bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemical Composition of Turnip Roots Stored or Intermittently Grown at Low Temperature
Authors: Shattuck V.I. , Kakuda Y. , Shelp B.J. , Kakuda N.
Published: January 2019

Field and greenhouse studies were conducted to investigate the effects of low temperature on the starch, sugar, ascorbic acid, and glucosinolate (GS) concentration in turnip [Brassica rapa ssp. rapifera (Metzg.) Sinsk] roots. Field-harvested roots were stored at 0C for 2 and 4 weeks. In the greenhouse, plants were grown at 0 to 12C for parts of 11 days before harvest. Cold-stored roots decreased in both starch and total sugar concentration (sucrose, fructose, and glucose) when compared to freshly harvested roots. Greenhouse-grown plants subjected to low temperatures had roots with a similar starch content but with a higher concentration of total sugars than the control. In both experiments, the cold treatments induced a slight but significant increase in root sucrose concentration. The ascorbic acid concentration of roots was not affected by low temperature. In both the field and greenhouse studies, low temperature did not change the total concentration of the eight major GSs identified in peeled root “and peel tissues, but did alter the concentration of specific GSs.
Peroxidase Activity, Isoenzymes, and Tissue Localization in Developing Highbush Blueberry Fruit
Authors: Miesle T.J. , Proctor A. , Lagrimini L.M.
Published: January 2019

The activity, isoenzymes, and histochemical location of peroxidase were studied in developing highbush blueberries (Vaccinium corymbosum L.). Total peroxidase activity increased during development when expressed on a fresh-weight basis, reaching a maximum in red berries and then declining. When peroxidase activity was expressed per berry it did not decline after the red-berry stage. Most of the enzyme was ionically bound to cell walls throughout development, with the number of isoenzymes increasing with maturity. Histochemical localization of peroxidase showed that enzyme activity spread throughout the berry during development.
Interaction of Simulated Acid Rain with Ozone on Freeze Resistance, Growth, and Mineral Nutrition in Citrus and Avocado
Authors: Eissenstat David M. , Syvertsen James P. , Dean Thomas J. , Johnson Jon D. , Yelenosky George
Published: January 2019

The combined effects of O3 and acid rain on freeze resistance, growth, and mineral nutrition were studied using broadleaf-evergreen citrus and avocado trees. Using a factorial design, `Ruby red' grapefruit (Citrus paradisi L.) trees on either Volkamer lemon (Citrus volkameriana Ten. & Pasq.) or sour orange (Citrus aurantium L.) rootstock and `Pancho' avocado trees (Persea americana Mill.) on `Waldin' rootstock were exposed to O3 and acid rain for 8 months in open-top chambers under field conditions. The O3 treatments were one-third ambient (0.3X), ambient (1X), twice ambient (2X), or thrice ambient (3X). Ambient O3 concentrations averaged 39.1 nl·liter-3 over a 12-hour day. The acid rain treatments had a pH of 3.3, 4.3, or 5.3 and were applied to simulate long-term rainfall averages. In general, the effects of acid rain on growth and freeze resistance were small. Rain of high acidity (pH = 3.3) offset the negative effects of O3 on growth (total leaf mass) in avocado and grapefruit/Volkamer lemon trees. In contrast, rain of high acidity magnified the detrimental effects of O3 on electrolyte leakage of leaf disks at subzero temperatures, especially for citrus. Freeze resistance, determined by stem and whole-plant survival following freezing temperatures, was lower in the most rapidly growing trees. Consequently, for trees exposed to a combination of O3 and acidic rain, leaf electrolyte leakage did not correlate significantly with stem survival of freezing temperatures. We conclude that the danger of acid rain to citrus and avocado in Florida is rather slight and would only present a potential problem in the presence of extremely high O3.
Activity of Phenylalanine Ammonia-Lyase (PAL) and Concentrations of Anthocyanins and Phenolics in Developing Strawberry Fruit
Authors: Cheng Guiwen W. , Breen Patrick J.
Published: January 2019

Studies on regulation of production of phenolics in strawberry (Fragaria X ananassa Duch,) fruit were initiated by monitoring phenylalanine ammonia-lyase (PAL) activity and levels of anthocyanins, flavonoids, tannins, and other soluble phenols throughout fruit ontogeny in `Tillikum'. PAL catalyzes the first step in the biosynthesis of phenylpropanoids, which are further modified into a wide variety of phenolic compounds. Peak in PAL activity (1 mol· s-1 = 1 kat) of 90 pkat· mg-1 protein was detected at 5 and 27 days after anthesis (DAA), when fruit was green and nearly ripe, respectively. PAL activity was only ≈10% of peak values in the white berry stage, when. fruit growth was most rapid. The second peak in PAL activity was followed by a rapid drop, to nearly zero in red-ripe fruit at 30 DAA. Total soluble phenols reached a maximum level soon after anthesis, just before the first peak in PAL activity, then declined to a low constant value well in advance of fruit ripening. Similar changes were observed in levels of tannins and flavonoids that, at anthesis, accounted for 44% and 51% of the soluble phenols, respectively. The concentration of anthocyanin was very low throughout most of fruit development, but beginning at 23 DAA it increased from <0.03 to >0.53 mg·g-1 fresh weight in 3 days. This accumulation paralleled the second rise in PAL activity. Accordingly, strawberry fruit have a developmental-dependent expression of PAL activity and accumulation of phenolic substances derived from the phenylpropanoid pathway.
Fertile Derivatives from Sparkleberry × Blueberry Crosses
Authors: Lyrene P.M.
Published: January 2019

