bluuebunny/crossref_metadata_2025 huggingface dataset:
A Nondestructive Method for Measuring Ripeness and Detecting Core Breakdown in ‘Bartlett’ Pears1
Authors: Wang C. Y. , Worthington J. T.
Published: August 2022

Difference in optical density (∆OD) of intact ‘Bartlett’ pears (Pyrus communis L.) between wavelengths 690 and 740 nm was measured at harvest and during ripening with a single-beam multiwavelength spectrophotometer. The ∆OD indicated the status of ripeness and detected core breakdown of ‘Bartlett’ pears nondestructively. The ∆OD decreased consistently with ripening and was associated with softening, climacteric rise in respiration, and ethylene production. The ∆OD increased in pears with core breakdown even before external symptoms were visible.
Respiration and Ethylene Production in Fruits of Species and Cultivars of Psidium and Species of Eugenia1
Authors: Akamine Ernest K. , Goo Theodore
Published: August 2022

Fruits of 4 species and cultivars of guava (Psidium guaiava L. cv. Beaumont, P. cattleianum Sabine, P. cattleianum f. lucidum Degener, and P. guajava L. cv. Allahabed Safeda) were found to be climacteric in their respiratory behavior with C2H4 triggering the respiratory rise. Fruits of 4 species of Eugenia (Eugenia malaccensis L., E. cumini (L.) Druce, E. uniflora L., and E. jambos L.) exhibited typical respiratory behavior of nonclimacteric fruits including the response to exogenous C2H4 treatments. The possibility of using respiratory data as a physiological tool for taxonomic differentiation of plants is discussed.
Honey Bee Foraging and Resultant Seed Set among Male-fertile and Cytoplasmically Male-sterile Carrot Inbreds and Hybrid Seed Parents1,2
Authors: Erickson E. H. , Peterson C. E. , Werner Patricia
Published: August 2022

A study of foraging by honey bees (Apis mellifera L.) among cytoplasmically male-sterile and malefertile seed parents of carrot (Daucus carota L.) revealed that honey bee discrimination between the fidelity to carrot phenotype and genotype were evident and often extreme. Some lines were extensively visited while others were virtually ignored. Wide differences in seed set were evident among male-sterile F1’s and inbreds and malefertile lines. Differences in seed yield were correlated with foraging preferences, but the quality of nectar from the stomachs of bees was not.
Differential Reaction of Leaves and Pods of Phaseolus Germplasm to Strains of Xanthomonas phaseoli and Transgressive Segregation for Tolerance from Crosses of Susceptible Germplasm1
Authors: Valladares-Sanchez Nicolas E. , Coyne Dermot P. , Schuster M. L.
Published: August 2022

The leaf and pod reactions of greenhouse-grown plants of reportedly tolerant lines of P. vulgaris L.: Plant Introduction (PI) 169727, PI 197687, PI 163117, PI 207262, PI 325684, PI 325691, ‘Great Northern Nebr. #1 sel. 27’; P. coccineus: PI 165421 and P. acutifolius: Tepary (Nebr. Acc. 10) to Xanthomonas phaseoli (E. F. Smith) Dowson isolates [Xp-S and Xp 816 (Nebr.), Xp-15 (Michigan), Xp-Br (Brazil)], and X.p. fuscans (Burkh.) Starr & Burk. [Xpf-UI (Uganda)], were studied. The multiple needle method was used to inoculate leaves and a dissecting needle was used to inoculate pods of these plants. A differential reaction of lines to isolates was observed for each of the reactions on leaves and pods. All P. vulgaris lines were susceptible or moderately susceptible to the new virulent Xp-Br strain. Leaves and pods of P. acutifolius were highly tolerant to all isolates while P. coccineus PI-165421 showed a differential reaction to all isolates: leaves were highly tolerant and pods highly susceptible. The internal reaction for pods was more severe than the external reaction. P. vulgaris PI 207262 showed a uniform tolerance of leaf and pod to the USA isolates, while ‘GN Nebr. #1 sel. 27’ had a tolerant leaf and susceptible pod. These results suggested differential genetic control of pod and leaf reactions. Transgressive segregation for a high level of leaf tolerance to the virulent Xp-Br strain (water soaking method of inoculation) was observed in field-grown P. vulgaris F2 plants from the crosses ‘GN Nebr. #1 sel. 27’ × PI 163117 and ‘GN Nebr. #1 sel. 27’ × ‘Guali’. Transgressive segregation was confirmed in greenhouse-grown selected F3 families. High leaf tolerance was not associated with pod tolerance. Linkage was detected among the major genes controlling late maturity and indeterminate plant habit, and the polygenes controlling common blight tolerance.
Breeding Strawberries for Fruit Firmness1
Authors: Barriti Bruce H.
Published: August 2022

Heritability estimates for fruit firmness of strawberry (Fragaria × ananassa Duch.) based on the regression of mean offspring performance on average parent performance varied from 0.49 to 0.67 over a 4 year period. Analysis of variance of progeny data showed that general combining ability variance (additive) was much greater than specific combining ability variance. Of 29 parent clones studied ‘Holiday’, ‘Linn’, ‘WSU 1522’ and ‘MD-US 3184’ had the firmest fruit and on the basis of progeny analysis had the highest general combining ability parental values. Low parental values were obtained for ‘Tamella’, ‘Benton’, ‘Puget Beauty’, ‘WSU 1019’, ‘OR-US 3291’ and ‘OR-US 3522’.
Effects of Big Vein Resistance and Temperature on Disease Incidence and Percentage of Plants Harvested of Crisphead Lettuce1
Authors: Ryder Edward J.
Published: August 2022

