bluuebunny/crossref_metadata_2025 huggingface dataset:
Visual Nutrient Deficiency Symptoms in Caladium × hortulanum Birdsey
Authors: Harbaugh Brent
Published: August 2022

Visual symptoms of N, P, K, Ca, Mg, Mn, Fe and B deficiencies were induced in Caladium × hortulanum Birdsey ‘Candidum’. Characteristic symptoms were photographed and described and a key summarizing these symptoms follows:

a. Chlorosis or necrosis not expressed;

b. Petioles brittle and/or leaves orbicular.........................................................................................................................B

bb. Plants grow slowly, but have no other symptoms......................................................................................................P

bbb. Rust colored spots on underside of leaf near petiole, spots may become “windows” (only the cuticle and epidermal layer remain)................................................................................................................................................. Ca

aa. Chlorosis and/or necrosis expressed;

b. Chlorosis primary symptom.

c. Interveinal and veinal chlorosis

d. Chlorosis evident as leaves unfurl............................................................................................................... Mn

dd. Chlorosis not evident as leaves unfurl, older leaf blades and veins may turn bright yellow as they abscise................................................................................................................................................................... N

cc. Interveinal chlorosis...................................................................................................................................................Fe

bb. Both chlorosis and necrosis expressed.

c. Interveinal chlorosis developing into necrotic spots, leaves turn bright yellow (except basal veins remain green) as they abscise............................................................................................................................................. Mg

cc. Necrotic specks (@ 1 mm) near veins, general chlorosis............................................................................... Mn

bbb. Necrosis primary symptom.

c. Necrotic lesions (2–5 cm) on leaf apex and distal m argin.................................................................................K

cc. Marginal necrosis.

d. Necrosis spreads toward the center of the leaf, margins dry but the leaf blade around petiole remains intact.......................................................................................................................................................................K

dd. Interveinal rust colored, blotchy areas.........................................................................................................Ca
Response Surface Analysis of Flowering in Chrysanthemum ‘Bright Golden Anne’
Authors: Karlsson M.G. , Heins R.D.
Published: August 2022

Chrysanthemum morifolium Ramat. ‘Bright Golden Anne’ plants were grown under 15 combinations of photosynthetic photon flux (PPF), day temperature, and night temperature in a central composite design. Time to flower was a function of both irradiance and the interaction between day and night temperature. The surface response to temperature was bowl shaped with delayed development as temperatures were either increased or decreased from the optimum combinations. High temperature delay was compensated for in part by increased PPF. Shoot length increased linearly as day temperature increased; final shoot length first decreased, then increased with increasing night temperature. The response surface appeared as a rising valley with the longest shoot lengths at high day temperatures. Total flower area per plant increased as PPF increased or as night temperature decreased. For any PPF and night temperature, maximum flower area occurred near 20°C. At a constant PPF, the response surface appeared as a rising ridge with maximum flower area at low night temperature.
Interplot Interference in Field Plots with Leaf Rust of Maize
Authors: Randle W.M. , Davis D.W. , Groth J.V.
Published: August 2022

Interplot interference, or the influence of one host genotype on another when grown in adjacent plots, can be a problem with the evaluation of partial resistance to airborne pathogens. Moreover, interplot interference may affect selection in the plant breeding nursery. To estimate the degree of interference in a typical sweet corn (Zea mays L.) breeding nursery, the partial resistance of 3 hybrids grown in several field plot treatments was examined. Treatments consisted of differing spatial arrangements of the 3 hybrids. In a 2-year study, mean rust level differed significantly for 5 field plot treatments. As the potential for leaf rust increased, the ability to distinguish between hybrid disease reaction diminished. In addition, the variability in disease reaction was reduced as rust potential increased for hybrid and field plot treatment, indicating that when high levels of leaf rust existed, disease gradients tended to flatten.
Accelerating Highbush Blueberry Selection Evaluation by Early Propagation
Authors: Draper A.D. , Chandler C.K.
Published: August 2022

Studies were conducted on the feasibility of shortening the evaluation period of highbush blueberry (Vaccinium corymbosum L.) selections by propagating by softwood cuttings taken from each of the single-plant selections at the time of fruit evaluation row the following spring. Softwood cuttings were taken from a single plant of 5 early, 5 midseason, and 5 late ripening selections in June, July, and August. July cuttings (60%) rooted better than June (37%) and August (31%) cuttings. Early selections (34%) rooted about the same as midseason (32%) and late (35%) selections. The earlier the cuttings were potted, the larger the root system they developed before frost when grown in an unheated greenhouse. None of the rooted cuttings potted 30 Sept, developed root systems large enough to survive field planting. Supplemental heat and light after potting increased root growth of plants potted 25 Aug. but not those potted 10 Sept. Eighty percent of the plants transplanted to the field survived.
Response of Container-grown Rabbiteye Blueberry Plants to Irrigation Water Quality and Soil Type
Authors: Haby V.A. , Patten K.D. , Cawthon D.L. , Krejsa B.B. , Neuendorff E.W. , Davis J.V. , Peters S.C.
Published: August 2022

