bluuebunny/crossref_metadata_2025 huggingface dataset:
Endogenous Abscisic Acid in Relation to Rest and Bud Burst in Three Vitis Species1
Authors: Emmerson John G. , Powell Loyd E.
Published: August 2022

Endogenous abscisic acid (ABA) decreased during chilling in buds of several cultivars of Vitis vinifera L., Vitis riparia Michx. and Vitis labruscana Bailey, both in field grown and greenhouse vines. During bud burst, ABA decreased on a concentration basis only, until just prior to leaf unfolding. Bud scale removal hastened bud burst. Although ABA content was higher in scales than in primordia, changes in ABA level during chilling and bud burst occurred only in primordia. Lateral buds, which are committed to grow the year of formation, had higher ABA levels than dormant axillary buds which require a chilling period to grow. Applications of ABA, gibberellic acid (GA3), and (2-chloroethyl)trimethylammonium chloride (CCC) to dormant, chilled grape cuttings had no effect on time to burst, while zeatin hastened burst. These results suggest that, if there is an interaction between chilling and ABA, it is of secondary importance in bud burst of grape.
Influence of Photoperiod and Light Quality on Stolon Formation and Flowering of Chlorophytum comosum (Thunb.) Jacques1
Authors: Heins R. D. , Wilkins H. F.
Published: August 2022

Irradiating the all-green Chlorophytum comosum Thunb. with incandescent or red cellophane wrapped fluorescent lamps during the night increased the mean number of stolons formed per plant. A night interruption was more effective in stimulating stolon formation than irradiating the plants prior to sunrise or at sunset. There were no significant differences in stolon numbers formed between the two light sources within an irradiation treatment. Less and less time was required between the advent of subsequent stolons under all treatments during the 25 week experiment. Photoperiod treatments had no effect on time from visible stolons to anthesis. Plants in all treatments formed stolons and flowered.
Chromosome Numbers of Apple Species, Cultivars, and Sports V1
Authors: Pratt Charlotte , Joh Sun Paik , Way R. D. , Einset John
Published: August 2022

Chromosome counts derived from sectioned buds of 137 apple clones are reported. Of these 128 were determined to be diploid (2n = 34) and 9 to be triploid (2n = 51).
Effect of Salinity in Water Supplies on Greenhouse Rose Production1
Authors: Hughes Howard E. , Hanan Joe J.
Published: August 2022

‘Forever Yours’ roses (Rosa hybrida L.) grown in 20-liter containers filled with gravel or soil, were irrigated with solutions of varying salinity and composition over a 2-year period. Results indicated that HCO3− ion was highly toxic to rose production, resulting in chlorosis whenever concentrations exceeded 2 meq liter−1. Sodium and Cl− gave increasing problems above 4 meq liter−1. Sulfate was innocuous except as the ion contributed to total salinity of the solution. Yield was significantly reduced when electrical conductivity exceeded 1800 μmhos cm−1, and at 1300 μmhos cm−1 if ion proportions were adjusted. Treatments in soil were highly variable, with effects slower to appear.
Root and Shoot Growth Rate Relationships of Two Cultivars of Japanese Holly1
Authors: Mertens W. C. , Wright R. D.
Published: August 2022

Rooted linears of Ilex crenata Thunb. ‘Helleri’ and ‘Rotundifolia’ were grown in polyvinyl chloride pipe sections from which longitudinal sections could be removed for root observations. Plants were fertilized at either 150 or 300 ppm N with a 20N–8.7P–16.5K soluble fertilizer. Rate of root and shoot growth was determined through 2-3 flushes of growth by taking weekly measurements of shoots and roots. Root growth of both cultivars was episodic in nature with active root growth usually preceding a shoot growth flush by 1 to 2 weeks. This growth pattern was observed in both fertility levels.
The Relationship Between Vegetative Maturity and the Onset of Winter Dormancy in Red-osier Dogwood1
Authors: Seibel Janice R. , Fuchigami L. H.
Published: August 2022

Potted plants of red-osier dogwood (Cornus sericea L., syn. C. stolonifera Michx) were grown under 3 different dormancy-inducing regimes. Each week 5 plants per group were defoliated and placed in a warm greenhouse. Plants were checked daily for regrowth and new leaves were removed. When defoliation ceased to induce bud break, the plants were considered to be in a state of winter dormancy. Plants were observed for damage the following spring to determine when they had reached vegetative maturity, and it was found that vegetative maturity corresponded to winter dormancy development in all 3 growing conditions.
Modeling the Vegetative Maturity of Red-osier Dogwood1
Authors: Renquist A. R. , Wensink R. B. , Fuchigami L. H. , Seibel J. R. , Nissila P. C. , Bates E. M.
Published: August 2022

A computer model was developed to predict autumn vegetative maturity, end of summer dormancy of red-osier dogwood (Cornus sericea L. syn. Cornus stolonifera Michx.). Empirical equations were developed from growth chamber data and applied to results obtained from lath house grown plants. The model required input parameters of 2-hourly temperatures and daylengths. From the data daily phototemperature values were determined. The empirical model over-estimated the time to maturity of the lath house grown plants by only 4 days, perhaps indicating the need for a more precise measure of the critical photoperiod.
Performance of Processing Peas to Foliar Applications of Daminozide1
Authors: Ryerson D. K. , Oplinger E. S. , Gritton E. T.
Published: August 2022

