bluuebunny/crossref_metadata_2025 huggingface dataset:
Storage Procedures, Low Oxygen, and Low Carbon Dioxide Atmospheres on Storage Quality of ‘Golden Delicious’ and ‘Delicious’ Apples
Authors: Lau O.L.
Published: August 2022

In a 4-year laboratory and commercial study, ‘Golden Delicious’ and ‘Delicious’ apples (Malus domestica Borkh.) stored in 1.0% to 1.5% O2 + 1.0% to 1.9% CO2 at 0° to 0.5°C and 90% to 92% RH for 6 to 10 months maintained a higher firmness and acid level than apples stored in standard commercial atmospheres of 2.5% O2 + 1.0% to 1.5% CO2 at 0°. Fruit stored in 1.0% to 2.5% O2 with a rapid CA procedure were firmer than those with a slow CA procedure. There was no fruit injury or increased alcohol or off-flavor production resulting from the 1.0% to 2.5% O2 + 0.5% to 2.0% CO2 storage atmospheres established by the rapid CA procedure. Reduction of storage CO2 from 2.0% to 0.5% did not affect the firmness of ‘Delicious’ apples kept in 1.0% or 2.5% O2, but appreciably reduced firmness of ‘Golden Delicious’ kept in 2.5% O2 and to a lesser extent in 1.0% O2.
Yield Component Analysis in Five Cowpea Cultivars
Authors: Fernandez George C.J. , Miller J. Creighton
Published: August 2022

A field study was conducted to determine the effects of rhizobial inoculation (cowpea ‘EL’ mixed strain) and N-fertilization with 100 kg/ha nitrate nitrogen (CaNO3 — 15.5% N) on seed and biomass yield in cowpea [Vigna unguiculata (L.) Walp.]. Four indeterminate cultivars, ‘Mississippi Silver’, ‘California Blackeye #5’, ‘Lady’, ‘Brown Crowder’, and one determinate, early maturing cultivar, ‘Bush Purple Hull’, were used. Seed yield in inoculated and N-fertilized plants was significantly greater than that of the unfertilized, uninoculated control treatment. Generally, yield of inoculated plants was equivalent to or greater than that obtained with 100 kg N. The indeterminate cultivars yielded more biomass than did ‘Bush Purple Hull’ in all 3 treatments. Seed yield was higher in the indeterminate cultivars with inoculation or N-fertilization than in ‘Bush Purple Hull’; however, there were no significant differences in seed yield among cultivars in the control treatment. Harvest index in the indeterminate cultivars was increased by inoculation but not by N-fertilization. Harvest index of ‘Bush Purple Hull’ was at least 3 times higher than the indeterminate cultivars. Among the major seed yield components, only pods/plant was influenced by all 3 treatments, whereas seeds/pod and seed weight were fairly stable and cultivar specific. Standardized regression analysis revealed that pods/plant was the major component which accounted for the variability in seed yield of inoculated plants within a cultivar, but not in ‘Bush Purple Hull’, where dry matter accumulation/plant/day was the major component. Factor analysis on the yield and N2 fixation components also indicated that cowpea cultivars behaved differently in the expression of traits which influenced seed yield. A measure of genetic divergence among these cultivars using Mahalanobis distances confirmed that the 5 cowpea cultivars differed significantly.
Use of Early Flowering Genes to Reduce Generation Time in Backcrossing, with Specific Application to Lettuce Breeding
Authors: Ryder Edward J.
Published: August 2022

A partially dominant allele for early flowering in lettuce (Lactuca sativa L.) reduces flowering time by about one-half. This property is useful in backcross breeding procedure to accelerate the transfer of useful alleles to a desired recurrent parent. Application of the technique to transfer resistance to lettuce mosaic is described through 4 backcrosses. Generalization of the technique for other species is discussed.
Fruit Set and Carbohydrate Status in Alternate and Nonalternate Bearing Citrus Cultivars
Authors: Schaffer Arthur A. , Goldschmidt Eliezer E. , Goren Raphael , Galili David
Published: August 2022

A comparative study of fruit set of an alternate bearing cultivar of Citrus (‘Murcott’, a C. reticulata hybrid of unknown origin) and a nonalternating cultivar [C. sinensis (L.) Osbeck ‘Shamouti’] was conducted. ‘Murcott’ set a higher percentage of flowers (13.6%) than ‘Shamouti’ (3.8%), because of a higher abscission rate in ‘Shamouti’ throughout the fruit set period. Prebloom girdling increased fruit set significantly in ‘Shamouti’ but had a smaller effect in ‘Murcott’. The nonstructural carbohydrate balance of ‘Murcott’ and ‘Shamouti’ fruiting branches during fruit set as affected by girdling also were investigated. ‘Murcott’ generally had a higher starch content in the fruiting twigs and a higher starch and soluble sugars content in the mature, source leaves. Girdling increased the starch content in mature leaves and twigs of both ‘Murcott’ and ‘Shamouti’. This increase was observed in ‘Murcott’ 2 weeks after girdling, but only 4 and 8 weeks after girdling in ‘Shamouti’ leaves and twigs, respectively. ‘Shamouti’ mature leaves and twigs also had increased soluble sugars content because of girdling. In expanding new leaves, ‘Shamouti’ had similar or higher amounts of nonstructural carbohydrates than did ‘Murcott’, but during maturation, ‘Murcott’ young leaves developed a higher sugar starch content than ‘Shamouti’ young leaves, similar to the situation in mature one-year-old leaves. These results are discussed in terms of source-sink relationships and fruit set.
Influence of Flooding on Root Morphological Components of Young Black Beans
Authors: Kahn Brian A. , Stoffella Peter J. , Sandsted Roger F. , Zobel Richard W.
Published: August 2022

