 3.47 mg·g-l (mean 1.45) for 15 clones at another location. Achenes from red-ripe fruit ranged from 1.37 to 21.65 mg·g-1 (mean 8.46) for 34 clones at one location and from 2.81 to 18.37 mg·g-1 (mean 8.93) for 15 clones at another location. Leaf ellagic acid content ranged from 8.08 to 32.30 mg·g-1 of dry weight (mean 14.71) for 13 clones examined. Large differences in ellagic acid content were found among cultivars, but tissue values were not consistent within cultivars. Values from one tissue type did not correlate consistently with values of the other tissues. Sufficient variation was found among cultivars to suggest that increased ellagic acid levels may be achieved in progeny from crosses with selected parental material.
Eustoma Quality is Adversely Affected by Low pH of Root Medium
Authors: Harbaugh B.K. , Woltz S.S.
Published: February 2019

Foliar chlorosis or bleaching, interveinal chlorosis, leaf edge and tip necrosis, a poor root system, and stunted growth of Eustoma grandiflorum (Raf) Shinn seedlings were associated with a medium pH of 5.0 or 5.5 but not when the values ranged from 6.4 to 7.5. The range in medium pH resulting in the best growth of seedings and flowering plants was 6.3 to 6.7. Responses to medium pH were similar, regardless of fertilizer solution pH or cultivar. Eustoma seedling and shoot fresh weights for pH 5.0 and 5.5 were only 23% to 66% of corresponding values for plants grown at pH 6.4. Leaf tissue Zn was extremely high (1050 mg·kg-l dry leaf tissue) at a medium pH of 5.0, but other macro- and micronutrients in leaves were not at abnormal levels.
Fall-applied Preemergent Herbicides in a Missouri Vineyard Do Not Control Annual Weeds the following Season
Authors: Kaps Martin L. , Odneal Marilyn B.
Published: February 2019

Nine preemergent herbicides were applied at maximum label rate in Fall 1986, 1987, and 1988 to a `Catawba' grape (Vitis labrusca L.) vineyard in the Missouri Ozark region. The untreated controls showed 30% total weed cover by 28 Apr. 1987, 21 May 1988, and 18 Apr. 1989. In 1988, less rain fell early in the growing season; thus, weed cover in the untreated controls was delayed until late in the season. The herbicides norflurazon, oryzalin, and oxadiazon gave the longest period of acceptable grass control. Dichlobenil, diuron, oxyfluorfen, and simazine gave the longest period of acceptable broadleaf control. Most of the herbicides lost residual activity by early summer. For this reason, fall preemergent herbicide application cannot be relied on to give season-long control the following year in southern Missouri. Chemical names used: 2,6-dichlorobenzonitrile (dichlobenil); N' -(3,4-dichlorophenyl) - N,N -dimethylurea (diuron); N,N -diethyl-2-(1-napthalenyloxy)-propanamide (napropamide); 4-chloro-5-(methylamino)-2-(3-(trifluoromethyl)phenyl)-3(2H)-pyrdazinone (norflurazon); 4-(dipropylamino)-3,5-dinitrobenzenesulfonamide (oryzalin); 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5 -(l,l-dimethylethyl) -l,3,4-oxadiazol-2- (3H)-one (oxadiazon); 2-chloro-l-(3-ethoxy-4-nitrophenoxy) -4-(trifluoromethyl) benzene (oxyfluorfen); 3,5-dichloro-N-(l,l-dimethyl-2-propynyl)benzamide (pronamide); and 6-chloro- N,N' -diethyl-1,3,5-triazine-2,4-diamine (simazine).
Root Carbohydrate, Organic Acids, and Phenolic Chemistry in Relation to Sweetpotato Weevil Resistance
Authors: Son Ki-Cheol , Severson Ray F. , Snook Maurice E. , Kays Stanley J.
Published: February 2019