Foliar applications of succinic acid-2,2-dimethyl hydrazide (daminozide, SADH) at 1.0 and 2.0 kg/ha increased yields of ‘Early Perfection’ processing pea (Pisum sativum L.) by 10 and 11%, respectively, averaged over 3 growing seasons but had no significant affect on ‘Puget’, ‘Alaska’, and ‘Dane’. Daminozide consistently reduced plant height; but had variable effects on tenderometer values.
Intraspecific Variability for Nitrogen Fixation in Southernpea (Vigna unguiculata (L.) Walp)1
Authors: Zary K. W. , Miller J. C. , Weaver R. W. , Barnes L. W.
Published: August 2022

The extent of intraspecific variability for N2 fixation among 100 southernpea (cowpea) genotypes was determined, and a screening technique was developed to measure the character. Significant differences in N2 fixation efficiency were found among host plant genotypes following application of a standard commercial mixed strain Rhizobium inoculant. These differences were obtained whether the criterion used was nodule mass, nodule number of nitrogenase activity, as measured by the acetylene reduction assay. This variability is evidence of genetic control of the trait and suggests the possibility of breeding for increased N2 fixation efficiency in cowpea.
Removal of Ten Elements by Vegetables and by Alfalfa1
Authors: Peck N. H.
Published: August 2022

Peas (Pisum sativum L.), table beets (Beta vulgaris L.), cabbage (Brassica oleracea L. capitata group), snap beans (Phaseolus vulgaris L.), sweet corn (Zea Mays L.), and alfalfa (Medicago sativa L.) were grown at 4 rates of concentrated superphosphate (CSP) and 4 rates of potassium chloride (KC1) fertilizers in a Honeoye fine sandy loam soil. Removal of P, K, Ca, Mg, Na, S, Cl, Zn, Mn, and Fe by each crop was determined. CSP increased the removal of P. KC1 increased the removal of K and Cl. Table beet plants removed more elements by weight and by equivalences of cations per ha than any other vegetable crop. Two years of alfalfa hay removed more elements per ha than 5 years of the harvested portions of the 5 vegetable crops. Vegetative structure of the crops had wider ranges than the reproductive structures in concentrations of P due to CSP fertilizer treatments and especially wide ranges of K and Cl due to the KC1 fertilizer treatments.
Role of Wound Ethylene in Fruit Set of Hand-pollinated Muskmelons1
Authors: Natti Tom A. , Loy J. Brent
Published: August 2022

Application of a lanolin paste containing the aminoethoxy analog of rhizobitoxine, aminoethoxyvinylglycine (AVG), to the base of perfect flowers improved fruit set in emasculated, hand-pollinated flowers of muskmelon (Cucumis melo L.). Applications of indoleacetic acid (IAA) improved fruit set slightly, but reduced seed yields. Combinations of IAA and AVG were more effective than IAA alone, but were less effective than AVG alone at the optimum dosage. AVG prevented would ethylene production by excised, hand-pollinated flowers. The results support the contention that would ethylene production by emasculated, hand-pollinated flowers is an important factor in lowering fruit set.
Effects of Freezing, Thawing, and Cooking on the Appearance of Highbush Blueberries
Authors: Sapers G. M , Burgher A. M. , Phillips J. G. , Jones S. B. , Stoen E. G.
Published: August 2022

Increases in the darkness and redness of both thawed and cooked highbush blueberries (Vaccinium corymbosum L.), indicated by tristimulus measurements, were cultivar-related but not dependent on blueberry pH or anthocyanin content. Waxy bloom was retained in thawed berries but lost during cooking. Pigmented exudate appeared with some cultivars during thawing. Differences among cultivars in exudate formation and reddening during thawing are explained in terms of changes in epidermal cells, cuticle, and wax structure which were observed by light and electron microscopy. The color of blueberry cooking water depended primarily on the berry anthocyanin content, acidity, and the extent of leaching.
In Vitro Induction of Tetraploidy in Vaccinium darrowi, V. elliottii, and V. darrowi X V. elliottii with Colchicine Treatment
Authors: Perry J. L. , Lyrene P. M.
Published: August 2022

Three diploid taxons (Vaccinium darrowi Camp, V. elliottii Chapm., and interspecific V. darrowi x V. elliottii) were treated with various colchicine concentrations and treatment durations to determine the best method for inducing autopolyploidy in in vitro blueberry cultures. Shoot-tip cuttings were the best in vitro planting material for induction of shoots with increased diameter, an indicator of polyploidy. Tetraploids were produced at colchicine concentrations from 0% to 0.20%. The best treatment combinations were genotype-dependent.
Anatomical Aspects of Abscission in Pistachio
Authors: Lin Tzong-Shyan , Crane Julian C. , Polito Vito S.
Published: August 2022

In pistachio (Pistacia vera L. cv. Kerman), when flowers did not set or when young fruits were removed, pedicels and/or portions of the rachis or of the primary branches subtending these parts abscised. Inflorescence buds on fruiting shoots and those on nonbearing shoots treated with (2-chloroethyl) phosphonic acid (ethephon) also abscised. Abscission of the above organs, as well as of leaflets and compound leaves, occurred in definite zones. The first manifestation of the abscission process was transverse cell division in the abscission zone. A separation layer developed in the distal portion of the abscission zone in these organs. The newly formed cells in the proximal area of the abscission zone of pedicels, rachises, and ethephon-treated inflorescence buds became protective layers. However, the counterpart in abscising inflorescence buds on fruiting shoots was largely degraded as abscission progressed. Abscission of mature fruits of pistachio was not preceded by cell division but involved separation and collapse of cells in the fruit mesocarp and exocarp surrounding the distal portion of the pedicel.
Growth Regulators, Fruit Drop, Yield, and Quality of Navel Orange in Florida
Authors: Lima Jose Eduardo O. , Davies Frederick S.
Published: August 2022