Diploid plants in Vaccinium section Cyanococcus, including plants of V. darrowi Camp, V. atrococcum. Heller (diploid V. corymbosum L.), a V. atrococcum × V. darrowi F1 hybrid, and a V. atrococcum × V. elliottii Chapmn. F1 hybrid, were hand pollinated in a greenhouse with pollen from diploid V. arboreum Marsh. (Section Batodendron). The resulting seeds were germinated and the seedlings were transplanted to a high-density field nursery. Forty of these F1 intersectional hybrids were selected after 2 1/2 years and transplanted to a 1.5 × 4-m spacing. Most of these plants were vigorous and flowered heavily in subsequent years, but only a small percentage of the flowers produced fruit. In 1990, however, >4000 berries were harvested from the 35 surviving plants. Open-pollinated seed from a much smaller number of berries was planted in Dec. 1987; these seeds produced ≈200 seedlings, some of which had moderate to high fruit set in a field nursery in 1989. Six of these seedlings, which were selected for high vigor, high fruit set, and characteristics intermediate between section Cyanococcus and section Batodendron, had fruit set ranging from 19.4% to 92.7% when pollinated with pollen from tetraploid V. corymbosum cultivars. One of the six seedlings was highly self-fruitful, and some intercrosses among the six seedlings produced much viable seed. Large-scale introgression of V. arboreum genes into tetraploid highbush cultivars likely will be possible by the methods used in this study.
Fruit Set, Pollen Fertility, and Combining Ability of Selected Tomato Genotypes under High-temperature Field Conditions
Authors: Dane Fenny , Hunter A. Gene , Chambliss Oyette L.
Published: January 2019

Selected tomato (Lycopersicon esculentum Mill) genotypes were evaluated for their fruit-setting ability under high-temperature field conditions. A temperature-controlled greenhouse study was conducted to determine the percent fruit set from the total number of flowers and fruit produced per plant. Ratings for set obtained under high-temperature field conditions were significantly (P = 0.001) correlated with percent fruit set determined under similar greenhouse conditions. Most of the Asian Vegetable Research and Development Center (AVRDC) selections, Beaverlodge lines, `Nagcarlan', and `Red Cherry' could be considered heat-tolerant. Small-fruited, abundantly flowering genotypes were less affected by heat stress than larger-fruited cultivars. Prolonged periods of high temperature caused drastic reductions in pollen fertility in most genotypes, except `Red Cherry' and L. esculentum var. cerasiforme (PI 190256). Stigma browning and stigma exsertion commonly occurred on all lines, except AVRDC CL-5915-553 and PI 190256. Diallel analyses indicated that pollen fertility and fruit set under high field temperatures were primarily under additive gene control.
A Two-stage Micropropagation System for Cranberries
Authors: Marcotrigiano Michael , McGlew Susan P.
Published: January 2019

A two-stage micropropagation system was devised for cranberries (Vaccinium macrocarpon Ait.). Shoot-tip explants taken from four cultivars of greenhouse-grown plants were placed on media composed of Anderson's major salts, Murashige and Skoog's (MS) minor salts and organics, plus various concentrations of 2iP, IBA, and GA3. In other experiments, explant source, salt formulations for media, and rooting treatments were studied. Optimal multiplication and shoot quality occurred when nodal explants taken from greenhouse-grown or micropropagated plants were placed on medium containing 150 μm 2iP, 1.0 μm IBA, and no GA3. Histological examination revealed that the initial response of nodes to culture is axillary bud proliferation, but adventitious shoot formation occurred after 4 to 6 weeks. Cultures that contained only axillary shoots were not evident unless low levels of 2iP were used, at which point only axillary buds present on the explants were released. Proliferated shoots could be rooted ex vitro without auxin treatment. Optimal rooting occurred under high-light conditions. Plants were transplanted to the field for comparison to conventionally propagated material. Chemical names used: gibberellic acid (GA3), N-(3-methyl-2-butenyl)-1H-purin-6-amine (2iP), 1H-indole-3-butanoic acid (IBA).
Supercooling in Floral Buds of `Danka' Black and `Red Lake' Red Currants
Authors: Warmund Michele , George Milon , Takeda Fumiomi
Published: January 2019

Differential thermal analyses (DTA) and freeze viability tests were conducted to investigate the biophysics of freezing in floral buds of `Danka' black (Ribes nigrutn L.) and `Red Lake' red currants [Ribe.s sativum (Rchb.) Syrne] sampled from Nov. 1989 through Mar. 1990. Scanning electron microscopy was also used to determine the relationship between floral morphology and the freezing characteristics of the buds. Floral buds had multiple abrupt low-temperature exotherms (LTEs) and one or two broad LTEs in DTA tests. Abrupt LTEs from DTA were associated with apparent injury to the inflorescence in viability tests. The number of LTEs did not correspond to the number of racemes or flowers per bud, indicating that several flowers froze simultaneously. DTA experiments conducted in Dec. 1990 revealed that the broad exotherm detected between - 14 and - 20C in `Danka' samples resulted from freezing of supercooled water in the outer nonliving region of the periderm of cane tissue attached to the bud.
CO2 Enrichment of Greenhouse Roses Affects Neither Rubisco Nor Carbonic Anhydrase Activities
Authors: Beeson R.C. , Graham M.E.D.
Published: January 2019

The effect of prolonged CO2 enrichment on the activities of ribulose l,5-bisphosphate carboxylase/oxygenase (Rubisco) and carbonic anhydrase (CA) of greenhouse roses were studied. Plants of Rosa × hybrids `Red Success' were grown for 2 years at ambient and 900 μl CO2/liter during winter and spring with 75 μmol·m-2·s-1 photosynthetically active radiation supplemental lighting for 2 years. Measurements of initial and Mg+2-CO2-activated activities of Rubisco and CA were made during shoot development and at different positions within the plant canopy. Generally, there were no significant differences measured in the enzyme activities between the two CO2 concentrations. The results suggest that the photosynthetic capacity did not change and that there were no characteristic adaptations to long-term growth (up to 20 weeks) at elevated CO2 concentrations. The maintenance of Rubisco and CA activities with prolonged exposure to CO2-enriched atmospheres is proposed as the reason for long-term yield increases in roses when grown in enriched environments.
Embryo Culture of Lycopersicon esculentum × L. peruvianum Hybrid Genotypes Possessing Heat-stable Resistance to Meloidogyne incognita
Authors: Cap G.B. , Roberts P.A. , Thomason I.J. , Murashige T.
Published: January 2019

