bluuebunny/crossref_metadata_2025 huggingface dataset:
The Inheritance of Parthenocarpy in Oregon T5-4 Tomato
Authors: Kean D. , Baggett J.R.
Published: August 2022

The inheritance of a tendency to set parthenocarpic fruit in tomato (Lycopersicon esculentum Mill.) line Oregon T5-4 (T5) was studied in the field in crosses with 3 normal, seeded cultivars. F1, F2, and backcross data indicated that the parthenocarpic tendency in T5 is recessive. F2 data fit a 9 seeded : 7 seedless ratio, indicating that normal seediness requires 2 complimentary dominant genes. Parthenocarpic plants were earlier than seeded plants. Early ripening in T5 crosses resulted in most instances from a reduced period of time from first flower to first ripe fruit, and not from early flowering. The F2 from a cross of T5 with ‘Severianin’, an unrelated parthenocarpic cultivar, approached a theoretical 27 seeded : 37 seedless for 3 complimentary gene pairs and demonstrated that parthenocarpic tendency is determined by different factors in these 2 parents.
Quantitative Inheritance of Plant Growth Habit in Blueberry Progenies
Authors: Luby J.J. , Finn C.E.
Published: August 2022

Genetic variance components, narrow-sense heritabilities, and general combining ability (GCA) effects were estimated for plant growth habit traits from a partial diallel cross among 17 blueberry (Vactinium corymbosum L., V. angustifolium Ait., and V. corymbosum x V. angustifolium hybrids) parents. Plant height, plant diameter, and a subjective stature rating were recorded for parent and progeny plants in 1984 after 9 growing seasons at Becker, Minn. General and specific (SCA) combining ability variances were significant for all traits. GCA variance components were larger than SCA components for height and stature rating, and heritabilities (family-mean basis) were 0.68 and 0.64, respectively, indicating the relative importance of additive genetic variance for these traits. Desired stature or height in this population should be recoverable through recurrent phenotypic selection. SCA variance components were much larger than GCA components for plant diameter measures, and heritability was low. Vaccinium angustifolium parents had very negative GCA effects for plant height and stature ratings, while parents with largely V. corymbosum ancestry had positive effects. Coefficients of determination between parental phenotype and GCA effects indicated that progeny performance should be predicted by parental phenotype for stature or height but not for diameter.
Intergeneric Hybridization in the Juglandaceae: Pterocarya sp. X Juglans regia
Authors: McGranahan G.H. , Tulecke W. , Arulsekar S. , Hansen J.J.
Published: August 2022

Intergeneric hybrids between wingnut (Pterocarya sp.) and walnut (Juglans regia) were developed by regenerating plants from somatic embryos produced on immature cotyledons of seed from control-pollinations. Hybridization was confirmed by isozyme analysis using starch gel electrophoresis. To the best of our knowledge, this is the first report of hybrids between wingnut, which has a high level of resistance to Phytophthora spp. and nematodes, and walnut. Wingnut may now be used as a source of germplasm for improving walnut rootstocks.
Influence of Cultivar and Temperature on Lima Bean Yield and Quality
Authors: Smittle Doyle A.
Published: August 2022

Experiments were conducted during 1981 and 1982 to determine the yield and quality responses of lima bean (Phaseolus lunatus L.) cultivars to air temperatures preceding harvest. Temperature conditions and cultivars that produced large lima bean plants at blossom increased seed yields. Quality parameters of seeds after separation into maturity groups by salt brine were influenced by cultivars and air temperatures. Sugar content, green color intensity, and chlorophyll content decreased as seeds matured. Sugar contents of ‘Nemagreen’, ‘Bridgeton’, and ‘Thorogreen’ were greater than ‘Kingston’ at comparable stages of maturity. Sugar content increased when air temperatures during the period of 0–7 days preceding harvest were high. Air temperatures were most closely related to sugar content of mature seeds. Chlorophyll content was closely correlated with tristimulus chlorimeter – a value. The chlorophyll contents at all maturities were reduced by high air temperatures preceding harvest. The average temperature during the period of 7–14 days before harvest had the greatest influence on the chlorophyll content. The influence of air temperatures on chlorophyll content during this period was 3 to 4 times greater for immature (25% total solids) than for mature (35% total solids) seeds, and minimum air temperatures were more closely correlated with chlorophyll contents than were maximum air temperatures. These results indicate that quality (intensity of green color) was affected more by high air temperatures than was seed yield. Chlorophyll contents were more closely related to minimum than to maximum air temperatures, indicating that the effect of high temperature would be increased in humid areas where night temperatures are high.
Influence of Nutritional Conditioning on Muskmelon Transplant Quality and Early Yield
Authors: Dufault Robert J.
Published: August 2022

Pretransplanting nutritional conditioning (PNC) regimes were evaluated for their effects on improving tolerance to transplant shock and increasing early fruit production. Muskmelon seedlings (Cucumis melo var. reticulatus L. ‘Magnum 45’) were fertilized twice weekly with solutions containing N, P, and K to determine nutrient needs required to produce high-quality transplants. Seedling height, stem diameter, leaf area, shoot and root dry weights, leaf number, and shoot: root ratios of 27-day-old transplants increased as N rates increased from 10 to 250 mg liter−1. These growth variables also increased with P from 5 to 25 mg·liter−1 but decreased as P increased from 25 to 125 mgliter−1. Increasing K rates from 10 to 250 mg·liter−1 increased seedling height, stem diameter, and leaf area. Nine PNC regimes ranging from low to high N-P-K status were tested under field conditions to determine any long-term advantage. Generally, as PNC levels increased, transplant shock (percentage of necrotic leaves) increased as measured 12 days after transplanting. However, vining, female flowering, fruit set, and early yields increased as PNC levels increased. A high level of PNC (250N-125P-250K, mg·liter−1) conditioned transplants to overcome shock and to resume growth sooner and yield earlier than those at lower PNC levels.
Studies on Abscission of Phthalimide-induced Parthenocarpic Sour Cherry Fruits
Authors: Retamales Jorge B. , Bukovac Martin J.
Published: August 2022