In 5 spring trials, the percentage of lettuce plants (Lactuca sativa L.) showing big vein symptoms was consistently low for the resistant line 72-136 and consistently high for the susceptible ‘Great Lakes 65.’ Results were less consistent for the moderately resistant ‘Merit’ and for ‘Calmar.’ During periods of low temperatures a lower percentage of big vein infected plants than healthy plants was harvested. Results were variable at high temperatures but, in general, differences were less.
Effects of Photoperiod on the Yield and Composition of Peppermint Oil1
Authors: Clark R. J. , Menary R. C.
Published: August 2022

Peppermint (Mentha piperita L.) was grown under growth room conditions with two photoperiodic treatments, short day and long day. Each treatment received a total of 13 hours light per 24 hour cycle, either continuously (13H) or as an interrupted night treatment (131) with 1 hour of light in the middle of the dark period. In addition to the previously reported changes in dry matter yield of herb, oil yield, growth habit and flowering, the photoperiodic treatments strongly influenced the proportions of several individual monoterpenes in peppermint. The long day treatment resulted in reduced levels of menthofuran, pulegone, menthyl acetate and limonene as well as increased levels of menthone, menthol, neo menthol acetate (+ unknown), trans-sabenine hydrate, cineole and β pinene + sabenine.
The Importance of Harvest Date and Plant Density on the Yield and Quality of Tasmanian Peppermint Oil1
Authors: Clark R. J. , Menary R. C.
Published: August 2022

Oil yield of peppermint (Mentha piperita L.) per unit area obtained from plant density treatments 30 and 40 plants/m2, reached a maximum early in the growing season, whereas oil yield from the lower density treatment, 10 plants/m2, continued to increase even at a menthol content of 50%. The latter density treatment yielded less oil per unit area. At the 2 highest densities, herb harvested at a stage when oil contained 45% free menthol resulted in maximum oil yield and optimum oil quality. Delaying harvest once the above stage had been reached resulted in increased levels of menthol but at the expense of increased levels of menthofuran and decreased oil yields. As the growing season progressed, menthol and menthyl acetate contents of oil increased while menthone decreased. This effect was accelerated at the high plant densities.
Factors Associated with Surface Pitting of Sweet Cherry1,2
Authors: Facteau T. J. , Rowe K. E.
Published: August 2022

Six annual surveys indicated that % soluble solids and fruit weight were the only consistent predictor variables for fruit surface pitting in ‘Lambert’ sweet cherry (Prunus avium L.). Both were inversely related to pitting. Similar associations were found ‘Bing’ when fruit were handled excessively. In spite of tree-to-tree variation, the degree of pitting was relatively uniform in a given orchard in a given year. High and low percentage pitting orchards appeared to be fairly consistent over the 6 years, but intermediate ones were extremely variable. Postharvest factors (time delay prior to storage, hydrocooling temperature, or storage temperature) had little or no effect on surface pitting. Foliar sprays of gibberellic acid (GA3 or GA4+7) applied 3 weeks prior to harvest increased fruit firmness and reduced color. Gibberellic acid sprays reduced pitting when the disorder was present (1974 and 1976) or where the fruit were bruised. Mechanical bruising of cherries increased the incidence of pitting. Surface pitting of sweet cherries may be caused by bruising but fruit characteristics (% soluble solids, size and firmness) can indicate whether or not pitting may occur on bruised fruit.
The Development of Standard Ranges for Leaf Nitrogen in the Filbert1
Authors: Chaplin M. H. , Dixon A. R.
Published: August 2022

Nitrogen, as urea, was applied to filbert (Corylus avellena L.) trees at the rates of 0, .68, 1.36, and 2.72 kg N/tree/year from 1971-1977. Nitrogen applications significantly increased leaf N, yield, and tree size. Leaf P levels were reduced by N applications in all years. Soil pH, measured after 7 years of N application, significantly declined as N application rate increased. Leaf Mn levels were increased by N applications in all years, probably due to the decrease in soil pH. Yields were expressed as a quadratic function of N and the standard ranges for leaf N in filbert were categorized as follows: deficiency (visible symptoms present) < 2.0% dry weight; below normal 2.0 − 2.2%; normal 2.2 − 2.4%; above normal > 2.4%.
Effects of Row Spacings, Fertilizers, and Harvest Dates on Table Beets1
Authors: Mack H. J.
Published: August 2022

Yield and size grades of table beets (Beta vulgaris L.) as affected by row spacings of 60, 45, 30, and 15 cm, fertilizer rates and harvest dates were determined in 4 field experiments. Total yields were significantly lower from 15 cm rows than from the conventional 60 cm row spacing. Highest yields of small roots, 25-51 mm diame-ter, were produced from narrow rows. Delaying harvest increased total and weighted yields. Fertilizer rates were varied in 3 experiments, and increasing the fertilizer rate increased total yields in 2 experiments. Concentration of N in leaves was decreased as row spacings were decreased in 2 experiments but P concentration in leaves was highest in 15 cm rows. Leaf concentration of N was highest at the highest fertilizer rate but K concentration was lowest. Concentrations of other elements in leaves were not consistently affected by row spacings or fertilizer rates.
Descriptions, Genetics, and Independent Assortment of Red Stem and Pale in Muskmelon (Cucumis melo L.)1
Authors: McCreight J. D. , Bohn G. W.
Published: August 2022

