bluuebunny/crossref_metadata_2025 huggingface dataset:
Relative Effectiveness of Dilute and Concentrated Abscission-chemical Sprays in Loosening ‘Valencia’ Oranges from Trees1
Authors: Rasmussen G. K.
Published: August 2022

Ethylene production, hydrolytic enzyme activity, and fruit removal force (FRF) were more uniform and consistent when abscission chemicals were applied as dilute as compared to concentrated sprays to ‘Valencia’ orange (Citrus sinensis (L.) Osbeck). Cycloheximide (Acti-Aid), glyoxal-dioxime (Pik-Off), 5-chloro-3-methyl-4-nitro-1H-pyrazole (Release), and Acti-Aid plus chlorothalonil (Sweep) were applied to ‘Valencia’ orange branches, each holding 100 to 120 fruit. The FRF's resulting from commercial concentrate and dilute sprays of Acti-Aid and Acti-Aid plus Sweep were similar to those in the branch tests. Equal amounts of chemical were applied in the dilute and concentrate sprays. Likely, the variation in coverage from concentrate sprays caused ethylene levels to vary greatly in the fruit (0 to 5.7 ppm). In turn, levels of hydrolytic enzyme activity varied as much as 10×, and fruit loosening was inconsistent (0 to 9.7 kg FRF). Release and Acti-Aid plus Sweep were more consistent than Pik-Off and Acti-Aid in dilute spray applications.
Responses Associated with Low Temperature Seed Germinating Ability in Tomato1
Authors: Maluf Wilson R. , Tigchelaar Edward C.
Published: August 2022

Factors contributing to genetic differences in low temperature seed germination of tomato (Lycopersicon esculentum Mill.) were examined by comparing the cold germinating (CG) accession PI 341985 the non-cold germinating (NCG) ‘Centennial’ and random F4 lines with varying low temperature germinating abilities. Rate of radicle elongation at 10°C was similar for both parental genotypes indicating that differences in emergence at 10° are not due to growth rates, but rather to more rapid initiation of germination activities in CG. Preincubation of seeds in hypertonic salt solutions enhanced rate of germination at 10°C equally in both lines, but did not substitute for the genetically based cold germinating ability. Low temperature germinating ability is associated with sprouting at high osmotic concentrations, and with a several fold higher rate of increase in peroxidase activity during the first 10 days of incubation at 10°. Germination at 10° of the NCG lines is improved by activated carbon in the germination media whereas no enhancement occurred in CG lines. Inhibition and/or delay in germination at 10° in NCG lines is due, in part, to low temperature induced formation of activated carbon adsorbable inhibitors of seed germination.
Avocado Pectinmethylesterase Activity in Relation to Temperature, Ethylene, and Ripening1
Authors: Awad M. , Young R. E.
Published: August 2022

Investigation of optimum conditions for extraction, titrimetric assay and activity of avocado (Persea americana Mill cvs. Fuerte, Hass) pectinmethylesterase (PME) showed maximum extraction was obtained from lyophilized mesocarp using 0.4 m NaCl. Best assay conditions required a substrate of 0.5% pectin in 0.1 m NaCl. The enzyme was released from the tissue by salt but not by nonionic detergents. The Arrhenius plot between 3 and 32°C was a straight line which indicates no involvement with membrane lipid. Incubation with air or ethylene did not affect the enzyme. PME activity declined rapidly as ripening was initiated and reached a minimum shortly before the peak in respiration and ethylene production.
‘Delicious’ Apple Fruit Size and Quality as Influenced by Radiant Flux Density in the Immediate Growing Environment1
Authors: Seeley E. J. , Micke W. C. , Kammereck R.
Published: August 2022

Fruits of ‘Delicious’ apple (Malus domestica Borkh.) were grown under differing radiant flux densities (rfd nm) from 45 days post-bloom until harvest. The rfd nm affected red fruit color, soluble solids, starch content and size, but not firmness, pH or total acidity at harvest or after 105 days of storage at −0.5°C. Levels of rfd nm sufficient to enhance red color development in red sports of ‘Delicious’ were not necessarily sufficient to insure flesh quality.
The Effect of Artificial Aging on the Concentration of Ca, Mg, Mn, K, and Cl in Imbibing Cabbage Seed1
Authors: Loomis Edward L. , Smith Orrin E.
Published: August 2022

Unimbibed seeds of cabbage (Brassica oleracea L. Capitata group, cv. Early Jersey Wakefield, were artificially aged at 40°C in 100% relative humidity for up to 20 days. Aged seed and non-aged seed were imbibed in H20 at 25° in the dark up 0, 1, 4 or 16 hours, after which concentrations of Ca, Mg, Mn, K, and Cl in the whole seed were determined by neutron activation analysis. Concentrations of Ca, Mg, and Mn did not significantly change during the imbibition period for either control or aged seed. However, as the aging time increased, seeds lost increasing amounts of K and Cl during imbibition. The concentration of K decreased continually throughout the imbibition period in both aged seed and control seed. The decrease was significantly greater in the aged seed. Cl, too, was lost during imbibition and like K, the greater loss occurred in aged seed.
Characterization of Thatch, Rhizomes, Carbohydrates, and Spring Deadspot in Twenty Cultivars of Bermudagrass1
Authors: Dunn J. H. , Nelson C. J. , Sebaugh J. L.
Published: August 2022