Fruit drop of navel orange [Citrus sinensis (L.) Osbeck], which occurs after June drop, was studied from 1980 through 1982 in 2 groves in north-central Florida. Summer drop, which occurs from June to August, and summer-fall drop, which occurs from late August through October, were the major periods of fruit drop. Fruit drop was significant in 1981, ranging from 63 to 200 fruit per tree. A dilute spray of 10 or 20 ppm 2,4-dichlorophenoxyacetic acid (2,4-D), alone or in combination with 20 ppm gibberellic acid (GA) and applied 5 to 9 weeks after midbloom, reduced summer fruit drop in all seasons. The same materials applied 13 weeks after midbloom were ineffective. An application of 2,4-D at 5 weeks after midbloom increased yields in 1981, but not in 1982, because summer drop was minor in that year. Midbloom application of GA + 2,4-D increased splitting and summer-fall drop in 1981, but generally these materials had no effect. Sprays of 2,4-D, GA, or the combination did not adversely affect internal fruit quality, although GA or GA + 2,4-D increased rind firmness when applied 13 weeks after midbloom.
Seasonal and Genotypic Effects on Yield and Physico-chemical Seed Characteristics Related to Food Quality in Dry, Edible Beans
Authors: Hosfield G. L. , Uebersax M. A. , Isleib T. G.
Published: August 2022

The yields and physico-chemical seed traits related to food quality of 25 strains of dry beans (Phaseolus vulgaris L.) representative of the Black Turtle Soup commercial class were evaluated for 3 seasons. The strains differed significantly over seasons for washed drained weight, textural properties, and surface color characteristics of cooked seeds. All the other traits were nonsignificant in the combined analysis. Trait expression was strongly influenced by genotype × season interactions. Spearman's coefficient of rank correlation between pairs of years indicated that the interactions were due primarily to inconsistent strain rankings from year-to-year. The season and genotype × season variance component estimates for yield, soaking, and several cooked bean traits were larger than the genotypic component, indicating that seasonal effects predominated over genotypic effects. These results suggested that several years of testing are needed to assess strain performance accurately for food quality. The contribution made by each strain to the genotype × season variance component was ascertained by calculating a “stability variance” statistic. Based on this statistic, strains were found to differ in their genetic potential to respond to varying environments. Several genotypes were phenotypically stable for most traits. Strain no. 23 (CIAT pedigree FF 4-13-M-M-M-M), which had good yield (2.8 MT/ha) and protein percentage (27.7%) and favorable culinary quality, was of particular interest.
Irrigation Management, Fruit Quality, and Storage Life of Apple
Authors: Proebsting E. L. , Drake S. R. , Evans R. G.
Published: August 2022

‘Delicious’ and ‘Golden Delicious’ apples (Malus domestica Borkh.) on seedling rootstock were grown with trickle and sprinkler irrigation, both operated at high frequency of irrigation (daily). Trees with trickle irrigation developed lower leaf water potentials and produced less vegetative growth than trees with sprinkler irrigation, but fruit and productivity were similar. Apples from the trickle-irrigated trees had less water content and higher soluble solids than those from sprinkler-irrigated trees. Titratable acidity tended to be lower and both red color in ‘Delicious’ and yellow color in ‘Golden Delicious’ tended to be higher in fruit from trickle-irrigated trees than from sprinkled trees; firmness at harvest was similar regardless of irrigation procedure. Storage life was not influenced consistently by irrigation. Where differences did occur, the fruit from trickle-irrigated trees was softer after storage. Changes in fruit quality similar to those observed in trickle-irrigated trees were produced by imposing, through high frequency deficit irrigation with sprinklers, similar moisture deficits on apple trees, as measured by leaf water potential.
The Morphology of Staminate Flower Differentiation in Pecan
Authors: Wetzstein Hazel Y. , Sparks Darrell
Published: August 2022

Inflorescence and staminate flower development in pecan [Carya illinoinensis (Wang.) K. Koch] were examined using scanning electron microscopy. Organogenesis was described from inception to pollen dehiscence. The order of organ initiation was: a single bract, rounded floral apex, 2 lateral bracteoles, and 3-7 stamens. The initiation and time when stages of floral differentiation occur were determined for 1 protandrous and 2 protogynous cultivars. The time of early inflorescence development and the initiation of floral primordia and bracts were similar in both cultivar types, occurring about 12 months prior to staminate maturity. However, the initiation time of later floral development stages was divergent. The floral stages in the protandrous cultivar up to anther lobing occurred during the previous growing season. In the protogynous cultivars, initiation of bracteoles, the floral apex, stamen primordia and anther lobing took place in the spring of their anthesis.
Development of Seedless Orange and Grapefruit Cultivars through Seed Irradiation
Authors: Hearn C. J.
Published: August 2022

Seed of ‘Pineapple’ orange [Citrus sinensis (L.) Osbeck] and ‘Duncan’ and ‘Foster’ grapefruit (C. paradisi Macf.) were exposed to gamma rays at 10, 15, 20, 25, and 30 krad. Seedling emergence was delayed. LD50 levels were 10-15 krad for ‘Pineapple’, 15 krad for ‘Duncan’, and ≤10 krad for ‘Foster’. The greater sensitivity of ‘Foster’ may have been due in part to higher seed moisture content at treatment. Seedless mutants were obtained following gamma irradiation and fruiting of small numbers of seed and seedlings. The frequency of seedless mutants of ‘Pineapple’ and ‘Duncan’ was highest following treatments of 20-25 krad.
Light and Scanning Electron Microscopy of Intumescences on Tissue-cultured, Sweet Potato Leaves
Authors: Wetzstein Hazel Y. , Frett John J.
Published: August 2022