Genotypes of Lycopersicon peruvianum (L.) Mill. and L. peruvianum var. glandulosum (Rick), selected from accessions that possess resistance to Meloidogyne incognita [(Kofoid and White) Chitwood] at high soil temperature (30C), were used as male parents in crosses with L. esculentum (Mill.) susceptible cultivars UC82, Lukullus, Tropic, and male-sterile line ms-31, respectively. The incongruity barrier between the two plant species was overcome by embryo callus and embryo cloning techniques. Hybridity of the F, progeny obtained from each cross was confirmed by differences in leaf and flower morphology, plant growth habits, and by acid phosphatase isozyme phenotypes using polyacrylamide gel electrophoresis. In greenhouse inoculation experiments, F1 plants were highly resistant to M. incognita in soil at 25 and 30C. These results confirmed the successful transfer and expression of heat-stable resistance to M. incognita from L. peruvianum to hybrids with L. esculentum as a preliminary step to introgressing additional root-knot nematode resistance into tomato.
Characterization of Cornus (Dogwood) Genotypes Using DNA Fingerprinting
Authors: Culpepper John H. , Sayavedra-Soto Luis A. , Bassam Brant J. , Gresshoff Peter M.
Published: January 2019

Several horticulturally important members of the genus Cornus were characterized at the DNA level to identify genotypes. Random genomic DNA fragments from Cornus florida L. `Barton' were cloned into pBR322 and λ Gem-11 and used to search for restriction fragment length polymorphisms (RFLPs) among C. sericea L., C. kousa Hance., and four cultivars of C. florida: `Barton', `Cherokee Princess', `Cloud 9', and `Mary Ellen'. Total DNA from these genotypes was restricted with several endonucleases (of which BamHI, EcoRI, and HindIII were used to search for RFLPs), vacuum-blotted onto nylon membranes, and probed with the C. florida `Barton' DNA clones. RFLPs were common among the Cornus species sericea, kousa, and florida, suggesting considerable DNA sequence divergence at the species level. RFLPs were less common among the cultivars of C. florida. These cultivars were selected from a narrow geographical area in North America from nursery-grown trees and exhibit much less DNA sequence divergence.
Growth of Dendranthema ×grandiflorum (Ramat.) Kitamura under Various Spectral Filters
Authors: McMahon M.J. , Kelly J.W. , Decoteau D.R. , Young R.E. , Pollock R.K.
Published: January 2019

`Spears' (nonpinched and pinched) and `Yellow Mandalay' (pinched) chrysanthemums were grown in growth chambers equipped with panels filled with liquids that served as spectral filters. Light quality was altered by reducing blue light, increasing red: far-red (R: FR) light, or reducing R: FR. Control panels did not selectively alter light transmission. Photosynthetic photon flux was the same in all chambers. All plants grown under increased R: FR filters had reduced height, reduced internode length, and increased chlorophyll content compared to controls. Reduction in blue light decreased chlorophyll content of pinched plants compared to controls. Pinched plants grown under increased R: FR light and !ong days developed fewer nodes than controls due to the formation of abnormal capitula; the controls and plants from the other treatments developed more nodes before producing similarly abnormal capitula. Stem diameter and leaf area did not differ due to treatments.
Ethylene-increased Accumulation of Fluorescent Lipid-peroxidation Products Detected during Senescence of Parsley by a Newly Developed Method
Authors: Meir Shimon , Philosoph-Hadas Sonia , Aharoni Nehemia
Published: January 2019

A newly developed rapid and convenient method was used for fractionation and analysis of fluorescent compounds (FCs) formed during lipid peroxidation in parsley (Petroselinum crispum Mill.) leaves. These lipofuscin-like FCs [which arise in vivo from reaction of malondialdehyde (MDA) with amino acids] were found to increase during the senescence of detached parsley leaves, following the commencement of chlorophyll degradation and proteolysis. However, accumulation of FCs in response to exogenous ethylene coincided with the onset of chlorophyll loss and proteolysis on day 2 and was accelerated markedly later. Unlike FC accumulation, levels of aldehydes and MDA in control leaves increased more drastically during senescence, but were not affected significantly by exogenous ethylene. The results suggest that the accumulation of FCs in detached parsley leaves exposed to exogenous ethylene is an early senescence-associated process.
Ethylene Biosynthesis and Polyamine Accumulation in Apples with Watercore
Authors: Wang Shiow Y. , Faust Miklos
Published: January 2019

Ethylene biosynthesis and polyamine content were determined in normal and watercore-affected apple (Malus domestics Borkh. cv. Delicious). Fruit with watercore produced more ethylene and contained higher amounts of putrescine (PUT), spermidine (SPD), 1-aminocyclopropane-1-carboxylic acid (ACC), and 1-(malonylamino) cyclo-propane-1-carboxylic acid (MACC). The activities of ACC synthase and ethylene-forming enzyme (EFE) in watercore-affected fruit were also higher than in normal fruit. The EFE activity in severely affected flesh was inhibited, resulting in ACC accumulation and low ethylene production. S-adenosylmethionine (AdoMet) was maintained at a steady-state level even when C2 H4 and polyamides were actively synthesized in normal and affected fruit.
External Morphological Characteristics for Histogenesis in Pecan Anthers
Authors: Yates I.E. , Sparks Darrell
Published: January 2019