AC 94377 (alone and in combination with an auxin), GA3, and BA were evaluated for induction of parthenocarpy and subsequent retention of sour cherry (Prunus cerasus L. ‘Montmorency’) fruit. The persistence of AC 94377-treated fruit was enhanced by addition of CFPA or NAA, persistence and growth being greatest with AC 94377 (3.0 × 10−3 m) + CFPA (7.5 × 10−5 m). CFPA alone (7.5 × 10−5 m) often prevented abscission of flowers, but failed to induce significant fruit growth. Parthenocarpic fruit weighed 30-40% less than seeded fruit. Abscission of parthenocarpic fruit occurred primarily during June drop, and was reduced by an additional application of AC 94377 + CFPA with or without GA3 3 weeks after bloom. AC 94377 and NAA sprayed 2 and 3 weeks after full bloom did not affect the magnitude of June drop of open-pollinated fruit. The rate of fruit abscission was related to time after application, presence or absence of seeds, and relative position between seeded and parthenocarpic fruit. When AC 94377, GA3, and CFPA were applied in lanolin paste to defruited pedicels, only mixtures including CFPA reduced the abscission rate significantly. Chemical names used: l-(3-chlorophthalimido)-cyclohexanecarboxamide (AC 94377); 2-chloro,4-fluorophenoxyacetie acid (CFPA); N-(phenylmethyl)-lH-purin-6-amine (BA); gibberellic acid (GA3); 1-naphthaleneacetic acid (NAA).
Effects of Delayed Cooling and Delayed Low-ethylene CA Storage on the Keeping Quality of ‘McIntosh’ Apples
Authors: Liu F.W.
Published: August 2022

‘McIntosh’ apples (Malus domestica Borkh.) from trees field-sprayed with daminozide were kept in unstoppered 19-liter jars in air at 3.3°C for various periods of time before being sealed and exposed to low-ethylene controlled atmosphere (CA). Similar apples were kept in sealed jars with flow-through low-ethylene CA at 20° for various periods of time before being cooled to 3.3°. After the prestorage treatments of delayed establishment of low-ethylene CA storage (delayed CA) or delayed cooling, these apples were stored in the same jars with a flow-through simulated low-ethylene CA (2.5-3% O2, 3% CO2, <1 μl·liter−1 ethylene, 2.2°-3.3°) for 7.5 months. Delayed cooling or delayed CA for one to 4 days had little adverse effect on the keeping quality of the apples. Delayed cooling for 5 days or delayed CA for 5 to 7 days caused slight decreases in fruit firmness and acidity after storage and sometimes caused slight increases in ethylene production of the apples during storage. Delayed cooling for 7 to 11 days or delayed CA for 9 to 11 days often caused significant decreases in firmness and acidity and large increases in ethylene production. The adverse effect of extended periods of delayed cooling was greater than that of delayed CA. Chemical names used: butanedioic acid mono (2,2-dimethylhydrazide) (daminozide).
Predicting Poststorage Disorders of ‘Cox's Orange Pippin’ and ‘Bramley's Seedling’ Apples by Regression Equations
Authors: Autio Wesley R. , Bramlage William J. , Weis Sarah A.
Published: August 2022

Equations were developed that could predict the incidence of senescent breakdown, bitter pit, and decay in ‘Cox's Orange Pippin’ apples and senescent breakdown and bitter pit in ‘Bramley's Seedling’ apples. The parameters used to predict the incidences of disorders included fruit Ca, P, and K concentrations; fruit weight; respiration rate; and fruit maturity. Each disorder and each cultivar had a unique prediction equation. Such equations must be established individually for a disorder, cultivar, and, probably, growing region. Given an appropriate data base, this method seems to have broad applicability as a predictive tool for these disorders. However, core flush and low temperature breakdown could not be predicted using the parameters measured in this study.
Water Relations and Water Potential Measurements for Vegetative Poinsettia
Authors: Barrett James E. , Nell Terril A.
Published: August 2022

Pressure chamber and thermocouple psychrometer measurements of leaf water potentials in vegetative Euphorbia pulcherrima Willd. cv. Eckespoint C-l Red were evaluated. The 2 methods agreed within 0.2 MPa between −0.3 and −1.8 MPa and were equal at −1.1 MPa. Minimum daily water potential for nonstressed plants reached −0.67 MPa by 1230 hr. Abaxial water vapor conductance and water potential varied little between 1230 and 1630 hr. When drought was imposed, incipient stomatal closure occurred at −0.8 MPa with full closure observed at −1.2 MPa. Complete loss of turgor pressure occurred at water potentials between −1.2 and −1.4 MPa. The linear correlation coefficient for conductance and leaf-air temperature differential was 0.96, with leaf and air temperature equal when conductance was 0.6 cm·s−1. Xylem pressure potentials of upper leaves on drought-stressed plants declined to −1.7 MPa in 8 days and abscission of proximal leaves began. There was little change in xylem pressure potentials of upper leaves after leaf abscission began.
In Vitro Production of Jojoba Liquid Wax by Zygotic and Somatic Embryos
Authors: Wang Yi-Chang , Janick Jules
Published: August 2022