Red stem, found in PI 157083, is controlled by a single recessive gene, r. Red pigment appeared in vascular traces of hypocotyls about 2 weeks after planting. Seed coat color of red-stemmed plants was reddish or tan, in contrast to white or yellow seed coats of green-stemmed plants. Pale, a spontaneous mutant in a second backcross hybrid from ‘Campo’ × PI 180280, is controlled by a single partially dominant gene, Pa, which acts as a recessive lethal: Pa/Pa plants die; Pa/+ are pale; and +/+ are normal. Pale did not affect expression of red stem. Testcross segregations fit the expected ratio for independent assortment of the 2 loci.
Plant and Row Spacing, Mulch, and Fertilizer Rate Effects on Watermelon Production1
Authors: Brinen G. H. , Locascio S. J. , Elmstrom G. W.
Published: August 2022

The effects of plant and row spacing, mulch, and fertilizer rate on ‘Charleston Gray’ watermelons [Citrullus lanatus (Thunb.) Matsum. & Nakai] were evaluated in field studies on 2 Florida sandy soils. Marketable fruit yields decreased while yield/plant and mean fruit weight increased with an increase in plant spacing from 0.6 to 2.4 m and row spacing from 1.5 to 4.5 m. On a Kanapaha sandy soil with adequate water, yields and mean fruit weights were higher with mulch than without and with 1680 than 840 kg/ha of 12-7-13 (N-P-K) fertilizer.
Water Relations and Yields of Three Rabbiteye Blueberry Cultivars with and without Drip Irrigation1
Authors: Andersen P. C. , Buchanan D. W. , Albrigo L. G.
Published: August 2022

Drip irrigation applied to cultivars of rabbiteye blueberry (Vaccinium ashei Reade) maintained soil moisture at 25 to 35%, (volume basis), –0.07 bars soil-water potential while no irrigation resulted in 12.5% soil moisture, –2 to –3 bars. Irrigation reduced leaf diffusive resistance (rL) by 50% and increased transpiration (T) by 70% but had no significant effect on midday stem xylem pressure potentials (ψx). Both yield and berry weight from irrigated plots were increased from 20 to 25% over those on nonirrigated plots. Seasonal changes in ψx, rL, and T of nonirrigated bushes suggested this species has some characteristic adaptations to drought conditions, one such adaptation being wax rodlets observed in and adjacent to stomatal pores. These may have contributed to a favorable water balance under stress by increasing leaf diffusive resistance.
Determination of Several Elements in Orchid Plant Parts by Neutron Activation Analysis1
Authors: Yamaguchi S.
Published: August 2022

Concentrations of several elements in orchid plants (Dendrobium nobile Lindl) were determined by instrumental neutron activation analysis, a rapid and sensitive method for Na, K, Mg, Ca, Mn, Zn, Fe, Cl and Br. Among young and old leafless shoots, an increase in content of Br and a decrease of Fe and Zn were found with age.
Nitrate Compensation Points of Several Plum Clones and Relationship to Nitrate Uptake Effectiveness1
Authors: Therios Ioannis N. , Weinbaum Steven A. , Carlson Robert M.
Published: August 2022

The Nitrate Compensation Points (NCP) of 4 plum clones, Marianna 2624 (Prunus cerasifera Ehrh. × P. munsoniana Wight & Hedr.?), M-17 (P. cerasifera × P. munsoniana?), Myrobalan 3-J (P. cerasifera) and Myrobalan B. (P. cerasifera) were determined following depletion from aerated nutrient solutions. Differences among NCP's were statistically significant; however, since the NCP's were low (ca. 5 μm ) relative to the [] of typical agricultural soils, the relevance to uptake effectiveness under field conditions remains unresolved. Maximum influx took place above 20 μm , but 15 hour exposures to higher ambient [] resulted in higher NCP's. Both decreased influx and increased efflux of may have contributed to higher NCP.
Some Characteristics of Water Flow through Isolated Rose Stem Segments1
Authors: Durkin Dominic J.
Published: August 2022

Water flow through isolated 5 cm stem segments of rose (Rosa hybrida L. cv. Cara Mia) increased for 4-7 hours and then decreased linearly for several hours thereafter. Decreased rate of flow has been termed blockage rate. Flow rates varied inversely with segment length and directly with head pressure but blockage rates were unaffected by either variable. Maximum flow increased and blockage rates decreased as solution pH was decreased over a range from pH 6 to pH 3. Flow rates at 3°C were about half of flow rates at 24° and the addition of sucrose to the solution further reduced flow. Viscosity differences account for the flow rate decrease at lower temperature but did not account for the sucrose effect. Millipore filtration of water from a variety of sources resulted in substantial increase in flow rates.
Foliar Uptake of Nutrients by Selected Ornamental Plants1
Authors: Paparozzi Ellen T. , Tukey H. B.
Published: August 2022

Rooted cuttings of Pilea cadierei Gagnep. & Guillaum., Chrysanthemum morifolium Ramat. cv. Giant #4 Indianapolis White, Hedera helix L. cv. Thorndale, Pachysandra terminalis Siebold & Zucc. and young plants of Juniperus chinensis L. cv. Mint Julep and Ligustrum X vicaryi were exposed for 3 weeks to either water mist or mist to which a complete all soluble fertilizer (23N-8P-14K) was added; roots and root medium were protected from the mist. The N, P and usually K content of all plants increased after foliar application of nutrients. Pilea, pachysandra and Hedera increased in height, dry weight, and number of lateral breaks; privet increased in height and overall greening of the foliage occurred. The optimum concentration of foliar-applied nutrients was 600 ppm for Pilea, 750 ppm for Hedera and pachysandra and 300 ppm for Ligustrum; higher concentrations caused foliage injury. Injury occurred to chrysanthemum and juniper at all concentrations studied. Cuticle thickness and plant tolerance to foliar nutrition were not correlated.
Rates of CO2 and Ethylene Production and of Ripening of ‘Honey Dew’ Muskmelons at a Chilling Temperature after Pretreatment with Ethylene1
Authors: Lipton Werner J. , Aharoni Yair , Elliston Elizabeth
Published: August 2022

