bluuebunny/crossref_metadata_2025 huggingface dataset:
In Vitro Studies of Ethephon-induced Abscission in Olive. II. The Relation between Ethylene Evolution and Abscission of Various Organs1
Authors: Lavee S. , Martin G. C.
Published: August 2022

Leaves, stems, inflorescences and fruits from excised ‘Manzanillo’ shoots of olive (Olea europaea L.) basally fed with (2-chloroethyl)phosphonic acid (ethephon) were used to study the relation between ethylene evolution and abscission. The abscission response of the various organs to ethephon was directly related to concentration and length of exposure to a given treatment concentration. After an ethephon pulse treatment, stem tissues evolved increased levels of ethylene for a longer period than leaves, whereas the effect on petioles was shorter than leaves. Leaf abscission occurred after ethylene evolution from them declined. Inflorescences did not abscise even though induced to evolve high levels of ethylene. The rate of leaf ethylene evolution and abscission was higher in reproductive shoots than in nonreproductive shoots and was influenced by the number of inflorescences present on the shoot. Leaves on shoots with a large number of inflorescences senesced more rapidly than those with fewer inflorescences in our in vitro system and developed a marked chlorosis after 24 hours. Ethylene evolution from fruits on ethephon-fed shoots was low and abscission was erratic. The abscission layer between fruit and stem developed at no specific site along the pedicel or peduncle. Probable reasons for the specific levels and duration of ethylene evolution from the various tissues after an ethephon pulse are discussed.
Effects of Harvest Date on Ripening Capacity and Postharvest Life of ‘d’ Anjou’ Pears1
Authors: Chen P. M. , Mellenthin W. M.
Published: August 2022

’D‘Anjou’ pears (Pyrus communis L.) were harvested at weekly intervals for a 3-week period beginning at the start of commercial harvest in the Hood River Valley, Oregon. Late-harvested fruit at flesh firmness of 5.9 to 5.4 kg ripened with fair to good quality following 30 days storage at -1.1°C. Fruit harvested at optimum flesh firmness of 6.4 to 6.1 kg required 60 days of postharvest chilling to ripen with quality. The development of ripening capacity corresponded to the increase in internal ethylene to 1.5—2.0 ppm during cold storage. Dessert quality of late-harvested fruit declined after 90 days of storage while quality of optimum-harvested fruit continued to improve until 150 days in storage. Flesh firmness and ethanol-soluble matters indicated that fruit harvested over the 3-week period were of different maturities. Concentrations of titratable acids and soluble solids varied among different harvest groups.
Regeneration of Plants from Callus-derived Protoplasts of Salpiglossis1
Authors: Boyes C. J. , Sink K. C.
Published: August 2022

Callus cells were used as the cell source for isolating protoplasts of Salpiglossis sinuata L. Callus was initiated on the cut edges of leaf sections cultured on Uchimiya and Murashige (UM) medium under 24 μEm-2s-1 at 30°C. Friable callus from subcultures on UM was subjected to an enzymatic solution of 1% Driselase, 0.75% Pectinase, 2% Cellulase R-10, and 8% mannitol in CPW salts, and incubated at 50 rpm, for 4-5 hr to release protoplasts. Following washing, counting, and dilution, protoplasts were plated in liquid Murashige and Skoog medium (MS) modified by deleting the ammonium ions and adding (mg/liter): 250 L-glutamine, 0.1 L-serine, 2.0 thiamine, 0.5 indoleacetic acid (1AA), 1.0 2,4-D, 0.5 6-benzylamino purine (BA) and 9% mannitol. Within 2-5 days, cell wall synthesis and the first cell division occurred. Green-yellowish colonies, 2 to 3 mm in diameter, formed in 2.5 months and were transferred to MS + 1.0e mg/liter N6-isopentenyladenine (2iP), where shoot primordia were evident within 21 days. After full development and elongation of shoots, they were dipped in 1000 ppm indolebutyric acid (1BA) and placed in MS + 0.001 mg/liter 2,4-dichlorophenoxyacetic acid (2,4-D) to initiate roots. Rooting was carried out at 22±2°C under 80µm-2s-1 Cool White fluorescent tubes. Nine of 10 regenerated plants examined cytologically were 2n = 44, normal for the species, and 1 plant was 2n =88.
Effects of Overtree Misting for Bloom Delay on Pollination, Fruit Set, and Nutrient Element Concentration of ‘Golden Delicious’ Apple Tree1
Authors: Crassweller R. M. , Ferree D. C. , Stang E. J.
Published: August 2022

Overtree misting for bloom delay reduced fruit set of ‘Golden Delicious’ apple (Malus domestica Borkh.) flowers hand-pollinated with ‘Jonathan’ or ‘Golden Delicious’ pollen in 1978, or open-pollinated or hand cross-pollinated with ‘Jonathan’ pollen in 1979. Misting did not affect fruit set of flowers that were open-pollinated in 1978 or self-pollinated in 1979. The number of seeds per fruit was not reduced. Soil Ca, Mg, pH and base saturation of Ca and Mg were increased, and flower and spur leaves contained lower concentrations of N, P, K, B, Mn, Fe, Zn, and Cu at either full bloom or petal fall as a result of misting. Foliar sprays of B increased B concentrations but did not influence fruit set on either misted or nonmisted trees.
The Influence of Sustained and Alternating Dark Periods on the Growth of Three Foliage Plants1
Authors: Biran Isaac , Kofranek Anton M.
Published: August 2022