Zygotic embryos of jojoba (Simmondsia chinensis Link) accumulated liquid wax in vivo from 10 mg dry weight to maturity (800 mg dry weight) with relatively constant proportions of 36 to 46 carbon length wax esters. Immature zygotic embryos (initial dry weight, 1.6 ± 0.5 mg se), cultured on a semisolid basal medium supplemented with 15% sucrose for 10 weeks, reached 64.7 ± 20.5 mg se dry weight and produced 50% wax, an efficiency twice that of in vivo zygotic embryos of the same size. Somatic embryos (initial dry weight, 0.3 mg) cultured on semisolid basal media containing 9% sucrose for 12 weeks averaged 92.5 ± 32.7 mg se dry weight with 20% wax, 74% of the efficiency of zygotic embryos in vivo of the same size. The proportion of wax esters accumulated by zygotic and somatic embryos produced in vitro was similar to that of in vivo-produced wax.
Effects of Water Stress on Pollen of Phaseolus vulgaris L.
Authors: Shen Xiu Ying , Webster Barbara D.
Published: August 2022

Pollen of plants of Phaseolus vulgaris L. ‘Red Mexican’ is affected adversely by water stress. The critical stress period occurs 10-13 days after emergence, during the transition from the vegetative to the reproductive phase of development. The transition phase is characterized by the presence of tiny green buds (>0.5-2.0 mm in length), bearing anthers that contain tetrads or free microspores. Pollen abortion of plants stressed during the transition phase is significantly higher than that of pollen from nonstressed plants or from those stressed during later phases of reproductive development. The percentage of pollen germination and total pollen production also are reduced in transition phase-stressed plants. Exine development is abnormal. This abnormal development is particularly interesting because the exine is regarded as so genetically stable that it is regularly used for species identification. Results of these experiments raise questions about the infallibility of identifications, since an environmental stress (such as water) imposed at a critical time of gametophytic development can markedly alter exine patterning.
Bulb Organ Changes and Influence of Temperature on Gaseous Levels in a Modified Atmosphere Package of Precooled Tulip Bulbs
Authors: Prince T.A. , Herner R.C. , Lee J.
Published: August 2022

Modified atmosphere (MA) packages of tulip bulbs (Tulipa gesneriana L. ‘Kees Nelis’) composed of 5 bulbs sealed in low-density polyethylene film (LDF-301, Dow Chemical) were exposed to 20°C for one week followed by 3 weeks of temperature regimes between 15° and 25°. The temperature changes resulted in little change in package CO2 and O2 equilibrium levels. Bulbs held in air flowered poorly after 3 or 4 weeks at most of the temperature regimes. Packaged bulbs held below 25°C yielded 80–100% normal flowers after 3 or 4 weeks storage. The dry weight (DW) of daughter bulbs within bulbs in air increased 7-fold during 4 weeks storage. These bulbs also lost 25% of total bulb DW, 35% of scale DW, and 20% of floral shoot DW. There was little daughter bulb enlargement and few significant changes in DW of other bulb organs in film-packaged bulbs during storage.
Identification of Apple Rootstock Cultivars by Isozyme Analysis
Authors: Menendez Ricardo A. , Larsen Fenton E , Fritts Robert
Published: August 2022

Thirty-three clonal apple (Malus domestica Borkh.) rootstocks were characterized by their peroxidase, esterase, acid phosphatase, and idoleacetic acid oxidase isozyme banding patterns. Polyacrylamide disk-gel electrophoresis of shoot bark protein extracts, with a 5% to 15% acrylamide concentration gradient in the separating gel, provided adequate resolution for the anionic isozymes for all 4 enzymes, while a 5% to 20% gradient was used to separate the cationic isozymes of peroxidase and acid phosphatase. Growing conditions (greenhouse and 3 different field locations) and sample timing (February, May, August, and November) did not affect banding patterns. Virus-tested clones showed isozymic differences compared with the original contaminated material. Tissue culture propagated selections from EMLA 7 and MAC 9 stoolbeds expressed different banding patterns compared to original stocks.
Photosynthetic Characteristics During Leaf Development in ‘Bing’ Sweet Cherry
Authors: Roper Teryl R. , Kennedy Robert A.
Published: August 2022

Potted sweet cherry (Prunus avium L.) trees, grown under constant environmental conditions, were used to determine characteristics of leaf photosynthetic development separate from environmental influences. A maximum rate of photosynthesis of 38 mg CO2/dm2 (per hour) was reached at a leaf plastochron index (LPI) of 10, which is about 80% of full leaf expansion. During development, CO2 compensation points decreased to about 25 μl·liter−1 CO2 at LPI 12, but gradually increased to a value of about 35 for mature leaves. Of 3 leaf ages studied, (LPI 5, 10, and 15) response to low O2 was the least at LPI 10. Carboxylation efficiency doubled between LPI 5 and 10, while stomatal conductance was highest and mesophyll resistance was lowest from about LPI 10 to 13. Light saturation occurred at about 500 μmol·s−1·m−2, and optimal temperature for photosynthesis in sweet cherry was 19° to 25°C. Light and temperature effects were apparently independent of leaf age. Our results indicate major influences of leaf development on photosynthesis in sweet cherry and serve as the basis of continuing studies aimed at the importance of leaf developmental stage for cultural and production practices.
Anthocyanin Patterns in Ripening Thornless Blackberries
Authors: Sapers Gerald M. , Hicks Kevin B. , Burgher Anita M. , Hargrave Donna L. , Sondey Scott M. , Bilyk Alexander
Published: August 2022

The pigments of thornless blackberry fruit were investigated by analytical and preparative high performance liquid chromatography (HPLC) to characterize anthocyanin patterns in representative cultivars and to determine the effects of ripening on these patterns. Cyanidin-3-glucoside and cyanidin-3-rutinoside were positively identified. In addition, a cyanidin derivative containing xylose and 2 dicarboxylic acid-acylated derivatives of cyanidin-3-glucoside were tentatively identified. Five different anthocyanin patterns were seen among the 33 cultivars and selections compared. During ripening, cyanidin-3-glucoside increased to a greater extent than the other pigments. The accumulation of individual anthocyanins was linearly related to the total anthocyanin content and to the soluble solids : acidity ratio. Cultivar differences in anthocyanin patterns and changes in individual anthocyanins in fruit approaching full ripeness are insufficient to influence fruit color.
Flowering and Fruiting Characteristics of Vaccinium ashei and Vaccinium ashei-Vaccinium constablaei Derivative Blueberry Progenies
Authors: Ballington J.R. , Isenberg Y.M. , Draper A.D.
Published: August 2022