The occurrence and structure of abnormal outgrowths developed on leaves of sweet potato [Ipomoea batatas (L.) Lam] on sterile meristem plantlets maintained in culture tubes were described using light and scanning electron microscopy. The outgrowths or intumescences generally were wart-like, hemispherical forms or irregular, perpendicularly elevated protuberances that formed on both abaxial and adaxial surfaces. Their development resulted from a hypertrophy and hyperplasia of epidermal and mesophyll cells, which resulted in greatly enlarged, roughly isodiametric cells. Swelling and enlargement of stomata were evident; rupture of the epidermal surface did not occur.
Isolation and Culture of Protoplasts from Apple Callus and Cell Suspension Cultures
Authors: Hurwitz Charles D. , Agrios George N.
Published: August 2022

Protoplasts were isolated from actively growing callus and cell suspension cultures initiated from apple leaf discs. Callus and cell suspension cultures incubated in a solution of 0.7 m mannitol, 0.01 m CaCl2, 2% cellulysin, 0.5% macerase yielded protoplasts from about 75% of the callus cells and 90% of the suspension cells. Protoplast viability was 95–98% upon isolation, and 80–85% after a 2-week culture in a modified Murashige and Skoog (MS) medium. About 60% of the protoplasts regenerated cell walls, and 5–10% of the original protoplasts exhibited cell division.
Sampling Procedures for Minimizing Variation in Peach Fruit Quality
Authors: Marini R. P. , Trout J. R.
Published: August 2022

Peach [Prunus persica (L.) Batsch cv. Harken] fruit were harvested at the firm-mature stage on 5 different dates. Fruit of uniform size were sampled randomly on each date from each of 4 quadrants per tree and evaluated for color, firmness, and soluble solids using the red and green sides of each fruit. A statistical model was used to identify and separate the sources of within- and among-tree variation in fruit quality indices. All quality indices were affected by harvest date. Fruit- and tree-related interactions accounted for a major part of the total random variation. Variance estimates were used to determine numbers of trees per treatment and fruit per tree needed to detect fruit quality differences of a desired magnitude. In general, 6 trees per treatment and 12 to 16 fruit per tree could be expected to detect meaningful differences in fruit quality in experiments involving 2 treatments.
Evaluation of Combining Ability, Heterosis, and Genetic Variance for Fruit Quality Characteristics in Bush Muskmelon
Authors: Kalb Thomas J. , Davis D. W.
Published: August 2022

A 6-parent diallel was established in 1981 at Excelsior, Minn, and at Santa Paula, Calif, to analyze combining ability and heterosis for fruit quality of traits in bush muskmelon (Cucumis melo L.). GCA variance exceeded SCA variance for all traits. Minnesota breeding lines were superior in GCA for most interior quality traits, but inferior to Florida and California lines in exterior quality. Correlations between the performance of parents and the average of their hybrids were consistently positive, and often significant. Favorable heterosis over the midparent was shown for soluble solids, net density, and net rope, and, to a lesser extent, for flesh amount, rind thickness, cavity amount, and cavity dryness. A 3 × 10 design II at Excelsior showed estimates of additive variance exceeding those of dominance variance for all traits except fruit weight, shape index, and vein tract. The large estimates of additive variance provided for moderately high (40–70%) estimates of heritability for most traits.
Scarf Skin on ‘Rome Beauty’: Time of Origin and Influence of Fungicides and GA4+7
Authors: Ferree David C. , Ellis Michael A. , Bishop Bert L.
Published: August 2022

‘Rome Beauty’ apples were enclosed in perforated polyethylene bags at various times or treated with selected fungicides, GA4+7 or nutrient sprays to determine the influence on development of scarf skin. Bagging at petal fall (PF) reduced scarf on both the green and colored sides of the fruit. The longer the bags were in place, the greater the reduction in scarf skin up to 60 days after PF. Fruit weight was reduced by as little as 10-day enclosure in bags applied at PF, and the longer the period of enclosure the greater the reduction in size. Bagging explains a decrease in the scarf skin rating which is not explained by the corresponding decrease in fruit weight. Bagging 10 days after PF reduced fruit set, but bagging at PF or 20 or 30 days after PF had no influence on fruit set. Full season fungicide programs of benomyl or dikar increased the amount of scarf skin. Nutrient dips of either solubor or CaCl2 or the insecticide dimethoate had no influence on scarf skin. GA4+7 dips during the critical period for development significantly decreased scarf skin but not to the level achievable with a polyethylene bag. Fruit samples from different orchard sites differed in the level of scarf skin present.
The Effect of Growing Location and Harvest Maturity on the Storage Performance and Quality of ‘Hayward’ Kiwifruit
Authors: Crisosto Gayle Ullrich , Mitchell F. Gordon , Arpaia Mary Lu , Mayer Gene
Published: August 2022

Kiwifruit from 3 growing locations were harvested at 4 maturity levels. Weight, length, width, flesh color, flesh firmness, harvest soluble solids, titratable acidity, respiration, and ethylene production were measured at harvest, and subsequent storage behavior and sensory quality of the fruit were evaluated. The results indicate that a combination of initial soluble solids content at harvest, and flesh firmness, similar to the maturity index for pear, seems promising as a maturity index for kiwifruit.
Influence of Mycorrhizal Fungi on Cytokinin Production in Sour Orange
Authors: Edriss M. H. , Davis R. M. , Burger D. W.
Published: August 2022