External “morphological characteristics of catkins from one protogynous (`Stuart') and one protandrous (`Desirable') cultivar of pecan [Carya illinoensis Wangenh.) C. Koch] were examined to define markers of cellular differentiation in the anthers. The angle between the catkin rachis and the bract, visibility of the bracteole, rachis, and anther, and anther color proved to be markers by which development could be categorized into five stages. `Stuart' catkins with bracts as the only externally visible portion of the floret (Stage I) commonly had two locules in each anther lobe. When bracteoles became externally visible (Stage II), cellular specialization had occurred to form a central core containing reproductive cells and tapetal cells differentiated and separated from the exterior layers of the anther wall. Disintegration of tapetal cells and thickening of endothecium eel! walls occurred as the angle between the rachis and bract increased to 45° (Stage III). The anther wall was reduced to only two cell layers, epidermis and endothecium, as the anthers became visible (Stage IV). The pollen grains were mature when the anthers developed a yellowish tinge (Stage V) just before anther dehiscence. Tapetal cells had developed distinguishing traits in anthers of Stage I `Desirable' catkins and endothecial cells of Stage II. Internal anther development was similar for both cultivars from Stages III-V. Trichomes, a common feature-on the surface of the staminate floral parts, became less dense with proximity of the floral parts to the interior of the floret and with catkin maturity.
Yield, Growth, and Mineral Nutrition of Young `Ray Ruby' Grapefruit Trees under Trickle or Flood Irrigation and Various Nitrogen Rates
Authors: Swietlik Dariusz
Published: January 2019

Growth, fruiting, and mineral nutrition of trickle- or flood-irrigated young `Ray Ruby' grapefruit (Citrus paradisi Macf.) trees on sour orange (C. aurantium L.) rootstock were compared in a 4-year field study. Trickle irrigations (two emitters per tree) were scheduled based on: 1) 0.7 (first 3 years) or 0.5 (4th year) of Class A pan evaporation (TPAN) adjusted to the ground area covered by tree canopies, or 2) tensiometer readings (TTEN) of - 0.02 MPa at 30-cm soil depth. The flood irrigations (FLOOD) were scheduled at 50% available soil water depletion at 30 cm (first 3 years) or 30- and 60-cm soil depth (the 4th year). Nitrogen at NO (none), N1(20, 40, 80, 160 g N/tree per year in the four consecutive years), or N2(twice the amount of NJ was injected into the trickle lines from January to August or, under FLOOD, split into January and May soil applications. TPAN and TTEN trees were irrigated with <10% of the water amount applied to FLOOD trees without negatively affecting tree growth, yield, or fruit size. Growth of the trees was not affected by N fertilization, but fruit count and yield and leaf N concentration were increased by the N1 and N2 treatments in the fourth growing season. Frequent N fertigations under the trickle system provided no benefits over two split-soil broadcast applications under the flood system. Fruit size was reduced by the N2 treatment. Based on the water amounts applied to TTEN trees, irrigation needs under the trickle system were estimated to be 0.75, 0.57, 0.30, and 0.20 of Class A pan evaporation adjusted to the ground area covered by the plant canopies, in the first, 2nd, 3rd, and 4th year of orchard life. The decreasing pan coefficient indicated increasing extraction of water from outside the irrigated zones. Roots of TPAN and TTEN trees grew at least 210 cm past the wetted zones into the row middles. More than half of the roots in the TPAN and TTEN treatments were found at 60- to 230-cm soil depth compared to only 17% in the FLOOD treatment.
Harvest Date as a Factor in Carbohydrate Storage and Cold Hardiness of Cabernet Sauvignon Grapevines
Authors: Wample Robert L. , Bary Andy
Published: January 2019

Cold-hardiness evaluations and soluble and insoluble-nonstructural carbohydrate analysis of dormant Vitis vinifera L. cv. Cabernet Sauvignon buds and cane tissue indicate a positive relationship between soluble carbohydrates and primary bud cold hardiness. Seasonal variations in soluble and insoluble carbohydrates appear to be related to changes in air temperatures and the dormancy status of the tissues. No differences were found in bud cold hardiness and only limited differences in carbohydrate levels of buds or stem tissues collected over 3 years from early harvest, normal harvest, or unharvested vines. These findings contrast with the widely held opinion that delayed harvest or failure to remove fruit results in reduced cold hardiness as a consequence of low storage carbohydrate content of the plants.
Growth and 14C-Photosynthate Allocation in Citrus Nursery Trees Subjected to One of Three Bud-forcing Methods
Authors: Williamson J.G. , Castle W.S. , Koch K.E.
Published: January 2019

Three commercially employed treatments to force scion bud growth were compared using greenhouse-grown `Carrizo' citrange [Citrus sinensis (L.) Osb. × Poncirus trifoliata (L.) Raf.] seedlings budded with `Hamlin' orange [Citrus sinensis (L.) Osb.]. Scion buds were forced either by 1) cutting off (removing the rootstock shoot above the bud union); 2) lopping (cutting half-way through the rootstock shoot above the bud union and breaking over the rootstock stem); or 3) bending (bending the rootstock shoot to its base and tying it in position). Plants were harvested, dried, and weighed at various times after scion shoot emergence. Plants on which rootstock shoots remained attached (lopping or bending) had the largest scion leaf area and gained the most scion and whole-plant dry weight. Bending rootstock shoots also resulted in a longer scion, more leaves, and higher root dry weight than did removal of rootstock shoots by cutting off. Few differences in overall growth were observed among trees retaining their rootstock shoots after two scion growth flushes. Removal of rootstock shoots after the first scion growth flush reduced leaf area and dry weight gain of the second scion growth flush; however, it did not affect total scion leaf area or dry weight. Analysis of 14C-photosynthate transfer from labeled rootstock leaves showed that bending allowed the greatest movement of labeled assimilates to other plant parts during the 24 hours after 14CO2 fixation. Radiolabeled photosynthates from rootstock leaves were partitioned primarily to shoots during scion growth flushes and to roots during periods between growth flushes.
Matriconditioning of Vegetable Seeds to Improve Stand Establishment in Early Field Plantings
Authors: Khan Anwar A. , Maguire James D. , Abawi George S. , Ilyas Satriyas
Published: January 2019

