bluuebunny/crossref_metadata_2025 huggingface dataset:
Isobutylidene Diurea and Sulfur-coated Urea as N Sources for Potatoes
Authors: Elkashif M.E. , Locascio S.J. , Hensel D.R.
Published: August 2022

Isobutylidene diurea (IBDU) and sulfur-coated urea (SCU) alone or in combinations with NH4NO3 were evaluated as N sources for potatoes (Solanum tuberosum L.) on 2 sandy soils. Nitrogen was applied either all preplant or in split application at 134 or 201 kg N/ha. Tuber yields were highest with NH4NO3 alone or with NH4NO3 combined with IBDU or SCU, and were lowest with 100% IBDU and SCU. Marketable yields obtained with NH4NO3 were 25% and 27% higher than with 100% IBDU and SCU, respectively. Marketable and total yields increased and tuber specific gravity decreased slightly with increased N. Split applications of N increased marketable and total yields at one location. Leaf N, Mg, and Ca concentrations were higher and K was lower with NH4NO3 alone or with NH4NO3 with IBDU or SCU than with IBDU and SCU. Nitrogen sources had no significant effect on soil total soluble salts, NO3-N, or NH4-N, 7 and 12 weeks after fertilization.
Consumptive Water Use of Irrigated Pecans
Authors: Miyamoto S.
Published: August 2022

Water-use characteristics of irrigated pecan trees [Carya illinoensis (Wang) K. Koch] were evaluated in 7 commercial orchards in the El Paso—Las Cruces valleys. Test trees (8- to 35-years-old) were surface-irrigated ‘Western’, having various sizes (13–53 cm in trunk diameter) and planting densities (60–120 trees/ha). A neutron moisture probe was used for evaluating soil water depletion. Soil water depletion below a depth of 100 cm was minimal and independent of the horizontal distance from tree trunks except in young trees. Consumptive water use was highly dependent of tree size and planting density, and close-spaced, full-grown trees used 100 to 130 cm per season. Based on these field data, an empirical equation was developed for computing crop coefficients and consumptive use from trunk diameters, planting densities, and weather data.
Changes in Glucosinolates during Refrigerated Storage of Cabbage
Authors: Chong Calvin , Bérard Luce S.
Published: August 2022

Changes in glucosinolates, determined by quantifying their hydrolytic breakdown products, volatile isothiocyanates, thiocyanate ion, and vinyl-oxazolidine-2-thione (goitrin), was studied at intervals in heads of 3 cultivars of cabbage, Brassica oleracea L. (Capitata group), kept in refrigerated air storage at 1 ± 1°C between 5 and 215 days. There were substantial fluctuations in these glucosinolate products which occurred during storage in descending order of yield, volatile isothiocyanates, thiocyanate ion, and goitrin. During storage ‘F1 Mercury’ cabbage was higher in quality and showed less storage disorders than ‘Hidena’ and ‘Safekeeper’ cabbages, in this order. Yields of total glucosinolates in the 3 cultivars averaged over the storage period occurred in the same corresponding order: ‘F1 Mercury’ > ‘Hidena’ > ‘Safekeeper’.
Relationship of Air Temperature to Water Content and Supercooling of Overwintering Peach Flower Buds
Authors: Quamme H.A.
Published: August 2022

In overwintering flower buds of ‘Redhaven’ peach [Prunus persica (L) Batsch], seasonal changes in the supercooling point were correlated significantly with seasonal changes in water content of the whole flower bud and its parts, the flower primordium within the flower bud and the vascular traces just below the flower primordium. Both the supercooling point and the water content of the whole flower bud and its parts were correlated significantly with the 2- and 5-day mean air temperature preceding collection. Controlled-temperature studies with ‘Siberian C’ and ‘Redhaven’ revealed that the water content of the flower primordium and vascular traces and not that of the whole flower bud was critical to the level of supercooling attained. Supercooling of the flower primordium appeared to be related directly to its water content. Water content of the vascular trace appeared to be important during the initial stages of freezing for preventing spread of the ice boundary into supercooled regions of the flower primordium. Water content of the 2 critical tissues appeared to be determined by migration from and to these tissues during freezing and thawing. During freezing, water was lost from the flower primordium and vascular traces by migration to the flower bud scales which appeared to act as an ice sink. After prolonged exposure to freezing outdoors, water was also lost to the exterior of the flower bud. After thawing, the flower primordium and vascular traces regained water content by transfer from the ice sinks within the flower bud and sources external to the flower bud. Loss of flower bud hardiness occurred during storage at 0°C for 10 days, which was not due to change in water content of the flower bud or its parts. The excised flower buds of the hardier ‘Siberian C’ supercooled to a lower temperature than excised flower buds of the less hardy ‘Redhaven’ at equivalent water content.
Genotypic Differences in Morphogenic Capacity of Cultured Leaf Explants of Tomato
Authors: Maraffa Kurtz Sharon , Daniel Lineberger R.
Published: August 2022

Cultured leaf sections of 12 cultivars of tomato, Lycopersicon esculentum Mill., were evaluated concerning their morphogenic responses to 24 combinations of indoleacetic acid (IAA, 0–2.0 mg/liter) and 6-benzylamino purine (BA, 0–10 mg/liter). Morphogenic responses were cultivar-dependent and exhibited broad maxima over a range of growth regulator concentrations. Media containing 0.2 mg/liter IAA and 1.0 or 5.0 mg/liter BA were optimal callus induction media for most cultivars. Leaf explants of all cultivars rooted on a medium supplemented only with 0.2–2.0 mg/liter IAA. Genotypic differences were observed in ability to regenerate shoots and average number of shoots regenerated. Optimal shoot regeneration medium varied with cultivar, but most often contained 0.2 or 1.0 mg/liter IAA + 2.5 or 5.0 mg/liter BA. ‘Better Boy’, ‘Starfire’, and ‘UC 134-1-2’ regenerated shoots most readily, averaging more than 10 shoots per culture. ‘Starfire’ was most amenable to in vitro shoot regeneration with as many as 19 shoots per culture.
Differential Thermal Analysis and Freezing Injury of Deacclimating Peach and Sweet Cherry Reproductive Organs
Authors: Andrews Preston K. , Proebsting Edward L. , Gross Dennis C.
Published: August 2022