Net photosynthesis, as measured by dry matter changes, was reduced following the dark periods when foliage plants were grown in extended, alternate dark-light cycles. Longer dark periods resulted in greater reduction; however, recovery was observed if the light duration was increased. No visual quality reduction was observed in Tradescantia fluminensis Veil and Asparagus setaceus Jessop which was grown under 14 days light: 14 days dark cycles for 84 days. Similarly, the quality of mature leaves and stems of Philodendron scandens Subsp. oxycardium (Schott) Bunt grown under 24 days dark: 24 days light cycles for 96 days was not impaired; however, new shoots and leaves were abnormal. Dry matter partitioning of Philodendron was affected by light conditions and growth activity. In plants with no active growth, the dry weight of leaves, stems, and roots was increased under adequate light condition and decreased under darkness. Stems were stronger sinks than leaves. In all treatments, when new shoots started their active growth, they became the main carbohydrate sinks with a concomitant reduction of weight of the mature organs. Reduction in percent dry matter following the lowering of the light intensity was observed. Determining and measuring the critical percent dry matter at which plant injury occurs are suggested as practical methods to evaluate the plant’s condition and how it may respond during and after the marketing period.
Relationships of Apple Sensory Attributes to Headspace Volatiles, Soluble Solids, and Titratable Acids
Authors: Watada Alley E. , Abbott Judith A. , Hardenburg Robert E. , Lusby William
Published: August 2022

Correlations between sensory attributes and concentrations of headspace volatiles, soluble solids, and titratable acids of ‘Golden Delicious’ and ‘York Imperial’ apples (Malus domestica Borkh.) were examined. Stepwise regression analysis indicated that variation of sweetness of ‘York Imperial’ and acidity of ‘Golden Delicious’ and ‘York Imperial’ can be accounted for in part by soluble solids, titratable acids, and headspace volatiles of apples. Astringency, mustiness, starchiness, and floral-fruitiness correlated poorly with the volatiles, soluble solids, and titratable acids.
Reducing Leaf Epinasty in Mechanically Stressed Poinsettia Plants1
Authors: Saltveit Mikal E. , Larson Roy A.
Published: August 2022

Foliar sprays of either 10 mM aminoethoxyvinylglycine or 3 mM silver ions applied 24 hours before potted poinsettia plants (Euphorbia pulcherrima Klotzsch ex. Willd., cv. Annette Hegg Diva) were sleeved for 24 hours, significantly reduced the development of leaf epinasty after removal of the sleeves.
Responses of ‘McIntosh’ Apples to Low Oxygen Storage1
Authors: Lidster P. D. , McRae K. B. , Sanford Katherine A.
Published: August 2022

Storage of ‘McIntosh’ apples (Malus domestica Borkh.) in low O2 atmospheres (1.5% CO2 + 1.0% O2) maintained fruit firmness by an average of 0.86 kg over 40 grower lots, compared with the same fruit stored in conventional controlled atmospheres (5% CO2 + 2.8% O2). Low O2 storage resulted in fruit which were higher in titratable acids and were significantly crisper, more acid, and juicier to sensory panelists. Fruit maturity at harvest was a significant factor in determining the losses of firmness and titratable acids in low O2 storage.
Economics of Harvest Timing for Once-over Harvesting of Cucumbers1
Authors: Colwell H. T. M. , O’Sullivan John
Published: August 2022

An economic model involving simulation methodology was used, in conjunction with data from field experiments, to examine the economic effects of delayed or premature harvest of pickling cucumbers (Cucumis sativa L.) on yield and several measures of size grade distribution. It was shown that, for once-over harvesting of cucumbers, profitability of cucumber production was extremely sensitive to untimely harvesting. Profitability/ha was reduced on average by $1091 and $722 respectively for harvesting 3 days earlier or later than optimum. Harvest criteria which maximized profit were identified for both conventional cucumber production and production based on gynoecious cultivars and treatment with chlorflurenol. Substantial differences in the effect of harvest timing on profitability/ha and in optimum harvest criteria occurred between these production systems. Maximum margins occurred in production methods involving gynoecious cultivars and chlorflurenol when 54.6% of the fruit were classified as grade 1. The comparable value for conventional production methods was 27.3%.
Origin, Expression, and Significance of Gene B in Cucurbita pepo L.1
Authors: Shifriss Oved
Published: August 2022

Two systems of fruit pigmentation exist in Cucurbita pepo. In the standard B+-system, the onset of color differentiation (orange, yellow, cream, or white) occurs after the “bud phase.” In the precocious B-system, the onset of color occurs during the bud phase. The source of the precocious system is a group of bicolor-fruited cultivars of the ornamental gourds. The yellow portion of a bicolor fruit is precociously pigmented, but the extent of precocious pigmentation may vary greatly even among fruits borne on the same plant. Starting with a single bicolor-fruited plant of the ‘Pear’ gourd, a program of self-reproduction and selection was initiated in an attempt to establish true-breeding lines which differ in extent of precocious fruit pigmentation. Many plants of successive inbred generations proved to be unstable genetically or phenotypically or both. But 2 genetically stable plants of known breeding history were identified as BB and BwBw (Bw for a “weak” allele). Inbred BB produces completely yellow fruits in one environment and somewhat variable fruits in another environment. Inbred BwBw produces fruits which exhibit a wide range of variation in extent of precocious pigmentation in different environments. Substitution of B for B+ in several edible cultivars has revealed the following facts: 1) BB lines of some backgrounds produce completely yellow fruits in diverse environments. 2) BB+ heterozygotes of different backgrounds differ from one another in extent of precocious fruit pigmentation and in the range of fruit variation on the same plant. 3) B is stable in some backgrounds and unstable in other backgrounds. 4) B can exert “secondary” effects on plant growth, sexuality, and fruit quality, some of which are detrimental and others, beneficial. 5) The secondary effects are separable in breeding experiments. It is suggested that the initial source of B and its precocious alleles is genetic instability which occurs spontaneously in some stocks during gametogenesis; that the extent of precocious fruit pigmentation depends on time at which B (or its allele) blocks chlorophyll synthesis during the bud phase; that the determination of this time is affected by the “strength” of the B alleles present, their dosage, modifier genes, and non-genetic factors; that the secondary effects of B result from different interactions between B and other genes; and that superior precocious cultivars could be developed in which the beneficical effects of B are enhanced and its detrimental effects are suppressed through selection of new gene recombinations.
Performance of Bearing Cherry and Prune Trees under Very Low Irrigation Rates1
Authors: Proebsting E. L. , Middleton J. E. , Mahan M. O.
Published: August 2022