A matriconditioning procedure based on the matric properties of Micro-Cel E and expanded vermiculite #5 has proved effective in improving seedling emergence in growth chambers. The major objectives of this study were to examine some physical characteristics of the carriers and their effectiveness as preplant conditioning media in improving stand establishment of vegetable seeds in field plantings. Carrier characteristics included no detectable solute or osmotic potential, low electrical conductivity (0.48-0.04 mmho/cm), high water-retaining capacity (450% to 600%), a pH range of 7.0 to 8.4, and ability to effectively control seed hydration (conditioning) at low matric potential. The seed: carrier: water ratio for seed conditioning ranged from 1:0.3-0.5:1-2 (by weight). In a field trial, conditioning of `Long Imperator' and `Nantes' carrot (Daucus carota var. sativus Hoffm.) seeds reduced the time to 10% of final emergence (T10) by 2.6 to 2.8 days and to 50% of final emergence (T50) by 2.1 to 3.0 days. Conditioning increased the final emergence percentage by 39% in 1-year-old `Long Imperator' compared to 150% in 4-year-old `Nantes' seeds. In another field trial, the effect of conditioning on stand establishment was evaluated in `Jackpot' tomato (Lycopersicon esculentum Mill.), `California Wonder' pepper (Capsicum annuum L.), and `BBL 47' snap bean (Phaseolus vulgaris) seeds. In tomato, conditioning reduced the T10 by 0.9 day, had no effect on T50, and increased the emergence percentage by 86%. In pepper, conditioning reduced the T10 and T50 by 1.5 days and increased the percentage emergence by 30%. In snap bean seeds, conditioning in Micro-Ccl E reduced the T10 and T50 by 0.8 day but adversely affected the percentage emergence. Further reductions in T10 and T50 (1.2 and 1.6 days, respectively) and restoration of percentage emergence to control level occurred upon addition of 0.001 mM GA3 during conditioning. Fungicides added to carrot, tomato, and pepper seeds, with or without conditioning, showed no additional improvements and, in a few cases, adversely affected emergence. A preplant conditioning in Micro-Ccl E, alone or in combination with GA3, smears to be a viable alternative to conditioning! seeds in liquid carriers. Chemical name used: gibberellic acid (GA3)
Nematode Populations and Peach Tree Survival, Growth, and Nutrition at an Old Orchard Site
Authors: Evert Dean R. , Bertrand Paul F. , Mullinix `Benjamin G.
Published: January 2019

Bahiagrass (Paspalum notatum Flugge cv. Paraguayan-22) growing under newly planted peach [Prunus persica (L.) Batsch.] trees severely stunted the trees. Neither supplemental fertilizer nor irrigating with two 3.8-liters·hour-1 emitters per tree eliminated tree stunting emitters were controlled by an automatic tensiometer set to maintain 3 kpa at a depth of 0.5 m under a tree in bahiagrass. Preplant fumigation with ethylene dibromide at 100 liters·ha-1 increased tree growth, but not tree survival. Fenamiphos, a nematicide, applied under the trees each spring and fall at a rate of 11 kg-ha -1 had no positive effect on tree survival, tree growth, or nematode populations. Bahiagrass tended to suppress populations of Meloidogyne spp. under the trees., Meloidogyne spp. were the only nematodes present that had mean populations > 65 per 150 cm3 of soil. Leaf concentrations of several elements differed between trees growing in bahiagrass sod and in. bare ground treated with herbicides. Leaf Ca was low for all treatments in spite of a soil pH near 6.5 and adequate soil Ca. The severe stunting of trees grown in bahiagrass, irrespective of the other treatments, demonstrated that bahiagrass should not be grown under newly planted trees. The low populations of parasitic nematodes in bahiagrass showed that bahiagrass has potential as a preplant biological control of nematodes harmful to peach trees. Chemical name used: ethyl 3-methy1-4-(methylthio) phenyl (1-methylethyl) phosphoramidate (fenamiphos).
Surfactants Influence Foliar Absorption of Gibberellic Acid by Sour Cherry Leaves
Authors: Knoche Moritz , Bukovac Martin J.
Published: January 2019