The freezing patterns of flower buds in peach [Prunus persica L.) Batsch ‘Redhaven’] and sweet cherry (Prunus avium L. ‘Bing’) changed significantly during spring deacclimation. Nucleation temperature, measured by differential thermal analysis (DTA), and freezing injury were monitored for reproductive organs as affected by the presence and absence of vegetative tissue, surface moisture, and the ice nucleation-active (INA) bacterium Pseudomonas syringae van Hall. The flower buds retained the capacity to deep supercool until early bud swell, when the low temperature (LT) exotherm distribution widened and fewer LT exotherms were produced. Following the disappearance of the LT exotherms until the petals tips first appeared through the calyx, the nucleation temperature of the flower buds increased 1° to 3°C. During this period the presence of stem tissue had no effect on nucleation temperature, whereas surface moisture increased the nucleation temperature several degrees. After full bloom, flowers attached to the stem froze at higher temperatures than excised flowers whether wet or dry. From the time the flower buds lost the capacity to deep supercool until petal tip emergence, freezing injury was reduced significantly by increasing the ice nucleation temperature, either by wetting peach flower buds or by inoculating sweet cherry flower buds with INA P. syringae bacteria. Following petal tip emergence, the higher nucleation temperatures no longer reduced freezing injury. Apparently, the flower buds of these Prunus species avoid freezing during the winter by deep supercooling of the dormant flowers, yet tolerate freezing during the early stages of flower development in the spring.
ABA Levels in Tomato Seeds and Fruit as Affected by Fruit Maturation and Fermentation
Authors: Velasco James , Stoner Allan K.
Published: August 2022

Abscisic acid (ABA) levels in seeds of tomato (Lycopersicon esculentum Mill.) fell about 10-fold during fermentation to remove mucilaginous tissue. Imbibing seeds in 20 µg/ml ABA prevented germination and increased ABA content of the seed 15-fold. Subsequent germination in water averaged greater than 90%.
Genetic Control of Quantitative Variation in Phaseolin Seed Protein of Common Bean
Authors: Sullivan Joseph G. , Bliss F.A.
Published: August 2022

Three populations of near-homozygous inbred backcross lines of common bean (Phaseolus vulgaris L.) were produced using ‘Sanilac’ as the recurrent parent and 3 donor parents, ‘BBL 240’, 15R-148, and ‘Swedish Brown’. The method for producing inbred backcross lines included 2 successive backcrosses to the recurrent parent followed by 3 or 4 generations of self-fertilization using single seed descent. There was no conscious selection during the backcrossing or selfing stages. Lines were grown in the Held and analyzed for seed protein content, percentage of protein, seed yield, and seed size. In each population, the frequency of lines recovered having enhanced levels of phaseolin (compared to ‘Sanilac’) suggested that one or a few major genes (effective factors) for phaseolin had been contributed by the donor parent. In population 2, derived from ‘Sanilac’ crossed to ‘BBL 240’, there was evidence for possible linkage between enhanced phaseolin and the gene(s) controlling the electrophoretic banding pattern of the phaseolin polypeptide subunits. The nonprotein portion of the seeds of these lines was also less than that of the recurrent parent, resulting in generally smaller seeds. In contrast, some families in population 6 (donor 15R-148) having enhanced phaseolin also showed increased levels of the nonprotein constituents of the seed. Population 8 (donor ‘Swedish Brown’) was unique since lines with enhanced levels of phaseolin were recovered although the donor parent had a low phaseolin concentration (phaseolin/100 g flour) but large seeds with a high concentration of the nonprotein fraction. These results show that breeding lines with increased levels of phaseolin seed protein can be produced either directly by increasing the phaseolin concentration or indirectly by decreasing the nonprotein fraction of seed.
Expression of Enhanced Seed Protein Content in Inbred Backcross Lines of Common Bean
Authors: Sullivan Joseph G. , Bliss F.A.
Published: August 2022

Four populations of inbred backcross lines of common bean (Phaseolus vulgaris L.), developed from crosses between ‘Sanilac’, the recurrent parent, and 4 donor parents (‘BBL 240’, 15R-148, ‘Swedish Brown’, and PI 229815), were analyzed for total seed protein percentage. In each population a substantial number of lines having significantly higher protein levels than ‘Sanilac’ were recovered. The basis for enhanced protein percentage was attributed to increased amounts (g/seed) of phaseolin and nonphaseolin protein, either singularly or together, and either with or without a decrease in the nonprotein seed fraction. Lines from different populations were characterized by different combinations of altered levels of the various seed fractions. Although seed size varied depending on the seed fractions present, no obviously shriveled seeds were observed. Lines having enhanced protein and seed yields comparable to or greater than the recurrent parent, ‘Sanilac’ were recovered.
Inhibition of Shoot Growth in Greenhouse-grown Tomato by Periodic Gyratory Shaking
Authors: Heuchert John C. , Mitchell Cary A.
Published: August 2022