Three black bean cultivars (Phaseolus vulgaris L.), ‘Midnight’, ‘Black Turtle Soup’, and ‘T-39’, were grown in a sand culture in a series of greenhouse experiments. Seedlings were subjected to various flooding treatments beginning at the time the first true leaves were fully expanded and continuing for up to 14 days. Root systems were partitioned into adventitious, basal, and tap components at harvest. Basal roots accounted for the greatest proportion of the total root biomass in control plants. Adventitious roots became the dominant root component in plants which had been flooded for up to 7 days and then allowed to recover for 7 days. The production of adventitious roots by flooded plants reduced their shoot:root ratios to values closer to those of unflooded control plants. ‘Midnight’ plants usually had larger basal roots and higher total root and shoot weights than plants of the other 2 cultivars. All 3 cultivars, however, were proportionally affected to the same extent by flooding.
Occurrence and Cause of Shoot-tip Necrosis in Shoot Cultures
Authors: Sha Liu , McCown Brent H. , Peterson Lloyd A.
Published: August 2022

A shoot-tip necrosis in actively-growing shoot cultures of various species has been observed. Using 3 cultivars of Solatium tuberosum grown on media differing in Ca concentration (0.3, 3.0, and 30 mm Ca), typical necrosis was induced or suppressed. Potatoes at 0.3 mm contained about 0.1% Ca g1 dry weight of shoot and also showed the highest incidence of shoot-tip necrosis, ranging from 48% to 72%, depending on the cultivar. Potatoes grown at 3 or 30 mm Ca contained 0.5% or 3% Ca g−1 dry weight of shoot, respectively, and showed only 0% to 9% necrotic shoots, depending on cultivar. In addition to medium Ca content, Parafilm used as the vessel closure promoted shoot-tip necrosis, but increased levels of Ca in the medium tended to overcome the effect. Although cultivar differences in tissue content of other minerals were apparent, these were not associated with the shoot-tip necrosis problem. We conclude that shoot-tip necrosis is associated with a Ca deficiency in actively-growing shoot cultures.
Predicting the Dates of First Commercial Harvest of Selected Ontario Peach Cultivars
Authors: Smith Richard B.
Published: August 2022

Multiple linear regression analysis was used to develop commercial harvest prediction dates for peach ‘Earlired’, ‘Redhaven’, and ‘Loring’. Prediction equations were developed using degree day summations and date of full bloom as variables. These equations were adjusted for geographic microclimatic variation and tested in 6 commercial peach orchards over 4 years. Predicted dates and actual first commercial harvest dates differed by 4 days or less for 100%, 96%, and 84% of the predictions for ‘Earlired’, ‘Redhaven’, and ‘Loring’, respectively.
Changes in Water Soluble Polyuronides in the Pulp Tissue of Ripening ‘Bosc’ Pears following Cold Storage in Air or in 1% Oxygen
Authors: Chen P. M. , Borgic D. M.
Published: August 2022

‘Bosc’ pears (Pyrus communis L.) harvested at an optimum maturity, based on flesh firmness (about 62 N), were stored either in air or 1% O2 (plus <0.03% CO2) at −1°C. Fruit stored in air for 1 to 3 months softened rapidly after 2 days of ripening at 20°C and reached ripeness with flesh firmness of 20 N or lower by the 9th day. Ripening was associated with a reduction in extractable juice (EJ) and an apparent increase in water soluble polyuronides (WSP). Fruit stored in air for 4 to 5 months also softened rapidly after 2 days of ripening, but flesh firmness was still between 26 and 30 N after 9 days; however, EJ and WSP of fruit did not change appreciably during 9 days of ripening. The WSP content in fruit stored in either air or 1 % O2 increased substantially during 6 months of storage at −1°C. Increased WSP content during storage did not affect the quantity of EJ. Fruit stored at 1% O2 showed a reduction in EJ and an increase in WSP during the 9-day ripening period, whereas, in long-term air-stored fruit, EJ did not decline while WSP was degraded. Correlation of EJ and WSP during each ripening period provided an estimation of storage life. Increased WSP after ripening might be responsible for the increase in hygroscopic binding capacity of the ripened pulp tissue.
Factors Affecting in Vitro Germination and Storage of Jojoba Pollen
Authors: Lee Chin Won , Thomas John C. , Buchmann Stephen L.
Published: August 2022

Conditions for in vitro germination of jojoba [Simmondsia chinensis (Link) Schneider] pollen were optimized in order to study the influence of storage temperature on viability. A medium consisting of 300 mg·liter−1 CaCl2·2H2O, 100 mg·liter−1 KNO3, 10 mg·liter−1 H3BO3, 20% sucrose, and 4% to 5% Difco Bacto-agar was optimal for germinating both fresh and stored pollen. Pollen germinated readily in media with a pH range of 4 to 8. The optimum incubation temperature range for pollen germination was 25° to 30°C. When stored at room temperature (22° to 25°), the initial pollen viability was decreased to 50% in 3 weeks and to 0% after 10 weeks, as determined by in vitro germination. Pollen stored at 4° maintained its initial viability for 10 weeks, followed by a gradual decrease in germination to 70% in 17 weeks and 0% after 22 weeks. Pollen stored at −196° in liquid nitrogen for 2 years retained a germination percentage as high as that of fresh pollen. The eryogenieally stored pollen, when used in controlled pollinations, produced normal fruit set comparable to that with fresh pollen.
Carbohydrate Accumulation and Color Development in Watermelon
Authors: Brown Alex C. , Summers W. L.
Published: August 2022