Cherry (Prunus avium L.) and prune (P. domestica L.) trees were trickle irrigated daily or weekly at 100%, 50%, and 15% of evaporation from a standard Class “A” pan, adjusted to the area of the tree canopy (Ec), for one full growing season. Soil moisture remained above the wilting point throughout the soil profile with 100% Ec but reached the wilting point except for a wetted zone near the emitters for 50% Ec and 15% Ec. Leaf water potential of shaded cherry leaves at midday averaged near -14 bars for 100% Ec, near -20 bars for 15% Ec, reaching as low as -28 bars for prunes in late July and August. Growth of fruit and vegetative parts was reduced by severe stress but the trees survived on 15% Ec. Prunes recovered to normal yield and growth by the second year after treatment. Peripheral branches of cherries died back during the year of treatment and in the following year. Cherries grew and fruited normally by the third year after treatment except for reduced bearing surface.
Control of Peach Tree Growth and Productivity by Regulated Water Supply, Tree Density, and Summer Pruning1
Authors: Chalmers D. J. , Mitchell P. D. , van Heek L.
Published: August 2022

Root competition (tree density), summer pruning, and regulated irrigation were studied to determine whether they can be used to control tree vigor and productivity in ultra-dense orchards of peach [Prunus persica (L.) Batsch]. All methods appeared to inhibit tree growth, but regulated irrigation combined with root competition generated from high tree density was most effective. Fruit yields and fruit growth were significantly increased (up to 30%) by high tree density combined with low rate of water application when water stress limited shoot growth but stimulated subsequent fruit growth. Periods of low rate of water application are specified.
Floral and Vegetative Bud Development of ‘Sungold’ and ‘Sunlite’ Nectarine as influenced by Evaporative Cooling by Overhead Sprinkling during Rest1
Authors: Gilreath Phyllis R. , Buchanan D. W.
Published: August 2022

Evaporative cooling by overhead sprinkling during rest advanced bloom of ‘Sungold’ nectarine [Prunus persica (L.) Batsch] about 11 days. The bloom advance was due to water applied to the canopy and not to increased water in the root zone. A rest prediction model for low chilling nectarines which accurately predicted rest completion for all unsprinkled treatments failed to predict the date of rest termination for sprinkled treatments, suggesting other factors are involved in addition to temperature.
Chemical Loosening Agents to Assist Mechanical Harvest of Olive1
Authors: Martin G. C. , Lavee S. , Sibbett G. S.
Published: August 2022

(2-chloroethyl)phosphonic acid (ethephon) applied at pH 6.8 to 7.0 resulted in fruit loosening which allowed mechanical harvest of at least 85% of the olive crop but there was excessive leaf loss. Inclusion of calcium salts helps offset leaf loss, but also decreases fruit loosening. 2-chloroethyl-tris-(2-methoxyethoxy)-silane (Alsol) and (2-chloroethyl)-methyl-bis-(phenylmethoxy)-silane (CGA 15281) appeared to be more superior looseners than either ethephon or GAF 7767141 (an ethylene generating material) with less leaf loss following treatment.
Peach Floral Bud Break and Abscisic Acid Content as Affected by Mist, Light, and Temperature Treatments during Rest1
Authors: Freeman Mark W. , Martin George C.
Published: August 2022

Mist, low light, and low temperature during dormancy significantly promoted subsequent floral bud growth in peach (Prunus persica L. Batsch) while high temperature and high light intensity significantly decreased it. Chilling hours at 10°C bud temperature were half as effective as hours at 6°. No significant changes occurred in abscisic acid (ABA) levels in floral bud scales. ABA content of primordia within misted buds was significantly lower than of primordia in other treatments. The data support the concept that fog influences bud rest through temperature, light, and leaching effects. Results also indicate that ABA content in buds may not be the primary factor that determines termination of rest.
Diurnal Variation in Water Potential Components and Stomatal Resistance of Irrigated Peach Seedlings1
Authors: Young Eric , Hand J. Mark , Wiest Steven C.
Published: August 2022

Peach [Prunus persica, (L.) Batsch] seedling growing in irrigated soil showed strong diurnal variations in totalwater potential, turgor potential, and stomatal resistance. A significant positive correlation existed between turgor potential and total water potential while osmotic potential remained fairly constant. There appeared to be no rapid, diurnal osmotic adjustment to maintain constant turgor, although there may have been some slight, long-term osmotic adjustment over the 2-week experimental period. When turgor approached zero, a depression of osmotic potential due to water loss through transpiration maintained turgor above zero. Stomatal resistance remained low throughout the day, even though total water potential dropped below –16 bars and turgor potential was below 2 bars. Stomatal resistance was negatively correlated with irradiance level but not with turgor potential.
Inheritance of Low Temperature Sprouting Ability in F1 Tomato Crosses1
Authors: De Vos D. A. , Hill R. R. , Hepler R. W. , Garwood D. L.
Published: August 2022

Inheritance of the ability of tomato (Lycopersicon esculentum Mill.) to sprout at 10°C was evaluated in a diallel study involving 7 inbred parents. For each parental and F1 progeny family, sprouting indices were used to estimate genetic and environmental components of variation. Significant additive gene effects with partial dominance for inability to sprout at low temperature were found. Epistatic gene effects were not important, but a significant maternal effect was found. The estimate of narrow sense heritability was 69% and that for broad sense heritability was 85%.
Performance of Hermaphroditic Pollen Parents in Crosses with Gynoecious Lines for Parthenocarpic Yield in Gynoecious Pickling Cucumber for Onceover Mechanical Harvest1
Authors: El-Shawaf I. I. S. , Baker L. R.
Published: August 2022