Seedlings of tomato (Lycopersicon esculentum Mill. cv. Rutgers) were agitated periodically on a gyratory shaker. Shaking plants at 175 rpm for 5 minutes once daily during the winter reduced leaf area, stem length, and water content and dry weight of both leaves and stems. This treatment was ineffective when applied during the summer. Five- to 20-minute treatments applied 2 or 3 times daily reduced growth during either season, but were more effective during winter. Responses were independent of the time of day at which treatment took place. Leaf area, stem length, water content of leaves and stems, leaf dry weight, and specific stem water content were reduced progressively relative to undisturbed controls as the shaking rate increased from 125 to 175 rpm during the winter. Leaf area, specific leaf water content, and specific stem water content were reduced by shaking at 44% of full summer sunlight, but not at 31% or 17%. Shaking enhanced specific stem weight only at 44% light, whereas stem length was reduced most by shaking at 17% light. Differences in relative plant response to shaking between summer and winter remained even when seasonal differences in solar flux density were minimized by use of shadecloth during the summer.
High Pressure Liquid Chromatographic Analysis of Flavonoids in Geranium Florets as an Adjunct for Cultivar Identification
Authors: Asen S. , Griesbach R.
Published: August 2022

High pressure liquid chromatographic (HPLC) procedures were developed for the resolution and quantitation of naturally occurring flavonoids in florets of geranium (Pelargonium X hortorum Bailey). Anthocyanins identified were the 3,5-diglucosides of cyanidin, pelargonidin, peonidin, malvidin, delphinidin, and petunidin. Related flavonoid copigments were: the 3-glucoside, 3-galactoside, 3-xyloside, 3-arabinopyranoside, 3-arabinofuranoside, 3-rutinoside, 3-rhamnosylgalactoside, and 7-glucoside of kaempferol and the 3-glucoside, 3-galactoside, 3-rhamnoside, 3-rutinoside, and 3-rhamnosylgalactoside of quercetin. Significant qualitative and quantitative differences between the 20 flavonoid chemical markers distinguished all but 2 of the 20 cultivars examined. It is believed that the 2 indistinguishable cultivars arose as sports from the same cultivar and are genetically identical for floral pigmentation.
Environmental Stress and Seasonal Changes in Proline Concentration of Citrus Tree Tissues and Juice
Authors: Syvertsen J.P. , Smith M.L.
Published: August 2022

The purpose of this study was to evaluate seasonal changes in the free proline content of citrus roots, leaves, fruit peel, and juice in response to low-temperature and water stress. Nonirrigated trees generally had higher proline in all tissues than did irrigated trees except immediately after a freeze. At this time, nonirrigated trees were less water-stressed because of the greater amount of freeze-induced defoliation that nonirrigated trees had sustained. Using data from an entire year, proline concentration was not correlated with water stress of leaves or fruit. This lack of correlation probably was due to the interacting effects of water stress and low temperature on proline accumulation. Leaves accumulated proline in response to stress before roots and fruit. These data support the idea that the free proline increases first in the leaves in response to stress and subsequently is transported to other tree tissues. Even though proline content in the juice increased with fruit maturity, proline may not be a good indicator of juice quality since it did not always correspond with Brix:acid ratio and fruit in the most exposed canopy positions tended to have the highest proline content.
The Occurrence of Mesocarpic Stone Cells in the Fruit of Cultivated Highbush Blueberry
Authors: Gough R.E.
Published: August 2022

Stone cells of highbush blueberry (Vaccinium corymbosum L.) were distributed primarily toward the periphery of the fruit; they apparently differentiated from ground parenchyma shortly after anthesis. Secondary cell wall material continued to be accreted through harvest, with lamellations about 1μm in width. The lignified walls were heavily pitted, with pits contiguous with those of adjacent stone cells. The number of stone cells may be correlated positively to the length of the growth season for each cultivar.
The Effect of Paclobutrazol on Growth and Response to Water Stress of Apple Seedlings
Authors: Swietlik Dariusz , Miller Stephen S.
Published: August 2022

The addition of (2RS, 3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-1,2,4-triazoI-1-yl-) pentan-3-ol) (paclobutrazol, PP333) at 0.05 or 0.20 ppm to a nutrient solution in which 4-month-old apple (Malus domestica, Borkh.) seedlings were growing, reduced terminal growth and increased root to leaf ratio. Plants pretreated with 0.20 ppm PP333 did not show a reduction in transpiration due to subsequent applied water stress induced by polyethylene glycol (PEG), whereas untreated plants decreased their transpiration in response to PEG stress at −0.5 and −0.75 MPa. The PP333 pretreatment at 0.20 ppm improved water balance of the seedlings since they had a higher water potential than untreated seedlings at equal or higher transpiration rates. Leaf osmotic adjustment to lower water potentials was shown to be leaf age-dependent irrespective of PP333 pretreatment.
Interactions between Air and Root Temperatures on Greenhouse Tomato: II. Mineral Composition of Plants
Authors: Gosselin André , Trudel Marc J.
Published: August 2022

Tomato plants (Lycopersicon esculentum Mill. cv. Vendor) were maintained at 5 root temperatures (12°,18°, 24°, 30°, and 36°C) and 4 night air temperatures (12°, 15°, 18°, and 21°) for a period of 3 months. Although N content of the shoots was increased at 24° and 30° root temperatures, a reduction of this element was measured in the 4th fully expanded leaves. An increase in root temperature from 12° to 24° increased P, K, Mg, Ca, Fe, and Mn content of leaves, but had the opposite effect on Na. High night temperature (21°) favored the absorption of Ca and Na but reduced the concentration of P in the leaves. The results indicate that fertilization of tomato plants should be adapted to root and night air temperatures to avoid excessive vegetative growth and flower abscission and to maximize yield.
Population Analysis of Vigor and Growth Pattern of Apple Seedlings with Short Internode Parentage
Authors: Zagaja S.W. , Faust Miklos
Published: August 2022