Methanol extracts of external (outer 3 mm) and interior root tissue of four sweetpotato [Ipomoea batatas (L.) Lam.] cultivars (`Centennial', `Jewel', `Regal', and `Resisto') having different levels of susceptibility to the sweetpotato weevil [Cylas formicarius elegantulus Summer] were analyzed for simple carbohydrates (fructose, glucose, sucrose, inositol) and organic acids (malic, citric, quinic) by gas chromatography and for phenolics (caffeic acid, caffeoylquinic acids, rutin) by high-performance liquid chromatography. There were significant differences among cultivars in the concentrations of total sugars and phenolics in the external tissue (P < 0.05). In addition, the distribution of carbohydrates, organic acids, and chlorogenic acid [3-O-caffeoylquinic acid] differed between external and interior tissues. Sucrose was the major water-soluble carbohydrate in all cultivars. With the exception of malic acid, the concentration of carbohydrates, organic acids, and phenolics did not correlate with cultivar susceptibility to the sweetpotato weevil.
Histology and Morphology of Asparagus Somatic Embryos
Authors: Levi A. , Sink K.C.
Published: February 2019

The histology and morphology of developing asparagus Asparagus officinalis L.) somatic embryos arising in callus cultures were examined and contrasted with that documented for zygotic embryos. Histological sections of lateral bud-derived callus cultured for 2 weeks on embryo induction medium consisting of Murashige and Skoog salts and vitamins (MS) with 1.5 mg NAA/liter and 0.1 mg kinetin/liter indicated the formation of distinct groups of embryogenic cells. At 4 weeks, the callus was comprised of embryos in the early and late globular stages and a few bipolar embryos. Within 2 weeks on embryo development medium consisting of MS with 0.05 mg NAA/liter and 0.1 mg kinetin/liter, the globular embryos developed a bipolar shape having an expanded upper region that formed the cotyledon and a smaller region that formed the radicle. Within 4 to 6 weeks on this latter medium, each mature bipolar embryo was opaque and had a large cotyledon, a distinct shoot apex at the cotyledon-hypocotyl junction, and vascular connections between the radicle, shoot apex, and cotyledon. Many mature somatic embryos resembled the asparagus zygotic embryos in having a crescent shape, whereas others had a short but wide cotyledon. Both somatic embryo types converted to plantlets at equal rates. Chemical names used: N- (2-furanylmethyl)-1 H -purin-6-amine (kinetin); 1-naphthaleneacetic acid (NAA).
Low-temperature Preservation of Clianthus formosus Pollen
Authors: Hughes H.G. , Lee C.W. , Towill L.E.
Published: February 2019

Pollen from Clianthus formosus (G. Don) Ford and Vickery was tested for viability after desiccation and exposure to low temperatures. Desiccation for 3 hours before freezing at –180C was sufficient for maintaining pollen germination. Pollen dried for a longer time showed reduced germination when plated directly. However, when pollen was rehydrated by exposure to high humidity before plating, germination was not reduced.
Inheritance of a Chlorophyll Deficiency in Hazelnut
Authors: Mehlenbacher Shawn A. , Thompson Maxine M.
Published: February 2019

A chlorophyll deficiency expressed as yellowing of leaves was observed in hazelnut (Corylus avellana L.) progenies. Segregation ratios approximated 3 green: 1 yellow, indicating control by a single recessive gene designated chlorophyll deficient #1, for which the symbol c, is proposed. `Barcelona', `Butler', `Compton', `Lansing', Willamette', and the ornamental selection `Redleaf #3' are heterozygous. Pedigree analysis strongly suggests that all heteroxygotes inherited the recessive allele from `Barcelona'. A cross of `Barcelona' with the yellow-leafed ornamental Corylus avellana L. var. aurea Kirchn. produced no yellow-leafed seedlings, indicating that the chlorophyll deficiencies from these two sources are controlled by different loci. Progenies segregating simultaneously for this trait and the gene controlling presence of anthocyanin indicated that the two traits are inherited independently. Seedlings deficient in chlorophyll but with anthocyanin were able to survive under field conditions, while leaves of yellow-leafed seedlings lacking anthocyanin became scorched and the trees died.
Rapid Production Methods for Ottawa-3 Rootstock and Branched Apple Nursery Stock
Authors: Hague Eugene J. , Neilsen Denise
Published: February 2019