Hexaploid Vaccinium hybrid progenies, including F1, F1 intercross, F1 × F2, BC1, BC1 intercross, and BC1 × F2 crosses between V. ashei Reade and V. constablaei Gray, and an intercross between late-blooming V. ashei genotypes, established in the commercial blueberry production area in eastern North Carolina, were compared among themselves and with 2 highbush blueberry (V. corymbosum L.) cultivars for flowering, ripening, primary mummy berry infection, crop, and fruit characteristics. There were significant differences among progenies for all traits, with sufficient variability for selection within most progenies. Differences reflected specific parent combinations rather than type of cross with the V. ashei–V. constablaei derivative progenies. The experiment included both V. ashei and V. ashei–V. constablaei derivative progenies that produced a high percentage of seedlings flowering with or later than highbush blueberries. Two percent of the V. ashei–V. constablaei derivative seedlings bloomed and ripened with the early ripening highbush cultivar ‘Croatan’. Crop ratings were variable in all progenies, and high sds for the cultivars indicated that a high percentage of the variation was environmental. Primary mummy berry infection significantly reduced the crop in several progenies but was not responsible for the poor overall crop performance of most. Mean fruit size of the V. ashei intercross was large enough for hand harvest, while all but the 2 smallest-fruited V. ashei- V. constablaei derivative progenies were large enough for mechanical harvesting. Fruit of most progenies were commercially acceptable for color, picking scar, firmness, and flavor.
Inhibitors of Ethylene Synthesis and Action: A Comparison of Their Activities in a Lettuce Root Growth Model System
Authors: Abeles F.B. , Wydoski S.G.
Published: August 2022

The activity of purported inhibitors of ethylene synthesis and ethylene action was tested in a lettuce (Lactuca sativa L. ‘Grand Rapids’) root growth model system. Ethylene production by lettuce seedlings was inhibited by three purported inhibitors of ACC-synthase: AOA, l-canaline (CAN), and AVG. However, except for AVG, these compounds did not increase root growth, suggesting that the endogenous basal rate of ethylene production did not play a role in controlling the growth of these seedling roots. The promotive effective of AVG on root growth was not due to an inhibition of ethylene production, since it retained its effect in the presence of externally supplied ethylene. Of the five purported inhibitors of ethylene action studied, only NBA and silver thiosulfate (STS) demonstrated anti-ethylene action without toxic side effects. Three other compounds reported to block ethylene action—CO2, DIHB, and MCEB—inhibited growth by themselves and failed to provide clear evidence that they blocked ethylene action in the lettuce root growth assay system. Chemical names used: 1-aminocyclopropane-1-carboxylic acid (ACC); (aminooxy)acetic acid (AOA); [S-(E)]-2-amino-4-(2-aminoethoxy)-3-butanoic acid (AVG); 2,5-norbornadiene (NBA); 3,5-diiodo-4-hydroxybenzoic acid (DIHB); and 5-methyl-7-chloro-4-ethoxycarbonylmethoxy-2,1,3-benzothiadiazole (MCEB).
Growth and Mineral Composition of Radish in Response to Nitrification Inhibitors
Authors: Stratton Margie Lynn , Barker Allen V.
Published: August 2022

Nitrapyrin, etridiazol, fenaminosulf, sodium azide, and a formulated product of aromatic substances and alkenes were evaluated as nitrification inhibitors under greenhouse conditions for radish (Raphanus sativus L. ‘Cherry Belle’) fertilized with sewage sludge. Nitrapyrin and etridiazol inhibited nitrification, but their use restricted plant growth and lowered the Ca and Mg concentrations of the plants. Nitrification was inhibited slightly by fenaminosulf, which had little effect on plant growth and composition. Sodium azide and the formulated product were not effective as nitrification inhibitors. The azide was phytotoxic, but the formulated product had no toxic effects on growth. The toxic effects of chemicals with efficacy as nitrification inhibitors were due largely to the accumulation of NH4-N in the medium. Chemical names used: 2-chloro-6-(trichloromethyI)pyridine (nitrapyrin); 5-ethoxy-3-trichloromethyl-1,2,4-thiadiazole (etridiazol); and sodium p-(dimethylamino)benzenediazosulfonate (fenaminosulf).
Intercellular Volume And Resistance to Air Flow of Fruits And Vegetables
Authors: Calbo A.G. , Sommer N.F.
Published: August 2022

A technique to measure intercellular air volume was developed, based on the relationship between pressure reduction and air expansion, with correction for water vapor pressure. This technique yields air efflux curves, and the extracted air can be used to measure the gas composition of internal atmospheres. ‘Grevenstein’ apple (Malus domestica Borkh.), ‘Bartlett’ pear (Pyrus communis L.), ‘Hayward’ kiwifruit (Actinidia chinensis Planchon), ‘Independence’ nectarine [Prunus persica (L.) Batsch], and ‘Russet’ potato (Solanum tuberosum L.) had intercellular volumes of 16.6%, 5.14%, 3.64%, 5.76%, and 1.64%, respectively.
Interaction of Asparagus Root Filtrate with Fusarium oxysporum f.sp. asparagi
Authors: Peirce Lincoln C. , Colby Lindsey W.
Published: August 2022

