bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in Water Relations and Elastic Properties of Apple Fruit Cells during Growth and Development
Authors: Steudle E. , Wieneke J. 
Published: August 2022

Abstract
Water relations parameters of individual cells in the cortex of apple fruit (Malus domestica Borkh., ‘Cox's Orange Pippin’) were determined during 2 growing seasons between the end of June and the end of September. Apple and cell diameters doubled during this time. Cell turgor pressure (P) of sliced tissue incubated in a nutrient solution ranged between 6 and 12 bar (0.6 and 1.2 MPa). The elastic cell modulus (∈) increased with both cell turgor and cell volume. For high turgor pressures (P > 5 bar), the average values of ∈ ranged between 30 and 180 bar (3.0 and 18.0 MPa). The half-times (T1/2) for the water exchange of individual cells with their adjacent tissue increased during the seasons from 8–10 s to 20–25 s which was partly due to a decrease of the hydraulic conductivity of the cell membrane (Lp) during ripening. Lp decreased from about 3 to about 1 · 10−6cm · s−1 · bar−1 (from 3 to 1 · 10−7m · s−1 · MPa−1). The probe data allowed estimates of the diffusion coefficient for the propagation of a change in water potential, volume and turgor pressure across the tissue (Dc) · Dc ranged between 3 and 9 · 10−7 cm2 · s−1 (3 and 9 · 10−11m2 · s−1) and increased continuously during the season. The results indicate that the reduction in the elastic extensibility at the cell level (1/∈) does not correspond with the reduction of the firmness of the fruit as maturity is approached. On the contrary, the fruit become softer. Therefore, the physiological meaning of tissue Young's moduli as determined by other methods has to be questioned. The results are discussed with respect to the development of fruit disorders.
Seasonal Response of ‘Anjou’ Pear Trees to Different Irrigation Regimes. I. Soil Moisture, Water Relations, Tree and Fruit Growth
Authors: Brun Charles A. , Raese J. Thomas , Stahly Edward A. 
Published: August 2022

Abstract
Mature bearing pear [Pyrus communis L. ‘Beurre d’Anjou’ (‘Anjou’)] trees in an arid climate were irrigated weekly at 125% of pan evaporation (wet), biweekly at 100% of pan evaporation (normal), or irrigated only twice (dry) during the summer (1980, 1981), and were fertilized with and without 0.9 kg of supplemental N. Prior to final fruit harvest in 1981, depletion of available soil moisture (ASM) averaged 10%, 16.7%, and 89% for the wet, normal, and dry treatments, respectively. Mid-day leaf water potential (ψL) was correlated with the level of ASM only on bright days of high vapor pressure deficit. Stomatal conductance (κs) and transpirational flux density (F) of dry treatment leaves was lower than that of either wet or normal treatment leaves ψL exceeded −1.4 to −1.7 MPa. Resistance to vapor (water) transport (Rν) of fruit was independent of irrigation regime. Terminal buds had set on shoots from all 3 irrigation regimes at 58 days after full bloom (AFB) in 1981, but resumed growth on normal and wet treatment shoots at 87 days AFB. On 7 of 10 sampling dates during 1981, dry treatment fruit weighed less than normal or wet treatment fruit.
Annual Root Growth Pattern of Young Citrus Trees in Relation to Shoot Growth, Soil Temperature, and Soil Water Content
Authors: Bevington Kenneth B. , Castle William S. 
Published: August 2022