A system for the rapid production of Ottawa-3 (0.3) rootstock (Malus domestica Borkh.) and branched apple nursery stock in the greenhouse is described. The time required for production of a finished' tree, ≈1 year, compared favorably with traditional methods. Cuttings derived from tissue-cultured 0.3 rootstocks rooted well (up to 94% success rate), and the rooting effect persisted in cuttings from tissuecultured rootstocks grown for 1 year in the field. All combinations of two levels of N and P in a Long Ashton nutrient solution were applied weekly to pots containing either tissue-cultured rootstocks or cuttings. The growth rate of tissue-cultured rootstocks exceeded that of cuttings. The growth rate of both sources of rootstocks increased in response to added P and N. Growth of scion shoots (`Royal Gala') increased in response to N. Branch production of `Royal Gala' was greater for trees with the higher P and N rates. Trees on tissue-cultured rootstocks had more branches than those on cuttingderived roostocks at the higher level of N.
Effect of Dry Storage on Bacterial Counts in Stems of Cut Rose Flowers
Authors: van Doorn Wouter G. , de Witte Yke
Published: February 2019

The number of bacteria in the basal 5 cm of the stems of cut rose flowers (Rosa hybrida L. cv. Sonia) stored in water for 1 to 4 days was positively correlated with the number of bacteria in the water. Subsequent dry storage of the flowering rose stems resulted in an increase in the number of bacteria in the stems, similar to that occurring in stems that were held in water. Low temperatures during dry storage (SC) reduced the reproduction rate of bacteria in the stems. Use of aluminum sulfate (0.8 g-liter-`) during the rehydration period before dry storage limited the number of bacteria in the stems and prevented their subsequent increase during dry storage.
An Exploratory Study of Reciprocal Apple Rootstock and Scion Hardiness with Two Methods of Assessment
Authors: Embree C.G. , McRae K.B.
Published: February 2019

Root hardiness for the apple (Malus domestica Borkh.) rootstocks M.26, MM.106, MM.111, M.7A, and M.7EMLA at - 8 and - 11C and trunk survival for the tender cultivar Gravenstein and the hardy cultivar Wealthy at -25 and -35C were evaluated both destructively (tissue examination) and nondestructively (regrowth measurement the following season). No differences in root survival were detected at -8C by either method; at - 11C, MM.111 rated better than the others, while regrowth was higher on M.26, MM.111, and M.7A than on MM.106 or M.7EMLA. Root survival did not differ for the scions at either temperature, but regrowth was greater for `Gravenstein' than Wealthy' at both temperatures. Trunk tissue survival at -25C was consistently lowest for scions on M.7EMLA, and regrowth was less than on M.26 and MM.111. At -35C there were no significant rootstock effects. For the scions, lateral wood tissue survival at -25C was highest for Wealthy', but the weight of the new growth did not differ. At -35C bark tissue survival and regrowth was greater for Wealthy' than for `Gravenstein'. Evidence is presented in support of the occurrence of reciprocal effects. Correlation between the two methods was highest for root exposure at - 11C and for the assessment of trunk bark.
Fertigation and Growth of Young `Hamlin' Orange Trees in Florida
Authors: Willis Leah E. , Davies Frederick S. , Graetz D.A.
Published: February 2019