Carbohydrate content varied among cultivars of bermudagrass (Cynodon dactylon L.) at 3 sampling dates during dormancy and greenup. Sucrose and starch decreased in rhizomes between March and May while reducing sugars remained constant. Concentration of stored carbohydrate was correlated positively with the number of rhizomes near the soil surface during winter and early spring. Spring deadspot injury ranged from 60% of the plot area for ‘KSU, (Kansas State University) T-5, to zero for ‘Royal Cape’, ‘Mich. C-53’, ‘Midway’ and ‘KSU D-17.’ Earliest to greenup in spring was ‘KSU T-3’ while ‘KSU T-5’, ‘F-4’, ‘Md. 23’, ‘24’ and ‘U-3’ were only 13-33% green on the same date. Injury was less severe where cultivars utilized carbohydrate and greened early in the spring. Early greenup was associated with thinner layers of thatch. There was no association between thickness or number of rhizomes and spring deadspot.
Turbulent Heat Fluxes above a Heated Orchard1
Authors: Bland William L. , Panofsky Hans A. , Martsolf J. David , Norman John M.
Published: August 2022

Spatial and temporal components of the turbulent heat flux above a heated orchard are discussed. Direct measurements of the temporal component of the turbulent flux at 2 locations are reported. Drag anemometry and fine-wire thermocouples provided measurements of u, v, w, and T at 30 Hz. About 10% of the energy provided by heating escaped the crop zone by the temporal flux. Variation in the flux measured at a given location was caused by changes in wind speed and direction, and heater proximity.
Flood-induced Shift of Electron Flow Between Cyanide-sensitive and Alternative Respiratory Pathways in Roots of Tolerant and Intolerant Tree Species1
Authors: Carpenter James R. , Mitchell Cary A.
Published: August 2022

Effects of cyanide (as KCN) and/or salicylhydroxamic acid (SHAM) on respiratory rates (QO2) of excised tree roots were evaluated before and after flooding intact plants. CN, an inhibitor of cytochrome oxidase, stimulated QO2 in flood-intolerant sugar maple (Acer saccharum Marsh.) and Japanese yew (Taxus cuspidata Sieb. and Zucc.), but not in flood-tolerant red maple (Acer rub rum L.), and inhibited QO2 in very flood-tolerant baldcypress (Taxodium distichum (L.) Rich). Eight days of flooding eliminated CN-stimulation of QO2 in sugar maple. SHAM, an inhibitor of the alternative oxidase, had little effect on QO2 of any species when used alone, but greatly inhibited QO2 of all species when combined with KCN, indicating the presence of substantial amounts of both respiratory pathways in flood-tolerant and intolerant species, as well as the ability of electrons to flow from one pathway to another when one is blocked by a specific inhibitor. Flooding reduced root respiration capacity in all species, affecting intolerant species the most and tolerant the least. The exception was QO2 of dormant Taxus roots, which was not inhibited by flooding. CN-sensitive QO2 was lost from roots of intolerant species in particular, and to a lesser extent from more tolerant species. A limiting leveL of O2 (0.5%) suppressed SHAM-sensitive QO2 more than CN-sensitive QO2 indicating a greater affinity for O2 by the CN-sensitive path-way. The evidence is consistent with a model for relative flood tolerance based upon differential damage to the aerobic respiratory mechanism.
Breeding for Resistance in Cabbage and Cauliflower to Cabbage Looper, Imported Cabbageworm, and Diamondback Moth1
Authors: Dickson M. H. , Eckenrode C. J.
Published: August 2022

Resistance to Trichoplusia ni (Hubner), Pieris rapae (L.), and Plutella xylostella (L.) in cabbage [Brassica oleracea L. (Capitata group)] and cauliflower (B. oleracea, Botrytis group) was studied using a 5-parent diallel. Resistance was quantitatively inherited without undesirable linkages. When Plant Introduction (PI) 234599 (a glossy-leaved cauliflower) was used as a parent, narrow sense heritabilities of 22-47% were obtained for resistance. This resistance was maintained irrespective of plant age or presence or absence of alternate oviposition hosts. Plants with moderate tolerance only express it at maturity. The highest levels of resistance were transferred with difficulty into desirable type cauliflower and cabbage with slight bloom.
Promotion of Leaf Abscission in Intact Ficus benjamina by Exposure to Water Stress1
Authors: Peterson John C. , Sacalis John N. , Durkin Dominic J.
Published: August 2022

Leaf abscission was promoted in Ficus benjamina L. (weeping fig) by withholding water from plants growing in sand and by the addition of polyethylene glycol 6000 to hydroponically-grown plants. Leaf shedding occurred when plant water potential decreased below about −6 bar in sand and below −3.5 bar in water culture. Shoot and root environmental conditions modified the water status of plants. Leaf shedding can be dramatically reduced by manipulating environmental conditions to maximize water absorption and minimize transpiration.
Inheritance of Tolerance to Rhizoctonia Fruit Rot of Tomato1
Authors: Werner R. A. , Sanders D. C. , Henderson W. R.
Published: August 2022

The inheritance of tolerance to rhizoctonia fruit rot incited by Rhizoctonia solani Kuhn differed depending upon the source of the plant material of tomato (Lycopersicon esculentum Mill.). The tolerance in USDA 75B 846-1-1 was controlled by 1 major gene without dominance. The tolerance in USDA 75B 610-3 was polygenic with 4 major genes. Tolerance in USDA 75B 846-1-1 had a narrow-sense heritability of 71% while in USDA 75B 610-3 heritability was 30%. Fruit rot tolerance and resistance to puncture pressure were highly correlated in both families. Fruit shape and fruit rot tolerance were also highly correlated in the family with USDA75B 846-1-1.
Synthesis of Pisolithus tinctorius Ectomycorrhizae on Seedlings of Four Woody Species1
Authors: Maronek Dale M. , Hendrix James W.
Published: August 2022