Abstract
The annual pattern of root growth of ‘Valencia’ orange [Citrus sinensis (L.) Osb.] trees on rough lemon (C. jambhiri Lush.) and Carrizo citrange [Poncirus trifoliata (L.) Raf. × C. sinensis] rootstocks was studied in relation to shoot growth, soil temperature, and water stress in Plexiglas-walled root observation chambers. The chambers were filled with a reconstituted profile of a fine sand soil and were installed below-ground at a field site in central Florida. The chambers periodically were raised above-ground to record root growth. Under nonlimiting soil water conditions, continuous root extension growth was evident from February to November. The overall seasonal trend in root growth was significantly correlated with soil temperature. The most intense root growth occurred when soil temperatures were above 27°C, and was limited at soil temperatures below 22°. Root growth was cyclic. During periods of shoot elongation, the number of growing roots and the rate of root elongation declined. Shoot growth was a major factor controlling the intensity of root growth when soil temperature and soil water content were nonlimiting. When the soil water content was decreased intentionally, root growth was checked at a soil matric potential of −0.05 MPa. After rewatering, there was a lag period of 2 days before root growth increased. Both number of growing roots and rate of root elongation were influenced by shoot growth, soil temperature, and soil water content; however, the growth response of the root system to these factors was mediated largely through the number of roots initiating growth. No rootstock differences were apparent in the pattern of root growth.
Growth, Carbohydrate, and Mineral Element Status of Shoot and Spur Leaves and Fruit of ‘Spartan’ Apple Trees Treated with Paclobutrazol
Authors: Steffens G. L. , Wang S. Y. , Faust M. , Byun J. K. 
Published: August 2022

Abstract
‘Spartan’ apple (Malus domestica Borkh.) trees were treated with paclobutrazol, a gibberellin biosynthesis inhibitor, in the spring of 1982 and again in 1983. In 1983, extension shoot and fruiting spur growth was reduced as were leaf number and area. Shoot and spur leaf chlorophyll levels were not affected. Treatment reduced fruit size and weight slightly, but firmness and soluble solids at harvest were unchanged. Sorbitol was signficantly higher in leaves from paclobutrazol-treated trees at all 4 sampling dates [78, 112, 134, and 163 days-after-full-bloom (DAFB)]. Paclobutrazol treatment had little effect on leaf fructose, glucose, and sucrose but increased starch. Treatment had no effect on apple flesh carbohydrate levels. Bud and wood carbohydrate levels in early 1984 differed at various sampling dates but overall carbohydrate metabolism during bud development appeared to be unaffected by treatment. Mineral element content of spur leaves was not affected by treatment, but shoot leaves showed significantly increased Ca levels 112 and 134 DAFB. Mineral content in apple flesh and skin was not changed by paclobutrazol treatment. Chemical name used: β-[(4-chlorophenyl)methyl]-α-(1,1-dimethylethyl)-1-H-1,2,4-triazole-1-ethanol (paclobutrazol).
Chemical Treatments to Delay Bloom in Peach
Authors: Coston D. C. , Krewer G. W. , Elkner T. E. , Williamson J. G. , Sims E. T. 
Published: August 2022

Abstract
CGA-15281 applied in the fall delayed bloom in peach (Prunus persica L. Batsch) by 4–9 days without damage to the trees. The length of the delay was cultivar and concentration dependent. Fall ethephon applications (500 ppm) damaged trees severely, but delayed bloom 10–18 days, whereas 125 or 250 ppm ethephon caused little tree damage and delayed bloom 3–5 days. Bloom delay from application of ethylene-generating compounds resulted from both prolonging rest and slow bud development once rest was complete. Daminozide applied in January caused bloom delay in 1983 but not in 1984. Silver nitrate had little effect on bloom delay or blossom density at any time of application. Dimethipin and merphos applications in late summer caused defoliation and reduced blossom density, but did not affect date of bloom. Thidiazuron did not induce defoliation or delay in bloom, but greatly reduced blossom density. Chemical names used: (2-chloroethyl)methylbis(phenylmethoxy)silane (CGA-15281); (2-chloroethyl) phosphonic acid (ethephon); butanedioic acid mono (2,2-dimethylhydrazide (daminozide); 2,3-dihydro-5,6-dimethyl-1,4-dithiin 1,1,4,4-tetraoxide (dimethipin); N-phenyl-N′-1,2,3-thiadiazol-5-ylurea (thidiazuron); Tributyl phosphorotrithioite (merphos).
Remobilization of Nonstructural Carbohydrates from Vegetative Tissues to Fruits in Tomato
Authors: Hewitt J. D. , Marrush M. 
Published: August 2022