Nonmycorrhizal or mycorrhizal (Glomus fasciculatum, G. etunicatum, or Gigaspora heterogama) sour orange (Citrus aurantium L.) seedlings were fertilized with 3 phosphorus levels applied in the irrigation water. At 0 mg P/L fertility, dry weight and cytokinin production of mycorrhizal plants were more than twice those of the nonmycorrhizal plants. Concentrations of P in leaves of mycorrhizal plants also were greater than the concentrations of P in the nonmycorrhizal plants. At 50 mg P/L fertility, concentrations of P in leaves were similar whether or not plants were mycorrhizal. Dry weight and cytokinin production of the mycorrhizal plants, however, were still twice those of the nonmycorrhizal plants. At 100 mg P/L fertility, dry weight and cytokinin production did not differ between nonmycorrhizal plants and plants infected with 2 of 3 mycorrhizal fungi. In G. heterogama-infected plants, cytokinin production was greater than that of nonmycorrhizal plants despite similar dry weights and P concentrations in the leaves. Enhancement of cytokinin production seemed to be associated with mycorrhizal infection rather than with increased P uptake.
The Effects of Corn Leaf Rust on Maturity and Quality of Fresh Market Ears of Sweet Corn
Authors: Randle W. M. , Davis D. W. , Groth J. V.
Published: August 2022

The influence of common leaf rust (Puccinia sorghi Schw.) on 2 sweet corn (Zea mays L.) hybrids was compared in rusted and nonrusted plots for several maturity and ear quality characters. Differences were found for time of silking, ear length, ear diameter, and percentage of moisture between rusted and nonrusted plots. The percentage of Brix ranged from 4% to 25%, with the rusted plots always having reduced mean values. Correlations (P = 0.01) were found between ear diameter and percentage of moisture, percentage of Brix and percentage of moisture, and between ear length and ear diameter.
Fruit Quality Characterization of 11 Vaccinium Species
Authors: Ballington J. R. , Ballinger W. E. , Swallow W. H. , Galletta G. J. , Kushman L. J.
Published: August 2022

Eleven species in sections Cyanococcus and Polycodium of the genus Vaccinium were compared among themselves and with standard cultivars for soluble solids, titratable acidity, soluble solids/acid ratio, weight/berry (g), stem scar diameter (pedicel diameter at the berry), scar depth, fruit removal force (picking ease), and firmness. Vaccinium ashei Reade populations collected in either Florida or Georgia showed consistent differences in acidity, fruit size, and firmness. No such pattern in geographical differences occurred with V. corymbosum L. Vaccinium stamineum L. (section Polycodium) was outstanding for high soluble solids, large fruit size, small scar diameter, and firmness. Vaccinium elliottii Chapm. seemed promising for mechanical harvesting and processing with high-acid fruit, a favorable soluble solids/acid balance, small scar diameter, and easily harvested fruit. Vaccinium angustifolium Ait. was noted for high soluble solids, small shallow scar, and picking ease; V. pallidum Ait. for high soluble solids and small shallow scar; V. amoenum Ait. for small shallow scar and picking ease; and tetraploid V. corymbosum for high acidity and favorable soluble solids/acid balance. Sufficient variability occurred among and within species for selection for improvement of most traits; however, several generations of backcrossing or recurrent selection would be required for producing genotypes with commercial fruit size.
Construction of a Milled Pine Bark and Sand Potting Medium from Component Particles I. Bulk Density: A Tool for Predicting Component Volumes
Authors: Pokorny F. A. , Henny B. K.
Published: August 2022

Volume of loose media was determined accurately by a devised mechanical method and used for bulk density (BD) calculations. BD associated with increasing percentages of pine bark and/or sand potting media were plotted. Linear increase in BD associated with increasing percentage of sand in the medium was used to predict the percentage by volume of sand and/or bark in an unknown mixture of the two components. The technique should be useful in synthesis studies utilizing pine bark and sand as medium components.
Estimating Fruit Ripening Date of Rabbiteye Blueberries
Authors: Gupton C. L.
Published: August 2022

Fourteen rabbiteye bluberry (Vaccinium ashei Reade) cultivars were evaluated for contribution of component flower bud and fruit development stages to ripening date. Rate of bud, flower, and fruit development were estimated from the regression of flower bud stage and cumulative ripe fruit on time. Except for one instance, the best fitting curve for rate of bud development was described by a quadratic polynomial. Rate of fruit ripening was linear for ‘Bluebelle’ and ‘Centurion’; all other curves were described by quadratic equations. From the curves, Julian date of bud break, anthesis, 1st ripe fruit, and 50% ripe fruit were estimated. Intervening time periods comprised stages of development that could be evaluated for their contribution to ripening date of cultivars. Time required to complete the final development stage most influenced ripening date. Sample shoots could be utilized to select individual plants for ripening date, and repeatability of ripening date among clones is sufficient to select on the basis of evaluation in a single year.
Light Acclimation in Citrus Leaves. I. Changes in Physical Characteristics, Chlorophyll, and Nitrogen Content
Authors: Syvertsen J. P. , Smith M. L.
Published: August 2022