Fresh and stored vegetative mycorrhizal inoculum of Pisolithus tinctorius (Pers.) Coker & Couch were incorporated into steamed media containing slow-release fertilizer. Austrian pine {Pinus nigra Arnold.), Norway spruce (Picea abies (L.) Karst.) and Canadian hemlock (Tsuga canadensis (L.) Carriere) seedlings were grown in 165-ml tubes in a greenhouse for 7 months. Yellow birch (Betula alleghaniensis Britt.) seedlings were grown in 7.6 cm diameter pots. All species formed mycorrhizae but the percent of seedlings which formed mycorrhizae differed among species. Stored inoculum was inferior to fresh inoculum. Differential growth responses to P. tinctorius also occurred among the species. P. tinctorius significantly increased height and stem diameter of Norway spruce only, and reduced the stem diameter of Austrian pine.
Resistance of Phaseolus vulgaris L. Cultivars to Hypocotyl Inoculation with Rhizoctonia solani Kuehn1,2
Authors: Moody A. R. , Benepal P. S. , Berkley B. , Koch E. J.
Published: August 2022

Seven-day-old hypocotyls of 149 bean cultivars were inoculated with Rhizoctonia solani and incubated in a growth chamber for 72 hours at 30°C. Based on the mean size of the largest lesion, and 10 most resistant cultivars were: ‘Dwarf Horticultural Long Pod’, ‘Yellow Eye’, ‘White Kidney’, ‘Romano Pole’, ‘French Horticultural’, ‘Red Kidney’, ‘Manitou’, ‘Sutter Pink’, ‘Wren’s Egg’, and ‘Red Mexican UI 37’. The mean largest lesion for ‘Dwarf Horticultural Long Pod’ (the most resistant) was 3.0 mm2 while that for the Bush Blue Lake 274 (susceptible) was 64.4 mm2. These 10 cultivars were further tested using 5 different isolates of R. solani. ‘Yellow Eye’ was the most resistant to all 5 isolates with a mean largest lesion size of 10.0 mm2 while ‘Bush Blue Lake’ had a mean lesion size of 90.9 mm2. The root rot ratings were highly correlated with the areas of the largest lesion, and the number of lesions. ‘White Kidney’ was the only white-seeded resistant cultivar.
Overcoming Self-incompatibility in Raphanus sativus L. with High Temperature1
Authors: Matsubara Sachiko
Published: August 2022

Self-incompatibility of Raphanus sativus L. was partially overcome by exposing plants to temperature of 30 to 50°C. The most effective treatment was 50°C for 25 minutes. Scanning electron microscopical (SEM) observation of pollen tubes on the papillae surface have shown that exposure of the gynoecium to 50°C for 25 minutes resulted in pollen tube growth following self-pollination that resembled that of cross-pollination. Openings of papillae and detached pollen grains and tubes were found as the result of successful pollen tube penetration of papillae. Fluorescence microscopical (FM) observation served to confirm these observations made by SEM. However, incompatible pollen failed to germinate although pollen grains were attached to the papillae by aid of their waxy surface substances.
Studies of Ovipositional Preference of Cabbage Looper on Progenies from a Cross between Cultivated Lettuce and Prickly Lettuce1
Authors: Kishaba A. N. , McCreight J. D. , Coudriet D. L. , Whitaker T. W. , Pesho G. R.
Published: August 2022

F1 progenies from a cross between Lactuca sativa L. breeding line 54671 and L. serriola L. PI 274372 (resistant to the cabbage looper, Trichoplusia ni (Hubner), averaged 42 ± 6 looper eggs per plant, compared to 213 ± 25 for the 54671 parent and 17 ± 4 for PI 274372. Two F2 populations varied widely in plant damage inflicted by the resulting larvae when they were exposed to 4 releases of adult loopers but the damage distribution was skewed towards the resistant parent. Antixenosis of 16 F3 progenies was independent of plant size (r ranged from 0.02 to 0.52) and of plant type (r ranged from 0.00 to 0.57).
Response of Sweet Cherry and Apricot Pollen Tube Growth to High Levels of Sulfur Dioxide1
Authors: Facteau T. J. , Rowe K. E.
Published: August 2022

Pollen tube growth of ‘Tilton’ apricot (Prunus armeniaca L.) was reduced by exposure to SO2. An empirical model, based on modified spline functions, described the decrease in pollen tube growth due to increasing dose (hours exposure × concentration of SO2) expressed on logarithmic scale. The response curve, based on this analysis, was “S-shaped” with a decrease from 98.5% pollen tube growth (PTG) for unexposed pollen tubes, based on percent of the style that the longest pollen tubes had grown to 91.6% at ℓ n dose 4.0. These was then a very sharp decrease in PTG to about 45% at ℓn dose 5.7, then a gradual curvilinear response to <1% PTG at the maximum ℓn dose of 7.7. There data strongly indicate that there is a threshold response to SO2 with respect to PTG. Response of ‘Van’ PTG in ‘Napoleon’ sweet cherry (P.avium L.) styles was similar to apricot, but not as definitive because of greater within year variation and differences between years. In one year (1979), a spline function model of PTG in cherry suggested a threshold value at about ℓn dose of 2.1, while in another year (1978), there was a nearly linear decrease in PTG with increasing ℓn dose.
Meiotic Chromosome Behavior in Intersectional and Intergeneric Species Hybrids in the Oncidium Alliance1
Authors: Phang V. P. E. , Charanasri U. , Kamemoto H.
Published: August 2022

The intersectional hybrids, Oncidium altissimum × O. sarcodes and O. floridanum × maculatum, and the intergeneric hybrid, Odontoglossum stenoglossum × O. macuiatum (all with 2n = 56), showed near normal meiosis with 27 or 28 bivalents per pollen mother cell indicating strong homology of parental genomes. Trichocentrum albopurpureum (2n = 24) × O. lanceanum (2n = 26) exhibited fair homology of parental genomes with the formation of 6 to 10 bivalents out of the possible 12. The other intersectional hybrids, O. pulvinatum (2n = 42) × O. floridanum (2n = 56), O. triquetrum (2n = 42) × O. floridanum (2n = 56), O. microchilum (2n = 36) × O. floridanum (2n = 56) and O. microchilum (2n = 36) × O. onustum (2n = 56) and the intergeneric hybrid, Comparettia falcata (2n = 42) × O. onustum (2n = 56) showed highly irregular meiotic behavior with poor chromosome pairing. The number of bivalents in these hybrids ranged from 1.4 to 9.5, indicating poor genome relationships of the parental species.
Effects of Immature Fruit and Holding on Strawberry Puree Quality and Color Stability1
Authors: Spayd S. E. , Morris J. R.
Published: August 2022