Asparagus (Asparagus officinalis L.) root filtrate (RF) depressed asparagus seedling emergence in a sterile peat–vermiculite medium. In a medium inoculated with Fusarium oxysporum f. sp. asparagi (FO), the effect was magnified. The response to RF dose, regardless of level of FO infestation, was quadratic. Comparisons with a sucrose solution of the same percentage of soluble solids as the RF suggested that reduced emergence may have been due in part to enhancement of FO growth by the energy source added to the medium. However, after germinating seeds in RF until radicle emergence, then rinsing and transferring them to FO-inoculated medium, emergence was reduced relative to controls. Therefore, depression of emergence apparently related both to an autotoxin somehow predisposing young radicles and/or hypocotyls to increased FO infection and to stimulation of FO in the rhizosphere by the soluble solids content of the root exudate. Infection was confirmed to be the only role of FO: sterilization of the spore suspension by Millipore (0.2 µm) filtration eliminated pathogen toxicity.
Influence of Maturity, Storage Procedure, Temperature, and Oxygen Concentration on Quality and Disorders of ‘Mcintosh’ Apples
Authors: Lau O.L. , Yastremski R. , Meheriuk M.
Published: August 2022

A firmness benefit in a low-O2 atmosphere (1.0–1.2%) was observed in ‘Mcintosh’ apples (Malus domestica Borkh.) stored with a “rapid CA”, but not with a “slow CA” procedure. Incidence of “corky” flesh browning was high in fruit harvested at commercial maturity and stored at 1.7°C (a standard temperature for 2.5% O2 storage in British Columbia) for 6 months or longer in low-O2 atmospheres. The incidence of the disorder varied greatly with fruit lot and was reduced markedly by the use of higher storage temperatures (e.g., 3.0°) in fruit of correct maturity. Advanced maturity (10% or more of the fruit with internal ethylene >1 ppm, starch–iodine index >5, and lower harvest firmness) was conducive to development of this disorder. The results suggest that “corky” flesh browning is a low-temperature, low-O2, and senescence-related disorder.
Germination and Priming of Tomato, Carrot, Onion, and Sorghum Seeds in a Range of Osmotica
Authors: Haigh Anthony M. , Barlow E.W.R.
Published: August 2022

Germination responses of tomato, carrot, onion, and sorghum seeds to solutions of K2HPO4, K2HPO4 + KNO3, KNO3, K3PO4, K3PO4 + KNO3, and polyethylene glycol (PEG) 6000 at osmotic potentials between −0.25 and −1.75 MPa at 15°C were studied. Seeds that did not germinate in solutions subsequently were germinated in H2O to evaluate the efficacy of priming. Germination was more closely related to ionic strength than to osmotic potential of the imbibitional solution. Carrot seeds germinated in all salt solutions up to an ionic strength of 0.8 mol ions/liter, while onion and sorghum seeds had a threshold of about 1.0 mol ions/liter in salt solutions, except in K3PO4, which had a reduced threshold for both species. Tomato seeds, however, showed a wide range of thresholds between osmotica. The species also differed in their responses to individual osmotica. Differences in effect of osmotica for one germination parameter were not consistent for all germination parameters. Salt solution priming of tomato and carrot seeds was more beneficial to subsequent germination than PEG priming. Salt solution priming of onion seeds was less beneficial than PEG priming, while salt solutions were toxic to sorghum seeds. Tomato and carrot seeds primed in solutions that contained KNO3 had much shorter time spreads of germination than those primed in solutions without KNO3. The use of priming solutions of osmotic potential lower than that needed to inhibit germination resulted in underpriming of the seeds, which could cause a time spread of germination longer than that of untreated seeds. The presence of KNO3 in the priming solution was shown to alleviate some of the disadvantages of underpriming.
Greenhouse CO2 Enrichment Alternatives: Effects of Increasing Concentration or Duration of Enrichment on Cucumber Yields
Authors: Peet M.M. , Willits D.H.
Published: August 2022

Extended duration (delayed venting) and greater intensity were investigated as alternatives for CO2 enrichment of fall and spring greenhouse cucumber (Cucumis sativus L.) crops in North Carolina. The use of rockstorages allowed greenhouses to be enriched an average of 83% longer than was possible in conventionally ventilated greenhouses. Differences in daily enrichment times between rockstorage and conventionally ventilated houses were greatest during periods of high temperatures and high solar radiation levels in the early fall and late spring. In the rockstorage houses, enrichment increased fruit weights from 31–57%. Plants enriched to 600 μl·liter−1 yield as well or better than those enriched to 1000 or 1200 μ·liter−1 CO2. In the conventional houses, enrichment to 1000, 3000, and 5000 μl·liter−1 raised yields 18.5–34.5% in Fall 1983, Spring 1984, and Fall 1984. Cucumbers enriched to 1000 μl·liter−1 produced slightly less than the control plants in Spring 1983, however. In the conventionally vented houses, spring crops yielded best at the highest CO2 enrichment level, whereas for the fall crops the reverse was true.
Physiological Response of Rhododendron Cuttings to Different Light Levels During Rooting
Authors: Davis Tim D. , Potter John R.
Published: August 2022

Leafy cuttings of Rhododendron catawbiense Michx. ‘Roseum Elegans’ were rooted under 0%, 55%, or 95% shade in a greenhouse. Compared to the low-light treatment, higher light induced high photosynthetic rates, high sucrose and starch levels, and low leaf water potential, but these differences only persisted for the initial part of the 23-week rooting period and did not influence subsequent rooting percentage. However, in cuttings receiving 95% shade, dry weights of leaves and stems and rootball size were relatively small after 23 weeks, suggesting that growth was reduced by lack of photosynthate. The reduced size of cuttings rooted under 95% shade apparently did not affect vigor because the size of the above-ground portion of all plants was equal after 2 months of growth in a greenhouse.
The Effects of Postharvest Infiltration of Calcium, Magnesium, or Strontium on Decay, Firmness, Respiration, and Ethylene Production in Apples
Authors: Conway William S. , Sams C.E.
Published: August 2022