Watermelon [Citrullus lanatus (Thunberg) Matsumura and Nakai], cultivars ‘Allsweet’, ‘Charleston Gray’, ‘Crimson Sweet’, and ‘Iopride’ were grown from transplants at Ames, Iowa, harvested at 4-day intervals for a total of 11 harvests. Carbohydrates from fruit juice extracts were determined by high-pressure liquid chromatography, and flesh color was determined by using a colorimeter. The reducing sugars, fructose and glucose, generally increased in concentration from 20 to about 36 days after anthesis and thereafter declined in each of the 4 cultivars. Sucrose was measurable in the fruit tissue 20 days after anthesis and thereafter increased. Total sugar concentration increased from 20–60 days after anthesis, with its most rapid increase occurring between 20 and 36 days. For the 4 cultivars sampled, relative sweetness index and total sugar concentration values were similar. Results confirm that ‘Charleston Gray’ develops its maximum red flesh color before reaching maximum sweetness. Such a developmental pattern may have a negative affect on per capita consumption when fruits are harvested on the basis of flesh color rather than edible quality.
Concentration of Anthocyanins Affecting Spathe Color in Anthuriums
Authors: Iwata R. Y. , Tang C. S. , Kamemoto H.
Published: August 2022

In the article “Concentration of Anthocyanins Affecting Spathe Color in Anthuriums” by R.Y. Iwata, C.S. Tang, and H. Kamemoto [Journal 110(3):383–385], the Figure 1 caption was incorrect. The correct caption should read: Spathe color expressions of anthurium clones in relation to the proportions of cyanidin 3-rhamnosylglucoside and pelargonidin 3-rhamnosylglucoside expressed as OD per gram fresh weight. • Dark Red, ◯ Bright Red, △ Red, ⬣ Light Red, □ Pink, ▴ Light Coral, ≪ Coral, ▪ Orange.
Effects of Shoot, Root, and Shank Chilling during Rest in Apple and Peach on Growth Resumption and Carbohydrates
Authors: Young Eric , Werner Dennis J.
Published: August 2022

One-year-old nursery trees of ‘Redchief’ apple (Malus × domestica Borkh.) on MM106, M9, and seedling rootstocks and ‘Redhaven’ peach [Prunus persica (L.) Batsch.] on Lovell rootstock were subjected to root and shoot chilling treatments for 1500 and 1200 hr, respectively, followed by forcing in the greenhouse. Budbreak and new shoot and root growth were increased by chilling the apple root and shoot. In contrast, only shoot chilling increased these parameters in peach. When shanks of clonal apple rootstocks were treated as part of the shoot, statistical interaction between shoot and root chilling was eliminated when the shank was treated as part of the root. The root chilling effect was significant for both clonal and seedling apple rootstocks. Rootstock temperature (4° or 16°C) did not affect starch, soluble sugars, or sorbitol levels in scion, shank, or roots of apple and peach. Starch and soluble sugars generally decreased throughout the chilling and forcing phases, while sorbitol increased.
Firmness of Sweet Cherry Fruit following Multiple Applications of Gibberellic Acid
Authors: Facteau T. J. , Rowe K. E. , Chestnut N. E.
Published: August 2022

Multiple applications (1-3) of 10 and 50 ppm GA3 to ‘Bing’ and ‘Lambert’ (Prunus avium L.) sweet cherries increased fruit firmness and weight, and delayed harvest. Firmness was positively related to dose of GA3 (number of applications × concentration), soluble solids (SS), and In leaf/fruit ratio. GA3 interacted with SS so that the effect of GA3 dose on firmness was increased at higher SS levels. Fruit coloring was delayed by GA3. Chemical name used: gibberellic acid (GA3).
Seasonal Response of ‘Anjou’ Pear Trees to Different Irrigation Regimes. II. Mineral Composition of Fruit and Leaves, Fruit Disorders, and Fruit Set
Authors: Brun Charles A. , Raese J. Thomas , Stahly Edward A.
Published: August 2022

Mature bearing pear [Pyrus Communis L. ‘Beurre d'Anjou’ (‘Anjou’)] trees were irrigated weekly at 125% of pan evaporation (wet), biweekly at 100% of pan evaporation (normal), or irrigated only twice (dry) during the summers of 1980 and 1981. Fruit Ca concentration of dry treatment fruit generally was greater than the concentration in normal or wet treatment fruit. Although irrigation treatment did not consistently alter fruit K or Mg concentration, the K/Ca ratio of normal or wet treatment fruit typically was greater than that for dry treatment fruit. Dry treatment fruit had the lowest concentrations of peel and flesh N from 42–144 days after full bloom in 1981, resulting in lower N/Ca ratios than normal or wet treatment fruit. Fruit from the lower half of tree canopies had a greater Ca concentration resulting in lower N/Ca and K/Ca ratios than in fruit from the upper canopy positions. The lowest incidence of fruit disorders (alfalfa greening and cork spot) occurred in the dry treatment trees. Fruit disorders, especially cork spot, were positively correlated with increased irrigation, shoot growth, fruit N and K concentrations, fruit N/Ca and K/Ca ratios, and early (5-1-81) levels of fruit B, Fe, Mn, and Zn, but negatively correlated to Ca. Although there was no significant effect of irrigation treatment on bloom density in 1981, fruit set was reduced in trees subjected to the dry irrigation regime.
Evidence for Chromosomal Differentiation of Allium fistulosum and A. cepa
Authors: Peffley E. B.
Published: August 2022

Interspecific F1 hybrid plants between Allium fistulosum L. and A. cepa L. exhibit bivalent pairing suggesting genomic homology; however, chromosomal variants exist rendering meiotic abnormalities. The occurrence of multivalent associations suggest at least 1 translocation differentiates the 2 species. The chromosome bearing the nucleolus organizer is apparently involved in the translocation. The presence of bridges and fragments in anaphase and telophase I also indicates the occurrence of at least 1 inversion. A minimum of 2 heteromorphic bivalents were observed which probably reflects the translocation and/or inversion(s).
Effect of Tillage on Sweet Corn Development and Yield
Authors: Petersen Kerry L. , Mack Harry J. , Booster Dean E.
Published: August 2022