Abstract
Soluble sugar and starch levels were measured in leaf, stem, and petiole tissues of 3 tomato (Lycopersicon esculentum Mill.) cultivars throughout plant development in order to 1) assess the contribution of reserve carbohydrates to final fruit yield and quality and 2) determine whether genotypic variation exists for this trait. In all 3 cultivars — ‘VF145B-7879’ (‘7879’), ‘UC82’ (‘82’), and ‘BL6807’ (‘6807’) — leaf tissue was found to accumulate high levels of both soluble sugars and starch. Stem and petiole tissues, although having high sugar content, accumulated little starch. An estimate of the proportion of fruit dry weight attributable to remobilization of nonstructural carbohydrate (NSC) from vine tissue was made by determining the dry weight of sugars and starch lost from vegetative tissue once the vine had ceased gaining weight and dividing by the final fruit dry weight. Values for ‘6807’ and ‘7879’ were 4.8% and 0.3%, respectively. No remobilization of NSC was apparent in ‘82’. The primary remobilized carbohydrate was leaf starch in both ‘6807’ and ‘7879’. Leaf and stem sugars were also remobilized in ‘6807’. The relatively high degree of remobilization in ‘6807’ was associated with early maturity and a high fruit/leaf ratio.
Reduction of Initial Plagiotropic Growth of Softwood Fraser Fir Cuttings
Authors: Wise Farrell C. , Blazich Frank A. , Hinesley L. Eric 
Published: August 2022

Abstract
Timing of severance, auxin treatment, and staking were evaluated for their effects on reducing abaxial-concave bending of softwood Fraser fir [Abies fraseri (Pursh) Poir.] stem cuttings. Cuttings collected 21 July 1983, were much less plagiotropic after a 135-day rooting period than those collected 3 weeks earlier. This upright habit was related to stronger internal support from increased amounts of xylem and lignified pith at severance. Staking also reduced abaxial-concave bending, but postseverance auxin treatment had no effect. Stakes apparently provided external support until stems became lignified. Nonstaked cuttings collected 30 June 1983 continued to exhibit greatest bending at the end of the 2nd growing season. Basal defoliation and wounding in preparation for rooting increased plagiotropic growth and reduced survival during rooting, but did not affect the percentage of rooting. Evaluation of xylem distribution indicated that abaxial-concave bending in the 2nd season was caused by greater production of compression wood and total xylem on adaxial than on abaxial sides of the original cutting segments.
Water Relations, Growth, and Yield in Two Snap Bean Cultivars Infected with Root Knot Nematode, Meloidogyne hapla (Chitwood)
Authors: Wilcox D. A. , Loria R. 
Published: August 2022

Abstract
Seedlings of snap bean (Phaseolus vulgaris L.) ‘Strike’ and ‘Kentucky Wonder’ were inoculated with 0, 6,000, 12,000, or 18,000 Meloidogyne hapla (Chitwood) larvae/pot. Leaf xylem potential, stomatal conductance, transpiration, root hydraulic conductivity, leaf area, and plant weight were measured 4 weeks after inoculation. In a 2nd experiment, inoculated plants were grown for 7 weeks to obtain yield data. Leaf area, xylem potential, and yield were significantly reduced by nematode infection. The 2 cultivars differed in their response to M. hapla. Yield was reduced more at high nematode populations in ‘Kentucky Wonder’ than in ‘Strike’. This differential response also occurred with xylem potential. There was a trend toward decreased hydraulic conductivity in infected ‘Kentucky Wonder’, but not ‘Strike’ roots. Cultivar tolerance in beans appears to be related to the effects of nematodes on plant water relations.
Changes in Cytoplasmic and Vacuolar pH in Harvested Lettuce Tissue as Influenced by CO2
Authors: Siriphanich Jingtair , Kader Adel A. 
Published: August 2022