The effects of selected surfactants and surfactant blends, frequently used in spray application, on deposit formation and foliar absorption of GA3 by sour cherry (Prunus cerasus L. cv. Montmorency) have been investigated. Globular deposits were observed on droplet drying from solutions without surfactants or when the surfactants Activator 90, Tween 20, or Silwet L-77 were present, while annular-shaped deposits were observed with Regulaid, Ortho X-77, and Triton AG-98. Absorption of GA3 without surfactant was 5- and 17-fold higher by the abaxial (8.5% and 20.2% of applied in 1988 and 1989) than adaxial surface (1.6% and 1.2% of applied in 1988 and 1989). Over 24 hours, Ortho X-77 and Activator 90 (45.7% vs. 33.7% in 1988, 42.5% vs. 41.7% in 1989) were most effective in enhancing GA3 penetration through the abaxial surface, followed by Triton AG-98 (38.6% in 1988), Tween 20 (28.6% in 1989), and Regulaid (23.6% in 1988, 16.8% in 1989). Silwet L-77 significantly reduced GA3 uptake (10.7% in 1989) compared with the nonsurfactant control (18.2% in 1989). GA3 uptake increased at a decreasing rate during a 96-hour absorption period when GA3 was applied alone or with Ortho X-77. However, uptake increased linearly with time in the presence of Regulaid, yielding significantly higher GA3 penetration 96 hours after application (44.8%) compared with GA, alone (11.3%) or GA3 with Ortho X-77 (27.7%). GA3 penetration was independent of Tween 20 concentration in the range from 0.0313% to 0.25% but increased with increasing Ortho X-77 concentration (0.0313$%0 to 0.25%) over a 24-hour absorption period. Chemical names used: alkylpolyoxyethylene ether, free fatty acids, isopropanol (Activator 90); alkylarylpolyoxyethyleneglycols, free fatty acids and isopropanol (Ortho X-77); polyoxyethylenepolypropoxypropanol, alkyl 2-ethoxy-ethanol (Regulaid); polyalkyleneoxide modified polydimethylsiloxane copolymers (Silwet L-77); alkylarylpolyethylene glycol (Triton AG-98); polyoxyethylene (20) sorbitan monolaurate (Tween 20); gibberellic acid (GA3).
Predicting Market Quality of Grapefruit after Hot-air Quarantine Treatment
Authors: McGuire Raymond G. , Reeder William F.
Published: January 2019

Early, mid-, and late-season grapefruit (Citrus paradisi Macf.) were treated with hot air at 46, 48, and 50C for 3, 5, or 7 hours to determine the effects of time and temperature on market quality. Early and late-season fruit were more easily' damaged by the higher temperatures than midseason fruit. Increased times at the lower temperatures had less of a deleterious effect on weight loss, loss of firmness and color, and susceptibility to scalding injury and fungal decay than did shorter times at the higher temperatures. Nevertheless, regression equations predicted that 3 hours at 48C or 2 hours at 49C would not adversely affec: market quality of early and midseason fruit. The suitability of these equations was verified through taste tests of Juice. It may not be possible, however, to raise the treatment temperature for late-season fruit above 47.5C without damaging the quality of juice from these fruit.
Preplant Moisture Content and Compaction of Peatwool using Two Irrigation Techniques on Potted Chrysanthemums
Authors: Blom Theo J. , Piott Brian D.
Published: January 2019

High-volume top irrigation (Chapin) was compared to subirrigation (ebb and flow) using 15-cm-diameter (1.56 liter) pot-grown chrysanthemums [Dendranthema ×grandiflorum (Ramat.) Kitamura] with peatwool (50 peatmoss: 50 granulated rockwool) as the growing substrate. Preplant moisture contents (25%, 125%, and 250%, gravimetric) and compaction (0, 20, and 50 g·cm-2) of the peatwool were also studied. Shrinkage of growing substrate was large (>309'6 of pot volume) when peatwool in the pots was not compacted. Compaction reduced shrinkage and produced plants with larger leaves, more fresh weight, and longer stems than without preplant compaction. Drainable pore space, container capacity, and total porosity was not affected by compaction. The higher preplant moisture contents increased drainable pore space but had no effect on plant growth. Chapin-irrigated plants had significantly more fresh weight (+ 24%) at the pea-size bud stage than plants grown in the ebb-and-flow system. The difference in growth was similar at flowering but significant only at P = 0.08. Soluble salts concentration in the peatwool and foliar nutrient contents differed at flowering for the two irrigation systems.
Growth Response of Chrysanthemum to Various Container Medium Moisture Tension Levels
Authors: Kiehl P.A. , Lieth J.H. , Burger D.W.
Published: January 2019

A computer-controlled drip irrigation system was used to implement three types of moisture regimes in the potting medium of container-grown chrysanthemum [Dendranthema × grandiflorum (Ramat.) Kitamura] plants: “constant” moisture tension treatments were maintained by setting low- and high-tension set-points to the same value; “variable” tension treatments were imposed by setting the low- and high-tension set-points to 2 and 7 kPa, respectively, “timed” irrigation consisted of irrigating once per day for a fixed (excessive) duration that resulted in fluctuations in tension ranging from O to 10 kPa. Constant moisture tension conditions in the range of 0.8 to 16 kPa showed decreasing fresh and dry weight patterns with increasing tension, decreasing average moisture content, decreasing amounts of applied irrigation solution, and, consequently, with decreasing amounts of nutrients applied. Plants grown under conditions where the moisture content fluctuated appreciably (variable and timed) tended to be larger than those grown within the narrow tension ranges (constant); for the latter, optimal plant growth occurred at the lowest tension (0.8 kpa) and highest average moisture content (71%). For fluctuating conditions, the control (with the widest fluctuations) had the highest dry weight growth. The variable tension treatments, while resulting in average moisture tensions of 4.4 to 4.9 kpa, resulted in plant growth similar to plants grown at constant low tension (0.8 to 1.6 kPa), rather than those grown at tensions between 4 and 5 kPa.
Economic and Horticultural Evaluation of Chemical and Mechanical Weed Control Strategies for Cowpea
Authors: Kahn Brian A. , Schatzer Raymond Joe
Published: January 2019