The vigor of growth and branching pattern of about 2000 apple seedlings were assessed. The seedlings were 8 years of age and were obtained by intercrossing 4 ‘Goldspur Delicious’ × ‘Redspur Delicious’ hybrids. The seedlings differed considerably in their vigor; the largest tree measured 16 times larger than the smallest one. The short internode condition seemed to exert some dwarfing effect on tree size but was not, however, the sole factor accounting for the degree of dwarfing observed. Measurements revealed that short internode conditions occurred within the most vigorous tree class as well as within the least vigorous one. A continuous variation rather than discontinuous segregation was observed with regard to both vigor of the trees and presence of spurs. Branching pattern also differed with the most numerous pattern being trees with upright branches, some of which produced only a limited number of third-order branches while the others produced a more pronounced number of second-order laterals. Trees with spread-shape crowns consisted of about 20% of the total count, while trees with natural-shape crowns, only 8%.
Rest Completion Prediction Model for ‘Starkrimson Delicious’ Apples
Authors: Shaltout Assem D. , Unrath C.R.
Published: August 2022

A chill unit model was developed for ‘Starkrimson Delicious’ (Malus domestica Borkh.) apples grown under the wide range of temperature and elevations in North Carolina. The model relates air temperature to effective chill units and predicts rest completion for North Carolina-grown apples more accurately than previously reported models. The model proposes a broader range of effective temperatures and incorporates a greater negative effect when temperatures exceed 21°C for rest. According to the model, 1200 chill units are required to break rest of apple buds. Growing degree hours correlated with each apple bud developmental stage, as well as from projected date of rest completion to full bloom, were determined using various base temperatures.
Symptom Development of Chilling Injury in Pineapple Fruit
Authors: Pauli Robert E. , Rohrbach Kenneth G.
Published: August 2022

Symptoms of chilling injury (Cl) expressed as internal browning (IB) in fresh pineapple [Ananas comosus (L.) Merr.] began to appear within 2 days at 22°C after a period of storage at temperatures less than 12°. Fruit not subjected to chilling temperatures during storage also developed similiar symptoms when held for 0 to 10 days at between 18° and 30°. Fruit stored for longer than 3 weeks at temperatures of 8° and 3° showed fewer CI symptoms than similar fruit held at 12°. Waxing fruit either before or immediately after exposure to chilling temperatures was equally effective in reducing CI symptoms. Low oxygen (3%), with or without (5%) carbon dioxide during chilling did not reduce symptom expression. Storage of fruit under low oxygen following chilling significantly reduced CI symptom expression. A model for CI symptom development is presented and related to the metabolic events leading to IB of pineapple fruit, stored at chilling temperatures.
Quality Measurements of Carnation Treatment Solutions in Relation to Flower Silver Distribution and Longevity
Authors: Gorin N. , Staby G. , Klop W. , Tippet N. , Leussing D. L.
Published: August 2022

Various silver containing solutions were evaluated for their effectiveness in extending the life of cut carnations (Dianthus caryophyllus, L. ‘Improved White Sim’) by simple chemical tests of the solutions. Effective solutions formed an immediate white or yellow precipitate (AgI) when 3.0 ml of the solution reacted with 0.15 ml of 2.0 m KI solution, whereas no precipitate formed when reacted with 0.15 ml of 2.0 m NaCI solution. When no precipitate formed with KI, there was insufficient silver in the solution to extend flower life, and hence, no silver was detected in a combined stem and leaf sample or in the flower head (consisting of receptacle, pistil, bracts, calyx and petals). A precipitate forming with both KI and NaCI indicated that the solution contained silver but in the wrong formulation to extend life. Flowers treated with this solution had silver in the combined stems and leaves, but practically none in heads. When solutions were effective, more silver was detected in heads than in the stems and leaves combined.
Effect of Low-oxygen Atmosphere on Storage Scald and Quality Preservation of ‘Delicious’ Apples
Authors: Chen P. M. , Olsen K. L. , Meheriuk M.
Published: August 2022

Studies of low-O2 storage of ‘Delicious’ apple fruit (Malus domestica Borkh.) were conducted in Oregon (1981), Washington (1982), and British Columbia (1981 and 1982). A combination of 1% O2 with 1% CO2 was the most promising for control of storage scald and quality preservation of ‘Delicious’ apple fruit grown in Oregon. A combination of 1% O2 with <0.03% CO2 effectively reduced or eliminated the incidence of storage scald and preserved dessert quality of apples grown in Washington. Early-harvested apples from British Columbia developed a high incidence of storage scald after 7 months of storage in 1% O2 with 0.05% CO2. Apples harvested at commercial maturity, however, developed only slight or minimal storage scald symptom after 7 months of storage in 1 and 0.5% O2 with 0.05% CO2. A high incidence of low-O2 injury (i.e., ribbon-like, depressed skin browning) was found in fruit from Oregon stored for 9 months in 0.5% O2 (with or without CO2) and in 1.0% to 1.5% O2 with <0.03% CO2. No low-02 injury was found in fruit from Washington or British Columbia after low-O2 storage.
Regulation of Ethylene Biosynthesis and Action in Cut Carnation Flower Senescence by Cytokinins
Authors: Cook Douglas , Rasche Madeline , Eisinger William
Published: August 2022