Purees were prepared from green (G, immature and mature green 1:1) and ripe (R, firm ripe and processing ripe 1:1) fruits of ‘Cardinal’ and A-5344 strawberries (Fragaria × ananassa Duch.). Blends of 25%R + 75%G, 50%R + 50%G, 75%R + 25%G, and 100% R were prepared before and after holding purees at 10, 30 and 50°C for 0, 12, 24 and 36 hours. The decrease in puree color caused by the addition of puree of green fruit to puree of ripe fruit was a dilution effect rather than a synergistic effect, since pures of green and ripe fruits combined after holding were equal in color to purees of comparable proportions of purees of G and R fruits combined before holding. Holding strawberry puree for up to 36 hours at 30° and 50°C increased discoloration and reduced total anthocyanins, pelargonidin-3-monoglucoside content, COM “a”, and visual color. Holding at 50° resulted in the greatest reductions in color.
Influence of Various Growth Chamber Environments on Growth, Flowering, and Senescence of Tulipa gesneriana L. cv. Paul Richter1
Authors: Dosser Amy L. , Larson Roy A.
Published: August 2022

‘Paul Richter’ tulips were forced in controlled environment chambers at 26/22, 22/18, and 18/14°C day/night temperatures using high and reduced light intensity and short and long daylengths. Photoperiod had no influence on growth or flowering. Reduced light intensity with the coolest temperature treatment significantly increased the forcing period. Increased forcing temperatures had the greatest impact on plant growth, resulting in reduced Plant flower length, and forcing period. In a second experiment, ‘Paul Richter’ was forced in controlled environment chambers under 8 combinations of day/night temperatures from 18 to 26° day and from 14 to 22° night. The warmer day or night temperatures decreased the forcing period. Plant height was increased with increasing day temperatures, but decreased with increasing night temperature. Flower length decreased with increasing day or night temperatures. First internode length was increased with increasing day temperature but decreased with increasing night temperature, with the exception of a slight increase at a day temperature of 18°. Last internode length was increased only slightly with increasing night temperature. Flower longevity and total length were decreased slightly by increased forcing temperatures.
Lambkill Control in Lowbush Blueberry Fields with Glyphosate and 2, 4-D1
Authors: Ismail Amr A. , Yarborough David E.
Published: August 2022

N-(phosphonomethyl)glycine(glyphosate) or 2,4-D (2, 4 dichlorophenoxy)acetic acid (2, 4-D) was applied on 2 dates (October 28 or November 10) after leaf abscission of blueberry (Vaccinium angustifolium Ait.) in a commercial field containing lambkill (Kalmia angustifolia L.); plots were thermally pruned the following spring. Lambkill plant stand decreased with increasing rates of glyphosate or 2, 4-D. A late application of glyphosate was more effective than 2, 4-D in reducing lambkill plant stand. Increasing the rate of glyphosate resulted in a greater number of blueberry stems, more flower buds per stem, and a higher yield. Glyphosate applications reduced the length of reemerging lambkill stems but 2, 4-D did not. Glyphosate was as effective in reducing lambkill plant stand at 2.2 kg/ha as 2, 4-D was at 4.5 kg/ha.
Some Effects of Emulsifiable Coatings on Weight Loss, Stem Discoloration, and Surface Damage Disorders in ‘Van’ Sweet Cherries1
Authors: Lidster P. D.
Published: August 2022

Preharvest antitranspirant sprays were most effective in decreasing the incidence of surface pitting in ‘Van’ sweet cherries (Prunus avium L.) when applied immediately prior to harvest. Antitranspirant or wax coatings applied to ‘Van’ cherries as a postharvest dip decreased weight loss in storage, the incidence of discolored stems and surface pitting in storage. Antitranspirant concentration in the postharvest dipping solution was negatively correlated to the incidence of surface pitting.
Infiltration of Calcium Solutions into ‘Jonathan’ Apples Using Temperature Differentials and Surfactants1
Authors: Lee J. J. L. , Dewey D. H.
Published: August 2022

Ca infiltration into the flesh of mature ‘Jonathan’ apples (Malus domestica Borkh.) from a postharvest dip was enhanced by increasing the CaCl2 concentration, decreasing the temperature and surface tension of the cooling solution, increasing the initial fruit temperature, and increasing the submersion duration. Increases of fruit Ca to levels normally adequate to control storage disorders were achieved by cooling fruit at 21°C for 10 minutes in 4% CaCl2 plus 0.1 % surfactant L-77 at -1°. The results suggest that hydrocooling apples with a refrigerated CaCl2 solution would offer a practical means of postharvest Ca enrichment.
Genetic Advance through Mass Selection for Tenderness in Sweet Corn1
Authors: Ito Glenn M. , Brewbaker James L.
Published: August 2022