One-year-old `Hamlin' orange [Citrus sinensis (L.) Osb.] trees on sour orange rootstock (C. aurantium L.) were used to compare various fertigation frequencies and rates with application of granular materials. In Expt. 1, granular fertilizer was applied five times per year or liquid fertilizer was applied five, 10, or 30 times per year at 0.23 kg N/tree per year as an 8N-3.4P-6.6K formulation. In Expt. 2, an additional treatment of granular and liquid material was applied three times per year, but fertilizer rate and formulation were the same as in Expt. 1. Experiment 3 included the same application frequencies as Expt. 1, but with two rates of N (0.11 or 0.06 kg N/tree per year). Soil samples were taken from each treatment 1, 4, and 7 days after fertilization at depths of 0-15, 16-46, and 47-76 cm for nutrient analyses. Trunk diameter, shoot growth, and tree height were similar for all treatments 8 months after planting in Expts. 1 and 2, while trees in Expt. 3 had significantly less growth at the lower rate. Soil NH4-N and NO3-N concentrations for all liquid treatments within 1 week of fertilization were highest for the five times per year treatment at the 0- to 15-cm depth, but nutrient concentrations of all liquid treatments were similar at the other depths. For most dates and depths, NH4-N and NO3-N concentrations were similar for both fertilizer rates.
Clinoptilolitic Zeolite as an Amendment for Establishment of Creeping Bentgrass on Sandy Media
Authors: NUS J.L. , Brauen S.E.
Published: February 2019

In a field experiment, clinoptilolitic zeolite was compared to sphagnum peat and sawdust as sand amendments at 5%, 10%, and 209” (v/v) to enhance `Penncross' creeping bentgrass (Agrostis palustris Huds.) establishment and to compare their gravimetric and volumetric cation exchange capacities and their effects on moisture retention and cation exchange capacities of the resultant mixes. In addition, cation exchange capacities and exchangeable K+ and \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document}; were analyzed from clinoptilolitic zeolite of particle sizes ranging from <0.25 mm to >5.0 mm. All amendments, except 10?ZO and 20% sawdust, resulted in superior establishment compared to unamended sand. Peat-amended sand retained significantly more moisture than sawdust- or zeolite-amended sand at –6, –10, –33, and -250 kpa soil matric potentials. Zeolite exhibited a much higher volumetric cation exchange capacity than either sawdust or sphagnum peat. Cation exchange capacity and exchangeable potassium of clinoptilolitic zeolite was greatest when particle size was <0.5 mm; however, little exchangeable ammonium nitrogen was detected.
Selective Limb Pruning Intensity Influences Mature Pecan Tree and Nut Characteristics
Authors: Worley Ray E.
Published: February 2019

Pecan [Carya illinoensis (Wangenh.) C. Koch] tree height was gradually reduced by removing one, two, or three limbs per year at a height <9 m. Pruning improved tree vigor and color, increased trunk circumference, terminal shoot growth, nut size, and leaf N, P, and Mg, but reduced leaf K and percentage of fancy grade kernels relative to unpruned trees. Yield was not influenced by selective limb pruning.
Paclobutrazol, Gibberellic Acid, and Rhizome Size Affect Growth and Flowering of Zantedeschia
Authors: Corr Brian E. , Widmer Richard E.
Published: February 2019

Growth and flowering of Zantedeschia elliottiana W. Wats. and Z. rehmannii Engl. were studied. Rhizomes of both species were produced either in a glasshouse or outdoors in California. Plants grown from glasshouse-produced rhizomes flowered within 90 days only when a preplant rhizome soak of 500 ppm GA, was applied. Control plants of both species flowered when grown from field-produced rhizomes, but a GA3 preplant rhizome soak significantly increased the number of flowers (spathe and spadix) produced. Paclobutrazol, applied as a preplant rhizome soak or as a soil drench when shoots were 2 to 3 cm long, significantly limited plant height of Z. rehmannii from either source if not treated with GA,. Paclobutrazol and GA, treatments interacted significantly to affect height and number of flowers of Z. rehmannii grown from field-produced rhizomes. Treatment with GA3 overcame the dwarfing effect of paclobutrazol, while paclobutrazol treatment limited flower production. Z. rehmannii rhizomes >6.5 cm in diameter produced more shoots and leaves than smaller rhizomes, regardless of GA3 treatment. Emergence, number of shoots, and number of leaves from Z. elliottiana were not significantly affected by the rhizome size-GA3 variable combination. Production of normal flowers was increased by GA3 treatment of all sizes of Z. rehmannii rhizomes except the smallest, with the most flowers being produced by plants from the largest rhizomes. Production of deformed flowers was greatest from rhizomes treated with 500 ppm GA3, with no deformed flowers on control plants.
Tolerance to Ammonia in the Common Edible Mushroom Induced in Vitro
Authors: Romaine C. Peter , Raid Laurie
Published: February 2019

