bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stimulation of “Hydrangea Distortion” Through Environmental Manipulations
Authors: Bailey Douglas A. , Hammer P. Allen 
Published: August 2022

Abstract
Plants of Hydrangea macrophylla Thunb. were grown in various environments to identify factors responsible for the appearance of malformed hydrangea leaves and to screen cultivars for tolerance to the foliar disorder. Ambient temperature, photosynthetic photon flux (PPF), and root system temperature were studied. Hydrangea leaf malformation is under thermal control and can be stimulated by ambient temperatures of 33/26C (light/dark), but these must be maintained to sustain the development of distorted foliage. Placement of plants with malformed leaves into a 26/22C (light/dark) environment resulted in subsequent development of typical leaves. A PPF of 506 μmol·s−1·m−2 resulted in a more rapid appearance of distorted leaves than a PPF of 224 μmol·s−1·m−2. Reducing the root system temperature below the ambient level of 32/28C to 20/18C (light/dark) reduced, but did not prevent, the development of malformed leaves. ‘Blau Donau’ and ‘Tricolor’ did not develop malformed foliage during 22 weeks of growth at 32/26C (light/dark). ‘Rose Supreme’, ‘Merritt's Supreme’, ‘Rosa Rita’, and ‘Dr. Bernard Steiniger’ had developed malformed leaves by week 8 of treatment. For ‘Rose Supreme’ and ‘Blau Donau’, leaves developing at the higher temperatures had shorter and narrower laminae, less fresh weight and surface area, and more dry weight per unit area than plants at the lower temperatures. Laminae developing at the higher temperatures were thicker due to an increase in adaxial palisade parenchyma tissue. Malformed ‘Rose Supreme’ leaves had fewer intercellular spaces than normal leaves and lacked an observable spongy parenchyma layer. However, laminae of ‘Blau Donau’ leaves developed a distinct, yet thinner, spongy parenchyma layer at the higher than at the lower temperatures; intercellular spaces were still prevalent in the spongy parenchyma layer at the higher temperatures.
Quality of Nectarines Stored in Insecticidal Low-O2 Atmospheres at 5 and 15C
Authors: Smilanick Joseph L. , Fouse David C. 
Published: August 2022

Abstract
The quality of several California-grown nectarine cultivars stored in 0.5% O2 (balance N2) at 5 and 15C for up to 12 days was investigated to determine their utility in control of insects. Treatment in 0.5% O2 for 3 days at 15C caused abnormal ripening, suppressed ethylene production, elevated ethanol and acetaldehyde contents, and increased internal browning. Treatment in 0.5% O2 for 6 days at 5C caused similar injuries, but these were less severe than those at 15C. Pre-softening in air or post-treatment storage for 2 weeks at 2.5C did not reduce the injuries induced by the 0.5% O2 treatment. Since these fruit were damaged after only 3 days’ treatment at 15C, the atmospheres used to control insects probably cannot be tolerated by nectarines. Increased alcohol content and reduced ethylene production were the most sensitive indicators of controlled atmosphere-induced changes.
Enzymes of Sugar and Acid Metabolism in Stored ‘Valencia’ Oranges
Authors: Echeverria Ed , Valich John 
Published: August 2022

Abstract
The activities of key enzymes of sugar and acid metabolism were measured in desalted protein extracts from ‘Valencia’ oranges [Citrus sinensis (L.) Osb.] at 0, 3, 6, and 9 weeks of storage at 15C to investigate the relationship between the activities of gluconeogenic and glycolitic enzymes with postharvest changes in sugars and organic acids. Fructose-1,6-bisphosphatase (regulatory enzyme of the gluconeogenic pathway) activity was present throughout storage. Activities of the enzymes of acid metabolism (malic enzyme, isocitrate dehydrogenase/aconitase, and alcohol dehydrogenase) either increased during the first 3 weeks (malic enzyme) or remained constant during storage. Activity of enzymes involved in sugar catabolism (hexokinase, sucrose synthase, UDPG pyrophosphorylase, and PPi-dependent phosphofructokinase) increased during storage. These enzymes are necessary for organic acid use and for the subsequent oxidization of sugars in harvested sweet oranges.
Tomato Plant Photosynthetic Activity as Related to Canopy Age and Tomato Development
Authors: McAvoy Richard J. , Janes Harry W. 
Published: August 2022