‘Honey Dew’ muskmelons (Cucumis melo L.) treated with ethylene (1000 ppm) ripened more rapidly than did untreated melons during a 24-hour treatment at 20°C and during a subsequent 15 to 19 days at 2.5°, a chilling temperature. During the exposure to ethylene, the respiration rate was substantially higher in treated than in control melons, but the rates differed little during subsequent storage in normal air at 2.5°. Ethylene production was lower in treated than in control melons during storage at 2.5°, even though ethylene evolution was stimulated by the initial ethylene treatment. The Hunter a/b ratio of the surface color decreased significantly during the 24-hour ethylene treatment, which indicates that ripening had progressed during the treatment.
Effects of Pinching on Growth and Floral Initiation and Development of Container-grown Rhododendron1
Authors: Purohit Amul , Dunham C. W.
Published: August 2022

Plants of Rhododendron × catawbiense Michx. cvs. Chionoides, Roseum Elegans, and Nova Zembla were cut back on May 14, 1974 and terminal buds removed at 2-week intervals throughout the summer starting on June 14 and examined microscopically for floral initiation and development. First evidence of floral initiation was found in samples taken on July 15 for ‘Chionoides’ and August 1 for ‘Roseum Elegans’ and ‘Nova Zembla’. Floral development continued in the buds of all cultivars into October, at which time buds were well developed and at the rest stage. The number of breaks resulting from removal of terminal buds was the greatest on plants pinched on August 1 and August 15. The percentage of breaks forming flower buds decreased on plants pinched after August 1 and no flower buds were formed on plants pinched after August 15.
Estimating Yield and Fruit Numbers of Apple Trees from Branch Samples1
Authors: Forshey C. G. , Elfving D. C.
Published: August 2022

Yield and fruit numbers data were collected from whole trees and sample branches in 4 orchards of 3 cultivars of apple (Malus domestica Borkh.) over a 4-year period. Coefficients of correlation between yield/tree and (crop load × geometric mean of trunk circumference and trunk cross-sectional area), and between number of fruits/tree and (fruit set × geometric mean of trunk circumference and trunk cross-sectional area), were 0.91 and 0.93, respectively. Using regression analyses, the error of estimate for individual trees was ±11.0% for yield/tree and ±10.4% for number of fruits/tree. The corresponding values for treatment means were ±6.4% and ±5.4%, respectively.
Attempting Chemical Induction of Haploidy Using Toluidine Blue1
Authors: Al-Yasiri S. , Rogers O. M.
Published: August 2022

Earlier references reported that toluidine blue would prevent the division of the generative nucleus in developing pollen tubes. These references suggested that a concommitant event might be stimulation of the embryo without fertilization resulting in the practical production of haploid seed. A test of this premise in tomatoes and corn is described herein. Haploids were not produced in excess of spontaneous levels. The probable cause is that fertilization of the diploid fusion nucleus does not occur. Thus there is no endosperm to provide a food supply for the embryo.
Iron - Manganese Relations of ‘Sungold’ Peaches in Western Colorado1
Authors: Rogers Ε well
Published: August 2022

Ammonium sulfate at 1620 and 2700 g and ammonium sulfate at 1620 g plus 56, 113, or 226 g per tree sodium ferric ethylenediamine di-(o-hydroxphenylacetate) or ammonium sulfate at 1620 g plus 136 or 272 g FeSOFeSO4 per tree were applied in April 1964 to 1966, inclusive, to ‘Sungold’ peach trees in Western Colorado. Sodium ferric ethylenediamine di-(o-hydroxphenylacetate) at 56, 113, and 226 g plus 1620 g ammonium sulfate significantly depressed the uptake of Mn in ‘Sungold’ peach trees. These treatments corrected iron chlorosis. All Ν treatments increased the Ν of the leaves. The treatments had no significant effect on Zn uptake, trunk or shoot growth or size, yield, and color of fruit.
Influence of Seeding Rate, Source and Level of Nitrogen on Collards1
Authors: del Valle C. G.
Published: August 2022

Yield, color, petiole-blade ratio, and percentage of fiber and Ν were evaluated for collards (Brassica oleracea L. var. acephala), grown under field conditions. The yield, color, and Ν percentage in tops were increased as the Ν level was increased from 40 to 160 lb N/A. A split application of 80 1b. N/A at planting and 80 1b 20 days after planting gave the best yield. Best color was obtained at seeding rates of 2 or 4 1b/A. Leaf color decreased as the seeding rate increased from 2 to 8 1b/A. The petiole-blade ratio and fiber percentage were not significantly affected by the seeding rate or level and source of N. It was possible to obtain equally good yields and color with NaNO3, (NH4)2SO4, or NH4NO3.
Regulation of Endogenous Indoleacetic Acid and Keeping Quality of Poinsettia1
Authors: Gilbart David A. , Sink Kenneth C.
Published: August 2022

A study was made of the changes with aging in the level of endogenous auxin and the activity of IAA-oxidase in the bracts of two poinsettia cultivars. The auxin level decreased with time in both cultivars but faster in the poor keeper. The activity of the IAA-oxidase system and the level of hydrogen peroxide increased with aging. The auxin level could be related to the activity of IAA-oxidase, which in turn could be related to the appearance of new forms of peroxidase. A hypothesis is developed to explain differences in keeping quality among poinsettia cultivars based on changes in the level of endogenous auxin.
The Relation of Physiological Stage, Preconditioning, and Rate of Fall of Temperature to Cold Injury and Decline of Peach Trees1
Authors: Daniell Jeff W. , Crosby Frederick L.
Published: August 2022