The top cross method was used to judge the performance of 17 hermaphroditic lines (pollen parents) for parthenocarpic yield and associated characters of cucumber (Cucumis sativus L.). Hybrid yields of 3 to 6 parthenocarpic fruits per plant were observed with 68 to 99.5% gynoecious expression. Four hermaphroditic lines were judged outstanding based on their hybrid performance for the necessary high percent of gynoecious expression combined with high yield. Significant correlations were detected between days-to-flower and nodal position of first-pistillate flower, and between the latter and yield. Heritabilities were 64%, 63%, and 73% for days-to-flower, nodal position of the first-pistillate flower, and gynoecious expression, respectively. The heritability for yield (number of fruit/plant) of parthenocarpic fruits was 20%. Accordingly, plant breeders might enhance selection gains for associated characters, but realize somewhat less success for yield (fruit number).
Combining Ability and Genetic Variances of G × H F1 Hybrids for Parthenocarpic Yield in Gynoecious Pickling Cucumber for Once-over Mechanical Harvest1
Authors: El-Shawaf I. I. S. , Baker L. R.
Published: August 2022

The parthenocarpic yield and associated traits of 20 gynoecious hybrids of pickling cucumber (Cucumis sativus L.) were measured by crossing 4 gynoecious with 5 hermaphroditic lines. The experimental hybrids were grown in the field and harvested for the once-over harvest system. Additive genetic variance was greater than non-additive for yield and associated characters, except gynoecious expression where non-additive was more important. The GCA for harvest-time, gynoecious expression, and yield of the female parents was greater than that of the male parents in this population. The converse was true for flowering-time. The dominance estimates indicated complete dominance for early flowering and over-dominance for gynoecious expression. The remaining characters appeared to be under the control of genes with additive effects and partial dominance. Narrow sense heritabilities of half-sibs (males and females) for fruit no. and fruit wt/plant were 53 to 60% and 32 to 65%, respectively. The genotypic and phenotypic correlations for flowering-time and nodal position of first-pistillate flower were high as was nodal position of first-pistillate flower with parthenocarpic yield.
Inheritance of Non-Wrapper Leaf Number, Efficiency Index, and Non-Wrapper Leaf Size in Cabbage1
Authors: Summers W. L. , Honma S.
Published: August 2022

A comparison of inheritance patterns and heritability estimates from a NCII crossing model which included green and red cabbage, Brassica oleracea L. Capitata group, indicated differences between green × green and red × green crosses. Green × green crosses exhibited dominance for few non-wrapper leaves, greater efficiency index, and smaller leaf size while red × green crosses showed the opposite dominance pattern.
Juvenility and Production of Fast-rooting Cuttings from Blueberry Shoot Cultures1
Authors: Lyrene P. M.
Published: August 2022

Shoots from tissue culture of 2 rabbiteye blueberry (V. ashei Reade) cultivars had smaller leaves, thinner stems, shorter internodes, and rooted faster than shoots from field-grown plants of the same cultivars. Rooting of cuttings taken directly from tissue culture or from 3-month-old tissue culture-derived plants averaged 95% for ‘Beckyblue’ and 96% for ‘Bluebelle’ after 19 days compared to 7% for ‘Beckyblue’ and 0% for ‘Bluebelle’ for softwood cuttings from field-grown plants. At 41 days, 100% of the cuttings taken from tissue culture or from tissue culture-derived plants had roots as compared to 54% for cuttings from field-grown plants.
Effect of Pear Vein Yellows Virus and a Nonviral Factor on the Performance of Pear Trees1
Authors: Fridlund P. R. , Drake S. R.
Published: August 2022

Pear Vein Yellows Virus (PVTV) did not significantly reduce growth, yield, or quality of several pear cultivars grown in a hot and arid region except for the cultivar ‘Anjou’ (Pyrus communis L.). Evidence was obtained for the presence of a heat-sensitive nonviral factor associated with the strain of PVYV from ‘Packham's Triumph’ pear. This combination caused reductions in growth and yield and an accumulation of abnormal amounts of phenolic compounds in the fruit.
Foliar Emergence from Bulblets of Lilium longiflorum Thunb. as Related to in Vitro Generation Temperatures1
Authors: Stimart Dennis P. , Ascher Peter D.
Published: August 2022

Bulblets of Lilium longiflorum generated in vitro in the dark at 30°C produced leaves more rapidly and more completely after transplanting to vermiculite than those generated in vitro at 25°. The product of temperature × time (days) was equalized by varying the number of days at the 2 temperatures to make treatments comparable. Therefore, the effect of temperature in vitro was not due to a linear relationship between bulblet development and the product of temperature × time. Bulblets formed at 30°C for half of the temperature × time product of the tissue culture period produced leaves after transplanting at rates similar to those of bulblets generated at a constant 30°C. Exposure of bulblets generated in vitro at 25°C to 4° for 2 weeks before planting in vermiculite resulted in leaf production not significantly different from that of chilled or non-chilled bulblets generated in vitro at 30°C. However, chilling significantly increased fresh weight of bulblets produced in vitro at either temperature. The data suggest that temperature during in vitro development affects Easter lily bulblet dormancy as measured by leaf production.
Developmental Responses of Lilium longiflorum Bulblets to Constant or Alternating Temperatures in Vitro1
Authors: Stimart Dennis P. , Ascher Peter D.
Published: August 2022