Mass selection for improved tenderness was conducted in the corn (Zea mays L.) cultivar ‘Hawaiian Super-sweet No. 9’. Two selection criteria were applied separately—a pericarp thickness measurement of mature kernels, and a bite test of immature ears on the plant. Selection was carried out at 10% intensity among 400 ears each for 3 cycles by pericarp thickness and for 4 cycles by bite test. Selection based on pericarp thickness led to a genetic advance of 9.2% per cycle (from average 73.6 to 53.3 μm), with a concomitant 2.9% increase per cycle in tenderness as evaluated by the bite test. Genetic advance following selection based on the bite test was 3.9% per cycle as evaluated by the bite test and 2.9% per cycle as evaluated by pericarp micrometry, the germinal and abgerminal sides of pericarp differed consistently, with germinal 14.5% thinner than the abgerminal, but correlated so well for all cycles that only one side is advised in a selection program. A significant correlation (r=0.98) was found between average bite-test scores and immature pericarp thickness, but correlations based on individual ears were low (r=0.24). Bite-test scores were subject to high error variability (CV =25%) as opposed to pericarp micrometry (CV=12%). Both techniques deserve recommendation for tenderness-selection programs, possibly as tandem criteria for successive cycles of selection.
Effects of Cooling Versus Seal-packaging wit High-density Polyethylene on Keeping Qualities of Various Citrus Cultivars1
Authors: Ben-Yehoshua S. , Kobiler Ilana , Shapiro B.
Published: August 2022

Seal packaging of orange [Citrus sinensis (L.) Osbeck cvs. Valencia and Shamouti], grapefruit (Citrus paradisi Macf. cv. Marsh) and lemons (Citrus limon Burnt, f. cv. Eureka) with high-density polyethylene (HOPE) film (0.01 mm in thickness) delayed softening and inhibited weight loss and deformation of the fruit more than cooling. Sealed fruit at 20°C and 85% relative humidity (RH) had better appearance and were firmer than non-sealed fruit at their lowest temperature possible without chilling injury and 85–90% RH. HOPE seal-packaging also inhibited chilling injury of grapefruit and lemons stored at 5° and 2°C, respectively. The C02 content of grapefruit was unaffected by seal-packaging, hut it was lower at cooler temperatures. Decay of citrus fruit depended more on the storage temperature than on the type of packaging. However, in storage up to 1 month, no significant difference was found in most experiments in decay percentage between orange, grapefruit, and lemon sealed with HOPE and stored in a packing house (13 to 25°C), and non-sealed fruits, at the lowest temperatures possible without chilling injury of 2, 10 and 14°C, respectively.
The Effect of Cane Morphology and Cultivar on the Phenological Development and Critical Temperatures of Primary Buds on Grape Canes1
Authors: Johnson D. E. , Howell G. S.
Published: August 2022

Cold resistance of primary buds from grapevines (Vitis spp.) decreased with advancing phenological development. Morphological characteristics of canes produced during previous growing season had no effect on bud hardiness at a given stage of development or on development rate when cuttings were forced in the greenhouse. Cultivar differences were found to affect both the rate of bud development and the hardiness at a given stage of buds forced from stored cuttings.
Response of Pear to Inbreeding1
Authors: Bell R. L. , Janick Jules , Zimmerman R. H. , van der Zwet T. , Blake R. C.
Published: August 2022

No consistent trend towards increased inbreeding has existed within the U.S. Department of Agriculture pear breeding program over 17 years of crosses based on the mean inbreeding coefficient and the percentage of non-inbred progenies. Selections did not tend to be more or less inbred than the population of all seedings. There was consistent, but small, trend towards a reduction in seedling vigor with increased levels of inbreeding as measured by 5th year stem diameter. A significant positive, but small, association between increased inbreeding and improved flavor, grit, and texture were observed, even after correction for the effects of parental values for these characters. Limited inbreeding does not adversely affect improvement of fruit quality and appears to be of some benefit in facilitating selection of favorable alleles.
Effects of Ethephon, Gibberellin, and BA on Fruiting of ‘Dancy’ Tangerines1
Authors: Jahn Otto L.
Published: August 2022

Young ‘Dancy’ tangerine (Citrus reticulata Blanco) fruit were thinned with 200 to 250 ppm (2-chloroethyl)phosphonic acid (ethephon) sprays. Ethephon treatments that thinned fruit to an average of about 1 per twig generally increased fruit size and crop value and reduced alternate bearing. Thinning was less effective under water stress conditions. Little or no leaf abscission was observed, even under dry grove conditions. Ethephon was most effective when it was applied near the end of the natural drop period in May, but before many of the fruit became larger than 15 mm in diameter. Gibberellin (GA3 or GA4,7) and/or 6-benzylamino purine (BA) did not reduce flowering or fruiting.
Cold Hardiness of Leaf and Stem Organs of Rhododendron Cultivars1
Authors: Holt Mary A. , Pellett Norman E.
Published: August 2022

Leaves and stems from 7 field-grown cultivars of Rhododendron were frozen in laboratory tests from September to December or January for 2 successive winters to determine the temperature causing injury to selected organs. In all cultivars, the leaf midrib, petiole, and stem extraxylary (cambium, phloem, and cortex) organs were the least cold-hardy, while the stem xylem and leaf intervein were the most cold-hardy. Organs of ‘Lee’s Dark Purple’ and ‘Cataw-biense Boursalt’ rhododendrons were the most cold-hardy by December while ‘Caractacus’, ‘America’, and ‘Nova Zembla’ were the least cold-hardy. Field temperatures similar to those causing injury in the laboratory resulted in leaf and stem damage in early December.
Identification of Modifier Genes Affecting the Extent of Precocious Fruit Pigmentation in Cucurbita pepo L.1
Authors: Shifriss Oved , Paris Harry S.
Published: August 2022

Data from a cross between ‘Table King’, B+/B +, bearing green fruits, and ‘Precocious Small Sugar’, B/B, bearing yellow fruits, revealed the existence of 2 independent modifier genes, designated Ep-1 and Ep-2, each of which can extend the boundaries of precocious fruit pigmentation conditioned by gene B. The effect of these modifiers of B is cumulative, but the dosage of B plays an important role in controlling the extent of precocious pigmentation. Some commercial hybrids are B/+ and these tend to produce bicolor fruits, an undesirable feature in squash. The present findings suggest that B/+ hybrids can produce yellow fruits exclusively, provided they carry 2 or more Ep genes.
Distribution of 14C Photosynthetic Assimilates in ‘Valencia’ Orange Seedlings at 10° and 25°C
Authors: Guy C. L. , Yelenosky G. , Sweet H. C.
Published: August 2022