‘Delicious’ apples (Malus domestica Borkh.) were pressure-infiltrated (68.95 kPa) above atmospheric at harvest with CaCl2, MgCl2, or SrCl2. After 5 months in storage at 0°C, the fruit were removed, wound-inoculated with a conidial suspension of Penicillium expansum, and kept for 7 days at 20°. Fruit then were rated for decay severity, ethylene production, respiration, firmness, and injury, and analyzed for the concentration of the appropriate cation. Calcium was the optimum cation for reducing decay, maintaining fruit firmness, and suppressing ethylene production. Cation treatments had little effect on respiration, and Mg was the only cation that caused distinctive injury to the fruit surface.
Freezing Tolerance and Rapid Cold Acclimation of Spinach
Authors: Fennell Anne , Li Paul H.
Published: August 2022

Freezing tolerance and rates of acclimation and deacclimation were determined for three Chinese spinach (Spinacia oleracea) cultivars (‘Harbin’, ‘Beijing’, and ‘Shantung’) and one American spinach cultivar (‘Bloomsdale’). Detached leaf and whole plant freezing tolerances were compared during cold acclimation. Freezing tolerance of detached leaves was equivalent to the freezing tolerance of whole plants. Using detached leaves, freezing tolerance of the cultivars was determined after 0, 1, 3, 7, 14, and 21 days of cold acclimation at 5°/2°C (day/night temperature) and then after 1, 3, and 7 days of deacclimation at 20°/17°. All four cultivars acclimated and deacclimated very rapidly. Depending on the cultivar, a 2° to 4° increase in freezing tolerance was observed after 1 day of acclimation. The greatest change in freezing tolerance occurred in the first 3 days of acclimation. The rate of acclimation diminished dramatically after 3 days, and there was little change in freezing tolerance after 14 days of acclimation. Upon exposure to deacclimating temperatures, fully acclimated plants lost 3° to 5° freezing tolerance within 1 day. There was no further decline in freezing tolerance after the 3rd day of deacclimation.
Endogenous Growth Substances in Relation to Shoot Growth and Flower Bud Development of Mango
Authors: Chen Wen-Shaw
Published: August 2022

Changes in gibberellin and cytokinin activities were investigated at the stages of leaf differentiation, mature green leaves, early flower bud formation (7 days after formation), and full bloom of 3-year-old mangos (Mangifera indica L.) in pot culture. Also, diffusible IAA and ABA in the diffusate of shoot tips were examined at the different developing stages. High gibberellin and diffusable IAA activity was found in the xylem sap at leaf differentiation. Diffusible IAA decreased to a low level in shoot tip diffusates, and ABA increased dramatically during early flower bud formation. At the same time, total cytokinin-like activity increased in the xylem sap, reaching a maximum level at full bloom. Chemical names used: 1H-indole-3-acetic acid (IAA); [S-(Z,E)]-5-(l-hydroxy-2,6,6-trimethyl-4-oxo-2-cyclohexen-1-yl)-3-methyl-2,4-pentadienoic acid [abscisic acid (ABA)].
Fusarium solani Root Rot Resistance in Sweet Potatoes
Authors: Campbell T. M. , Collins W. W.
Published: August 2022

Storage roots of 10 sweet potato clones [Ipomoea batatas (L.) Lam.] were screened for resistance to Fusarium solani (Sacc.) Mart, emend. Snyd. and Hans. Clones were inoculated after 0, 6, and 36 days of postharvest storage and incubated in sterile moist chambers for 23 days. Resistance was evaluated by measuring volume of rotted tissue in each clone at the end of the incubation period. Clones tested (in increasing order of average rot volume over three screenings) were: NC 910, NC 925, NC 928, ‘NC Porto Rico 198’, ‘Centennial’, NC 825, NC 835, NC 818, W 125, and ‘Jewel’. Differences among clones for mean rot volume were highly significant within each storage period, and mean rot volumes generally increased in all clones as the length of the preinoculation storage period increased. The average rot volume of roots of resistant clones NC Porto Rico 198, NC 928, NC 910 and NC 925 was 19% that of ‘Jewel’ roots. Correlations between rot volume and postharvest quality factors in comparably stored healthy roots of the same genotypes were too low to be useful selection indices for F. solani resistance.
Preparation and Characterization of Protoplasts from Citris Juice Vesicles
Authors: Echeverria Ed
Published: August 2022

A method for the preparation of protoplasts from juice vesicles of citrus fruits is described. Protoplasts were obtained after incubating juice vesicles for 16 hr at room temperature in a medium containing cellulase and pectinase. The solution containing the protoplast was filtered through a 200-μm nylon mesh and the filtrate layered on a Percoll density gradient of 4%, 3.5%, and 3%. After 1 to 2 hr at 4°C, protoplasts were collected from the 4% Percoll layer. Protoplast viability was assessed by different methods and estimated to be ≈ 85%. The use of several stains and observations with light and electron microscopy provided information on some anatomical and physiological characteristics.
Effects of Salinity on Growth and Accumulation of Organic and Inorganic Ions in Cultivated and Wild Tomato Species
Authors: Shannon M.C. , Gronwald J.W. , Tal M.
Published: August 2022