Bulblets from bulb-scale explants of Lilium longiflorum Thunb. cvs. Ace and Nellie White cultured in darkness on a semisolid Linsmaier-Skoog medium supplemented with 0.03 mg/liter α-naphthalene-acetic acid (NAA) bore no leaves when produced in vitro at constant 30°C but often did when produced at constant 25°. In vitro temperature regimes involving both 25 and 30° resulted in the largest number of leaves per explant. Time in vitro in each temperature regime was calculated to provide equal heat units so that differences could not be explained by a linear relationship between development and temperature × time. Physiological state of explants, measured by time lily bulbs were stored at 4° before tissue culture, interacted with in vitro temperature. Explants from bulbs stored 110 days or less produced significantly fewer but significantly larger bulblets at constant 25° as compared to constant 30°. This difference was not apparent when explants were taken from bulbs stored at 4° more than 110 days. In an experiment with explants from bulbs stored 80 days, there was no significant difference between ‘Ace’ and ‘Nellie White’ in number of scales per bulblet at either 25 or 30° but bulblets of both cultivars contained significantly fewer scales if generated at 30°. Mean width of meristems in ‘Ace’ bulblets was significantly greater when produced in vitro at 30°. Neither initiation of bulblets nor bulblet development appeared controlled by apical dominance.
Localization of Endogenous Growth Substances in Freesia hybrida ‘Moya’ Corms Before and After a Heat Treatment1
Authors: Gilbertson-Ferriss T. L. , Brenner M. L. , Wilkins H. F.
Published: August 2022

Freesia hybrida Bailey ‘Moya’ corms were analyzed for extractable indole-3-acetic acid (IAA), abscisic acid (ABA) and conjugated ABA (conj.-ABA) before and after 13 weeks of storage at 30°C. After 13 weeks of 30° storage, which is required for emergence, IAA levels did not change in the apical node + bud; however, there was a decrease in ABA and no statistically significant change in the conj.-ABA levels. IAA level increased (0.5 to 14 ng/g fresh weight) in the lateral buds after 13 weeks of heat while the ABA and conj.-ABA did not statistically change. Over the same period, IAA increased slightly (3 to 7 ng/g fresh weight) in the remaining corm tissue while ABA and conj.-ABA levels remained statistically constant.
Corm and Shoot Development of Freesia hybrida ‘Super Emerald Mixture’ as Related to Endogenous Abscisic Acid and Indoleacetic Acid Levels in the Developing Corm1
Authors: Gilbertson-Ferriss T. L. , Brenner M. L. , Wilkins H. F.
Published: August 2022

Corm, shoot, and flower development in seed grown Freesia hybrida Bailey cv. Super Emerald Mixture were compared with levels of endogenous indoleacetic acid (IAA), abscisic acid (ABA) and conjugated ABA (conj-ABA) in the developing corm tissue. Lowering the forcing temperature to below 15°C stimulated floral initiation and corm filling. IAA levels decreased midway through corm filling in 1977 whereas in 1978 the decrease was not statistically significant. During the period of rapid corm filling, ABA levels increased as the temperature decreased below 15° suggesting an association between temperature, corm filling, and ABA.
Cranberry Yield Components in Washington and British Columbia1
Authors: Shawa A. , Eaton G. W. , Bowen P. A.
Published: August 2022

Analyses of yield components of ‘BenLear’, ‘Bergman’ and ‘McFarlin’ cranberry (Vaccinium macrocarpon Ait.) were made in Washington state and British Columbia. Important yield components were fruit set, the proportion of uprights that flowered, and upright numbers. Negative correlations in ‘McFarlin’ between number of uprights and each of proportion flowering, fruit-set, and berry size suggest competition between components in this cultivar.
Calcium, Magnesium, and Potassium Interrelationships Affecting Cabbage Production1
Authors: Harrison H. C. , Bergman E. L.
Published: August 2022

Three cultivars of cabbage (Brassica oleracea L., Capitata group, cvs. Grandslam, Hybrid H, Resistant Danish) were field-grown during 1977 and 1978 to determine the relationship between the percentage of soil-exchangeable Ca, Mg, and K and yield, black speck disease severity and leaf Ca, Mg, K, N, P, Fe, Mn, B, Cu, Zn, and Al concentrations. Highest yields were obtained in soil with a cation exchange capacity of 5% Mg, 5% K and 75–80% Ca. Magnesium and K soil treatments had little consistent effect on elemental leaf concentrations. Leaf Cu and cultivar were related to severity of black speck. The cultivar showing no disease symptoms also had the lowest leaf Cu concentrations.
Seed Dormancy and Germination of Geranium (Pelargonium hortorum Bailey)1
Authors: Nell T. A. , Marsh P. M. , Cantliffe D. J.
Published: August 2022

No differences were observed in water uptake, respiration rate and seed coat morphology of ‘New Era Bright Red’ and ‘New Era Dark Red’ geranium. Water uptake in some seeds was rapid in the first 12 hours following initiation of imbibition. Radicle emergence and germination occurred 3 days after swelling and respiratory activity began as soon as seeds imbibed water. Nonswollen seeds did not germinate. Seed coat surfaces appeared wax-like in both cultivars and no relationship between occlusion of the hilum fissure and germination was observed. Dipping seed in concentrated H2SO4 or hot water, or removing a portion of the seed, increased germination rate and germination to nearly 100%. Results suggest the seed coat in geraniums can be impervious to water uptake.
Scanning Electron Microscope Examination of Flower Bud Differentiation in Sour Cherry1
Authors: Diaz D. H. , Rasmussen H. P. , Dennis F. G.
Published: August 2022

Axillary buds on ‘Montmorency’ sour cherry (Prunus cerasus L.) shoots were examined by scanning electron microscopy. On June 10, 4 weeks after anthesis, a doming of the apex signified the initial change from the vegetative to the reproductive stage. Flower primordia differentiated acropetally in the axils of bracts between late June and mid-July. Bract and flower primordia formed until all available space on the apex was occupied. Flower primordia changed from ovate to round as development proceeded. Sepal primordia were evident on July 30, 11 weeks after anthesis, and petal primordia had formed by August 15. Concentric rings of stamen primordia then developed followed by carpel differentiation in early September.
Effects of Low Oxygen and Temperature on Quality Retention of ‘Bing’ Cherries during Prolonged Storage1
Authors: Chen P. M. , Mellenthin W. M. , Kelly S. B. , Facteau T. J.
Published: August 2022