Cytokinins delay the onset of senescence in cut carnation flowers (Dianthus caryophyllus) by affecting the biosynthesis and action of ethylene in the tissue. The onset of senescence is marked by an increase in ethylene sensitivity and production by the tissue. A characteristic rise in 1-aminocyclopropane-1-carboxylic acid (ACC), the immediate precursor of ethylene, accompanies the initial stages, but the greatest increases in ACC are associated with the decline in ethylene production during the later stages of senescence. Cytokinins delay the onset of senescence and reduce ethylene sensitivity and production. Benzyladenine (BA), a cytokinin, prevents the rise in endogenous ACC levels and reduces the capacity of the tissue to convert ACC to ethylene. The effects of other anti-senescence agents, aminoethoxy vinylglycine (AVG), silver ions and cobalt ions, are compared with those of BA on ethylene sensitivity and production. The mechanism of action of BA in the delay in flower senescence is discussed.
Paclobutrazol: A Promising Growth Inhibitor for Injection into Woody Plants
Authors: Sterrett J. P.
Published: August 2022

Paclobutrazol [(2RS,3RS)-1-(4-chlorophenyI)-4,4-dimethyl-2-(1,2,4-triazol-1-yl-)pentan-3-ol)] was injected into bean plants (Phaseolus vulgaris L. ‘Black Valentine’), California privet seedlings (Ligustrium ovalifolium Hassk.), saplings of red maple (Acer rubrum L.), yellow poplar (Liriodendron tulipifera L.), white ash (Fraxinus americana L.), American sycamore (Platanus occidentalis L.), and one-year-old trees of ‘Golden-Delicious’ apple (Malus domestica Borkh), to evaluate growth inhibition response. Also, the extent of translocation and metabolism of injected 14C — paclobutrazol was determined in apple. The height growth, weight, and leaf size of bean plants decreased as the dose of paclobutrazol increased from 0.01 to 1,000 μg/plant. Sprout growth from stumps of privet was reduced as the dose of paclobutrazol increased from 1 μg to 1000 μg/tree. The shoot growth of sapling trees in the field was controlled for at least 2 months with doses of paclobutrazol ranging from 5 mg to 40 mg per tree. When obvious inhibition occurred in apple trees (27 days after injection), 23% of the 14C-activity had been translocated acropetally to the apical shoots. A high percentage of 14C-activity detected was paclobutrazol; 90% of the 14C-activity found in the xylem and phloem and over 85% in the shoot tissue chromatographed with paclobutrazol.
Influence of Prolonged Exposure to Chilling Temperatures on Bud Break and Heat Requirement for Bloom of Several Fruit Species
Authors: Couvillon Gary A. , Erez A.
Published: August 2022

Shoots of apple (Malus domestica Borkh.), cherry (Prunus avium L.), peach [Prunus persica (L.) Batsch] and pear [Pyrus communis × Pyrus pyrifolia (Burm.) Nakai] were collected and used in these studies. In all instances, chilling beyond that required for 50% bud break within a 2-week period (prolonged chilling) resulted in a decrease in the growing degree hours required for bud break. In many cases, over 90% of the variation in each study could be attributed to the added chilling.
Inheritance of Photoperiod Sensitivity, Hirsute Seed, and Albinism in Okra
Authors: Wyatt J. E.
Published: August 2022

Photoperiod-sensitive (short day) plants were found in okra [Abelmoschus esculentus (L.) Moench] PI 291124. These plants did not flower at Charleston, S.C., until mid-October. Segregation of populations derived from crosses with ‘Clemson Spineless’ (CS) indicated that photoperiod sensitivity was conditioned by a single recessive gene. Inheritance of hirsute seed, found in PI 172677, was determined by 2 separate genetic systems. The F1 of PI 172677 (hirsute) × ‘C S’ (glabrous) had hirsute hila and glabrous testae. In the F2, when data from seed parts were analyzed separately, hirsute hila was conditioned by 2 dominant genes, and glabrous testae was conditioned by 2 other dominant genes. When data on both seed parts were combined and independent assortment was assumed, 4 expected phenotypes were missing in the F2. Indirect evidence from the F2 and backcross populations indicated that there were linkages among the alleles which determine presence or absence of trichomes on okra seed. The possible linkage groups are described. An albino mutant, found in progeny of irradiated ‘CS’, was conditioned by a single recessive gene. The gene symbols sd and a are proposed for the genes conditioning the short day response and the albino mutant, respectively; the genes conditioning hirsute seed will not be named until linkage relationships can be resolved.
Physiological Changes Associated with Senescence of Cut Anthurium Flowers
Authors: Paull Robert E. , Chen Nancy Jung , Deputy James
Published: August 2022

Physiological changes accompanying anthurium flower (Anthurium andraenum Andre) senescence were monitored. Silver pulse treatment of flower stems was used to modify the senescence process. Florets on the spadix continued to open for 5-10 days after harvest. In both treated and untreated flowers, respiration rate was low until senescence began 8 days after harvest. The rate of increase in respiration of silver treated flowers was half that of the controls. Ethylene production remained low throughout the postharvest life of the flowers. Ten days from harvest spathe color began to change from red to blue with no significant changes in the ratios of the anthocyanins. There was a simultaneous change in tissue pH, from 5.2 to 5.6. Tissue organic acids remained constant during senescence. There was a significant increase in spathe tissue ammonium ion due, apparently, to protein breakdown which probably caused the increase in tissue pH. The concentration of tissue phenolics increased during senescence and could have intensified the color change by copigmentation. Flower senescence apparently was not due to a shortage of carbohydrates, though tissue starch levels did decline by about 25%. The ratio of free sugars in the stem, spathe and spadix remained constant with a slight decline in concentration during postharvest life. Senescence probably was caused by water stress due to stem plugging of undetermined nature. Silver-pulsing of the stem reduced the amount of plugging and therefore reduced the rate of change of all the senescence processes.
Effects of 2% O2 and Varying Concentrations of CO2 with or without C2H4 on the Storage Performance of Kiwifruit
Authors: Arpaia M. L. , Mitchell F. G. , Kader A. A. , Mayer G.
Published: August 2022