In the paper, Distribution of l4C Photosynthetic Assimilates in ‘Valencia’ Orange Seedlings at 10° and 25°C by C. L. Guy, G. Yelenosky, and H. C. Sweet (J. Amer. Soc· Hort. Sci. 106(4):433–437. 1981) the title for Table 1 should read: l4C-labeled fractions extracted from ‘Valencia’ orange seedlings exposed to l4CO2 (50 μCi for 3 hours) at 25° and 10°C and maintained at those temperatures for 28 days in controlled temperature light rooms.
Scanning Electron Microscopy and Size Analysis of Temperature-induced in Vivo Potato Starch Breakdown1
Authors: Wetzstein H. Y. , Wetzstein M. E.
Published: August 2022

The cold-temperature-induced starch breakdown which occurs in stored tubers of potato (Solanum tuberosum L.) was investigated using scanning electron microscopy and image analysis. Corrosion was superficial in nature, with the development of grooves, furrows, and circular depressions. Concentric rings and a surface peeling were observed. Area size distribution measurements found no significant relationship between size, storage temperature or storage duration, suggesting a simultaneous, nonspecific size breakdown of granules.
Inheritance and Association of Flower, Ovule, Seed, Pod, and Maturity Characters in Dry Edible Beans (Phaseolus vulgaris L.)1
Authors: Al-Mukhtar Faisal A. , Coyne Dermot P.
Published: August 2022

The accessions, PI 255960 (P1) (purple flowers, colored seed, curved pod tip, large seed) and G-19007 (P2) (white flowers, straight pod tip, white seed) of Phaseolus vulgaris L., both late maturing with many ovules and seeds per pod, were crossed with each other and with 2 early maturing, white flowered, white seeded, straight pod tip, low ovule number/pod parents, ‘Great Northern (GN) Emerson’ (P3) and ‘GN UI#59’ (P4). P1 and P2 appeared to possess the same genes for high ovule number/pod. The continuous distributions of ovule number/pod, seed number/pod, and seed weight in the F2 generations of the other crosses indicated quantitative inheritance. However, segregation data in their F3 generations suggested that ovule number/pod may be determined by additive action of the alleles of a single major gene. Moderately high broad sense heritability estimates were obtained for these traits. Purple flower color and seed-coat color were controlled by 2 different complementary dominant genes. Striped pod color and curved pod tip shape (Ct) were each controlled by different single dominant genes. Days to flowering was controlled by a single completely dominant gene; pod maturity was controlled by a single incompletely dominant gene for lateness. Linkage occurred between genes for flower color and pod color pattern, flower color and pod tip shape, and flower color and maturity. High seed number/pod was associated with purple flowers, colored seeds, and late maturity in the F2 of P3 × P1. Late maturity and high seed number/pod were also associated in the F2 of P4×P1, P3× P2 and P4 × P2. Moderately large negative correlations were found between number of seeds/pod and seed weight in all crosses involving P1 and P2. High ovule number/pod was associated with indeterminate growth habit and moderately late flowering in the F2 progeny from the indeterminate cultivar ‘G.N. Nebr. # 1’, crossed with a determinate isoline. No association between seed weight & seed-coat color was observed in the F2 of P3 × P1, and P4 × P1, but there was association between large seed and both late maturity and flower color.
Physical Properties of Three Container Media and their Effect on Poinsettia Growth1
Authors: Fonteno W. C. , Cassel D. K. , Larson R. A.
Published: August 2022

Three fundamental different media 3 pine bark (≤ 6mm): 1 sphagnum peat moss:l concrete grade sand; 2 loamy soil: 1 peat moss: 1 perlíte; and a peat-lite mix, (Metro Mix 350) were characterized by available water-holding capacity, bulk density and particle size distribution. All 3 media provided adequate water-holding capacities for container production of ‘Eckespoint C-1 Red’ and ‘Annette Hegg Diva’ poinsettias (Euphorbia pulcherrima Klotzsch ex. Willd.). Total porosity declined and bulk density increased in all media 9 weeks after potting due to shrinkage but there were no additional changes after an additional 4 weeks. Airspace and water buffering capacities did not change during the 13-week period indicating the loss in total porosity resulted in a loss of easily available water. Water release had linear and nonlinear components with respect to moisture tension. Poinsettia root systems appeared to be extensive throughout the growing media; root distributions varied with cultivar and medium.
Keeping Qualities of ‘Stayman’ and ‘Delicious’ Apples Treated with Calcium Chloride, Scald Inhibitors, and other Chemicals1
Authors: Hardenburg R. E. , Anderson R. E.
Published: August 2022

‘Stayman’ apples (Malus domestica Borkh.) dipped in 4% CaC12 were firmer after 5–6 months storage in air at 0°C and developed less senescent breakdown than untreated fruit. Use of the thickener Keltrol with CaC12 or vacuum infiltrating (VI) CaC12 resulted in the firmest fruit after storage and the highest flesh Ca levels. ‘Stayman’ stored 5 or 6 months in CA at 0°C were 1.5 kg firmer than air-stored fruit. Dipping apples in CaC12 prior to CA storage provided little additional benefit. Liquid concentrate formulations of diphenylamine (DPA) and ethoxyquin used alone or in combination with 4% CaC12 gave excellent scald control on ‘Stayman’ stored 5 or 6 months at 0° + 6 days at 20°. However, the same chemicals gave poor scald control for ‘Starkrimson Delicious’ picked early to midseason. The antioxidants BHT and BHA evaluated as postharvest dips at 2,000 ppm were less effective than DPA or ethoxyquin in controlling scald on ‘Stayman’. ‘Delicious’ apples were not significantly firmer after 6 months storage in air at 0°C when dipped in 3% CaC12 alone or with Keltrol, or when CaC12 was VI. When CaC12 was contaminated with Penicillium expansum spores, VI of the solution greatly increased decay of both ‘Delicious’ and ‘Stayman’.
Inhibitory Effects of Ammoniacal Nitrogen on Growth of Radish Plants. I. Characterization of Toxic Effects of NH4+ on Growth and its Alleviation by NO3−1
Authors: Goyal S. S. , Lorenz O. A. , Huffaker R. C.
Published: August 2022