The response of rabbiteye blueberry plants (Vaccinium ashei Reade) to rates and modifications of deep well water (pH 8.7) containing 0.695 dS·m-1 electrical conductivity (EC), a sodium adsorption ratio (SAR) of 29.7, and a bicarbonate concentration of 7.89 meq·liter-1 was compared to plants irrigated with rain and surface waters applied to 3 soils in a glasshouse-container study. Fresh weight increase and root fresh and dry weight were greater on plants irrigated with rainwater or pond water compared to plants irrigated with different rates of deep well water, or deep well water modified by the addition of gypsum or acidified with H2S04. Fresh weight increase, root fresh and dry weight, leaf fresh weight, and top:root ratios were higher on a loamy sand soil than on sandy loam or clay loam soils. Plant weight gain was positively correated with the percentage of sand, and negatively correlated with the percentage of clay and saturation-extract SAR. An increase in soil pH resulted from irrigation with deep well water which, along with its modifications, resulted in increased leaf Na and decreased leaf Ca and Mn, compared to rain or surface-water irrigations, which slightly lowered soil pH.
The Influence of Summer Pruning and Fruit Cropping on the Carbohydrate, Nitrogen, and Nutrient Composition of Apple Trees
Authors: Taylor B.H. , Ferree D.C.
Published: August 2022

Traditionally, the size control achieved in summer-pruned apple (Malus domestica Borkh.) trees has been attributed to the removal of shoot leaf area before it could replace the storage carbohydrate depleted during its initial growth. Therefore, tissues of young Top Red ‘Delicious’/M 9 trees grown in pots, and mature, field-grown ‘Jonathan’/M 26 trees were summer-pruned and subsequently analyzed for carbohydrate and nutrient element content. Increasing the severity of summer pruning (the length of shoot removed) did not affect the concentration of water-soluble reducing sugars (SRS) or insoluble hydrolyzable carbohydrates (IHC) in the basal shoot section of the Top Red ‘Delicious’/M 9 trees 11 weeks after pruning. Summer pruning 1) increased leaf SRS, N, K, B and stem IHC and 2) decreased leaf Ca and Mg in shoot regrowth. Levels of Fe, Ca, Zn, Al, and Na in the leaves of regrowth were not affected by summer pruning. There was no significant effect of pruning on SRS or IHC levels in the roots. A separation of the carbohydrates by gas chromatography revealed increasing glucose and fructose concentrations in the roots as pruning severity increased, but sorbitol, sucrose, and phloridzin concentrations in roots were not significantly affected. Neither previous season’s summer pruning nor fruit cropping of ‘Jonathan’/M 26 trees affected SRS or IHC of spur shoots in March or June, except that presence of fruit reduced IHC of spur leaves in June. SRS levels in roots in June were reduced by the previous year’s cropping, but not influenced by summer pruning. Root IHC was not influenced by either pruning or cropping treatments. Spur leaf N, Ca, Mg, Mn, and Al were reduced on defruited trees, with K, Ca, Mn, and Al generally being increased by summer pruning. Pruning and cropping treatments generally did not affect levels of P, Fe, B, Cu, Zn, or Na in spur leaves in June; but summer pruning increased K concentration in harvested fruit.
Strawberry Vegetative and Fruit Growth Response to Paclobutrazol
Authors: Braun Joseph W. , Garth Jeannie K.L.
Published: August 2022

Petiole and scape elongation, leaf expansion, and runner formation were reduced by soil application of paclobutrazol (PP333). Runner number was reduced 90–100% by paclobutrazol dosages of 0.2–0.4 mg a.i. per 15-cm pot, accompanied by smaller reductions in leaf expansion (14–29%), petiole elongation (31–59%), and scape elongation (24–47%). Subsequent foliar applied gibberellic acid (GA3) at 50 ppm alleviated the effects of paclobutrazol. Lateral crown formation was promoted in several experiments. Fruit weight was not affected at 0.6 mg a.i. paclobutrazol per pot, but scape elongation was reduced by 51%. Chemical names used: β-[(4-chlorophenyl)methyl]α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).
Quantitative Measurements of Mefluidide Protection of Chilled Corn Plants
Authors: Tseng Menq-Jiau , Zhang Cheng-lie , Li Paul H.
Published: August 2022