Commercial strains of Agaricus bisporus (Lange) Imbach that were grown in vitro at 32C for 4 to 5 weeks on a medium containing 250 μg amantadine/ml followed by hyphal tip-culturing showed an enhanced tolerance of ammonia in the compost during cropping trials. Yield of mushrooms by a treated off-white strain (GSP-18) and a treated white strain (Marlowe-503) was higher in composts with elevated levels of ammonia (0.11% to 0.27%) than that of the untreated cultures. Tolerance was related to the ability of the treated cultures to grow vegetatively in the ammonia-enriched compost. Tolerance was expressed by the cultures for at least 14 months following induction.
Longevity of Potted Chrysanthemums at Various Nitrogen and Potassium Concentrations and NH4: NO3 Ratios
Authors: Roude Nadia , Nell Terril A. , Barrett James E.
Published: February 2019

Plant height, flower diameter, days to flower, and longevity of `Iridon' chrysanthemums [Dendranthemum × grandiflorum (Ramat.) Kitamura] were not affected by various N and K concentrations (112, 225, 337, and 450 mg·liter-1) supplied during the last 5 weeks of production. However, increasing N concentration increased medium conductance, while varying K concentration had no effect on conductance. Visual grade of `Iridon' after 3 weeks in a simulated interior environment showed an interaction between concentrations of N and K. In a second study, growth and longevity of `Iridon' were affected by NH4: NO3 ratios. Plants receiving a 0:1.0 ratio flowered 4 days later than plants receiving a 0.5:0.5 ratio and were taller than plants fertilized with a 1.0:0 ratio. Longevity was greater in plants receiving a 0:1.0 ratio than in those receiving 0.5:0.5 or 0.75:0.25 ratios. Also, longevity was similar in plants receiving NH4: NO3 ratios of 0:1.0, 0.1:0.9, 0.2:0.8, and 0.3:0.7. Plants receiving 0:1.0 lasted 6 days longer than those receiving a 0.4:0.6 ratio.
Petroleum Spray Oil Effects on Net Gas Exchange of Grapefruit Leaves at Various Vapor Pressures
Authors: Syvertsen J.P. , Salyani M.
Published: February 2019

The effects of three highly refined petroleum spray oils and of ambient vapor pressure on net CO2 assimilation (A) and stomatal conductance of water vapor (gs) of single grapefruit (Citrus paradisi Macf.) leaves were investigated. Overall, gs of various-aged leaves was decreased by a large leaf-to-air vapor pressure difference (VPD). In the first experiment, oils with midpoint distillation temperatures (50% DT) of 224, 235, and 247C were applied with a hand atomizer at concentrations of 0, 1%, and 4% oil emulsions in water and 100% oil, all with 0.82% surfactant (by volume). There was a tendency for oils of the two higher DT to decrease net gas exchange during a subsequent 12 days, but significant differences could not be attributed to oil DT. Both A and gs were reduced by the two higher concentrations of oil mixtures. In the second experiment, a commercial airblast sprayer was used to apply the 224C oil at 4% or the 235C oil at 2% and 4% mixtures plus surfactant under field conditions. There were no significant effects of oil treatments on net gas exchange of leaves either measured under moderate VPD outdoors 1 day after spraying or under low VPD in the laboratory 2 days after spraying. No visible phytotoxic symptoms were observed in either experiment.