Freezing tests were conducted on 1-year-old ‘Elberta’ peach trees during the dormant season. The degree of injury was recognized by discolored cambial area, bud mortality, vegetative vigor of buds, and retardation of leaf development. Plants preconditioned at 70° until new tissue was evident and then subjected to low temperatures were injured more severely than those not preconditioned. The freezing rate had a greater effect on the degree of injury than the minimum temperature reached within the range tested. Severity of injury at a given temperature was associated with the physiological stage of the trees. Plants exhibited more injury when frozen just prior to a natural “leaf expansion” than at periods earlier in the dormant season, even though the plants were preconditioned to the same apparent growth state. These data along with data on natural temperature conditions in a region where peach-tree decline is severe are discussed in relation to peach-tree decline.
Growth of Seeded and Seedless Pistachio Nuts1
Authors: Crane Julian C. , Bradley Muriel V. , Nelson M. M.
Published: August 2022

As with most other drupe fruits, curves representing growth in length and diameter of seeded pistachio nuts reveal 3 distinct periods, 2 cycles of rapid growth separated by 1 of slow growth. Growth curves of seedless pistachios, however, are similar to those of almond (a dry drupe) in which a rapid growth phase is followed by one of inconsequential growth. Embryo development in the pistachio is delayed longer than in other drupes; it is not evident macroscopically until about 30 days after completion of the initial period of pericarp growth. Seedlessness, the symptoms of which are not manifest until after most pericarp growth has occurred, frequently appears to be associated with necrosis of the apical portion of the funiculus supporting the seed, and consequent seed abortion.
Factors Influencing the Cold Hardiness of Taxus cuspidata Roots1,2
Authors: Mityga H. G. , Lanphear F. O.
Published: August 2022

The root system of Taxus cuspidata Sieb, and Zucc. exhibited zones of varying cold hardiness. Root hardiness was greatest in sections close to the stem while the root tips were least hardy. The light-colored young roots did not develop hardiness under any of the environmental treatments. Hardiness of the dark mature roots was usually similar to that of the leaves. Under natural conditions mature root hardiness was greater than −29.0°C. Daily application of Alar3 as a soil drench, increased the hardiness of young roots to the hardiness level of mature roots. Amo 16184 was less effective and significantly decreased the hardiness of mature roots. Mature roots from girdled plants did not develop hardiness, indicating their dependence on the top of the plant for development of root hardiness. Roots dehardened more slowly than leaves in the spring.
Susceptibility of Lycopersicon spp. to Ozone Injury1
Authors: Gentile A. G. , Feder W. A. , Young R. E. , Santner Z.
Published: August 2022

Accessions, breeding lines, and varieties of Lycopersicon spp. and one accession of Solarium pennellii Correll were evaluated for sensitivity to controlled concentrations of O3 and to ambient air at Waltham, Massachusetts. The plant material was exposed in different stages of development to controlled O3 concentrations of 0.25 ppm for 3 hours, 0.05 ppm for 2 weeks and to 0.10 ppm for 4 weeks. Based upon the degree of foliar injury, the tested material was separated into tolerant, intermediate and sensitive populations. The highest degree of tolerance was observed in L. esculentum Mill, and the highest degree of sensitivity in L. pimpinellifolium. Germination of pollen from inflorescences exposed to 0.10 ppm was reduced 40% in sensitive accessions of L. pimpinellifolium when placed on artificial medium. No significant reduction was observed in the most tolerant accession of L. esculentum. Differences in percent germination were not observed when pollen of sensitive and tolerant accessions was placed on artificial medium and exposed to 0.10 ppm O3 for a six-hour period. Reciprocal cross pollinations between exposed and unexposed populations led to normal fruit development with viable seeds.
Effects of Trunk and Rootstock on Decline, Growth and Performance of Pear1
Authors: Westwood M. N. , Cameron H. R. , Lombard P. B. , Cordy C. B.
Published: August 2022

Pear plots established in 1923 and 1926 with trees composed of several rootstock and trunk combinations were assessed for tree size, susceptibility to pear decline and for fruit quality. In general, Pyrus ussuriensis Max. and P. pyrifolia Burm. & Nak. rootstocks resulted in small trees, P. communis L. and P. calleryana Decne. intermediate, and P. betulaefolia Bunge large. The latter was most resistant to decline, followed by P. calleryana and P. communis, with P. pyrifolia and P. ussuriensis susceptible. The use of the oriental hybrid cvs. Variolosa and Tolstoy as interstocks increased the severity of pear decline symptoms though all trees were not uniformly susceptible. The use of the P. communis cv. Old Home as a scion rooted trunkstock decreased the degree of decline. Fruit quality was good on most combinations but was generally better on P. calleryana than other rootstocks. Pyrus betulaefolia caused cork spot and poor quality of ‘Anjou’ but this same rootstock resulted in outstanding quality of ‘Seckel’.
Berry Response of ‘Thompson Seedless’ and ‘Perlette’ Grapes to Application of Gibberellic Acid1
Authors: Weaver Robert J. , Pool Robert M.
Published: August 2022