‘Jubilee’ sweet corn (Zea mays L.) was grown under conventional and strip tillage in 1982 and under conventional tillage, strip tillage, and no-till culture in 1983. Stand establishment was decreased by strip tillage in 1982, but was lower only in the no-till treatment in 1983. Midseason plant height in strip tillage was slightly less than in conventional tillage both years, whereas the no-till plants were much shorter than in other treatments the second year. Yields of husked ears from strip tillage were 7% and 16% lower than from conventional tillage in 1982 and 1983, respectively. In 1983, yield from the no-till treatment was 31% lower than from conventional tillage. The percentage of kernel moisture always was higher from plants in strip tillage and no-till, indicating these treatments had ears that were more immature at time of harvest than in conventional tillage. Average daily soil temperatures at the 5 cm depth for the first 30 days after planting in 1983 were highest for conventional tillage, followed by strip tillage and no-till.
Peat and Bark Media Nutrient Levels in Relation to Geranium Growth and Tissue Analysis
Authors: Widmer R. E. , Prasad M. , Marshall R. R.
Published: August 2022

The relationship between water extraction (1:1.5) values and nutrient uptake in geranium (Pelargonium × hortorum Bailey) growing in moss peat (peat), bark, or moss peat and soil media was investigated. Nitrogen, P, and K fertilizers were incorporated in increments in the starting media and applied again in solution, about at the crop midpoint. Desirable nutrient N(NH4+-N + NO3--N), P(H2PO4--P) and K(K+) values (DV) from media analysis at the start of the experiments (MDV) and midway to flowering (FDV) also were calculated from regression equations on the basis of maximum growth rates, maximum dry weight production at midharvest, and final harvest. The relationships between plant uptake of N, P, and K and the water extract concentrations were generally very good, except for K in bark for both harvests and in peat at the first harvest, and an underestimated P uptake in peat + soil and in bark. The media DV obtained using growth data were broadly similar to those using plant dry weight data, although somewhat lower for N during the early growing period.
Utilization of a Response Surface Technique to Study Light Acclimation of Indoor Flowering Plants
Authors: Kraszewski Renata A. , Ormrod Douglas P.
Published: August 2022

A central composite rotatable design was used to estimate polynomial equations describing the effect of a 2-phase sequence of light levels on growth and flowering of Browallia speciosa L. (browallia), Crossandra infundibuliformis Salisb. (crossandra), and Oxalis vulcanicola L. (oxalis) in controlled environments. Plants were subjected to 9 lighting regime combinations of 30 days at light levels that might be used by a producer (production light phase) and 30 days at levels that might be used by a consumer (postharvest light phase). In the first phase plants received photosynthetically active radiation (PAR) for 12 hr day ranging from 20 to 350 μmol s−1m−2 (400–700 nm) and in the 2nd phase levels of 17 to 300 μmol s−1m−2. Various growth, flowering, and aesthetic response variables were measured at the beginning and at the end of each phase for covariate analysis. The response surface equations were displayed as isometric (3-dimensional) plots with phase 1 and phase 2 light levels as the 2 base axes. If responses were significant in only one phase, 2-dimensional response curves were plotted. The response surfaces evaluated plant response to light level and extent of change in response to light level in the 2nd phase. Browallia increased in size at a wide range of light levels and some change in response to light occurred between phases. Crossandra increased in size and had high quality foliage at low light levels but there were fewer flowers. Oxalis increased in size and flowered profusely only when light levels were high in both phases. There was little evidence of change in light response in crossandra and oxalis with the treatment durations used in this study.
Structural Differences between Green and White Sectors of Variegated Scindapsus aureus Leaves
Authors: Araus J. L , Sabidó J. , Aguilá F. J.
Published: August 2022

Several anatomical and ultrastructural features, as well as some related physiological parameters, have been studied in green and white sectors of Scindapsus aureus variegated leaves. Incidence of structural variations in dark respiration rates of leaves also has been considered. Total chlorophyll content of white sectors is about 2% that of green ones. Dark respiration rate in white sectors is about half that measured in green sectors. There are no differences anatomically between both types of sectors. Plastid number and plastid long axis length are greater in green than in white sectors. Such differences explain why the plastid area to leaf area ratio in white sectors is about half that of green sectors. This ratio has been related to differences in dark respiration rate between green and white sectors. Mutant plastids are typical photobleaching mutants. There seems to be a good correspondence with Knoth's model for plastid degeneration. Mutant plastids have an extensive system of peripheral reticula.
Cauliflower, Broccoli, and Brussels Sprouts Responses to Concentrated Superphosphate and Potassium Chloride Fertilization
Authors: Peck Nathan H. , MacDonald George E.
Published: August 2022

Cauliflower (Brassica oleracea var. botrytis L. ‘Imperial 10-6’), broccoli (Brassica oleracea var. italica Plenck ‘El Centro’), and brussels sprouts (Brassica oleracea var. gemmifera Zenk. ‘Jade Cross’) were grown at 0, 84, 336, and 1344 kg of concentrated superphosphate (CSP) (0, 17.5, 70, and 280 kg P) and 0, 67, 268, and 1072 kg of potassium chloride (KC1) (0, 35, 140, 560 kg K) fertilizers per hectare, per application in a long-term plant nutrition experiment. Increasing the rate of CSP increased the concentrations of P, Ca and Mg but decreased K and Zn in leaf blades at midseason. Increasing the rate of KC1 increased the concentrations of K and Zn but decreased Ca and Mg in leaf blades. Increasing the rates of CSP and KC1 hastened maturity and increased yields of cauliflower and broccoli in harvest sequences, whereas brussels sprouts were less responsive to CSP or KC1 at one harvest. High rates of CSP without KC1 reduced the yield of cauliflower compared to the lower rates. Increasing the rate of KC1 increased the incidence of hollow stem, a quality defect, in cauliflower and broccoli. Best production of uniform maturity and yield was obtained with a combination of the CSP at 336 kg·ha−1 and KC1 at 268 to 1072 kg·ha−1 per application in a long-term rotation.
Effects of Sludge, Bed, and Genotype on Cucumber Growth and Elemental Concentrations in Fruit and Peel
Authors: Harrison Helen C. , Staub Jack E.
Published: August 2022