‘Bing’ sweet cherries (Prunus avium L.) harvested at commercial maturity were commercially packed and stored in 6 low-02 and 1 high-C02 controlled atmospheres (CA) at −1.1°C for 35 days and in a second study were stored in either 1.5% 02 and 0.8% C02 or 12% 02 and 10% C02 at 5.6°, 3.3°, or 1.1°C for 23 days. Fruit stored at 0.5–2.0% 02 with 0.03% C02 maintained a higher percentage of very green stems, brighter fruit color, and higher levels of titratable acids than those stored in air at −1.1°C for 35 days. High C02 atmospheres conserved fruit brightness and TA level but did not prevent stem discoloration. The only effect of lowering temperature from 5.6° to 1.1° was a slight increase in fruit firmness after storage.
Comparison of Several Chemical Pinching Agents on Greenhouse Forcing Azaleas, Rhododendron cv.1
Authors: Shu Lih-Jyu , Sanderson Kenneth C. , Williams J. C.
Published: August 2022

Applications of 0.5% dikegulac sodium (sodium salt of 2,3:4,6-bis-0-(l-methylethylidene-L-xylo-2-hexulofu-ranosonic acid) sprays produced significantly more new shoots on ‘Red wing’ or ‘King fisher’ azalea plants than manual pinching and other chemical pinching agents in 2 experiments. In 5 other experiments involving 5 other cultivars, dikegulac sodium-treated plants generally produced the most shoots, however, the shoot number was not different from shoot number on either manually pinched or 4.2% Off-Shoot-O-treated (mixture of C6 to C12 methyl ester of fatty acids) plants. Sprays of dimethyl dodecylamine caprylate at 0.2% and 0.5%, n-decanol at 2.5%, ethephon [(2-chloroethyl)phosphonic acid)] at 0.08%, and UBI-P293 (2,3-dihydro-5,6-diphenyl-1,4-oxathiin) at 1.0% gave inconsisent results but yielded shoot number comparable to dikegulac sodium in some tests. Off-Shoot-O, dimethyl dodecylamine caprylate, and n-un-decanol were destructive pinching agents at some concentrations and caused considerable plant injury. Dikegulac sodium caused minor injury and transient chlorosis. Ethephon, PBA [6-benzylamino-9(2-tetrahydropyran-2-yl)-9H-purine], and UBI-P293 did not produce any visible phytotoxicities. Shoots of plants sprayed with 0.5% dikegulac sodium and 1.0% UBI-P293 were of similar length or shorter than shoots of either manually pinched or untreated check plants 3 weeks after treatment.
Reduction of Soft Scald in Apples with Antioxidants1
Authors: Wills R. B. H. , Hopkirk G. , Scott K. J.
Published: August 2022

The application of fat soluble antioxidants to ‘Jonathan’ apples (Malu.s domestics Borkh.) after harvest reduced the incidence of soft scald which developed in the fruit during cool storage, increased the amount of unsaturated fatty acidss in the surface lipids, and reduced the level of hexanol in the fruit. Diphenylamine, butylated hydroxvanisole and ethoxvquin were the most effective of the compounds tested.
Effects of Time, Temperature, and Nitrogen Source on the Composting of Hardwood Bark for Use as a Plant Growing Medium1
Authors: Yates Nancy L. , Rogers Marlin N.
Published: August 2022

Hardwood bark, amended with either urea (CO(NH2)2) or ammonium nitrate (NH4NO3) was composted in 210 liter drums at 10 to 40°C or heated to 55°. In the supplemental heat composted (SHC) bark amended with CO(NH2)2, pH increased to 6.8 to 7.4 within the first week. Bark amended with CO(NH2)2 generated more heat than bark amended with NH4NO3. Phenolic content decreased (as indicated by the Folin-Ciocalteu (F-C) method), and germination percentage of Lactuca sativa L. cv. Grand Rapids seed in water extracts of bark samples increased with time. Additions of polyvinylpyrrolidone (PVP) to extracts decreased phenolic content and increased the percentage of seed germination. Plant growth assays using Chrysanthemum × morifolium Ramat ‘Bright Golden Anne’ revealed a possible N deficiency in SHC NH4NO3 treated bark. Plants grown in SHC CO(NH2)2 amended bark did not have as severe a N deficiency. As time of composting increased, naturally composted (NC) bark treated with either N source gave plant growth comparable to that of the control plants grown in a medium of peat:perlite:vermiculite:soil (3:2:2:1 v/v).
Involvement of Gibberellins in the Biennial Bearing of ‘Early McIntosh’ Apples1
Authors: Marino Francis , Greene Duane W.
Published: August 2022

Gibberellins A3 and A4+7 at 300 ppm inhibited flower bud formation on both spurs and 1-year-old wood of ‘Early McIntosh’ apple (Malus domestica Borkh.) trees when applied 10 days after full bloom (DAFB). Gibberellins A4+7 were more effective than GA3 in inhibiting flowering on spurs but not on 1-year-old wood. Seeds collected during the first 9 weeks after bloom had peak GA activity at 5, 15, and 60 DAFB. Gibberellin activity in diffusates of flowers or fruits was detected at bloom and continued to increase until 45 DAFB. Fruit-bearing spurs contained more GA activity than vegetative spurs. Peak gibberellin activity in seeds and diffusates was not paralleled by elevated activity in fruiting spurs. Inhibition of flowering in spurs may not be related solely to seed production or diffusion of gibberellins to the spurs during one short time period.
Responses of Bell Pepper to Nitrogen Sources1
Authors: Locascio S. J. , Fiskell J. G. A. , Martin F. G.
Published: August 2022