At a stage just after bloom, gibberellin (GA3) at 600 ppm induced maximum increase in berry size of ‘Thompson Seedless’ grapes. Seven days after fruit-set, only 25 ppm were required for maximum response. In both instances, regression lines of best fit between GA3 concentration and berry weight indicated a logarithmic response. At both late bloom and early fruit-set stages there was a large increase in berry size, but at a time halfway between these stages the response to GA3 was much less striking. After fruit-set there was a gradual decrease in response to GA3. Increase in berry size due to girdling, on both vines sprayed at bloom and fruit set with GA3 and on unsprayed vines was maximum when berry diameter was 3-10 mm at time of girdling. There was no interaction between berry response to girdling and to gibberellin application. At fruit-set, ‘Perlette’ berries generally responded to increases in GA3 concentration up to 600 ppm.
The Effect of Light Intensity on the Soluble Carbohydrate Level and Macronutrient Composition of Ilex opaca Ait.1
Authors: Fretz Thomas A. , Dunham Charles W.
Published: August 2022

Soluble leaf carbohydrates, macronutrient elements and growth responses to 3 levels of light were studied on field grown plants of Ilex opaca Ait. cv. Miss Helen. Soluble D-fructose, α-D-glucose, B-D-glucose and sucrose reached a maximum concentration expressed as a percentage of the dry weight of leaf tissue during the winter sampling periods, followed by a decline as bud-expansion approached. The maximum concentration of soluble D-galactose was found in newly matured leaf tissue. Soluble D-fructose, α-D-glucose, B-D-glucose and sucrose levels were not effected by the shade environments. The level of D-galactose increased under the shaded environment as compared to full sun plants.

P and K levels in the leaf tissue were at high concentrations in newly matured leaf tissues, while Ca and Mg were at low levels. Both K and Mg levels were observed to be higher in leaf tissue from plants grown under the 92% shade conditions compared to full sun plants.

Stem diameter was significantly reduced under the 92% shade conditions, while leaf size of plants grown under both 50% and 92% shade was significantly increased. Flower production was significantly reduced in plants grown under the 92% shade conditions.
Phosphorus Utilization From Internal and External Sources In the Growth of Woody Ornamental Plants1
Authors: Meyer Martin M.
Published: August 2022

The influence of P applications on the growth of Berberis x mentorensis L. M. Ames, Juniperus chinensis ‘Keteleeri’ Cornman, and Taxus x media ‘Hicksii’ Rehd., was studied for 2 growing seasons. During one summer P was applied at varying rates to plants grown in containers and the growth and P content of various plant parts were determined. The following spring the roots of these dormant plants were washed free of the growing medium and the plants were grown in solution culture at varying levels of P labeled with P32. The spring growth, the P content of all plant parts, and the % P coming from the solution into all plant parts during the spring were determined. Phosphorus applied during the summer caused little growth response except with young Taxus plants receiving a high P level. There were several significant growth responses during the spring due to P applications the previous season. A high P concentration during the spring increased the growth of some plants, but Taxus plants with a high internal P status showed little response. The P coming into the new spring growth from solution varied from 0 to 86% depending on the plant species used and the concentration around the roots. In Berberis the majority of the rest of the P moving into new growth originated from reserve P in the roots. In Juniperus the majority of the internally redistributed P came from the foliage and in Taxus both the foliage and roots were important sources of reserve P.
Associations Between Physical Soil Properties and Soluble Solids in Cantaloupes1
Authors: Davis R. M. , Schweers V. H.
Published: August 2022

Concentrations of soluble solids (SSC) in fruits of Cucumis melo L., cv. PMR 45, were positively correlated with 2 physical measures of soil samples from producing fields: a) the degree of cracking which occurred during dehydration, and b) the rapidity with which water or a CaSC>4 solution percolated the soils. Very low SSC was associated with sandy, non-cracking soils, which in addition permitted only low rates of percolation. Low SSC also was found to be associated with soils having subsurface hardpans or dense subsoil strata, and also with the distance to lower bounds of plant containers and experimentally placed barriers which obstructed downward root growth. SSC, under adverse conditions, varied further as a function of fruit numbers per plant.
Inheritance and Physiology of Response to Low Boron in Red Beet (Beta vulgaris L.)1
Authors: Tehrani G. , Munger H. M. , Robinson R. W. , Shannon S.
Published: August 2022

Genetic variation in foliar symptoms of B deficiency in the seedling stage of red beet was observed among inbred lines and commercial cultivars grown in sand culture in growth chambers. F1, F2 and backcross populations between the most susceptible and tolerant lines, tested at .001 ppm B, indicated that susceptibility was conditioned primarily by a single dominant gene. No linkage was established between this gene and the gene controlling red leaf color.

The most susceptible line was inherently more vigorous than the most tolerant line but this relationship was not evident among the other inbreds and cultivars tested.

Boron deficiency sumptoms on leaves of both tolerant and susceptible lines were significantly accentuated by reducing the Ca(NO3)2 content of the nutrient solution from 8 to 7 mEq/litre without altering B content. At both Ca levels the B content was greater in the tolerant than in the susceptible line. When supplied with adequate Ca but low B the susceptible line contained higher Ca, Na and P and lower Mg than the tolerant line.
Hormone-Directed Transport of 32P in Malus sylvestris Seedlings1
Authors: Hatch A. H. , Powell L. E.
Published: August 2022

Studies were conducted to determine the effect that plant hormones such as auxins, gibberellins, and cytokinins might have on the mobilization of 32P in apple seedlings grown in the greenhouse. Prior to the hormone treatments the seedlings were defoliated and the apex removed to avoid competition. Experiments with 32P indicated that auxins, gibberellins, and cytokinins could direct the transport of 32P especially when used in various mixtures. It was found that 32P could be mobilized acropetally, basipetally, and into and out of leaves depending on the area treated with the hormones. Their effect in mobilizing 32P was less evident in seedlings that had ceased growth, with subsequent terminal bud formation, than in growing seedlings. It was also found that 32P was mobilized through the phloem and required the synthesis of protein.
Sequential Development of the ‘York Imperial’ Apple As Related to Tissue Variances Leading to Corking Disorders1
Authors: Simons Roy K. , Hewetson Frank N. , Chu Mel Chih-Yu
Published: August 2022

Anatomical changes in ‘York Imperial’ apples were studied sequentially throughout the growing season to discover tissue variances occurring within the fruit at different stages of development. Several abnormalities have occurred during fruit enlargement, some of which may develop into corking disorders, including bitter pit and cork spot. Cellular abnormalities appeared contiguous to large lacunae, senescing vascular bundles or in tissues where cell proliferation was apparent.