‘Duncan’ grapefruit (C. paradisi Macf.) and ‘Pineapple’ sweet orange (Citrus sinensis L.) seedlings were grown in full sunlight, 50% and 90% shade; maximum photosynthetic photon flux densities (PPFD) of 2300, 1100 and 200 μmol s−1m−2, respectively. In fully expanded matured (hardened) leaves, leaf thickness, specific leaf weight (SLW), tissue density, and nitrogen content were highest in full sun leaves and lowest in 90% shade leaves. Leaf chlorophyll content was highest in 90% shade leaves. Half of the seedlings which were grown in full sunlight were transferred into 50% shade to simulate normal canopy development; half of the seedlings from 50% and 90% shade were moved into full sunlight to simulate changes that occur after hedging. Specific leaf weight and tissue density changed in the same direction as PPFD. Leaf nitrogen content decreased temporarily when leaves were exposed to new PPFD conditions regardless of the PPFD levels. Total leaf chlorophyll content initially decreased when seedlings were transferred into full sunlight but began to increase after 4–6 weeks. Chlorophyll content increased in seedlings transferred from full sun to 50% shade. Percentage of air space within leaf tissues did not change during acclimation to new PPFD levels. Changes in leaf anatomy, physical characteristics, and chemical components are mechanisms that enable citrus leaves to acclimate to a wide range of changing light environments, even after leaves are fully mature.
The Influence of Root Pruning on Water Relations, Net Photosynthesis, and Growth of Young ‘Golden Delicious’ Apple Trees
Authors: Geister Dagmar , Ferree David C.
Published: August 2022

Young ‘Golden Delicious’/M7 trees were root pruned on 2 sides at 2.5, 5.0, and 10.0 cm distances from the stem which removed 10%, 28%, or 59% of their roots. Net photosynthesis (Pn) was reduced 35% and 47% and transpiration (Tr) 29% and 45% one day after root pruning of 28% and 59%, respectively, and recovery began 10 days later. Root pruning reduced leaf water potential significantly for 6 hr; recovery was apparent after one day. Root pruning severity of 10% had no effect on Pn, Tr, or water potential. Shoot growth rates decreased with increasing root pruning severity. The greatest reduction of shoot extension occurred during the 2nd and 3rd week following root pruning, with increasing growth rates observed in the 4th week. Suppression of shoot diameter increase lasted for 2 weeks. Leaves that developed following 28% or 59% root pruning were smaller than leaves of unpruned trees and had increased specific leaf weights (SLW), while previously expanded leaves were not affected. As root pruning severity increased, fresh weight of leaves and current shoots were reduced 45%; older parts of the tree were not influenced. Four weeks after root pruning there was no difference in total fresh weight of roots. The distribution of small roots from root pruned trees was increased in close proximity to the stem and decreased at distances greater than 5 cm from the stem.
The Effect of European Red Mite Feeding on the Fruit Quality of ‘Miller Sturdeespur’ Apple
Authors: Ames G. K. , Johnson D. T. , Rom R. C.
Published: August 2022

Trees of Malus domestica (Borkh.) ‘Miller Sturdeespur’ were hand thinned to achieve light, medium, and heavy fruit loads. A heavy European red mite (ERM), Panonychus ulmi (Koch), infestation was encouraged by mite seeding and predator elimination in half the trees for each fruit load. The effect of these treatments were determined on fruit number, number and percentage of drops, fruit size, color, soluble solids, titratable acidity, pH, firmness, and percentage of foliar concentration for 5 macronutrients. Mite feeding increased the percentage of drop and reduced red pigmentation, soluble solids, and leaf phosphorus and calcium. Deleterious effects of mite feeding increased with increasing fruit load. With light fruit loads, heavy mite feeding had a negligible effect on fruit quality.
Pleiotropic Effects Associated with the Chlorophyll Intensifier Mutations high pigment and dark green in Tomato
Authors: Jarret R. L. , Sayama H. , Tigchelaar E. C.
Published: August 2022

The chlorophyll intensifíer mutations high pigment (hp) and dark green (dg) of tomato (Lycopersicon esculentum Mill.) were analyzed for their effects on fruit and vegetative characters. These mutations are nonallelic, and differences between them are primarily quantitative. Both mutations increased Vitamin C content at all stages of fruit development, and more than 90% was present in the reduced form in the mature-green and fully ripe mutant types and in normal fruit. Ascorbate levels in all fruit portions were increased by hp and dg, with the largest increase occurring in the outer pericarp. Chlorophyll in outer pericarp tissue of mutant fruit was increased 166% by hp and 320% by dg. Mutant fruit were smaller and more elongate than isogenic normal controls, but ripening was unaffected by either mutation. Vegetative and reproductive development were retarded by both chlorophyll intensifier mutations. The hp and dg mutations significantly reduced total leaf area, internode length, and whole plant fresh and dry weight, but did not reduce the number of nodes present at a particular stage of development. The effects of dg were always quantitatively greater than for hp. The similarity of effects associated with these 2 nonallelic mutants suggests that pleiotropy rather than close linkage accounts for the multiple effects of these genes.
Absorption and Metabolism of 14C(2-Chloroethyl)phosphonic Acid in Apples and Cherries1
Authors: Edgerton L. J. , Hatch A. H.
Published: August 2022

Radioactive (2-chloroethyl)phosphonic acid (ethephon) was applied to leaf and fruit surfaces 6 to 10 days before normal harvest date. Samples were collected periodically following application and analyzed with appropriate extraction and counting procedures. The level of radioactive ethephon increased in the fruit for about 48 to 72 hr, then decreased to a low level after 6 days. No intermediate metabolites were detected in the fruits. It was found that the majority of the ethephon in the fruits moved there from the application on adjacent leaves; relatively small amounts moved directly into the fruit from surface application. Radioactive ethylene was detected within 12 hr after application of the 14C-ethephon on the leaf surfaces.
Effects of Sub-Optimal Ripening Temperatures on Tomato Fruit Quality1
Authors: Koskitalo L. N. , Ormrod D. P.
Published: August 2022