The storage performance of kiwifruit (Actinidia chinensis Planch. ‘Hayward’) was evaluated during and after storage for up to 24 weeks in 2% O2 and 0%, 3%, 5%, and 7% CO2 at 0°C. In addition, the influence of exposure to 0.5 or 1 μl·-liter−1 C2H4 on fruit performance was evaluated. The rate of softening during storage was reduced in proportion to the CO2 level and was accelerated by C2H4. The presence of white core inclusions under controlled atmospheres (CA) plus C2H4 was dependent upon the CO2 concentration. Two other physiological disorders were observed, and their severity was influenced by the combination of elevated CO2 and C2H4. The results suggest that there are 2 types of interactions between CO2 and C2H4, competition and synergism, which occur in kiwifruit during storage.
Effect of Mutant Genotypes hp ogc and dg ogc on Tomato Fruit Quality
Authors: Wann E. V. , Jourdain E. L. , Pressey Russell , Lyon B. G.
Published: August 2022

The mutant genotypes high-pigment/crimson (hp ogc) and dark-green/crimson (dg ogc) were evaluated for their effect on tomato fruit quality. Mature green fruit from the mutant genotypes had 2 to 3 times the amount of chlorophyll in the pericarp and mesocarp tissue as their genetically related but normal counterparts or the control ‘Flora-Dade’. Fruit of the mutant lines were firmer than ‘Flora-Dade’ or their normal counterparts at the mature green stage, as well as when fully ripe. The mutant genotypes conditioned an intense red color in the ripe fruit; the result of a 2-fold increase in carotenoid pigments, especially the red pigment lycopene. Ripe fruit of the mutant genotypes were higher in ascorbic acid (Vitamin C) and beta-carotene (Provitamin A) than normal, but they were slightly lower in total soluble solids. There were no significant differences in pH, alcohol insoluble solids, or total pectin among normal or mutant genotypes. Enzyme analyses showed higher polygalacturonase and β-galactosidase activity in the mutant genotypes than ‘Flora-Dade’ or the normal counterparts. Line T4077 dg ogc had significantly less activity for these 2 enzymes than line T3995 hp ogc. The dg ogc line also had less activity for pectinesterase and invertase than any of the other lines, including its normal counterpart. The 2 mutant genotypes had similar effects on fruit quality characteristics. A sensory panel (n = 48) indicated no significant taste preference differences among the 5 lines.
Interactions between the Amount and Molecular Forms of Polygalacturonase, Calcium, and Firmness in Tomato Fruit
Authors: Brady C. J. , McGlasson W. B. , Pearson J. A. , Meldrum S. K. , Kopeliovitch E.
Published: August 2022

A range of tomato (Lycopersicon esculentum Mill.) cultivars was examined for changes during ripening in firmness, endopolygalacturonase (PG) activity and the molecular forms of polygalacturonase, Ca concentration, and the extractability of the Ca. Firm cultivars were firmer than the soft cultivars throughout ripening, and generally they contained less PG activity at each stage examined. In all cultivars, PG was predominately or entirely in the high molecular weight form (PG1) early in ripening, with the PG2 forms being increasingly prominent as ripening progressed. Differences in firmness were established while PG1 was the predominant PG. Uronic acid polymers in isolated cell walls were degraded rapidly by endogenous PG when citrate was present to complex Ca. In the presence of sufficient citrate, cell wall uronic acids of a firm and soft cultivar were equally susceptible to hydrolysis, suggesting that differences in the digestion of the walls by PG were dependent upon differences in Ca content or distribution. However, neither total, water, nor saline-extractable Ca showed consistent correlations with fruit firmness, and they also showed no progressive change during ripening.
Auxin-regulated Invertase Activity in Strawberry Fruits
Authors: Poovaiah B. W. , Veluthambi K.
Published: August 2022

Extracts of strawberry (Fragaria × ananassa Duch.) receptacles contain a soluble invertase and a bound invertase which can be extracted with 1 m NaCl. Both soluble and salt-extracted invertases had a pH optimum of 4.6. The soluble invertase was more sensitive than salt-extracted invertase to inhibition by I2 and HgCl2. The soluble invertase activity was high at an thesis and decreased markedly during receptacle growth. In contrast, salt-extracted invertase activity increased 80% to 100% during receptacle growth induced either by pollination or by the application of NAA. The possible role of salt-extracted invertase in establishing sink activity during auxin-induced strawberry receptacle growth is discussed. Chemical names used. 1-naphthaleneacetic acid (NAA).
Root and Shoot Growth Patterns of Newly Rooted Woody Plants
Authors: Bentz Susan E. , Stimart Dennis P. , McIntosh Marla S.
Published: August 2022

Changes in primary root number (RN), root dry weight (RDW), and shoot dry weight (SDW) on newly rooted stem cuttings of 7 woody ornamental plants were evaluated over 18 or 24 weeks after either no root removal or root removal where remaining RN equalled 25%, 50%, or 100% of the average RN at transplanting. Regardless of root removal treatment or season (February, June, or July), increases in primary RN occurred after transplanting and preceded increases in RDW and SDW. RDW and SDW increased progressively and together after primary RN ceased increasing. Cuttings started in February attained maximum RN in 12 to 18 weeks after transplanting, whereas those started in June and July required 6 weeks. Results suggest that stem cuttings of woody plants have a minimum, species dependent, primary RN which must be attained before measurable shoot growth is initiated.
Nitrogen Accumulation by Pepper as Influenced by Mulch and Time of Fertilizer Application
Authors: Locascio S.J. , Fiskell J.G.A. , Graetz D.A. , Hauck R.D.
Published: August 2022