Growth of radish (Raphanus sativus L.) was inhibited by NH4 as the source of N at concentrations from 1 to 240 ppm N. Higher levels of free NH4 accumulated in the plants as a result of NH4 nutrition. Nitrate equivalent to 10% or more of the NH4 concentration alleviated the inhibitor effects of NH4 on growth and also decreased the NH4 content of the plants. Five cultivars of radish responded similarly. Ammonium was also harmful for growth of etiolated seedlings, but NO3 did not reverse the inhibitory effects of NH4.
Water Stress, Growth, and Critical Water Potentials of Rabbiteye Blueberry (Vaccinium ashei Reade)1
Authors: Davies Frederick S. , Johnson Charles R.
Published: August 2022

Moderate and severe water-stress, as determined by decreases in stomatal conductance, resulted in significant reduction of leaf area and plant weight in 1-year-old containerized ‘Bluegem’ rabbiteye blueberry. Drought-tolerance appeared to be intermediate to other plant species based on a number of physiological factors. Critical water potential for stomatal closure was −2.2 MPa, transpiration ratio averaged 222 g of water transpired per g dry matter produced and relative water content changed 6.4% per 1.0 MPa change in water potential.
Storage and Processing Quality of Beans (Phaseolus vulgaris L.) Harvested at the Semi-dry Stage1
Authors: Gonzalez Alfredo R. , Edwards Kathleen M. , Marx David B.
Published: August 2022

The processing quality of kidney, pinto, and small white beans (Phaseolus vulgaris cv Redkloud, UI-111, and Aurora) was compared when harvested at the dry (11–14% moisture content) and semi-dry (50–60% moisture content) stage in the spring and fall growing seasons. Semi-dry harvested beans were canned immediately after harvest and after being storaged at 27°C for 24 hours. Dry harvested beans were canned after harvest. The respiratory rate of semi-dry harvested beans stored at 27° decreased with time in storage. Significant differences in objective and subjective evaluations were found between cultivars, harvest stage, storage treatments, and spring and fall growing seasons. Semi-dry harvested beans stored for 24 hours at 27° had fewer split beans than the non-stored counterpart and the dry harvested beans. Semi-dry beans with and without storage treatment were firmer than those harvested dry. An increase in color was observed in semi-dry beans of ‘UI-111’ and ‘Redkloud’ after being stored for 24 hours at 27°. Sensory panel evaluations indicated that beans harvested at the semi-dry stage and stored for 24 hours at 27° before canning had similar or higher acceptability than beans harvested dry.
Heritability of Efficiency in Phosphorus Utilization in Beans (Phaseolus vulgaris L.) Grown under Phosphorus Stress1
Authors: Fawole Iyiola , Gabelman W. H. , Gerloff G. C. , Nordheim E. V.
Published: August 2022

The heritability of efficiency in phosphorus utilization under deficiency stress was investigated using 6 bean families derived from crosses between selected efficient, moderately inefficient, and inefficient lines. Total plant dry weight (DW) was used as an index of efficiency. Epistasis, notably additive by additive and dominance by dominance gene effects, made imyor contributions to the efficiency in P utilization. Additive and dominance gene effects also made significant contributions. Estimates of broad sense heritability for total plant DW showed that efficiency in P utilization was a highly heritable trait. Narrow sense heritability estimates for total plant DW were high in all families studied.
Physiology of Sugar Accumulation in Carrot Breeding Lines and Cultivars1
Authors: Lester G. E. , Baker L. R. , Kelly J. F.
Published: August 2022

Cultivars and breeding lines of carrot (Daucus carota L.) with established differences in sugar accumulation capacity were studied by growth analyses to identify associations of sugar content with other traits. Carrots were grown on both organic and sandy loam soils. At both locations the seasonal patterns for sugar content of a high sugar-accumulating cultivar/line (HSL) and a low sugar-accumulating cultivar/line (LSL) were similar. There was little or no association of growth indicators (dry weight accumulation, tap root dry weight, and leaf area index) with high or low sugar accumulation. Differences in sugar yields were associated with mean net assimilation rate (), mean relative growth rate () and leaf area ratio (LAR) late in the growing season. The HSL had increasing (, , and LAR, whereas LSL had decreasing , , and LAR late in the growing season. In general, carrot cultivars and breeding lines producing high free-sugar concentrations were distinguished from low sugar-accumulating carrots by delayed physiological maturity resulting in prolonged photosynthetic activity late in the growing season.
Osmotic Regulation in Germinating Tomato Seedlings1
Authors: Taylor A. G. , Motes J. E. , Kirkham M. B.
Published: August 2022