Abstract
Tomato plants (Lycopersicon esculentum Mill. cv. Laura), pruned to a single-flower truss, were exposed to 90 μmol·s−1·m−2 supplemental photosynthetic lighting (0400 to 2200 hr) during the developmental period: a) anthesis to initial fruit set, b) anthesis to mature-green fruit, or c) anthesis to red-ripe fruit. The yield response was compared to plants receiving d) no supplemental photosynthetic lighting after incipient anthesis. The greatest increase in average fruit weight was produced with continued supplemental lighting during the developmental-period initial fruit set to the mature-green stage. Net photosynthetic activity, μmol CO2/min per dm2, was the greatest in the canopy during early anthesis and then steadily declined as the canopy aged. Net whole plant photosynthetic activity, μmol CO2/min per plant, increased steadily after the early anthesis stage of development to a peak rate during the rapid fruit development stage. Net whole plant photosynthetic activity then declined as the plant approached the mature-green and then finally the red-ripe stage of fruit development.
Seasonal Soil Waterlogging Influences Water Relations and Leaf Nutrient Content of Bearing Apple Trees
Authors: Olien William C. 
Published: August 2022

Abstract
Bearing ‘Macspur’/M.26 apple trees (Malus domestica Borkh.) were grown in plastic-lined basins under orchard conditions. Four treatments were imposed in each of 3 years consisting of controls and 6-week periods of soil waterlogging in the spring, summer, or fall. Stomatal conductance (gs), transpiration rate (E), leaf water content (LWC), and stem water potential (ψstem) were measured at the end of each waterlogging period. Stomatal conductance was significantly reduced by spring and summer waterlogging, but not by fall waterlogging. Reduction in g, and E generally increased over years. Stem water potential after spring and fall waterlogging averaged 8% less negative than controls in all 3 years, with no trend over the 3 years. In contrast, of summer-waterlogged trees was unaffected, 45% was more negative, and 31% less negative than controls in the first, second, and third year of treatment, respectively. Annual reductions in growth and yield due to the waterlogging treatments were related to decreased gs and to both negative and postive changes in ψstem. Leaf levels of N, P, K, and Cu measured in July were reduced only by summer waterlogging, with no trend in reponse over years.
Control of Pink Root Disease in Onion Using Solarization and Fumigation
Authors: Hartz T. K. , Bogle C. R. , Bender D. A. , Avila F. A. 
Published: August 2022

Abstract
Effects of solarization and fumigation on control of pink root disease of onion (Allium cepa L.) were determined in microplot studies in 1984. A 62-day solarization treatment significantly improved stand and productivity of ‘Granex 429’ onion while decreasing pink root expression. Metam-sodium fumigation gave equivalent improvement in stand and reduction in pink root expression, while causing an even greater onion growth response. Effects of these soil disinfestation techniques in onion seedbeds on subsequent field performance of onion transplants were examined in 1985–1986. Fumigation and solarization of individual soil beds virtually eliminated Pyrenochaeta terrestris infection of onion transplants. Seedbed treatment had no beneficial effect on yield, bulb diameter, or pink root expression at harvest when transplants were grown to maturity in an infested field. Chemical name used: sodium methyldithiocarbamate (anhydrous) (metam-sodium).
Green Ash Establishment Following Transplant
Authors: Arnold Michael A. , Struve Daniel K. 
Published: August 2022

Abstract
Bare-root 1-year-old green ash (Fraxinus pennsylvanica Marsh.) seedlings were transplanted into root observation boxes under greenhouse conditions to study timing of budbreak, root regeneration, and subsequent shoot growth during establishment. Green ash seedlings began shoot growth before root growth. Seven to 20 days after transplant, intact second- and third-order lateral roots (referred to here after as intact roots) began to elongate, followed 10 to 19 days later by initiation of long roots from callus at pruned root surfaces. Plants with earlier budbreak were larger and regenerated more roots faster than plants that broke bud later. During establishment, there was a strong correlation between shoot and intact root elongation and a low correlation between shoot and long root elongation. Root pruning after establishment resulted in bud set and/or cessation of shoot elongation within 3 to 6 days in 1985 and within 20 to 28 days in 1986. The days to bud set and cessation of shoot elongation were positively correlated with increased numbers of regenerated roots from pruned surfaces (long roots). Only long root elongation was significantly correlated with shoot growth after root pruning. Root pruning also induced reductions (12 days) in net photosynthesis, transpiration, and stomatal conductance, and increased stomatal resistance to water loss; however, all recovered after root regeneration.
Early Harvest of Almonds to Circumvent Late Infestation by Navel Orangeworm
Authors: Connell Joseph H. , Labavitch John M. , Sibbett G. Steven , Reil Wilbur O. , Barnett William H. , Heintz Chris 
Published: August 2022