The herbicides paraquat, trifluralin, and metolachlor were compared for efficacy of weed control in cowpea [Vigna unguiculata (L.) Walp.] with and without cultivation as a supplemental strategy. Herbicides also were compared against a no cultivation-no herbicide treatment (control) and against cultivation without an herbicide. Cultivation had no significant effect on seed yield, biological yield, or harvest index of cowpea. Paraquat, applied before seeding but after emergence of weeds, was ineffective for weed control and usually did not change cowpea yield from that obtained without an herbicide. Trifluralin and metolachlor more than tripled cowpea seed yield compared with that obtained without an herbicide in 1988, when potential weed pressure was 886 g·m-2 (dry weight). The main effects of trifluralin and metolachlor were not significant for cowpea seed yield in 1989, when potential weed pressure was 319 g·m-2 (dry weight). However, in 1989, these two herbicides still increased cowpea seed yield compared with that of the control and increased net farm income by more than $300/ha compared with the income obtained from the control. Chemical names used 1,1'-dimethyl-4,4' -bipyridlnium salts (paraquat); 2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl) benzenamine (trifluralin); 2-chloro-N-(2-ethyl-6 -methylphenyl)-N-(2-methoxy-l-methylethyl) acetamide (metolachlor).
Photosynthetic Compensation to Partial Leaf Area Reduction in Sour Cherry
Authors: Layne Desmond R. , Flore J.A.
Published: January 2019

The leaf surface area of l-year-old, potted `Montmorency' sour cherry (Prunus cerasus L.) trees was reduced by punching disks from some or all leaves to determine the threshold level of leaf area removal (LAR) necessary to reduce net CO2 assimilation (A) and whole-plant growth. Removal of 30% of the leaf area of individual leaves reduced A on a whole-leaf basis between 1 and 3 weeks following LAR. Less than 30% LAR was compensated for by higher estimated carboxylation efficiency and ribulose-l,5-bisphosphate (RuBP) regeneration capacity. The threshold level of LAR based on gas exchange of individual leaves was 20%. Although whole-plant dry weight accumulation was reduced at all levels of LAR, a disproportionately large decrease in dry weight occurred as LAR increased from 20% to 30%. This result indicates that 30% LAR exceeded the threshold LAR level that was noted for A (20% LAR). Wound ethylene production induced by leaf-punching ceased after 24 hours, which indicated that wounds had healed and that ethylene, therefore, did not influence A significantly. The observed threshoId of 20% LAR represents a significant compensation ability for sour cherry, but this threshold may change with crop load, environment, or both.
Promotive Effects of DCPTA on Seedling Development and Growth of Radish
Authors: Keithly J.H. , Yokoyama H. , Gausman H.W.
Published: January 2019

A radish (Raphanus sativus L. cv. Scarlet turnip white tipped) seedling growth test was developed to examine promotive effects of 2-(3,4-dichlorophenoxy) triethylamine (DCPTA) on seedling vigor and plant development. Compared with controls, seed treatment using 30 μm DCPTA significantly (P = 0.05) enhanced the rates of root and hypocotyl elongation and seedling dry weight. Enhanced hypocotyl development by DCPTA showed a significant linear correlation (r = 0.83) with the increased taproot yield of mature plants grown from DCPTA-treated seeds. The harvestable taproot yield and harvest index of plants grown from seeds treated with 30 μm DCPTA were increased 109% and 38%, respectively, as compared with controls. Incubation of radish seeds in 30 μm DCPTA with actinomycin-D, alpha-amanitin, amisomycin, or cordycepin significantly reduced DCTPA-mediated seedling growth. These results indicate that nuclear gene expression and translation of mRNA on 80S ribosomes are required for the acceleration of seedling development by DCPTA.
The Time of Floral Induction in the Olive
Authors: Fernandez-Escobar R. , Benlloch M. , Navarro C. , Martin G.C.
Published: January 2019

GA3 scaffold injections applied between May and November to nonbearing olive (Olea europea L.) trees inhibited flowering the following year, increased shoot width when applied in May, June, and July, and increased inflorescence length when applied in November and February. Fruit removal and seed destruction were effective in improving the return bloom in `Manzanillo' olives when done before endocarp sclerification. Depending on-the year, endocarp sclerification takes place 7 to 8 weeks after full bloom (AFB), usually about 1 July. Fruit removal had no effect on flowering when done after this time. Scaffold injection of paclobutrazol applied to bearing trees between May and September did not affect flowering the following year. The results of our research supports the hypothesis that olive flower induction occurs around the time of endocarp sclerification. Chemical names used: gibberellic acid (GA3), (2RS,3RS)-1-(4-chlorophenyl)-4-dimethyl-2-1,2-4-triazol-1-yl) pentan-3-ol(paclobutrazol).
Screening for Partial Physiological Resistance to White Mold in Dry Bean Using Excised Stems
Authors: Miklas P.N. , Grafton K.F. , Nelson B.D.
Published: January 2019

A laboratory procedure was tested to determine whether excised stems would allow a reliable indication of partial physiological resistance (PPR) to white mold [Sclerotinia sclerotiorum (Lib.) deBary] in dry bean (Phaseolus vulgaris L.). Excised stems from 11- and 28-day-old plants were inoculated with growing mycelium of S. sclerotiorum, incubated for 4 to 7 days (11- and 28-day assays, respectively), then assayed for lesion length (LL). A total of 15 bean genotypes were screened for PPR, as indicated by LL. Significant (P < 0.05) differences among LL means of small- and medium-seeded bean genotypes were detected in the 28-day assay, whereas only LL means among medium-seeded genotypes. differed significantly (P < 0.05) in the n-day assay. `Bunsi', `C-20', `Sierra', `Topaz', and snap bean breeding lines NY 5262, NY 5394, and NY 5403 had the highest PPR and `Upland', D76125, and `UI-114' the lowest. The results from both assays were repeatable. A moderately high correlation (r = 0.68, P < 0.02) was observed between PPR and field resistance. The 28-day assay has potential for evaluating dry bean germplasm for PPR to white mold disease caused by S. sclerotiorum. A 28-day assay also was used to measure virulence of 18 isolates of S. sclerotiorum. The 18 isolates did not differ (P < 0.05) for virulence when measured by LL. The lack of any genotype × isolate interaction for LL indicated lack of host-pathogen specificity.
Changes in Tolerance to Partial Desiccation and in Metabolite Content of Celery Somatic Embryos Induced by Reduced Osmotic Potential
Authors: Saranga Yehoshua , Kim Y.-H. , Janick Jules
Published: January 2019