Maintenance of adequate available soil N for bell pepper (Capsicium annuum L.) growth is essential to high production in Florida and requires mulching, fertilizer placement, and timing of fertilizer application. Slow-release N was supplied as sulfur-coated urea, isobutylidene diurea (1BDU), or ureaformaldehyde and was compared at 3 N rates with soluble sources such as urea, ammonium nitrate, and ammonium sulfate on ‘Yolo Wonder’ pepper. In the first season, highest yields and N concentrations of tissue occurred where IBDU and urea were applied broadcast with mulch as compared with band placement. In the second season, broadcast fertilizer placement with mulch was compared with 3 split-fertilizer applications without mulch. Fruit yield was affected by a significant interaction among N sources, N rates, and mulch. Highest fruit yields were obtained with SCU and IBDU applied under mulch at 224 kg N/ha. Leaf N was higher during the season with slow-release N than with soluble N. Soil analyses data from samples taken throughout the season showed that N source and rate significantly influenced the soil available N measured as urea-N, NH4-N, and NO3-N.
The Effect of Temperature and Quantum Flux Density on the Morphology, Physiology, and Flowering of Hybrid Geraniums1
Authors: Armitage A. M. , Carlson W. H. , Flore J. A.
Published: August 2022

Hybrid geraniums (Pelargonium × hortorum Bailey) cv. Sooner Red were grown at temperatures ranging from 10–32°C and at various quantum flux densities. The time to visible bud stage (<0.5 cm diameter) was negatively correlated to quantum flux density at a given temperature. The time required from visible bud to flower stage was negatively correlated with temperature while light had no effect. Leaf thickness, number of palisade layers, and specific leaf weight were negatively correlated with temperature, and specific leaf weight was positively correlated with quantum flux density at a given temperature. Net photosynthetic rate ranged from 5–38 mg CO2 dm-2hr-1 for temperatures of 10-37° and was optimum at 20-32°. The Q10 of respiration for hybrid geranium leaves was about 2.2.
Phloroglucinol and in Vitro Rooting of Apple Cultivar Cuttings1
Authors: Zimmerman Richard H. , Broome Olivia C.
Published: August 2022

Cuttings of apple (Malus domestica Borkh.) taken from in vitro proliferated shoots growing on a modified Murashige and Skoog medium were evaluated for ability to initiate adventitious roots in the presence or absence of phloroglucinol at several concentrations of indolebutyric acid (IBA). Phloroglucinol did not promote rooting of ‘Northern Spy’, ‘Summer Rambo’ or ‘Delicious’, had a minor or inconsistent effect upon ‘Nugget’, ‘Ozark Gold’, ‘Spuree Rome’, and ‘Stayman’ and stimulated rooting of ‘Spartan’ cuttings. However, phloroglucinol did not increase rooting of ‘Spartan’ cuttings above that obtained in preliminary experiments without phloroglucinol. Autoclaved phloroglucinol produced the same responses as filter sterilized when tested on ‘Spartan’, ‘Stayman’, and ‘Summer Rambo’. Including IBA in the medium improved rooting of all cultivars and this effect was greater than the effect of phloroglucinol except for ‘Spartan’. Phloroglucinol reduced formation of callus and misshapen roots on cuttings receiving IBA treatment. There was no evidence that phloroglucinol is essential to in vitro rooting of these apple cultivar cuttings.
Variation in Elemental Content of Lettuce Grown under Base-line Conditions in Five Controlled-environment Facilities1
Authors: Berry Wade L. , Krizek Donald T. , Ormrod Douglas P. , McFarlane James C. , Langhans Robert W. , Tibbitts T. W.
Published: August 2022

An interlaboratory comparison was made of the variation in elemental concentration of leaf lettuce (Lactuca sativa L. cv. Grand Rapids) plants grown under base-line conditions for 28 days in 5 controlled-environment facilities. Two studies were conducted by each of 5 investigators using a sphagnum peat-vermiculite mix obtained from a common source. Plant tissue from all studies was collected and analyzed at 1 laboratory for 10 essential elements (P, K, Ca, Mg, Fe, Mn, B, Zn, Cu, Mo) and 10 non-essential elements (Al, Si, Ti, Sr, Ba, Na, Pb, V, Li, and Sn) by arc emission spectrography. The 10 essential elements occurred at concentrations adequate for normal lettuce growth. Tissue analysis data showed large differences in elemental concentration among experiments conducted by the same investigator as well as by different investigators suggesting inadvertent contamination of the leaf samples by the rooting media or contamination of the watering system in each controlled-environment facility. These differences, however, had no observable effect on vegetative growth. Based on a nested analysis on variance, 95% of the elements showed significant plant to plant differences in concentration. However, based on an analysis of variance components, the greatest source of variation was found among investigators.
Field Performance and Phenotypic Stability of Tissue Culture-propagated Strawberries1
Authors: Swartz Harry J. , Galletta Gene J. , Zimmerman Richard H.
Published: August 2022

Vigor, petiole length, stand, runner production, yield per square meter of matted row, and numbers of trusses per crown were greater in tissue culture-produced plants when compared to runner plants of strawberry (Fragaria × ananassa Duch). Leaf area and shape, number of serrations per leaflet, petiole pubescence density, flowers per truss, yield per crown, harvest time, small fruit weight, and percent imperfect fruits did not vary appreciably between propagation methods. Size of large fruit and mean fruit weight were less in tissue culture-produced plants. All changes in performance were caused, at least in part, by the increased vigor and axillary bud activity of tissue culture-produced plants. Tissue culture propagation of strawberry is particularly adapted to production of planting stock for nurseries because 60% more runner plants are produced from tissue culture plants. Production of variant plants from tissue culture was largely limited to 1 meristem-tip line. For certain cultivars, some adjustment of nursery inspection procedures for off-type plants will be required.
Breeding and Selection for Salt Tolerance by the Incorporation of Wild Germplasm into a Domestic Tomato1
Authors: Rush Dale W. , Epstein Emanuel
Published: August 2022