Abnormalities adjacent to necrotic vascular bundles in the outer cortical region were apparent early in. the life of the fruit, by 14 days after full bloom. Changes in cellular structure continued 65 days after full bloom from the outer cortex to the epidermis, and extended to the bundles underlying this area. Cell division had ceased, and the cell walls were thick with a distinct demarkation line between the affected and unaffected tissues. Tissues of the basin region were susceptible to the development of corking disorders, while senescent vascular bundles and meristematic tissues were evident within the core line.

Necrosis of vascular bundles extended along the core line in the fruit apex 95 days after full bloom, and tissue proliferation occurred by 115 days. Fruit development 126 days after full bloom revealed large lacunae in the outer cortex and extreme cell proliferation resembling callus tissue in the cavity at the point of fruit-pedicel attachment.

Origin of corking disorders, visible on fruit nearing maturation (112 days after full bloom), could be traced from tissue anomalies in the outer cortex. The spots appeared irregular in outline, yellowish-green in color; while a glossy, scalded appearance surrounded this area. Meristematic activity of the parenchyma cells along the core line was apparent 126 days after full bloom.
Scanning Electron Microscope Studies of the Shoot Apex in Dianthus caryophyllus L. cv. Scania1
Authors: Emino E. R. , Rasmussen H. P.
Published: August 2022

Intact shoot apex development of the carnation was studied with a scanning electron microscope using fresh tissue. Reproductive meristems were more resistant to desiccation from the hard vacuum and electron beam than vegetative meristems. Vegetative meristems, however, can be studied if the work is done quickly.

Structural changes which occurred in the developing carnation shoot showed that leaf primordia are initiated in a circular whorl. Floral initiation was easily determined by the appearance of a flattened apex and a pentagonal whorl of sepal primordia. Subsequent centripetal initiation of flower parts was easily recognized and identified.
The Effect of Relative Humidity on Growth, Yield, and Water Consumption of Bean Plants1
Authors: O’Leary James W. , Knecht George N.
Published: August 2022

Red kidney bean (Phaseolus vulgaris L.) plants were grown continuously under 35-40%, 70-75%, or 95-100% relative humidity in growth chambers. There were no significant differences in fresh or dry weight of plants after 20 or 26 days’ growth in the chambers. Water consumption was significantly lowered by the highest humidity, and the dry weight produced per unit of water consumed was significantly greater in those plants grown at 95-100% relative humidity. After 47 days at the stated humidity levels, no significant differences were found in fresh or dry weight of the fruits. The only significant difference in seed dry weight was between the lowest and the medium humidity. The yield in the low humidity was 60% of that in the medium humidity. Thus, there are no significant reductions in either growth or yield of bean plants by continuous growth at near saturation relative humidity.
Biochemical Differences Between Embryonic Axes from Green and Sun-bleached Lima Bean Seeds: Synthesis of Carbohydrates, Proteins, and Lipids1
Authors: Abdul-Baki Aref A.
Published: August 2022

Green and sun-bleached seeds of cultivars ‘G 2’ and ‘Green Fordhook 861’ lima beans (Phaseolus lunatus L.) were analyzed for total chlorophyll in whole seeds, and for soluble protein and rates of synthesis of carbohydrates, proteins, and lipids in excised embryonic axes. Bleached seeds were lower in total chlorophyll than green seeds. Embryonic axes from bleached seeds synthesized less carbohydrates and proteins, but more lipids than embryonic axes from green seeds. When held in water for 3 hours, embryonic axes from ‘G 2’ lima beans had about 65% more soluble protein, and respired 20% faster than embryonic axes from ‘Green Fordhook 861’. Whole ‘G 2’ lima bean seeds also emerged faster than ‘Green Fordhook 861’ seeds. In each cultivar, green seeds had a higher percent emergence than bleached seeds.
Expression of Determinate Habit in Cucumbers (Cucumis sativus L.)1
Authors: Denna D. W.
Published: August 2022

Inheritance of determinate habit in cucumbers was reinvestigated using 3 different sources of the determinate character. The determinate genes in the 3 lines were allelic. The penetrance of a determinate gene when present in a single dose in the heterozygotes was dependent upon its relative dominance, the presence of modifiers, and the presence or absence of early fruit set.
Growth of Crabapple Seedlings in Controlled Environments: Effect of CO2 Level, and Time and Duration of CO2 Treatment1
Authors: Krizek Donald T. , Zimmerman Richard H. , Klueter Herschel H. , Bailey William A.
Published: August 2022