Controlled environment experiments were conducted to study the influence of 4 diurnal thermal regimes 17.8/25.6, 7.2/18.3, 4.4/15.6 and 2.8/13.9 on the quality of tomato fruit at 3 harvest dates. Fruit harvested at 17.8/25.6 had substantially higher pH values and lower titratable acidities than fruit exposed to lower temp. Temperature effects on total solids, soluble solids, reducing sugars and total pectic substances were not significant. Total pectic substances did not reflect firmness differences between treatments. Subjective assessments indicated that fruits harvested from the lowest temp regime were most firm. Satisfactory color development occurred in 7 days at 17.8/25.6 and in 14 days at 7.2/18.3. The 4.4/15.6 and 2.8/13.9 temp were too low to permit complete coloration of the fruit regardless of the ripening duration.
Relation of Ethylene and Cellulase Activity to Abscission of Freeze-Injured Citrus Fruit1
Authors: Young Roger
Published: August 2022

Freeze-injured citrus fruit produced above-normal amounts of ethylene 1 to 4 days after injury. Elevated ethylene levels were often found in fruit 3 weeks after injury. Cellulase activity in the abscission zone increased 4 to 8 days after injury and preceded abscission. Some severely injured fruit that did not abscise were responsive to abscission-inducing chemicals. High internal ethylene content did not correlate as well with abscission as did high rates of abscission-zone cellulase activity.
Effect of Daylength on the Growth and Flowering of Roses (Rosa hybrida)1
Authors: Carpenter W. J. , Rodriguez R. C. , Carlson W. H.
Published: August 2022

Four greenhouse rose cultivars were grown under 9, 12, and 16-hr daylengths from September to May during 1969-70 and 1970-71. Flower production was generally increased significantly under the 16-hr daylength, particularly during January and February. At this day length, rose stems flowered again more quickly, but with the same number of nodes present as in the other treatments. The internode between the 2 uppermost 5-leaflet leaves was significantly longer on plants grown at 16 and 12 hr than the 9-hr daylengths. Flower fresh and dry wt increased as the daylengths increased from 9 to 16 hr and the percentages of blind stems were found to decrease. Rose leaf and flower petal size were unchanged by the daylength.
Natural Crossing in Lens esculenta Moench1
Authors: Wilson V. E. , Law A. G.
Published: August 2022

Five selected lines of lentils (Lens esculenta Moench.) were used to determine percentages of natural crossing. First generation seed was classified into S1 and F1 groups after recessive fluorescent yellow cotyledonous maternal flowers were crossed naturally with pollen for dominant red cotyledonous flowers. Natural pollination between lines ranged from 0.01 to 0.08%. No F1 seed was produced on plants inside of wire screened cages although the cages included honeybees, air-borne pollen and maternal and paternal plants having alleles for yellow and red cotyledons, respectively. This indicates that neither honeybees nor air-borne pollen are major factors in natural cross pollinations. Seed yields from caged plants indicate that lentils are highly self-pollinated and need no agent to assist self-pollination.
Cation and Nitrate Accumulation in Pea and Cucumber Plants as Influenced by Nitrogen Nutrition1
Authors: Barker Allen V. , Maynard Donald N.
Published: August 2022

The accumulation of cations and NO3-N was higher in cucumber shoots than in pea shoots grown on nitrate nutrition. Total N concn in shoots did not differ between the species. Ammonium nutrition suppressed cation accumulation in cucumbers but not in peas. Differences in cation accumulation in the shoots are attributed to the form in which N is translocated from root to shoot.
Effects of Some Endogenous and Exogenous Growth Regulators on Plum Seed Dormancy1
Authors: Lin C. F. , Boe A. A.
Published: August 2022

Radicle growth of stratified Italian plum seeds (Prunus domestica cv. Italian) was inhibited when treated with extracts of unstratified plum seeds. An inhibitor was identified by gas-liquid chromatography as abscisic acid (ABA). Analyses of stratified seeds showed that gibberellin-like substances increased and ABA decreased during a 90-day period. Intact unstratified seeds did not germinate when treated with gibberellic acid (GA) and N-6-benzyladenine (N-6-BA), however, these materials did promote germination of unstratified seeds with testas removed.
Excessively High Temperatures of Seed Onion Umbels1
Authors: Tanner C. B. , Goltz S. M.
Published: August 2022

High temp may adversely affect onion seed production since the occurrence of physiological damage to the umbel, resembling sunscald, is associated with a reduction in the number of viable seeds produced. Temperature measurements show that the portion of the umbel directly facing the sun is the hottest plant part. Ovary temp as high as 60°C (140°F) have been observed at the “hot spot”, which would denature many plant enzymes. A method was developed from Wisconsin data for estimating the max and min possible temp of the umbel “hot spot” using only air temp and wind speed. This method was successful in predicting max and min umbel temp measured at Parma, Idaho. The temp rise of the hot spot above air temp is inversely proportional to the 2/3 power of wind speed. The cooling efficiency of the wind is not only a function of its speed but also of where it impinges on the umbel relative to the location of the “hot spot”; thus the direction of the sun and wind must be known to compute the actual hot spot temp, rather than the possible max and min extremes. When wind speed and direction, air temp, and hot spot location (or sun angles) are known, umbel temp can be predicted within 2 to 3°C.

The above results apply to “tight”, spherical umbels. “Loose” umbels will heat above air temp only about 1/5 as much as “tight” umbels; consequently, they are subject to much less heat stress.
Relationships Between Components Contributing to Quality Variation Among Tomato Lines1
Authors: Stevens M. Allen
Published: August 2022

Flavor evaluation studies with ‘Campbell 146’ and ‘Campbell 1327’ indicated that 2-isobutylthiazole concn and solids/acid ratio are important to the flavor difference between these 2 cultivars.