Peppers (Capsicum annuum L.) were grown during 2 seasons on Blichton fine sand (Arenic Plinthic Paleaquult) to evaluate the effects of black polyethylene mulch and timing of N application on accumulation of applied N by the shoots and fruit. Nitrogen was applied at 224 kg/ha as 15-N depleted (NH4)2SO4 in a split application or in a single application with and without mulch. During a relatively dry season, total fruit yields and N accumulation were not influenced by treatment. At the end of the crop season, N accumulation from the 224 kg N/ha averaged 16.5% in the shoots, 2.2% in the immature fruit, and 15.8% removed in the harvested fruit for a total utilization of 34.5% (77 kg/ha). The soil supplied about 43 kg N/ha. During an extremely wet season, fruit yields and N uptake were influenced significantly by treatments. Fruit yields were 25.1, 5.5, and 17.5 T/ha with the mulch, no-mulch single, and the no mulch split application treatments, respectively. Total N utilizations by plant shoots, immature fruit, and harvested fruit were 41.8% (94 kg/ha), 7.6% (17 kg/ha), and 23.9% (54 kg/ha) of the applied N with the 3 treatments, respectively. Nitrogen quantities utilized from the soil with the 3 treatments were 27, 11, and 15 kg N/ha, respectively.
Forecasting of N Fertilizer Requirements for Sweet Potatoes
Authors: Mascianica Martin P. , Bellinder Robin R. , Graves Boyett , Morse Ronald D. , Talleyrand Henry
Published: August 2022

Nitrogen treatments (0–134 kg N/ha) were applied on a sandy loam over 11 growing seasons to establish critical soil and tissue N levels, and to evaluate the effects of seasonal precipitation on annual variability in response of ‘Painter’ and ‘Centennial’ sweet potatoes [Ipomoea batatas (L.) Lam.] to applied N. Critical concentrations of soil NO3-N at 29 days after transplanting (DAT) and laminal N at 72 DAT were determined to be 37 μg N/g soil and 5% (dry weight), respectively. Correlation between soil NO3-N at 29 DAT and leaf N at 72 DAT was highly significant. Multiple regression analyses predicted a quadratic relationship between root yield and applied N and predicted a yield maximum at 88 kg N/ha. Inclusion of annual precipitation during the fallow season (1 Oct. – 31 May) in the N model significantly improved the prediction of response to applied N. Fallow season precipitation provided an index of N carry-over in sandy loam soils and could be used to improve estimates of N fertilizer requirements for sweet potatoes.
Association of Latex Pressure with Tipburn Injury of Lettuce
Authors: Tibbitts T.W. , Bensink J. , Kuiper F. , Hobé J.
Published: August 2022

Latex pressures in laticifers of lettuce, Lactuca sativa L., were obtained by inserting capillary tubes into vascular traces within leaves and stems. The pressure was determined by monitoring the counter pressure of compressed gas required to prevent latex entrance into the capillary. The latex pressure in seedling plants was 1.5 bars. This pressure increased during vegetative development to 9.3 bars and increased additionally during flowering stages to 12.5 bars. A maximum of 15.2 bars was measured in a flowering plant. Latex pressures were reduced in plants grown at reduced irradiance levels. Latex pressures also decreased with soil water stress, but, with rewatering of the soil, pressures increased to a level greater than present before initiation of the water stress. Osmotic potential of latex in plants in the vegetative stages was –13.5 bars. The pressure potentials and osmotic potential of the laticifers was compared to potentials in the xylem and mesophyll. It was concluded that turgor pressure fluctuations in laticifers can be a contributing factor for laticifer rupture and tipburn injury in lettuce.
Critical Deficiency and Toxicity Levels of Tissue Zinc in Relation to Cowpea Growth and N2 Fixation
Authors: Marsh Dyremple B. , Waters Luther
Published: August 2022

Studies were undertaken to determine the critical Zn levels for cowpea [Vigna unguiculata (L.) Walp] grown in low N medium and inoculated with Rhizobium. Cowpea ‘California Blackeye No. 5’ was grown for 40 days in a sand culture using Zn application rates of 0, 0.06, 0.5, 1.0, 1.5, 2.0, 2.5, 2.8, 3.0, 3.1, 3.4, 3.7, 4.0, and 4.5 ppm Zn as ZnSO4. N2 fixation was estimated by acetylene reduction. Critical Zn deficiency levels were determined as 12.5, 20, 30, and 50 ppm for upper leaf petioles, upper leaf blades, lower leaf petioles and lower leaf blades, respectively, Critical Zn toxicity levels for these tissues was determined as 145, 273, 300, and 440 ppm, respectively. It was concluded that upper, recently matured, leaf petiole tissue should be used to assess plant Zn status. The percentage of reduction of N2 fixation was greater than the percentage of reduction in dry-matter accumulation under Zn-deficient conditions. N2 fixation increased linearly with increased Zn content of nodules and roots. At Zn levels above 150 ppm for both tissues, however, N2 fixation declined significantly. Applied Zn did not affect the growth and development of the root system and had little effect on reproductive development.
Genetic Analysis of Fruit Length and Weight in Two Cucumber Populations Using the Inbred Backcross Line Method
Authors: Owens K.W. , Bliss F.A. , Peterson C.E.
Published: August 2022