Abstract
Third-generation navel orangeworm (Amyelois transitella) damage to almond (Prunus dulcis Mill.) kernels is a serious problem in the California almond industry. An early harvest is one means of reducing losses and increasing crop quality. A successful early harvest was accomplished 2 to 3 weeks before the normal harvest date, with no perceptible effect on kernel quality. Percent hullsplit was correlated with nut removal, providing a field guide to acceptable maturity. Within defined limits, yield, drying rate, and hullability of early harvested almonds were acceptable.
Hydration and Temperature Influence in Vitro Germination of Pecan Pollen
Authors: Yates I. E. , Sparks Darrell 
Published: August 2022

Abstract
In vitro germination of freshly collected pollen from pecan [Carya illinoensis (Wangenh.) C. Koch) was examined following exposure to relative humidities (RH) of ≈5%, 50%, and 97% and temperatures of 25, 35, and 45C in a factorial experiment. Maximum germination percentage occurred as RH increased and temperature decreased. Pecan pollen stored for nearly 2 years at −80C and −196C, but not −10C, retained germination capacity equal to freshly collected pollen if stored pollen was given a period of controlled rehydration before in vitro assay for pollen tube formation. Differences in germination of pollen stored at −10C and −196C were substantiated with the fluorochromatic test procedure as well as light microscopy. Pollen removed from storage at −196C and left at ambient laboratory conditions for 59 days retained the capacity for in vitro germination.
Gibberellins A4+7 Influence Fruit Set, Fruit Quality, and Return Bloom of Apples
Authors: Greene Duane W. 
Published: August 2022

Abstract
Several experiments were conducted to evaluate the influence of time, concentration, and number of GA4+7 applications on ‘McIntosh’, ‘Early McIntosh’, and ‘Empire’ apples (Malus domestica Borkh.). GA4+7 at 150 mg·liter−1 increased fruit set and inhibited flower bud formation on ‘McIntosh’ and ‘Early McIntosh’. Flower bud formation was inhibited on ‘McIntosh’ when GA4+7 was applied over a wide range of times from 6 days before full bloom to 34 to 35 days after full bloom. Applications made 45 and 60 days after full bloom had no effect. Following storage, ‘Empire’ fruit treated with GA4+7 were softer and had a higher incidence of senescent breakdown than controls. Postbloom sprays of GA4+7 increased fruit set on ‘Empire’ one year when applied from 0 to 150 mg·liter−1, while two applications of 50 mg·liter−1 on similar trees in another year caused thinning. GA4+7 sprays appeared to advance ripening of ‘Empire’ apples. Gibberellin sprays reduced seed number. GA4+7 inhibited flowering in ‘Empire’. Repeat applications 19 and 34 days after full bloom were only slightly more inhibitory to flowering than one application of 0, 50, 100, or 150 mg·liter−1 made 10 days after full bloom.
Residual Effects of Controlled Atmospheres on Postharvest Physiology and Quality of Strawberries
Authors: Li Chingying , Kader Adel A. 
Published: August 2022

Abstract
Low O2 (2.0%, 1.0%, or 0.5%) or elevated CO2 (10%, 15%, or 20%) concentrations and their combinations reduced respiration and ethylene production rates of ‘Selva’ strawberries (Fragaria × ananassa Duch.) stored at 2C. After transfer from the various controlled atmospheres (CA) to air, respiration and ethylene production rates increased, but were still significantly lower than those of the fruits kept continuously in air. Atmospheres of 1.0% O2 + 15% CO2 and 0.5% O2 + 20% CO2 led to the accumulation of ethanol, which was still present at concentrations >100 μl·liter−1 (ppm) in strawberry juice after their transfer to air for several days. Keeping strawberries in CA had residual effects on maintaining their flesh firmness and color, but had no significant effects on skin or juice color, titratable acidity, pH, soluble solids content, and ascorbic acid content. In general, as O2 concentration was decreased or as CO2 concentration was increased, the residual effects were more pronounced. The combinations of reduced O2 and elevated CO2 had more pronounced residual effects than either reduced O2 or elevated CO2 alone. Exposures to CA for 4 days had greater residual effects than exposure to CA for 1 to 3 days.
Ripening Characteristics of a Tomato Mutant, dark green
Authors: Tong Cindy B. S. , Gross Kenneth C. 
Published: August 2022