The salt tolerances of a cultivated tomato (Lycopersicon esculentum L. cv. Heinz 1350) and three wild species [L. cheesmanii (Hook) C.H. Mull, L. peruvianum (L.), and L. pennellii (Cornell) D’Arcy] were determined in both sand and solution cultures. Curvilinear and two-piece linear methods were used to obtain response curves for fresh and dry weights of shoots. In solution cultures containing 0, 50, 100, and 150 mM added salt composed of 1:1 molar ratio of NaCl and CaCl2, ‘Heinz 1350’ was as salt-tolerant as any of the wild species. On the basis of relative decreases in vegetative dry weight, ecotype 1400 of L. cheesmanii was more sensitive to salt than ecotype 1401. After 4 weeks growth in sand cultures irrigated with nutrient solutions containing 0, 12.5, 25, 50, 75, and 100 mM added salts (5:1 molar ratios of NaCl and CaCl2), L. pennellii had higher relative salt tolerance than the other species. After 14 weeks, the cultivated species and L. pennellii were more sensitive at low salinity than the other two species. However, relative yield decreases with increasing salinity were not significantly different between the cultivated tomato and the 1401 ecotype of L. cheesmanii at higher salt concentrations. L. peruvianum and L. pennellii accumulated less leaf Cl- and more leaf Na+ than the other species. Significant differences in the partitioning of ions between mature and developing leaves were found for all species. The physiological mechanisms involved in tolerance at moderate salinities may differ from those required for survival at high salinity.
Effect of Soil Management and Calcium Nitrate Fertilization on the Availability of Soil Nitrate and Cations in an Eastern Apple Orchard
Authors: Glenn D.M. , Miller S.S. , Habecker M.A.
Published: August 2022

Four annual applications of Ca(NO3)2 were made to ‘Golden Delicious’ and ‘Delicious’ apple trees beginning in the second leaf at rates of 0.5 to 8 times the recommended rate (45 g/tree per year of age) in each of three soil management systems: cultivated, herbicide, and mowed sod. Soil samples were collected in Mar. and July 1983 (fifth leaf) to a 120-cm depth at the tree drip line. July samples were analyzed for available Ca, Mg, K, Mn, percentage of base saturation, NO3-N, and soil pH (0.01 m CaCl2); March samples only for NO3-N. The sod system had the highest soil pH, Ca level, and percentage of base saturation; the herbicide had the lowest, and the cultivated treatment was intermediate. The rate of Ca(NO3)2 had no measurable effect on these values except in the surface pH levels (030 cm), where sod was unaffected but the cultivated and herbicide systems had a significant reduction in pH with increasing levels of Ca(NO3)2. Soil Mn availability and leaf Mn increased with increasing Ca(NO3)2 levels in association with the decreasing pH levels. Available soil Mg and leaf Mg decreased with increasing Ca(NO3)2 due to Ca displacement of soil Mg on the cation exchange complex. Leaf Ca was unaffected by Ca(NO3)2 rate or the soil management system. During the growing season (Mar.-July 1983), the herbicide system accumulated significantly more of the applied Ca(NO3)2 than the cultivated or sod systems. No yield response and minimal leaf NO3 response suggested differences in NO3 accumulation were due to variation in leaching due to the soil management systems.
Changes in the Cell Wall Components of Kiwifruit During Storage in Air or Controlled Atmosphere
Authors: Arpaia M.L. , Labavitch J.M. , Greve C. , Kader A.A.
Published: August 2022

Eight-one percent of the harvest firmness in kiwifruit (Actinidia chinensis Planch.) was lost during the first 8 weeks of storage in air at 0°C. As softening proceeded, a solubilization of uronic acids and the neutral sugar residues usually associated with pectic polymers (galactose, arabinose, and rhamnose) was detected. No consistent changes were noted in cellulose or the neutral sugars usually associated with hemicelluloses. Starch degradation also occurred coincident with softening. The amount of cell wall components soluble in water following fruit homogenization and the proportion of ethanol-precipitable pectic neutral sugars in this fraction increased during the first 8 weeks of storage. Once the rate of softening slowed (8 to 20 weeks), an equilibrium situation apparently was established between the amounts of the sugars formed in the ethanol-precipitable (i.e., polymeric) and ethanol-soluble fractions, suggesting that digestion of wall components continues after their excision from the insoluble wall matrix. Controlled atmosphere (2% O2+ 5% CO2; CA) storage retarded flesh softening relative to that measured in fruit held at 0° in air. A comparison of the changes in the cell wall components of air-stored and CA-stored kiwifruit suggests that, in addition to cell wall degrading processes contributing to fruit softening, starch degradation (possibly causing cell turgor changes) also may be involved in low-temperature softening of kiwifruit. The losses in water-insoluble cell wall pectic neutral sugars and uronic acids in air and CA storage were similar during the first 8 weeks of storage. Once softening slowed in CA, small but consistent reductions in the amount of cell wall turnover were observed as compared to air storage.
Storage Quality of Hand- and Machine-harvested Rabbiteye Blueberries
Authors: Miller W.R. , Smittle D.A.
Published: August 2022

Rabbiteye blueberry [Vaccinium ashei (Reade)] production is increasing rapidly and growers of large plantings are converting rapidly from hand harvesting to machine harvesting. In three tests conducted during 1985, machine-harvested ‘Climax’ and ‘Woodard’ blueberries were softer and had higher moisture loss and decay than handpicked fruit after 1, 2, or 3 weeks of storage at 3°C. For both cultivars, berry firmness remained relatively constant during storage, whereas decay and weight loss increased. Berries of ‘Climax’ were firmer, less acidic, and developed less decay than ‘Woodard’. These results will assist in identifying the best fresh-market berries for export from the United States to Western Europe.
Chilling Injury, Respiration, and Sugar Changes in Sweet Potatoes Stored at Low Temperature
Authors: Picha David H.
Published: August 2022