The effects of water deficits were examined on osmotic regulation of germinating seedlings of tomato (Lycopersicon esculentum Mill cv. Campbell 1327). Seed were germinated in aerated water and then grown for an additional 2 days in Petri dishes. The germinated seeds were then transferred to water potentials of 0 to −6 bars in 2-bar increments. Mannitol and water was used to obtain the desired water potential of the media. Water relations, growth rates and reducing sugars, non-reducing sugars, amino acids, proline, nitrates, phosphates, potassium, and electrical conductivity were determined for roots and shoots at different water stresses. As water stress increased, osmotic adjustment occurred in the roots which accounted for the maintenance of turgor and growth. During the same period, little adjustment occurred in the shoots and consequently growth decreased. Turgor potential was highly correlated with growth rates for both plant parts. All solutes measured, except proline, generally increased in the roots and decreased in the shoots as water stress increased. Proline increased in both plant parts during the same period. Thus, solute regulation occurred during water deficits. Osmotic regulation in germinating tomato seedlings appears to be an adaptive feature during periods of water stress.
Growth Regulator Effects on Fruit Set and Fruit Size in Navel Orange1
Authors: Southwick Stephen M. , Davies Frederick S.
Published: August 2022

Whole-tree sprays of gibberellic acid (GA) plus calcium dihydrophosphate Ca(H2PO4)2 increased fruit set of navel orange [Citrus sinensis (L.) Osb.] during 1979 and 1980. Gibberellic acid alone or a combination with Ca(H2PO4)2 or 6-benzylamino purine (BA) increased fruit set in 1980. Benzylamino purine did not increase fruit set or the fruit-setting effectiveness of GA. Calcium dihydrophosphate increased fruit set for approximately 5.5 weeks in 1980 even though leaves did not show signs of calcium deficiency. However, no increase in fruit set was observed 8.5 weeks after application. Fruit sprayed with GA were smaller than untreated fruit initially; however, no size differences were noted 8.5 weeks after full bloom.
Stability of Potato Tuber Isozymes under Different Storage Regimes1
Authors: Staub Jack E. , Kuhns L. J. , Grun P. , May B.
Published: August 2022

Extracts from freshly harvested tubers of potato (Solanum tuberosum L.) held at different temperatures and extracts taken from stored tubers were examined by starch gel electrophoresis. Storage of tubers at 10°C for up to 70 days or storage of extracts at −60° for 70 days did not affect isozyme banding patterns. Storage of fresh extracts for 14 days at 5° produced blurring of alkaline phosphatase (AKP) bands, altered isozyme mobility of malic enzyme, and added a band to glucosephosphateisomerase (GPI) zymograms. It did not affect the mobility or resolution of 6-phosphogluconate dehydrogenase. Addition of 0.1 m mercaptoethanol did not restore original resolutions or mobilities.
Distribution and Persistence of Trunk-injected Oxytetracycline in Blight-affected and Healthy Citrus1
Authors: Timmer L. W. , Lee R. F. , Albrigo L. G.
Published: August 2022

Blight-affected sweet orange [Citrus sinensis (L.) Osb.] trees on rough lemon (C. jambhiri Lush.) rootstock were injected with high concentrations of oxytetracycline (OTC) (10–30 g a.i./tree) under high pressure (1300–1700 kPa) in an attempt to induce remission of blight symptoms. OTC activity, determined by bioassay with Bacillus cereus var. mycoides, was distributed in 70–95% of the twigs sampled 3 weeks after injection. Activity persisted in the twigs and mature leaves for 3 to 5 months and in a few twigs as long as 7 to 8 months after a single injection. No activity was detected in small roots and downward movement appeared to be limited. Distribution and persistence of OTC in healthy trees was similar to that in blight trees. Trees with mild blight symptoms injected once with OTC continued to decline and had moderate to severe blight 2 years later. Of 16 healthy trees injected with OTC 4 times over 2 years, 1 became severely blighted and several others developed mild symptoms. Our trunk injection work with OTC does not support the hypothesis that blight is caused by a tetracycline-sensitive organism, but does not eliminate that possibility.
Effect of Root Zone Heating on Growth of Poinsettia1
Authors: Janes Harry W. , McAvoy Richard
Published: August 2022

Poinsettias (Euphorbia pulcherrima Willd. cvs. Annette Hegg Supreme, V-10, and Brilliant Annette Hegg) were grown on heated benches and exposed to root zone temperatures between 18° and 29° C. Increasing media temperatures affected bract size and development, internode length, fresh and dry weight of stems, leaves, and bracts, as well as the number of axillary shoots of cultivars differentially. In general, plants grown at higher temperatures were shorter, had more prominent axillary shoots, and developed anthocyanin sooner than unheated controls.
Effect of Mineral Nutrient Sprays on Photosynthesis and Stomatal Opening of Water-stressed and Unstressed Apple Seedlings I. Complete Nutrient Sprays1
Authors: Swietlik Dariusz , Faust Miklos , Korcak R. F.
Published: August 2022

Solution cultures altered with polyethylene glycol to induce a water stress of− 1.0 bar decreased net photosynthesis (Pn) and stomatal conductance (Cs) in the leaves of ‘York Imperial’ apple seedlings (Malm domestica Borkh.). Sprays with a complete nutrient solution produced similar responses and further decreased Pn and Cs in water-stressed plants. It appeared from the mesophyll conductance (Cm) calculation that reduction in Pn rate in water-stressed, as well as sprayed trees, was not caused solely by a stomatal factor. It is not known, however, whether nonstomatal limitation of Pn reflects a decreased capacity for CO2 fixation or increased light respiration, since mesophyll conductance was calculated assuming constant (zero) sink CO2 concentration in the leaf. In another experiment, decreasing to − 1.0 bar water potential of nutrient solution reduced daily water consumption and fresh weight of ‘York Imperial’ apple seedlings. Sprays with complete nutrient solution also tended to decrease daily water consumption of plants. Water stress decreased leaf Ca and root K and Mg concentrations, indicating that water stress may lower the absorptive capacity of the roots. However, water-stressed plants contained more Ca in the roots than unstressed plants, suggesting that lower leaf Ca concentration in stressed plants was caused by suppressed transport. Leaf sprays with complete nutrient solution increased Mg concentration in the leaves and stems and Ca concentration in the leaves.