Crosses were made between a salt tolerant wild tomato [Lycopersicon cheesmanii ssp. minor (Hook) C. H. Mull.] and a domestic cultivar (L. esculentum Mill. cv. Walter). Selections were made from resulting progenies for salinity tolerance at germination, seedling establishment, and the reproductive stage of their life cycle. The selected progenies were tested for survival and fruit production in salinized solution culture experiments, and in field greenhouse trials where they were irrigated with various dilutions of seawater applied to sand. Salt tolerance was shown to be a heritable trait. Plants selected from the F2 and successive backcrosses to ‘Walter’ survived and produced fruit when irrigated with up to 70% seawater in the sandy soil culture trials, whereas ‘Walter’ did not survive.
Offshoots vs. Stumps as Planting Materials for Globe Artichokes1
Authors: Ibrahim A. M. , Ryder E. J. , Rubatzky V. E.
Published: August 2022

Yield/plant of both stump-planted and offshoot-planted globe artichokes (Cynara scolymus L.) decreased as spacing decreased, but total yield increased. Highest yields were obtained at intermediate levels of number and spacing of shoots: 6 shoots/location at 1.2 × 1.2 m and 3 shoots/location at 1.2 × 0.9 m. Early yield of offshoot-planted artichokes was 7× that of stump-planted artichokes. Production from offshoots occurs in 2 discrete periods, a moderate yield 4 months after planting and a heavy yield during months 9 and 10. Production from stumps increased very slowly, peaking during the last 3 months of the experiment.
Low Oxygen Storage of Special Precooled ‘Kees Nelis’ and ‘Prominence’ Tulip Bulbs1
Authors: Prince T. A. , Herner R. C. , De Hertogh A. A.
Published: August 2022

Flowering of ‘Kees Nelis’ (Tulipa gesneriana L.) tulip bulbs was not impaired after 4 weeks of storage at 17°C in either 3 or 5% oxygen. ‘Kees Nelis’ bulbs stored in air or 1% O2 for 4 or 6 weeks and ‘Prominence’ bulbs stored at any reduced O2 level for 4 or 6 weeks flowered unsatisfactorily. Bulbs specially precooled later in the forcing season yielded unsatisfactory flowering after storage at 17°C regardless of cultivar. Low O2 levels (1 to 5%) reduced the respiration rate of bulbs stored at 17°C for 6 weeks compared to bulbs stored in air. Storage of ‘Kees Nelis’ bulbs for 3 weeks in air with 5 ppm ethylene caused flower abortion upon forcing. Three or 5% O2 reduced ethylene-induced flower abortion during storage.
Opening and Vase Life Extension of Peach Flowers on Detached Shoots with Sucrose and Ethanol1
Authors: Davies Frederick S. , Muñoz Carlos E. , Sherman Wayne B.
Published: August 2022

Detached shoots of double-flowered peach [Prunus persica (L.) Batsch] selections Fla. 6-1 and Fla. 0-5 were successfully opened in floral solutions containing 1 to 10% sucrose in deionized water. Addition of 8-hydroxyquinoline citrate (8-HQC), gibberellic acid (GA3), or 6-benzylaminopurine (BA) to solutions did not extend vase life. Solution uptake rate decreased over the 8-day life of the shoots and was influenced by solution molarity. Xylem plugging by pectic-type materials increased with time in solution. Addition of 1% ethanol to the floral solution hastened time of first opening, decreased the extent of xylem plugging, and extended vase life. Ethanol at 2% extended vase life and increased solution uptake rate over solutions containing sucrose alone.
Frost Injury of Tender Plants Increased by Pseudomonas syringae van Hall1
Authors: Anderson J. A. , Buchanan D. W. , Stall R. E. , Hall C. B.
Published: August 2022

Pseudomonas syringae van Hall, an ice nucleation active (INA) bacterium, increased frost susceptibility of tomato (Lycopersicon esculentum Mill.) and soybean (Glycine max L.) when sprayed on leaves prior to low temperature stress. Tomato and soybean plants inoculated with INA bacteria were nucleated and frozen at −4° and −5°C respectively. Control plants that were free of INA bacteria supercooled and survived to −8°. A threshold INA bacterial concentration of about 4 × 105 cells/ml was necessary for ice nucleation. Ice nucleating active bacteria preconditioned at 2° showed a marked increase in efficiency of ice nucleation. Preconditioned INA bacteria had ice nucleation temperatures 5° higher than INA bacteria held at 21°.
Inhibitory Effects of Ammoniacal Nitrogen on Growth of Radish Plants. II. Investigation on the Possible Causes of Ammonium Toxicity to Radish Plants and Its Reversal by Nitrate1
Authors: Goyal S. S. , Huffaker R. C. , Lorenz O. A.
Published: August 2022

The effects of NH4+ on several physiological and biochemical parameters of radish (Raphanus sativus L.) were determined. Photosynthetic CO2 fixation rates of radish plants cultured with NH4+ as the source of N were about 50% of those with NO3− but dark respiration rates were the same. Plants grown with NO3− fixed at least twice as much, 14CO2 in vitro into acid stable products using ribulose-1, 5-bisphosphate, ribose 5-phosphate, 3-phosphoglyceric acid and phosphoenolpyruvic acid as substrates. This suggests that CO2 fixation both in light and darkness was decreased by NH4+ nutrition. Chlorophyll and total soluble protein concentration of plants, cultured with NH4+ as the source of N, were about 33% and 70%, respectively, of those cultured with NO3−. In vitro activities of glutamate dehydrogenase and isocitrate dehydrogenase were higher and lower, respectively, in plants cultured with NH4+ over those with NO3. Results indicate that NH4+ toxicity in radish plants is closely related to inhibition of photosynthesis. Evidence is presented suggesting that NO3− facilitated NH4+ assimilation in radish plants.