Abstract
Respiration, ethylene production, firmness, polygalacturonase activity, cell wall composition, and soluble uronide content were measured during ripening of two tomato (Lycopersicon esculentum Mill.) genotypes, ‘Manapal’ and dark green (dg). Respiration rates and cell wall uronide contents of the two genotypes were similar. Climacteric ethylene production rates of dg fruit were about half that of ‘Manapal’ fruit. Firmness and polygalacturonase activity of dg tomatoes were similar to that of ‘Manapal’ fruit until 55 days postpollination, when dg fruit were twice as firm as ‘Manapal’ fruit and exhibited greater polygalacturonase activity. Soluble uronide content did not differ between the two genotypes, except at 50 days postpollination, when that of dg fruit was 60% that of ‘Manapal’ fruit. Cell wall uronide content of dg fruit was 1.5 times greater than ‘Manapal’ fruit at 55 days postpollination. Although dg fruit contained larger, absolute amounts of cell wall noncellulosic neutral sugars than ‘Manapal’ fruit, net changes in sugar composition were similar throughout ripening. Also, ratios of cell wall arabinosyl or galactosyl residues to cell wall galacturonic acid were similar in both genotypes. These data suggest that firmness differences between dg and ‘Manapal’ fruit are not due to differing activities of polygalacturonase or changes in cell wall composition during ripening, but to other factors that may affect solubilization of cell wall uronides.
Ethylene Evolution and Polyamine Accumulation by Tomato Subjected to Interactive Stresses of Ammonium Toxicity and Potassium Deficiency
Authors: Corey Kenneth A. , Barker Allen V. 
Published: August 2022

Abstract
Tomato plants (Lycopersicon esculentum Mill. ‘Heinz 1350’, yellow-green-5, and neglecta-1) were grown in sand culture with 15 mm or and with K+ varying from 0 to 8 mm. Other nutrients were provided at the concentrations of Hoagland's solution. The medium supplying was buffered with CaCO3 (pH 6.9) or was unbuffered (pH 3.4). Silver ions (0.01 μm) were incorporated in the nutrient solution in one experiment. Ammonium nutrition relative to nutrition elevated rates of ethylene evolution from all genotypes, but yg-5 and neg-1 showed resistance to toxicity and exhibited relatively low ethylene evolution. Ethylene evolution declined as K+ supply increased. Accelerated rates of ethylene evolution did not occur at tissue K+ concentrations >10 g·kg−1 of the dry weights of shoots with nutrition, but higher K+ levels were required with nutrition. Putrescine concentrations in leaves of ‘Heinz 1350’ supplied with were 2 to 5 times greater than in leaves of plants supplied with . Potassium deficiency increased putrescine accumulation regardless of N form. Spermidine concentrations in leaves of plants supplied with were lower than in those supplied with , whereas spermine concentrations were unaffected by treatments. ‘Heinz 1350’ grown in -based nutrient solutions with 0.01 μΜ Ag+ had low rates of ethylene evolution and developed few symptoms of toxicity. Quantities of ethylene and putrescine produced by tomato genotypes susceptible to the nutritional stresses were linked directly to the degree of stress imposed, and symptoms of toxicity were related to increased ethylene synthesis.
Light Stress Following a Frost Episode Influences the Frost Tolerance of a Wild Potato Species
Authors: Steffen Kenneth L. , Palta Jiwan P. 
Published: August 2022

Abstract
The effect of light stress following various levels of freezing stress on photosynthetic and respiratory functions in leaf tissue of Solanum acaule (Bitt.) was investigated under laboratory conditions. Terminal leaflets from plants grown at 18/16C (light/dark) and 400 μmol·s−1·m−2 photosynthetically active radiation (PAR) were slowly frozen in the dark to various minimum temperatures and then thawed on ice, also in the dark. Immediately after thawing, paired leaf disks were cut from a single terminal leaflet. Disks were then held at 1.0C for 3 hr, with one disk exposed to 800 μmol·s−1·m−2 PAR and the other disk of the pair was held in the dark. Our experimental approach allowed comparative studies on tissue from the same leaflet. Light during the post-thaw period, as compared to darkness, resulted in greater inhibition of photosynthetic processes, but had little effect on respiration. Our results demonstrate a) the importance of considering a light stress component during the assesment of relative frost tolerance in photosynthetic tissue and b) that chloroplast functions are much more sensitive than mitochondrial functions to a post-thaw light stress.
Interspecific Hybridization of Papaya with Other Carica Species
Authors: Manshardt Richard M. , Wenslaff Timothy F. 
Published: August 2022