Leaves of mefluidide-treated corn (Zea mays L.) plants showed significant protection from chilling injury compared with untreated, chilled controls. On a per-plant basis, leaves sprayed with 5, 10, 15, or 20 ppm mefluidide had 6%, 14%, 9%, or 12% damage, respectively, of the total leaf area after a 6-day exposure to 4°C, whereas controls had more than 60% damage. Treated plants had more leaf area, were taller, had greater fresh and dry weights, and flowered 6 days earlier than controls. Plant growth was stunted with a 20-ppm spray, although plants were protected from chilling injury. During a 6-day chilling period, a consistent level of about 10% electrolyte leakage was observed among treated plants, whereas from control tissue, electrolyte leakage increased from 10% to 40%. These results suggest that mefluidide may modulate the permeability of the plasma membrane in the chilling environments. Chemical name used: N-[2,4-dimethyl-5-[(trifluoromethyl)sulfonyl]amino]phenyl]acetamide (mefluidide).
Mineral Elements and Organic Acids in Branch and Root Xylem Sap of Healthy and Blight-affected Sweet Orange Trees
Authors: Wutscher H.K. , McDonald R.E.
Published: August 2022

Sap extracted by nitrogen gas pressure from branches and lateral roots of healthy and citrus blight-affected ‘Hamlin’ and ‘Valencia’ orange, Citrus sinensis (L.) Osbeck, trees on rough lemon (C. Union Burm. f.) rootstock in 2 commercial groves was analyzed for N, K, Ca, Mg, S, Na, Fe, Mn, Zn, Cu, CI, Si, and organic acids. The branch and root wood (from which the sap was extracted), leaves, and feeder roots were also analyzed. Sap extracted from branches of blight-affected ‘Hamlin’ trees in the spring had higher Zn, Cu, CI, and Si concentrations than sap of healthy trees. Nitrogen was increased twofold and Fe slightly increased with blight in the root sap. Branch sap collected from ‘Valencia’ trees in the fall showed no differences. Branch sap contained more organic acids than root sap and there was no difference between blighted and healthy trees. Citric and malic were the principal acids.
Influence of Soil Moisture Stress and Abscisic Acid Pretreatment in Modifying SO2 Sensitivity in Poinsettia
Authors: Krizek Donald T. , Mirecki Roman M. , Semeniuk Peter
Published: August 2022

Soil moisture stress (SMS) and abscisic acid (ABA) pretreatment had a marked effect in modifying SO2 sensitivity in 2 cultivars of poinsettia (Euphorbia pulcherrima Willd. ex Klotzch.) ‘Ruff and Reddy’ and ‘Rudolph’. Plants grown in 10-cm plastic pots in the greenhouse and exposed to SMS by withholding water for 2.5 days prior to SO2 fumigation in the growth chamber (4 hr at 3 μ1·liter−1) showed greatly reduced SO2 injury; both cultivars were protected similarly. SMS treatment also greatly decreased stomatal conductance and transpiration rate of the leaves. ‘Ruff and Reddy’ plants pretreated with ABA (200 mg·liter−1 of the racemic mixture) 4 hr prior to SO2 fumigation were injured less by SO2 than ‘Rudolph’ and had correspondingly lower stomatal conductance and transpiration rate. ‘Rudolph’ plants pretreated with ABA did not show significantly less SO2 injury, even though stomatal conductance and transpiration rate were lower than controls after ABA pretreatment. These findings demonstrate the importance of moisture stress preconditioning in modifying sensitivity of poinsettia plants to SO2 and suggest a protective role for ABA in certain cultivars.
Selection for Virus Tolerance in Strawberry
Authors: Sjulin Thomas M. , Robbins JoAnn , Barritt Bruce H.
Published: August 2022