Abstract
‘Climax’ lettuce (Lactuca sativa L.) exhibited more severe CO2 injury symptoms than ‘Salinas’ and ‘Winterhaven’ lettuce when exposed at 20°C to air for 1 day following treatment for 6 days at 0° with 15% CO2 in air. All 3 cultivars, however, had similar decreases as revealed by NMR analysis, of about 0.4 and 0.1 pH units in the cytoplasm and vacuole, respectively. This result indicates that variation in the buffering capacity was not related to differences in susceptibility to CO2 injury among these cultivars. Although CO2 reduced pH, it also reduced titratable acidity of lettuce tissue. This change resulted in a higher pH when the lettuce was moved to air. Exposure of lettuce at 0° to light reduced CO2 injury by about 50% relative to tissue kept in the dark. Lettuce tissue kept in air had a higher glucose-6-phosphate content than the CO2-treated lettuce. A hypothesis regarding alternate energy supply mechanisms for resistance of lettuce tissue to elevated CO2 injury is discussed.
Calcium Hydroxide Reduces Splitting of ‘Lambert’ Sweet Cherry
Authors: Callan Nancy W. 
Published: August 2022

Abstract
Preharvest applications of Ca(OH)2 reduced splitting of ‘Lambert’ sweet cherry (Prunus avium L.) in laboratory trials. Three sequential preharvest sprays of Ca(OH)2 consistently reduced splitting, while single sprays of Ca(OH)2 in combination with NAA, ethephon, or B were moderately effective. Ca(OH)2 was a more effective Ca source than CaCl2 for reduction of splitting. Ca applications did not affect fruit size, but 3 applications of Ca(OH)2 increased fruit soluble solids. Chemical names used: (2-chloroethyl)phosphonic acid (ethephon) and 1-naphthaleneacetic acid (NAA).
Soil Cultivation and Incorporation Effects on the Edaphic Properties of Turfgrass Thatch
Authors: Danneberger T.K. , Turgeon A.J. 
Published: August 2022

Abstract
Cultivation practices have been used to control thatch, principally by removal of organic constituents and by incorporation of soil to promote decomposition of the organic residues. The purpose of this study was to determine the influence of soil incorporation on the edaphic properties of turfgrass thatch. Field studies were performed on 2 creeping bentgrass (Agrostis palustris Huds.) and 2 Kentucky bluegrass (Poa pratensis L.) sites. Treatments included core cultivation and vertical mowing, separately and in combination; after 6 weeks, samples of the thatch and thatch like derivatives were taken for determining ash content, bulk density (BD), cation-exchange capacity (CEC), and pH. Soil incorporation into thatch reduced the percentage of ash content and CEC, but increased BD and CEC·BD — an expression of CEC on an undisturbed volume basis. The extent to which these changes occurred reflected the amount of soil incorporated by the number and type of cultivation methods employed.
A Reliable Actinometric Method for Characterizing the Light Regime in Plant Canopies
Authors: Avidan B. , Erez A. 
Published: August 2022

Abstract
The actinometric method, based on photolysis of uranyl oxalate, was adapted for measuring integrated light irradiance in plant canopies. The unique characteristics of the new actinometers are their small size, the avoidance of pressure build-up in the measuring cell, the good correlation with quantum sensors, and their response to the cosine law. The proposed system is inexpensive and reliable, integrates light measurement over a relatively long period, and needs little additional instrumentation. Numerous measurement points scattered in plant canopies can be determined simultaneously by this method, thus improving assessment of the light regime in fields and orchards. This paper describes such measurements in a peach meadow orchard planted at 2 densities, where 27 actinometers were dispersed in each density treatment and replicate
Effect of Soil Moisture Tension and Soil Water Content on the Growth of Chrysanthemum in 3 Container Media
Authors: Karlovich P.T. , Fonteno W.C. 
Published: August 2022