Abstract
Interspecific hybridizations were attempted between papaya (Carica papaya L.) and six Carica taxa, including C. monoica Desf., C. parviflora (A. DC.) Solms, C. pubescens Lenne et Koch, C. quercifolia (St. Hil.) Hieron., stipulata Badillo, and C. × heilbornii Badillo nm. pentagona (Heilborn). Prezygotic barriers were minimal; pollen tubes of wild species freely penetrated into the seed cavity of papaya, and papaya pollen tubes were similarly unhindered in reciprocal pollinations on C. pubescens. Postzygotic barriers were formidable due to ovule abortion and endosperm failure. However, dissection of more than 150 C. papaya fruits 90 to 180 days after interspecific pollination yielded at least a few hybrid embryos of each species combination. All crosses in which C. papaya was the male parent failed, with the exception of C. pubescens × C. papaya, which succeeded only after young ovules were cultured 30 to 45 days after pollination. Multiple embryos were common in all successful crosses, and these were shown to be of zygotic origin by analyses of isocitrate dehydrogenase, malate dehydrogenase, and phosphoglucomutase isozymes in parental and hybrid tissues. Hybrids successfully recovered from in vitro cultures included C. papaya × C. pubescens and reciprocal, C. papaya × C. quercifolia, and C. papaya × C. stipulata.
Root-lesion Nematodes, Potassium Deficiency, and Prior Cover Crops as Factors in Apple Replant Disease
Authors: Merwin Ian A. , Stiles Warren C. 
Published: August 2022

Abstract
Growth chamber evaluations of soil from an orchard replant site showed severe stunting of ‘Northern Spy’ apple (Malus domestica Borkh.) seedlings grown in field soil (FS) compared with pasteurized soil (PS) from the same site. The FS : PS seedling dry weight ratio of 0.44 indicated a serious replant problem. Leaf nutrient content was generally higher in PS than FS seedlings. Multiple-regression analysis indicated that leaf K and root-lesion nematode (Pratylenchus penetrans Filipjev) primary inoculum accounted for 75% of the variation in FS seedling dry weight. Apple seedling dry weight in FS was 97% of that in PS following a marigold (Tagetes patula L. cv. Sparky) cover crop, and 75% following oats (Avena sativa L. cv. Saia). Root-lesion nematodes were nearly eliminated from the plots with marigold. Other cover crops and a weed-free fallow period were less effective in controlling apple replant disease and/or phytonematodes.
Estimation of Peach Tree Water Use Using Infrared Thermometry
Authors: Glenn D. M. , Worthington J. W. , Welker W. V. , McFarland M. J. 
Published: August 2022

Abstract
Infrared (IR) thermometry has not been extensively applied in deciduous tree fruit production to determine water use. The objectives of this study were to a) examine IR measurement techniques for evaluating canopy temperatures in peach [Prunus persica (L.) Batsch.] trees; b) evaluate a foliage-minus-air temperature- (Tc – Ta) based diffusion equation for vapor flux used to predict tree water use; and c) measure the Tc – Ta response of irrigated peach trees over a range of air vapor pressure deficits. The mean Tc – Ta for a tree was similar for readings made from the canopy sides (horizontal orientation of the IR thermometer) or canopy tops (vertical orientation). Peach tree water use from weighing lysimeters was predicted within 9.4% ± 3% using the diffusion equation for vapor flux. Tc – Ta for irrigated peach trees was related to the air vapor pressure deficit (VPD). Data are presented to show that stomatal response to VPD does alter the Tc – Ta nonstressed baseline for peach at VPD > 2 kPa.
Skin Permeability to Oxygen in Apples Stored in Controlled Atmosphere
Authors: Andrich G. , Fiorentini R. , Tuci A. , Galoppini C. 
Published: August 2022

Abstract
The skin permeability to O2-diffusion and the mass transfer equilibrium constant for ‘Super Golden Delicious’ spur and ‘Red Stark’ (Malus domestica Borkh.) have been studied using a kinetic approach. A direct proportionality between the O2-exchange initial rate and the environmental PO2 is shown by a linear regression line passing near the origin of the axes. This confirms the suitability of the adopted mass-transfer equations and allows the calculation of the two involved constants: the equilibrium mass-transfer constant and the kinetic constant, which represents a suitable measure of permeability of the apple skin. As apple-skin permeability to O2 increases with fruit ripening, to reach a maximum near the commercial harvesting time, this parameter could be used as a ripening index.