Three cucumber hybrids (Cucumis sativus ‘County Fair’, ‘Calypso’, and ‘Southern Belle’) were grown in order to determine the effects of sludge application, bed type, and genotype on elemental concentration in edible plant tissue, vegetative growth, and crop yield. Actual and available soil elemental levels and soil temperature were recorded. Plants were grown in replicated field plots of silt loam amended with 90 MT/ha/year of industrial or municipal sludge and a control with no sludge application. Three bed types were used — level or flat bed, 15-cm raised bed, and 15-cm raised bed of unamended topsoil over prepared flat bed (overcover bed). Sludge and bed type had no effect on soil temperature. Highest yields were obtained from ‘County Fair’ grown on flat beds amended with municipal sludge. Consistent differences were found among genotypes for elemental accumulation in fruit and peel, with ‘Calypso’ showing the lowest levels for all elements when significant differences occurred. Sludge and bed effects on fruit and peel elemental accumulation were variable among years and elements.
Root-zone Temperature Effects on Pepper
Authors: Gosselin André , Trudel Marc-J.
Published: August 2022

Ten-week-old pepper plants (Capsicum annuum L. ‘Bell Boy’) were grown at 5 different root-zone temperatures (RZT) (12°, 18°, 24°, 30°, or 36° ± 2°C) for a period of 8 weeks. Maximum shoot dry weight and leaf area were measured at 24° and 30° RZT. Leaf area ratio (LAR) was not significantly affected by RZT treatments. Fruit weight was maximum at 30° RZT, but earliness was delayed at high RZT. Nitrogen, P, and K content of shoots were increased, but Mg and Ca concentrations were reduced at high RZT. Plant photosynthesis was the highest at 36° RZT. Increasing RZT improved both greenhouse or outdoor pepper production.
Fruit Age and Gibberellic Acid Effect on Epicuticular Wax Accumulation, Respiration, and Internal Atmosphere of Navel Orange Fruit
Authors: El-Otmani Mohamed , Coggins Charles W. , Eaks Irving L.
Published: August 2022

Relationships among fruit age, epicuticular wax, weight loss, internal atmosphere composition, and respiration were investigated in mature ‘Washington’ navel orange fruit [Citrus sinensis (L.) Osbeck]. Fruit epicuticular wax, internal CO2, and internal C2H4 increased, whereas as the season advanced, weight loss during storage and respiration decreased. Concomitantly, fruit conductance to CO2 was reduced. GA3 (10 ppm) application prior to fruit color break reduced the increase in epicuticular wax and thereby delayed the decrease of CO2 conductance, resulting in less of an increase in internal CO2. GA3-treated fruit were not consistently different for other parameters evaluated. Chemical name used: lα,2β,4aα,4bβ,10β)-2,4a,7-trihydroxy-l-methyl-8-methylenegibb-3-ene-l,10-dicarboxylic acid l,4a-lactone (gibberellic acid).
Physiological Changes Associated with Increased Lateral Branching of Apple Trees Treated with Aminoethoxyvinylglycine
Authors: Curry Eric A. , Williams Max W.
Published: August 2022

In late September of 1981 and 1982, eight-year-old ‘Oregon-spur Delicious’ apple (Malus domestica) trees on M7 rootstock were sprayed immediately after harvest with 500 ppm AVG. The following spring of both years the number of spur leaves and lateral shoots on one-year-old wood was increased on treated trees. Total N was reduced and sucrose and fructose were increased in dormant one-year-old shoots of AVG-treated trees. Cold hardiness was not affected. Throughout the dormant period both apical and one-year-old lateral buds excised from treated trees and incubated in the dark at 24°C produced less ethylene over a period of 24 hr than buds from untreated trees. In situ ethylene production from apical buds of treated trees was also reduced as growth resumed in the spring. Chemical name used: N-(phenylmethyl)-lH-purin-6-amine (AVG).
Seasonal Variation in Vegetative and Reproductive Development in Zinnia elegans Jacq.
Authors: Boyle Thomas H. , Stimart Dennis P. , McIntosh Marla S.
Published: August 2022

Cultivars of Zinnia elegans Jacq. were grown under long day (LD) photoperiods in the greenhouse in spring (Sp), summer (Su), fall (F), and winter (W) over 2 years to determine days from seed sowing to flowering (DTF), flower diameter (FD), height (H), node number below first inflorescence (NN), and the role of irradiance and temperature on DTF. All cultivars flowered earliest in Su, and latest in W. Cactus-flowered (cactus) cultivars (‘Carved Ivory’, ‘Rosy Future’, ‘Torch’) flowered later and were greater in H, FD, and NN compared to pompon cultivars (‘Cherry Ruffles’, ‘Pink Ruffles’, ‘Scarlet Ruffles’, ‘Yellow Ruffles’). The principal factor affecting DTF and NN was the season, whereas H and FD variation were due mainly to cultivar differences. Year X season interactions were significant for DTF, H, FD, and NN, but seasonal trends each year were similar. Mean daily temperature (MDT) from transplanting until flowering (DTFT) was lowest in W, highest in Su, and showed a linear correlation with DTFT for cactus (r = −0.89) and pompon (r = −0.92) cultivars. Mean daily photosynthetic photon flux (PPF) for DTFT was highest in Sp, followed by Su, F, and W due to greenhouse shading during Su and part of F; the relation between PPF and DTFT was described by a 2nd degree polynomial for cactus (r = −0.96) and pompon (r = −0.98) cultivars. DTFT was more a function of MDT than PPF for Sp, Su, and F crops, whereas late flowering of the W crop was due to lower MDT and PPF. Results demonstrate that Z. elegans can be accurately scheduled as a greenhouse crop on a year-round basis.
Manganese Toxicity Development in Muskmelons as Influenced by Nitrogen Form
Authors: Elamin Osman M. , Wilcox Gerald E.
Published: August 2022