Effects of reduced osmotic potential on somatic embryos of celery (Apium graveolens L.) were studied in an attempt to understand and improve their tolerance to partial desiccation. Embryos responded similarly to application of high osmoticum (384 mOs/kg H2O vs. 190 mOs/kg H2O in the control), achieved either by manipulation of sucrose or polyethylene glycol concentrations (PEG). Treatments of high osmotic concentration applied during the last 2 days of the embryo production cycle increased embryo survival and conversion after partial desiccation. The most striking effect of the high osmotic concentrations was the 4-fold increase in proline, while a 2-fold increase was obtained with 1 μm ABA alone. Application of high osmotica decreased reducing sugars, increased sucrose, but did not affect starch content of embryos; of these responses, only the change in sucrose was similar to that induced by ABA. Osmotic treatments did not affect total fatty acid content in the embryos compared to the 2-fold increase induced by ABA. Chemical name used: abscisic acid (ABA).
Grading, Hydrating, and Osmotically Priming Seed of Four Citrus Rootstock to Increase Germination Rate and Seedling Uniformity
Authors: Chilembwe Eric H.C. , Castle William S. , Cantliffe Daniel J.
Published: January 2019

Commercially processed citrus seeds of Carrizo citrange [Citrus sinensis (L.) Osb. × Poncirus trifoliata (L) Raf.], Swingle citrumelo (C. paradisi Macf. × P. trifoliata), Cleopatra mandarin (C. reticulate Blanco), and sour orange (C. aurantium L.) were used to test the effects of grading, hydrating, and priming on the rate of germination and seedling emergence. Sorting seed into groups by fresh weight or diameter did not generally improve seed performance. Seed fresh weight was highly correlated with maximum seed diameter; also, large seed weight and size were associated with a larger number of embryos. When seedlings from the extra embryos were removed, large seed produced the largest seedlings. Soaking seeds in aerated water significantly increased germination and emergence rates over unsoaked seeds. Soaking at 35C rather than 25C enhanced these differences. Priming seeds in one of three solutions of polyethylene glycol 6000 (—0.6 to—1.2 Mpa) was not successful> as germination and emergence Per centages were lower than in distilled water.
Rootstock Affect Bloom Date and Fruit Maturation of `Redhaven' Peach
Authors: Beckman T.G. , Okie W.R. , Meyers S.C.
Published: January 2019

Rootstock influence on bloom date and fruit maturation of `Redhaven' peach [Prunus persica (L.) Batsch] was studied over a 3-year period. Rootstock included seedlings (Lovell, Halford, Bailey, and Siberian C) and cuttings (GF677, GF655.2, Damas 1869, and `Redhaven'). Bloom dates of the various combinations differed in all 3 years, with a range of 3.6, 9.1, and 7.3 days in 1988, 1989, and 1990, respectively. Fruit development period differed each year with a range of 3.9, 5.8, and 4.4 days in 1988, 1989, and 1990, respectively. `Weighted-average harvest date also differed with a range of 3.6,2.9, and 5.6 days in 1988, 1989, and 1990, respectively. `Redhaven'/Lovell was the latest blooming and maturing combination in all 3 years of the study.
Yield Components among Sour Cherry Seedlings
Authors: Iezzoni Amy F. , Mulinix Colleen A.
Published: January 2019

Yield components were measured from 115 sour cherry (Prunus cerasus L.) hybrid seedlings from 13 full-sib families to investigate the potential of breeding for increased yield. Those families with the highest number of fruit and reproductive buds had the highest yields. In general, increased fruit size was not able to compensate for low fruit count. Fruit set and flower count per bud were inversely related, suggesting compensation between these two components. Yield components from six selections chosen for differing fruiting habits were measured for an additional 2 years. In year 1, those selections with a majority of their fruit on l-year-old wood had higher yield efficiencies (yield per branch cross-sectional area) than those with fruit on spurs; however, but year 3, the higher-yielding selections were those that fruited primarily on spurs. The data are discussed relative to selecting for yield in a sour cherry breeding program.
Brushing Influences Transplant Growth and Subsequent Yield of Four Cultivars of Tomato and Their Hybrid Lines
Authors: Johjima Tomio , Latimer Joyce G. , Wakita Hiroshi
Published: January 2019

Pot-grown seedlings of seven lines [`Red Cherry' (RC), `Moneymaker' (MM), `Dantobi-yohzu' (DY), `Furikoma' (FK), RC × FK, MM × DY, and MM × FK] of tomato (Lycopersicon esculentum Mill.) were brushed with a suspended steel bar for 1.5 minutes twice daily for 18 days (short-term treatment) before being transplanted to beds in a plastic greenhouse. Brushing was continued on a selected group of plants for an additional 10 days (long-term treatment). Short-term brushing slightly reduced the number of leaves, but markedly reduced leaf size and stem elongation of all lines. Dry weights of lamina, petioles, and stems of brushed plants of each cultivar except FK were less than those of the respective controls. However, the ratios of root: shoot dry weight of brushed plants were unchanged or higher than those of the respective controls. Short-term brushing did not increase the total number or weight of tomato fruits harvested over 1 month and did not improve fruit quality, size, or color. Long-term brushing reduced the total yield (number and weight) of fruits of RC and total fruit weight of DY. With respect to sensitivity to mechanical stress, cultivars with taller growth habits were more responsive to brushing than were those with shorter growth habits. These characteristic responses to mechanical stress also were exhibited by the hybrid lines.