The inbred backcross line method was used to analyze the inheritance of fruit length and weight in cucumber (Cucumis sativus L.). Two populations were produced by crossing a small-fruited, adapted breeding line as the recurrent parent with 2 unadapted and large-fruited lines as donor parents. Marker genes were used in both populations to test for Mendelian expectations. Segregation was normal for all markers in both populations. Nevertheless, significant deviations from binomial expectations occurred, indicating that there were difficulties in estimating gene number and genetic variance without bias. Heritability was moderately high for fruit length and intermediate for fruit weight in both populations. No major genes controlling fruit length or weight were detected using the inbred backcross line method, and only estimates of minimum gene number were obtained. Inbred backcross lines having fruit weight equal to or greater than the large-fruited donor parent were recovered in both populations. However, in neither population were lines recovered with fruit as long as those of the donor parent.
Time and Severity of Summer Pruning Influences on Young Peach Tree Net Photosynthesis, Transpiration, and Dry Weight Distribution
Authors: Rom Curt R. , Ferree David C.
Published: August 2022

Young peach trees 1) trained to a single shoot or 2) allowed to branch, were pruned by removing 50% of current growth at either or both of 2 summer dates. Another group of trees had 0%, 25%, 50%, and 75% shoot growth removed by pruning in midseason. Net photosynthesis (Pn) and transpiration (Tr) were increased within 3 days after pruning at either date. Plants pruned twice at 30-day intervals had a 2nd cycle of increased Pn and Tr, with rates returning to levels of unpruned controls within 24 days. Distribution of water soluble carbohydrates in various plant tissues was not altered by pruning. Pruning at 60 days reduced root starch, whereas pruning again at 90 days increased total root carbohydrate content. Pruning early in the season increased lateral shoot formation, and terminal bud formation was delayed by pruning. Plant dry weight was reduced by all pruning treatments, with delayed pruning and increasing pruning severity resulting in greatest reductions. Distribution of dry weight was not altered substantially by pruning, and a balance of growth was maintained between different plant parts.
Metabolism of 2,4-D in Grape
Authors: Ahmedullah M. , Marquis L. , Yang C. , Kawakami A.
Published: August 2022

Ring-labeled [14C] 2,4-D was applied to mature leaves of pot-grown ‘Concord’ grape plants at concentrations of 500 and 1000 ppm. The absorption, translocation and metabolism of 2,4-D was determined 1, 2, and 3 weeks after application. No further absorption occurred 1 week after application. Translocation was mostly acropetal and appears to have taken place in the first week. 2,4-D is metabolized extensively by ‘Concord’ to nonpolar and polar metabolites and insoluble residue. The ethyl acetate, water soluble and ethanol insoluble fractions were 47%, 9%, and 31%, respectively, of total 14C extracted from the treated leaf. Chemical name used: (2,4-dichlorophenoxy)acetic acid (2,4-D).
Predicting the Occurrence of Poststorage Disorders of ‘McIntosh’ Apples from Preharvest Mineral Analyses
Authors: Bramlage William J. , Weis Sarah A. , Drake Mack
Published: August 2022

In a 4-year study of the relationships between Ca, K, P, Mg, and N concentrations in ‘McIntosh’ apples at harvest and the quality of fruit after storage, Ca was the most variable element among samples within seasons and was the element most consistently related to disorders, being negatively correlated with senescent breakdown, rot, and scald. No element was correlated significantly with fruit firmness at harvest or after storage. Susceptibility of orchard lots of fruit to breakdown could be predicted from mineral analyses of fruit 2 weeks before harvest. An arbitrary scoring system incorporating all 5 elements was correct 69% of the time in identifying lots with high or low potentials for breakdown, but the middle range of scores was not closely related to breakdown potential. A regression equation was developed relating only Ca concentration in fruit at harvest with occurrence of breakdown after storage. This equation represented samples either stored in 0°C air for 5 months or in 3° CA storage for 8 to 9 months, and also represented samples taken in 2 different years. This equation was a better predictor of breakdown during storage than was the mineral scoring system, and we propose that such an equation could be used to predict storage potential for ‘McIntosh’ apples.
Effects of Fruit Maturity, Size, and Mineral Concentrations on Predicting the Storage Life of ‘McIntosh’ Apples
Authors: Marmo C.A. , Bramlage William J. , Weis Sarah A.
Published: August 2022

Fruit of equal size but varying Ca concentrations were harvested 4 times at weekly intervals for measurements of firmness, titratable acidity, soluble solids and starch, and of Ca, N, P, K, Mg, B, Fe, Mn, Zn, and A1 concentrations. In another experiment, fruit of 3 different sizes were measured generally as above. These measurements were compared with incidences of senescent breakdown, scald and rot after air storage at 0°C, and stepwise multiple linear regression was used to develop equations for predicting apple storage life. Among minerals and maturity indices, Ca, and starch concentrations, respectively, accounted for the most variations in senescent breakdown. Fruit diameter and fruit firmness also accounted for significant amounts of variation in breakdown after storage when fruit size varied. These results show that predictions of storage life based solely on mineral concentrations can be improved by incorporating maturity and size measurements at harvest when these factors are variable.
Predicting Dry Matter, N, P, and K Accumulation in Field-grown Early Forsythia
Authors: Hilen Andrew G. , Good George L.
Published: August 2022

Field-grown early forsythia (Forsythia ovata Nakai) plants were harvested every 2 weeks from 15 Apr. through 30 Nov. 1980 and from 15 Aug. to 15 Oct. 1981. Following harvest, plants were divided into roots, shoots formed during previous growing seasons, current season's shoots, and foliage. Plant parts were oven dried, weighed, and analyzed for N, P, and K. Nonlinear regression models of seasonal dry weight and N, P, and K accumulation observed in plants and component parts indicated that maximization of these factors occurred from mid-September to mid-October. Regression analyses indicated statistically significant relationships between observed and estimated dry weights and nutrient element content of each plant part. Harvesting the foliage at the time of peak accumulation of these factors provided the most accurate estimation of dry weight and N, P, and K of maximum seasonal accumulation in whole plants.