Muskmelon (Cucumis melo L.) ‘Harvest Queen’ seedlings were grown in sand culture at 2, 15, or 30 ppm Mn with 3 different N treatments to evaluate the effects of N form on growth, composition, and development of Mn toxicity. Nitrogen treatments consisted of NO3, NH4, and NH4 shifted to NO3 at 5 days, when Mn toxicity symptoms began to show on NO3-treated plants. Muskmelons produced the most growth with N supplied as NO3, least growth with NH4, and intermediate growth with the NH4-to-NO3 shift treatment. Plants grown with NO3-N at 15 or 30 ppm of Mn had restricted growth, developed Mn toxicity symptoms 5 days after the start of Mn treatments, and had a Mn composition of over 1500 ppm in dry shoot tissue. With NH4 the Mn treatments had no effect on growth, no Mn toxicity symptoms developed, and Mn composition of shoot tissue was <800 ppm. Shifting plants from NH4 to NO3-N resulted in the development of Mn toxicity symptoms and tissue Mn composition over 1500 ppm within 4 days after the shift.
Influence of Stock Plant Propagation Method on Tissue Culture and Leaf-bud Propagation of ‘Northblue’ Blueberry
Authors: Grout Jeanne M. , Read Paul E.
Published: August 2022

The propagation method and vegetative condition of ‘Northblue’ blueberry (Vaccinium corymbosum L.) stock plants influenced microshoot production in vitro and root formation on leaf-bud cuttings. In tissue culture (TC), explants from TC-derived stock plants produced longer shoots than explants from leaf-bud, standard- (ST-) derived stock on either Zimmerman’s (Zimm) medium at pH 4.8, Lloyd and McCown’s woody plant medium (WPM) at pH 4.8 or pH 5.2. Microshoots from explants of TC-stock plants also rooted more readily. Microshoot rootability decreased after 18 weeks on medium containing 68.6 μmol (12 mg/liter) 2iP. Microshoot production and rootability increased after 3 additional weeks on Zimm medium without 2iP present. Leaf-bud cuttings of ‘Northblue’ TC-stock plants treated with 5% and 10% concentrations of a commercial rooting compound (Dip-n-Grow) had a slightly higher rooting percentage and root rating than nontreated cuttings from ST-stock plants. However, cuttings from ST-stock plants of the same age showed larger increases in root formation and percentage of rooting in response to the same rooting compound treatments. Leaf-bud cuttings from vegetative TC-stock plants that developed shoots had more basal branches than those from floral ST-stock plants. Branch elongation was greatest and basal branches fewest on cuttings from floral ST stock plants. Successful propagation with cuttings and in vitro explants may be related to the condition of the stock plants, which have been altered by their own propagation methods and the plant growth regulators applied. Chemical names used: 1H-indole-3-acetic acid (IAA); 1H-indole-3-butanoic acid (IBA); 1-naphthaleneacetic acid (NAA); N-(3-methyl-2-butenyl)-2H-purin-6-amine (2iP).
Partitioning of 14C-photosynthate among Competing Sinks during Flowering and Early Fruiting in Snap Bean
Authors: Mauk Craighton S. , Breen Patrick J.
Published: August 2022

Photoassimilate distribution was evaluated in bush snap beans (Phaseolus vulgaris L. ‘Oregon 1604’) field-grown at low and high plant densities (33 and 54 plants·m−2) and irrigated when soil water potential reached −0.06 MPa (high) or −0.25 MPa (low irrigation). A single trifoliolate leaf per plant, either at a lower (node 2 or 3) or upper (node 5) canopy position, was briefly dosed with 14CO2 and plants harvested after 27 hr. This treatment occurred on 3 dates (25, 27, and 31 July), corresponding to the days when flowers at each of the 3 raceme nodes of the terminal inflorescence sequentially reached 1 to 2 days post-anthesis. 14C activity was measured in shoot parts, including individual flowers and pods. Partitioning was calculated as the percentage of distribution of 14C exported from the exposed leaf. Although irrigation-density effects on 14C-partitioning were slight, the percentage of 14C-assimilate translocated from the dosed leaf to its nearby inflorescence increased sharply at each successive sampling date. On 25 July, flowers at each of the 3 raceme nodes of the terminal inflorescence had only 2–4% of the 14C activity, whereas on 31 July those at the proximal 2 positions had 34% compared to 2% at the distal raceme node. Flowers and pods at distal raceme node positions received small percentages of exported 14C and tended to abscise, while those at proximal raceme nodes sequestered a much higher fraction of 14C and developed mature pods. Sink intensity (the percentage of 14C/dry weight) of flowers at a raceme node was lowest near anthesis, peaked 3 to 4 days after anthesis, and then declined. Maximum sink intensity of basal flowers in an axillary inflorescence lower in the canopy was twice as high as in comparable flowers of the terminal raceme. The reduced accumulation of photoassimilate and declining sink intensity in organs at distal raceme nodes may contribute to their increased rate of abscission.
Filbert Acclimation, Maximum Cold Hardiness, and Deacclimation
Authors: Hummer K. (Brainerd) , Lagerstedt H.B. , Kim S.K.
Published: August 2022