External chilling injury symptoms, primarily surface pitting followed by secondary fungal decay, developed in six sweet potato [Ipomoea batatas (L.) Lam] cultivars after an exposure to 7°C for 2 weeks or more followed by storage at 15.6°. Internal chilling injury symptoms, primarily darkening of the cambium and vascular bundles, were observed in noncured ‘Whitestar’ and ‘Rojo Blanco’ roots after exposure to 7° for 3 weeks and in ‘Centennial’ after exposure to 7° for 4 weeks followed by storage at 15.6°. ‘Jewel’ was the cultivar most tolerant to low temperature. Chilling injury and respiration rate were greater with increasing lengths of exposure to 7° and were greater in noncured than cured roots. Enhanced sucrose and total soluble sugar content occurred at 7° compared to 15.6°. The primary sugar responsible for low-temperature sweetening was sucrose, but there was considerable variation among cultivars in the extent of low-temperature sweetening and specific sugar changes.
Solar Radiation Influences Solar Yellowing, Chilling Injury, and ACC Accumulation in ‘Honey Dew’ Melons
Authors: Lipton Werner J. , Peterson Sharon J. , Wang Chien Yi
Published: August 2022

‘Honey Dew’ melon fruits (Cucumis melo L.) matured under filters that transmitted between 1% and 100% of total solar and between 2% and 100% of ultraviolet (UV) radiation. Solar yellowing (SY) developed predominantly on top of the melons and increased as their exposure to direct solar radiation increased. Degree of exposure to solar radiation during maturation and susceptibility to postharvest development of chilling injury (Cl) during 17 days at 2.5°C were inversely related. SY and Cl also were inversely related. Levels of ACC in the skin were low at harvest and unaffected by degree of exposure to solar radiation. Reducing the exposure to the sun by half nearly doubled the concentration of ACC during chilling; complete shading resulted in little additional increase in ACC. After chilling, the skin from the bottom of the melons consistently contained slightly more ACC than that from the top. Chemical name used: 1-aminocyclopropane-1-carboxylic acid (ACC).
Relationship of Harvest Date, Storage Conditions, and Fruit Characteristics to Bruise Susceptibility of Apple
Authors: Klein Joshua D.
Published: August 2022

In the article “Relationship of Harvest Date, Storage Conditions, and Fruit Characteristics to Bruise Susceptibility of Apple”, by Joshua D. Klein (J. Amer. Soc. Hort. Sci. 112:113–118, January 1987), the last paragraph of Materials and Methods, sixth line, should read “…of filtered extract rapidly with 1 ml of 0.1 m catechol…”, not 0.1 ml.
Shoot and Root Temperature Effects on Carbohydrate Levels During Budbreak in Young Apple Trees
Authors: Belding Robert D. , Young Eric
Published: August 2022

One-year-old apple trees (Malus domestica Borkh., MM. 106) were subjected to all combinations of 10° and 20°C root and shoot temperatures after their chilling requirement had been satisfied at 4°. Tree root temperature of 20° significantly increased percent budbreak over trees with roots at 10°. Trees with a shoot temperature of 20° caused accelerated budbreak over trees with 10° shoots, but the final (day 18) total budbreak was not different due to shoot temperatures. Shoot temperatures strongly influenced extension of new shoots, starch breakdown in fibrous roots, and soluble sugar increase in fibrous roots and root shank. Shoot temperature of 20° increased all these parameters over the 10° shoot temperature.
Relationships Between Leaf : Fruit Ratio and Varying Levels of European Red Mite Stress on Fruit Size and Return Bloom of Apple
Authors: Beers E.H. , Hull Larry A. , Grimm Jeffery W.
Published: August 2022

Fruit size and return bloom of apple (Malus domestica Brokh.) were examined in 1982-84 under varying levels of crop load and stress caused by the European red mite [Panonychus ulmi (Koch)]. Trees of ‘Rome Beauty’/MM.111 and ‘Yorking’ M.26 were subjected to two and three levels of mite stress, respectively, over a range of leaf : fruit ratios (LFRs). Regression models were used to explore the effect of LFR on fruit size and return bloom at the various mite injury levels. There was a curvilinear relationship between mean fruit weight and LFR for most of the check and mite-injured groups. The relationship between bloom density and LFR was linear over the range studied. Both experiments indicated reduced fruit size and return bloom with moderate to high mite damage, regardless of LFR.
Effects of Soil Moisture and Root Knot Nematode, Meloidogyne hapla (Chitwood), on Water Relations, Growth, and Yield in Snap Bean
Authors: Wilcox-Lee D.A. , Loria R.
Published: August 2022

Seedlings of the snap bean (Phaselous vulgaris L.), cv. Kentucky Wonder, were inoculated with ≈0, 240, 2400, or 24,000 root knot [Meloidogyne hapla (Chitwood)] nematodes per plant and grown in a sandy soil in the greenhouse at a soil water potential of either −0.025 (high soil moisture) or −0.075 (low soil moisture) MPa. Leaf xylem potential, transpiration, root hydraulic conductivity, and nematode populations in roots, as well as growth and yield data, were collected about 8 weeks after inoculation. Transpiration was reduced by decreasing soil moisture—maximum transpiration occurred about midday at high soil moisture and in the early morning at low soil moisture. Transpiration decreased late in the day with increasing nematode populations at high, but not low, soil moisture. Leaf xylem potential was reduced by low soil moisture and nematodes but interactive effects were not significant. Root conductivity was lower in plants exposed to low soil moisture than in plants maintained at high soil moisture. However, nematodes reduced conductivity in only one of two experiments, and interactive effects were not significant in either experiment. Root and shoot dry weight and leaf area were decreased in response to low soil moisture. Nematodes reduced shoot dry weight and leaf area, but not root dry weight, in one of two experiments and there were no significant interactive effects in either experiment. Total yields of beans were reduced at low soil moisture and in response to nematode inoculum. A significant interactive effect on early bean yield was also evident; nematodes lowered early yields more at high soil moisture than at low soil moisture. These data indicate that although soil moisture and M. hapla populations individually influenced water relations, growth, and yield of bean, the interactive effects were generally not significant. When an interaction could be demonstrated, it was due to a decreased effect of nematodes at low soil moisture.