Abstract
No differences in final height, top fresh weight, top dry weight, or flower number were observed in Chrysanthemum morifolium Ramat. ‘Spice’ grown in 16.5-cm azalea pots when allowed to dry to soil moisture tensions of 5, 10, 20, or 30 kPa between waterings. Differences did occur in these parameters among the 3 tested media. Differences also occurred across all 3 media based on the volume of water remaining in the pot prior to watering. Plants growing in media containing more than 500 ml water just prior to irrigation had increased growth compared to plants in media containing less than 500 ml water. Cubic regression models were used to describe the percentage of moisture in the pot at soil moisture tensions between 0 and 30 kPa. The model may be used to predict container capacity and air space for most container sizes.
Chilling Sensitivity of Tomato Fruit in Relation to Ripening and Senescence
Authors: Autio Wesley R. , Bramlage William J. 
Published: August 2022

Abstract
Postchilling ion leakage, respiration, and C2H4 biosynthesis were used to measure the degree of chilling injury to fruit of tomato (Lycopersicon esculentum Mill. ‘Heinz 1350’). Chilling sensitivity, as measured by ion leakage, first declined as the tomatoes began to ripen and then increased during the late stages of ripening. Both C2H4 biosynthesis and respiration rate were stimulated during the chilling response early in ripening. In the nonripening mutant, nor, chilling sensitivity did not show the early decline but showed the increase during senescence. Variation in chilling sensitivity during tomato ripening was biphasic, with a decline at the onset of ripening followed by a senescence-related increase. It is proposed that the latter may be due to an increase in membrane viscosity.
Kinetics of Sugar Transport in Isolated Vascular Bundles and Phloem Tissue of Celery
Authors: Jaleh Daie 
Published: August 2022

Abstract
Celery (Apium graveolens L.) is a favorable plant material for phloem loading studies, because vascular bundles and phloem tissue can be isolated from fleshy petioles with minimal manipulations. Uptake kinetics for sucrose loaded into phloem are different than uptake by phloem-free tissue. In isolated vascular bundles, uptake of phloem sugars (sucrose and mannitol) were biphasic kinetics, consisting of an active, saturating component operating at low sugar concentrations, and linear kinetics at higher sugar concentrations. Glucose uptake exhibited linear kinetics. However, when the glucose analog, 3-0-methyl glucose (unmetabolized) was used, biphasic kinetic profiles were obtained. Sucrose and mannitol uptake in isolated phloem tissue consisted of one saturating component showing Michaelis-Menten kinetics. In the homogenous storage parenchyma tissue, sucrose uptake kinetics were by diffusion and insensitive to carbonyl cyanide m-chlorophenyl hydrazone (identical to that of L-glucose). The data suggested the presence of different mechanisms for sucrose uptake across the sieve-tube companion cell complex and nonphloem cells. It is proposed that celery may be a useful system to obtain direct evidence on mechanism of solute loading. Chemical names used: carbonyl cyanide m-chlorophenyl hydrazone (CCCP).
Ice Nucleation and Supercooling in Freezesensitive Peach and Sweet Cherry Tissues
Authors: Andrews Preston K. , Proebsting Edward L. , Gross Dennis C. 
Published: August 2022