Stem sections of 31 filbert genotypes were collected, artificially frozen, and evaluated by visual browning of cambium and other tissues to determine cold hardiness during 5 sample dates in 1984 and 1985. Corylus heterophylla Fish. ex. Trau. was the most cold-hardy filbert tested, but it deacclimated sharply before the end of February. The tested filberts were divided into 3 temporal groups of acclimation to maximum cold hardiness—early, midwinter, and late. C. avellana L. ‘Butler’, ‘Tombul’, ‘Barcelona’, ‘Ennis’, and ‘Casina’ acclimated early; ‘Gasaway’, acclimated in midwinter season; ‘Daviana’ and ‘Hall’s Giant’ acclimated late. The genotypes tested also were separated into very hardy, hardy, and least hardy groups for cortex-cambium, pistillate bud, and staminate bud tissues. The general order of tissue hardiness from least to most was pith, xylem, cambium, and cortex. Vegetative buds in midwinter were as hardy or hardier than the cambium. Staminate flowers were hardier than pistillate in October, but most pistillate flowers were hardier than staminate by January. Several filberts had fully blooming pistillate flowers that were uninjured at −30°C in December and −40° in January. Filbert flower buds demonstrated maximum cold hardiness during nondormancy.
Response of Muskmelon to Three Floating Row Covers
Authors: Hemphill Delbert D. , Mansour N.S.
Published: August 2022

Floating row covers increased air and soil temperatures compared to black polyethylene ground mulch and increased both early and total yield of muskmelon [Cucumis melo (L.)]. In 1983, all 3 row covers increased transplant survival and total yield/plant but decreased mean fruit weight. Cover removal date had little effect on yield or earliness. Due to greater plant survival, total yields were higher with perforated (PCP) and slitted clear polyethylene (SCP) floating covers than with spunbonded polyester (SPE) covers. Direct-seeded plants under floating SCP produced higher total yields and reached peak production earlier than the noncovered transplants. In 1984, SPE and PCP increased yield and earliness but had no effect on mean fruit weight. Transplants outyielded direct-seeded plants and early yield increased with late row cover removal. Neither total nor early yield were significantly affected by type of row cover. Projected economic return was usually increased by the row covers for both transplants and direct-seeded plants.
Dry Matter Distribution and Responses to Pruning Within a Population of Standard, Semidwarf, Compact, and Dwarf Peach Seedlings
Authors: Scorza Ralph , Zailong Li , Lightner G.W. , Gilreath Lenard E.
Published: August 2022

Three-year-old limbs of unpruned standard (ST), semidwarf (SD), compact (CT), and dwarf (DW) seedling peach [Prunus persica (L.) Batsch] trees were separated into component parts at harvest. CT and DW trees had allocated higher percentages of dry matter to one- and 2-year-old branches than ST and SD trees. Although the proportion of dry weight in current season shoots was highest in CT trees compared with the other tree types, fruit dry weight was relatively low. In a separate study ST, SD, and CT trees were pruned and left unpruned, and current season shoot and fruit growth was recorded. Pruning increased the wood dry weight per trunk cross sectional area in current season growth in ST trees and increased the average length of shoots and lowered light penetration in ST and SD trees, but pruning did not affect current season shoot dry weight or length in CT trees. Shoot dry weight and shoot length were greatest in pruned ST trees. The number of shoots was not affected by pruning in any tree type. Total fruit dry weight did not differ with pruning or tree type.
Photoperiodic Responses of Hydrangea
Authors: Shanks James B. , Mityga Henry G. , Douglass Larry W.
Published: August 2022

Following the termination of rest, 16-, 20-, or 24-hr photoperiods hastened flower development of 7 cultivars of hydrangeas [Hydrangea macrophylla (Thunb.) Ser.] compared to those at 8- or 12-hr photoperiods. The interruption of a 16-hr dark period with 4- or 8-hr incandescent illumination was as effective as continuous light. Stem elongation and cyme expansion increased with length of photoperiod, while the interruption of the dark period had an intermediate effect upon these parameters. Plants undergoing continuous development without defoliation or a rest treatment responded similarly to rested and defoliated plants in rate and extent of growth and initiated flowers more uniformly at an 8-hr photoperiod than at longer photoperiods.
Peach Skin Discoloration
Authors: Denny E.G. , Coston D.C. , Ballard R.E.
Published: August 2022

Black, purple, and tan discolorations have been found within red-pigmented areas of the peach fruit skin. Scanning electron and light micrographs show damage caused by defuzzing and roller drying, which could facilitate entry of causal agents associated with peach skin discoloration. Comparisons of reflectance and transmittance spectra (380-700 nm) of discolored (purple) and nondiscolored (red) peaches show the mean reflectance value for discolored peaches is 100% darker than nondiscolored peaches. However, transmittance spectra of acidified extracts of discolored and nondiscolored peach skins are similar throughout these wavelengths. Extracted pigment color was altered by pH changes and metallic ion concentration. At low pH, discoloration may be caused by ion complexing with anthocyanin pigment. At high pH, discoloration may result from alkaline hydrolysis of the pigment molecule.
Characteristics of the Photoperiodic Response of California Poppy
Authors: Lyons R.E. , Booze-Daniels J.N.
Published: August 2022

California poppy (Eschscholzia californica Cham.) was increasingly sensitive to inductive long day (LD) conditions as the plant aged. A minimum of 10 expanded leaves was required for plants to flower in the shortest time once LD induction began. The amount of photosynthetic leaf area present during LD was not critical for flowering, suggesting specific leaf number to be a dominant factor in the photoperiodic flowering response of California poppy.
Evaluation of Inbred and Hybrid Populations of Streptocarpus × hybridus
Authors: Wolff David W. , Veilleux Richard E.
Published: August 2022