The growth of cutleaf crabapple [Malus toringoides (Rehd.) Hughes] seedlings was greatly accelerated by direct seeding under CO2-enriched atmospheres (400 or 2000 ppm) in controlled-environment chambers. CO2 treatment of 2000 ppm for 4 weeks from the time of seeding in the growth chamber produced the most striking results in terms of increase in node number and stem length. By the end of 4 weeks of treatment, stem lengths of seedlings treated for 4 weeks in the growth chamber with 2000 ppm CO2 were 3 times greater than those of plants grown at ambient CO2 (ca 350 ppm) in the greenhouse for 4 weeks, and 1.5 times greater than those treated in the growth chamber with 400 ppm CO2 for 4 weeks. The effect of CO2 enrichment on stem length was greater than that on node number. The stimulatory effects of CO2 enrichment persisted for 2-3 months after the plants were moved to the greenhouse at ambient CO2.
Effect of Light, Temperature, and Their Interactions on Germination of Seeds of Kentucky Bluegrass (Poa pratensis L.)1
Authors: Toole Vivian K. , Borthwick H. A.
Published: August 2022

The germination of Kentucky bluegrass, (Poa pratensis L.), seeds is profoundly influenced by two light reactions. One, the phytochrome reaction (P), is promotive, and the other, the so-called “high-energy reaction (HER)”, is inhibitory to germination. The level of germination displayed in 14 days as the resultant of these two opposing reactions is appreciably influenced by temperature.

In darkness, the seeds germinate well at certain temperature alternations but not at constant temperatures. At 15-25°C, the promotive effects of temperature alternation are accomplished in the first 5 to 6 cycles. The promotive effects of alternations are displayed in darkness when the daily period at 25° is between 4 and 14 hours.

Brief daily high-intensity fluorescent illuminances (approximately 4,000 ft-c) during otherwise continuous darkness at constant 20°C induce high germination in most lots. Continuous medium-to-high intensity illumination (approximately 1,200 ft-c) very weakly promotes germination and in potentially promoted seeds inhibits germination to about the level of the dark controls.

Inhibitory effects of continuous light on potentially promoted seeds are best displayed at 20°C constant although, in ‘Newport’ they are observable at 15-25°. The inhibition of ‘Newport’ at 15-25° is to a level below that of the dark controls but above that caused by prolonged illumination at 20°.

Thus conditions most promotive to germination are 15-25°C alternations and brief daily illuminances of high intensity. Simultaneous application of these 2 conditions causes higher germination than when either is applied alone and in one lot of ‘Newport’ the effects are strikingly additive.
Factors Influencing Chemical Characteristics of Peaches1
Authors: Cummings George A. , Reeves John
Published: August 2022

We determined the influence of fertilizer and cultural treatments upon peach flesh resistance to browning, soluble solids, titratable acidity, pH, and soluble ninhydrin-positive nitrogenous compounds. Nitrogen, P, K, and lime and severe pruning increased the resistance of macerated fresh fruit to browning. Soil profile modification and Mg application lowered browning resistance. Application of N or lime increased soluble solids in the fruit, but deep tillage decreased them. Soluble solids were higher when pruning was either less or more severe than that normally practiced. Titratable acidity was positively related to the application of P and K, but was decreased by N application. Application of K or lime increased pH whereas changing the N supply yielded inconclusive results. The soluble amino acids of the fruit were positively related to N supply and were reduced by K application. Interrelations of treatment effects upon the various components are discussed.
Effects of Water Quality on Canned Carrots, Sweet Cherries, and Apricots1
Authors: Chiang J. C. , Singh B. , Salunkhe D. K.
Published: August 2022

The chelating agents, monocalcium disodium salt of ethylenediaminetetraacetic acid (CaNa2EDTA) and sodium hexametaphosphate (Na-HMP), at 800 ppm, were used for canning ‘Honey Sweet’ carrots, ‘Van’ sweet cherries, and ‘Large Early Montgament’ apricots with water containing 0, 20, 40, 80, and 160 ppm of Ca and 20 ppm of magnesium. The control cans did not contain EDTA or Na-HMP.

The canned carrots, cherries, and apricots were stored at 70° or 100°F. Evaluations were made at 60-day intervals for 6 months. All 3 commodities had better organoleptic4 acceptibility when they were canned with CaNa2 EDTA or Na-HMP than the controls.

Carrots canned with CaNa2EDTA were firmer and retained better color than those canned with Na-HMP or the controls. The rate of loss of firmness and color increased with time of storage. Retention of firmness, volatile reducing substances, pH, and taste quality was improved in sweet cherries and apricots canned with CaNa2EDTA or Na-HMP.
Effect of Low Concentrations of Ozone and Sulfur Dioxide on Foliage, Growth and Yield of Radish1
Authors: Tingey David T. , Heck Walter W. , Reinert Richard A.
Published: August 2022

The radish cv. Cherry Belle was exposed to 5 pphm ozone and/or 5 pphm sulfur dioxide for 40 hr per week for 5 weeks and compared with controls grown in charcoal filtered air. Ozone and/or sulfur dioxide significantly reduced the plant fresh wt, leaf fresh wt, root fresh and dry wt and root length and width. The effects of the combinations of the 2 gases were additive except for plant fresh wt, root length and root fresh and dry weights where the effects were significantly less than additive. Low concns of ozone and sulfur dioxide can be significant factors in the growth and yield of radishes.
The Effect of Paraquat, Dinoseb and 2,4-D on Filbert (Corylus avellana L.) Suckers1,2
Authors: Reich J. E. , Lagerstedt H. B.
Published: August 2022

Foliar sprays of paraquat, dinoseb, and (2,4-dichlorophenoxy) acetic acid (2,4-D) each provided satisfactory control of filbert suckers. Paraquat and 2,4-D controlled vegetative regrowth to a greater extent than dinoseb. Use of oil with dinoseb increased its phytotoxicity towards filbert suckers.

Suckers should be treated when less than 1 foot in height and thoroughly wetted with spray. The herbicide 2,4-D controlled large suckers better than either paraquat or dinoseb. There was no evidence of injury to the mature trees following the use of these materials.