Fifty-five tomato lines from divergent sources were analyzed to study relationships among components contributing to quality variation. There were highly significant correlations among major components contributing to solids. As total solids increased, the proportion of reducing sugars, the predominant organic compounds, increased. Despite a highly significant negative correlation between pH and titratable acidity, there was a wide range in the [H+]/titratable acidity ratio. The data indicate that differential buffering is primarily responsible for this variation and that phosphate content of the fruit is a prime factor in differential buffering. Citrate, but not malate, concn was correlated with titratable acidity.
Estimates of Genetic and Environmental Effects on Several Traits in Peach1
Authors: Hansche P. E. , Hesse C. O. , Beres V.
Published: August 2022

Estimates were obtained of the means, variances, and heritabilities of 10 commercially important traits from approx 200 parents and their more than 2,000 offspring observed over a period of 8 years. After adjustment of measurements for the effects of yearly variations in climate, heritabilities were found to be very high for ripe date; high for bloom date, amount of bloom, fruit length, suture, and cheek; modest for fruit firmness and acidity; and low for percent soluble solids and crop. The implications of these results on the design and execution of breeding programs in such crops are discussed.
Appearance and Quality Characters in Muskmelon Fruit Evaluated by a Ten-Cultivar Diallel Cross1
Authors: Lippert L. F. , Legg P. D.
Published: August 2022

Ten cultivars of muskmelon were evaluated in a diallel cross at 3 locations during a single season for net appearance, absence of vein tract depression (sutures), rind thickness, percent soluble solids, percent flesh, and shape index (length/width). Variances among crosses were significant for all traits. Significant heterosis was favorable for percent soluble solids, but unfavorable for net appearance and shape index. General combining ability accounted for a greater portion of the variability among crosses than did specific combining ability, although both effects were highly significant for each of the traits. Crosses correlated favorably with cultivar performance for net appearance, vein tracts, and percent flesh. The combination of certain cultivars into a synthetic population for further improvement of muskmelon is discussed.
Diallel Analyses for Yield and Maturity Characteristics in Muskmelon Cultivars1
Authors: Lippert L. F. , Legg P. D.
Published: August 2022

The diallel cross was used to evaluate 10 muskmelon cultivars for several characteristics related to maturity, fruit size, and yield. From data obtained in 2 or 3 locations, both additive gene action (general combining ability, GCA) and nonadditive effects (specific combining ability, SCA) were significant in crosses for expression of days to 1st fruit harvested and avg wt of 1st 3 fruits harvested. GCA was significant for all traits when evaluated from single location data, and was more important than SCA for explaining differences among crosses. Heterosis was significant and favorable for 1st fruit harvested, avg wt of 1st 3 fruits and wt of all fruits per plant, but unfavorable for days between 1st and 3rd fruits harvested. Evaluation of these cultivars and predicted values for the characters in synthetic breeding populations formed from selected parents are presented. Breeding schemes for population improvement and cultivar development in muskmelon are discussed.
Effect of Intermittent Mist on Development of Fall Color in Foliage of Euonymus alatus Sieb. ‘Compactus’1
Authors: Lee Choong Il , Tukey H. B.
Published: August 2022

When Euonymus alatus ‘Compactus’ was grown under intermittent water mist for 2-4 months in autumn, the development of red foliage color was inhibited and dormancy and leaf abscission were delayed even during 4 weeks of cold temp (5°C) after the mist. Leaf tissues of misted Euonymus had a lower content of anthocyanins, total sugars, soluble N, and K and a higher content of starch, protein N, phenylalanine ammonia lyase, flavonols, flavans, leucoanthocyanins, and total phenolic substances than did non-misted plants. Substances involved in anthocyanin synthesis such as sugars, K, flavonoid compounds, and growth inhibitors were leached from the Euonymus by the mist. When the leached substances were added back to leaf discs from the misted leaves, anthocyanin content was equal to or greater than in leaf discs from non-misted plants. These results explain why rainfall in autumn reduces the intensity of red foliage coloration in Euonymus and perhaps other ornamental plants by leaching of metabolites, thus delaying the onset of dormancy and leaf senescence and inhibiting anthocyanin synthesis.
Postharvest Benomyl and Thiabendazole Treatments, Alone and With Scald Inhibitors, to Control Blue and Gray Mold in Wounded Apples1
Authors: Hardenburg R. E. , Spalding D. H.
Published: August 2022

Benomyl and thiabendazole (TBZ), at concn of 1,000 ppm, were compatible with commercial scald inhibitors (2,700 ppm ethoxyquin or 2,000 ppm diphenylamine). No injury was observed on ‘ Delicious’ or ‘Stayman’ apples given combined treatments and stored 5 months at 0°C plus 6 or 7 days at 21°C. Effectiveness of fungicide and scald inhibitor was not altered when combined.

Both benomyl and TBZ used as 10-15 sec dip treatments at 500 ppm controlled decay due to blue mold (Penicillium expansum) and gray mold (Botrytis cinerea) at puncture wounds in inoculated apples. They were less effective in controlling decay at bruises unless suspensions were heated in a range of 29°-45°C (84°-l 13°F) and used as a 2-min dip. Unheated benomyl was more effective than unheated TBZ in reducing blue mold at bruises. TBZ was less effective in controlling decay at punctures when treatment was delayed 24 hr after inoculation. TBZ added to water contaminated with blue mold spores, as in a dump tank, controlled decay at skin punctures but not at bruises during subsequent storage. Neither benomyl nor TBZ controlled Alternaria rot, which often developed at punctures when blue and gray mold rot were controlled.