Abstract
Ice nucleation temperatures were measured in peach [Prunus persica (L.) Batsch ‘Redhaven’] and sweet cherry (Prunus avium L. ‘Bing’) flowers, fruits, and stems by differential thermal analysis and by controlled freezing in test tubes and of droplets. The mean nucleation temperatures of peach and sweet cherry flowers were –4° to – 6°C, while those of 0.5-cm stem segments were –6° to –7°. The highest ice nucleation activity in peach flowers appeared to be associated with the pedicels. A logarithmic function described the relationship between stem weight and ice nucleation temperature, with 1.5-g (16-cm) stem segments freezing as high as –3°. Apparently, stem tissue contained a lower concentration of ice nucleators active above –5° than did the floral tissue. Homogenization of the tissues reduced their ice nucleation activity. Structural integrity may be necessary for the manifestation of optimal activity. Ice nucleation-active (INA) Pseudomonas syringae bacteria were isolated from the surfaces of peach and sweet cherry floral tissues only occasionally and then at low populations. The absence of epiphytic INA bacteria from these tissues suggested that ice nucleation was promoted by intrinsic ice nucleators within the plant. These intrinsic ice nucleators appeared to be active at temperatures similar to INA bacteria. Although these nucleators may be less numerous than bacterial ice nuclei on heavily colonized plant surfaces, their presence nonetheless suggests that control of INA bacteria or inhibition of the ice nucleation activity of INA bacteria alone may be insufficient to prevent ice nucleation and freezing injury of freeze-sensitive flowers and fruits during spring frosts in the orchard.
Cold Hardiness in the Genus Rhododendron
Authors: Sakai A. , Fuchigami L. , Weiser C.J. 
Published: August 2022

Abstract
Cold hardiness of 101 Rhododendron genotypes was assessed. In hardy rhododendrons, the difference in hardiness between floral primordia and other tissues or organs was greater than in the less hardy species. All rhododendrons tested were divided into 4 hardiness divisions: very hardy, semihardy, hardy, and tender. In all hardiness divisions, the vegetative buds, leaves, and stem cortex were hardiest, whereas the floral primorida were least hardy, with a lowest survival temperature (LST) of −35°C or higher. The majority of the very hardy division of rhododendrons, such as R. brachycarpum D., R. catawbiense Michx., and R. maximum L., belong to the ponticum series. In general, rhododendrons from cold regions were hardier than those from warm regions. The hardiness of the floral primordia of rhododendrons growing near the timberline (3900 m alt.) of East Himalaya and the high altitudes of the northwestern Yunnan area were similar (−20° to −23°). These were less hardy than those found in the subalpine forests of Japan and eastern North America, probably due to moderate temperature and high humidity during the winter in eastern Himalaya and northwestern Yunnan.
Somatic Embryogenesis in Jojoba
Authors: Wang Yi-Chang , Janick Jules 
Published: August 2022

Abstract
Somatic embryogenesis was induced from callus derived from immature zygotic embryos (3–4 mm in length optimum) of jojoba (Simmondsia chinensis Link) cultured on semisolid basal medium supplemented with 4.5 µM (1 mg/liter) 2,4-D. Somatic embryo initiated from single cells on the periphery of callus passed through typical stages of embryogenesis. Embryogenic-competent calli maintained on a medium containing 0.2 mM (40 mg/liter) sodium bisulfite antioxidant and 4.5 or 9 µm (1 or 2 mg/liter) 2,4-D continued to proliferate somatic embryos, but embryos remained in an arrested state of development until 2,4-D was withdrawn. Chemical names used: 2,4-dichlorophenoxyacetic (2,4-D); N-(phenylmethyl)-lH/-purin-6-amine (BA).
Development of Seedless Grapefruit Cultivars through Budwood Irradiation
Authors: Hearn C.J. 
Published: August 2022

Abstract
Buds from a mature ‘Foster’ grapefruit (Citrus paradisi Macf.) tree were exposed to 3, 5, 7, 9, and 11 kilorad (kr) of gamma irradiation. The irradiated buds were grafted to rootstocks in the nursery and greenhouse. The LD50 was near 5 kr for buds grafted in the greenhouse and 9 kr for those in the nursery; however, no buds receiving more than 5 kr initiated growth. Grafted trees that grew were field grown until fruiting and seed per fruit was counted. Several nonjuvenile, commercially seedless clones were developed among small populations of plants, and in significantly less time than required through seed irradiation.