Early generation inbreeding in one selection each of seed-propagated Streptocarpus x hybridus Voss ‘Concorde’ and ‘Mixed Nymph’ was characterized by reduced flower and leaf size, short peduncles, and increased frequencies of deformed flowers. Multivariate cluster analysis revealed exceptional genotypes that resembled the parent cultivar within the generally inferior inbred populations. Although inbreeding depression was apparent, the inbred populations did not increase significantly in homogeneity as determined by coefficients of variation. Reciprocal hybrids between selections of ‘Concorde’ and ‘Mixed Nymph’ and their first inbred populations, although apparently vigorous, were not statistically superior to parental lines. Reciprocal differences were observed for corolla width and length, and peduncle length between hybrids derived from selections of first generation inbreds of each cultivar. Development of superior seed-propagated Cape Primrose cultivars may be achieved through further inbreeding, selection, and hybridization.
Effect of Stratification Temperature and Time on Rest Fulfillment and Growth in American Ginseng
Authors: Konsler T.R.
Published: August 2022

Dormant one-year-old roots of American ginseng (Panax quinquefolium L.) were exposed to a range of stratification temperatures and times to define limits for these parameters and to quantify their effect on terminating rest when placed in a growing environment. Effective storage temperatures tested ranged from 0° to 9°C. A low percentage of roots produced tops with as few as 30 days of stratification; however, 60 to 90 days were required for 100% emergence. The number of days to emergence, after planting, decreased with increased time in stratification through the maximum storage time of 120 days. The number of days of dormancy (days in stratification + days to emergence) averaged 126 and was relatively constant over the range of effective temperatures and periods of stratification. The minimum predicted period of dormancy was 116 days and was associated with a derived 70 days in storage (1680 hr) at 3.1°. Root growth rate, after emergence, was greatest following 105 days of stratification.
Field Emergence of Tomato, Carrot, and Onion Seeds Primed in an Aerated Salt Solution
Authors: Haigh A.M. , Barlow E.W.R. , Milthorpe F.L. , Sinclair P.J.
Published: August 2022

Conditions for priming tomato (Lycopersicon esculentum Mill.), carrot (Daucus carota L.), and onion (Allium cepa L.) seeds in solutions of K3PO4 + KNO3 and K2HPO4 + KNO3 were optimized in a series of laboratory and field experiments. When primed in K3PO4 + KNO3 (−1.6 MPa) for 7, 14, or 21 days at 15°, 20°, or 25°C, the percentage of emergence was unchanged in tomato, increased in carrot, and decreased in onion. Although there were some species differences, all priming treatments reduced time-spread and increased median rate of emergence. For this solution, priming at 15° for 14 days was optimal for all 3 species. Detailed experiments using optimized priming solutions in an aerated column for tomato (K2HPO4 + KNO3, −1.0 MPa) and for carrots (K3PO4 + KNO3, −1.5 MPa) demonstrated that 18 days was necessary to prime tomato seeds maximally by reducing the time-spread of germination from 73 to 12 hr. With carrots, the maximal response was obtained after 16 days of priming. For both species, continued gains in germination could be obtained from prolonged priming, although only at the expense of a reduced percentage of germination. Air-drying and storing of tomato and carrot seeds for up to 28 days had no effect on subsequent emergence in the field. Conversely, air-drying of onion seeds reduced the percentage of emergence and increased time-spread and rate of emergence. In contrast, salt-primed tomato seeds exhibited an increase in percentage and rate of emergence, and a decrease in time-spread of field emergence. Primed carrot seeds exhibited a faster rate of field emergence than those not primed.
Influence of Crop Load and Maturity on Quality and Susceptibility to Bruising of ‘Bing’ Sweet Cherries
Authors: Spayd S.E. , Proebsting E.L. , Hayrynen L.D.
Published: August 2022

‘Bing’ cherries from lightly (LC) and heavily (HC) cropped trees were harvested at weekly intervals, subjected to impact damage (bruising), and stored at 4°C for up to 28 days in 1982 and 12 days in 1983. On a given harvest date, cherries from LC trees were firmer (higher bioyield) and riper, as indicated by higher soluble solids and total anthocyanin concentrations (TAcy) than those from HC trees. At a given color (TAcy) within the range of commercial shipping maturity, cherries from HC trees were more susceptible to bruising, were softer, and had lower concentrations of soluble solids, acid, and dry matter than cherries from LC trees.
Effect of Soil Acidity and Magnesium on Muskmelon Leaf Composition and Fruit Yield
Authors: Elamin Osman M. , Wilcox Gerald E.
Published: August 2022

The response of muskmelons (Cucumis melo L.) to Mg fertilization and soil pH was studied on a Princeton loamy sand that contained 34 kg·ha−1 available Mg at pH 4.8. Calcitic limestone was used to adjust the soil to pH 5.4 in 1984 and 5.8 in 1985. Magnesium was added for 2 years at 0, 56, 112, and 168 kg·ha−1. Lime application increased exchangeable soil Ca and decreased exchangeable Mn. Liming had no effect on exchangeable Mg, but Mg application increased exchangeable Mg linearly. Plants developed Mg deficiency in plots receiving no Mg treatment regardless of soil pH and Mn toxicity in unlimed plots at pH 4.8. Leaves developed Mg deficiency symptoms when the Mg concentration in leaf tissue was 0.30%. Magnesium application increased leaf tissue Mg and reduced leaf tissue Mn concentrations. Application of calcitic limestone increased leaf tissue Ca and reduced leaf tissue Mg and Mn concentrations. Muskmelon fruit yields were increased both by liming and Mg applications. Yield increases due to liming were attributed to reduced Mn levels in plant tissue.
Lettuce Infectious Yellows Tolerance in Lettuce
Authors: McCreight James D. , Kishaba Albert N. , Mayberry Keith S.
Published: August 2022

Lettuce (Lactuca sativa L.) cultivars and breeding lines differed in tolerance to lettuce infectious yellows virus. Correlations of symptom severity in field tests with fresh weight of control plants in a greenhouse test indicate a relationship between symptom severity and the inherent vigor of a cultivar. ‘Climax’ had the mildest symptoms and was the most vigorous cultivar. The level of tolerance exhibited by ‘Climax’ and a few other cultivars will not prevent occurrence of lettuce infectious yellows, but could ameliorate its effect on lettuce production.