Strawberry (Fragaria × ananassa Duch.) seedlings of a 4-parent diallel and runner plants of their parent cultivars were inoculated with naturally occurring complexes of mottle, mild-yellow edge, and crinkle viruses by infesting plants with viruliferous aphids. The parent cultivars, chosen to represent a range in tolerance to complexes of these viruses, were ‘Hood’, ‘Olympus’, ‘Rainier’, and ‘Totem’ (listed in order of increasing tolerance). Virus inoculation reduced seedling plant vigor, petiole length, leaflet width, leaf dry weight, and parent plant vigor, but increased the numbers of leaves per plant of both seedlings and parents in the greenhouse. After growing in the field, virus-tolerance ratings of inoculated seedlings were lower than ratings of control seedlings. General combining ability constants for inoculated seedlings were similar, in rank and separation, to those reported by previous investigators. Field virus-tolerance ratings were lower than controls for inoculated plants of only one parent (‘Olympus’) and were higher than controls at the final evaluation for inoculated plants of a 2nd parent (‘Totem’). Genotypic differences among seedlings and parents confounded the effects of virus inoculation in both the greenhouse and the field. Petiole length in the greenhouse was correlated most consistently with subsequent field virus-tolerance ratings. The mean virus-tolerance ratings of inoculated seedlings, selected on the basis of petiole length, was higher than the rating of all inoculated seedlings and did not differ from the rating of control seedlings.
Emergence at High Temperature and Seedling Growth Following Pretreatment of Lettuce Seeds with Fusicoccin and Other Growth Regulators
Authors: Nelson J.M. , Sharples G.C.
Published: August 2022

The rate and total emergence of lettuce (Lactuca sativa L. ‘Empire’) seedlings incubated at 33°C for 10 hr, alternating with 23° for 14 hr, was markedly increased by seed treatment with 0.5 mM fusicoccin (FC). Neither gibberellic acid (GA) nor kinetin (K) were effective in improving emergence when used alone. The combination of FC with GA or K appeared to give a synergistic enhancement of emergence rate. The radicle elongation of seedlings was reduced by seed treatment with FC, K, or combinations of FC, GA, and K in tests at 20°. The greatest reductions were caused by combinations that included FC. The inhibiting effect of FC on radicle growth was reduced by using a concentration of 0.05 mm. Treatment with 0.05 mm FC resulted in slower emergence but gave the same total emergence as 0.5 mm FC at high temperature. Both FC and GA stimulated hypocotyl elongation.
Effects of Genotype and Sewage Sludge on Cadmium Concentration in Lettuce Leaf Tissue
Authors: Yuran Gene T. , Harrison Helen C.
Published: August 2022

Leaf Cd concentrations were determined for 60 commercial cultivars and USDA plant introductions of noncrisphead lettuce (Lactuca sativa L.). This 2-year study evaluated each genotype in field plots receiving an industrial sludge, a municipal sludge, or no sludge amendment. Genotype and sludge treatment had significant effects on leaf Cd concentration. Although the genotype x year interaction was also significant, the Cd concentrations of some cultivars (‘Waldmann’s Green’ and ‘Summer Queen’) were consistently low while others (PI 278080, PI 167148, and ‘Citation’) were consistently high. Plots amended with the industrial sludge had the highest total and available Cd levels, and plants grown on these plots had the highest leaf Cd concentrations, ranging from 3.1 to 11.9 μg·g−1. Leaf Cd concentrations from plants grown on the municipal sludge-amended plots ranged from 1.4 to 5.5 μg·g−1 and from 1.2 to 2.5 μg·g−1 for the control plots.
Effect of Root Container Size and Location of Production on Growth and Yield of Tomato Transplants
Authors: Weston Leslie A. , Zandstra Bernard H.
Published: August 2022

‘Pik-Red’ tomato (Lycopersicon esculentum Mill.) transplants produced in 2 locations (Florida and Michigan), in 6 root cell sizes were compared for fruit productivity in Michigan. Transplants grown in large cells produced more early yields than those from small cells, but generally did not produce more total yields. Large root cell size had a greater effect on transplant size than did wide spacing in the flat. Speedling root cell size 175 (39.5 cm3) produced the largest transplants, the largest early fruit yields, and the greatest weight of marketable fruit. Transplants grown in Speedling trays in Michigan produced larger early yields than Speedling transplants grown in Florida.
Influence of 12 Ground Cover Systems on Young ‘Smoothee Golden Delicious’ Apple Trees: II. Nutrition
Authors: Shribbs J.M. , Skroch W.A.
Published: August 2022

Two-year-old ‘Smoothee Golden Delicious’ apples (Malus domestica Borkh.) on seedling rootstock were planted into cultivated soil in Spring 1981, and 12 ground cover systems were then established. Apple leaves, twigs from pruning cuts, soil samples, and ground cover clippings were analyzed for nutrient content in 1983 and 1984. Leaf N content had the highest positive correlation with tree growth. Leaf P and K contents were negatively correlated with leaf N and tree growth. Twig N, P, K, Mg, Ca, and Zn contents were positively correlated with leaf N content and tree growth. Soil nitrate content was positively correlated with tree growth and leaf N content. Results implicate N competition as a major factor of interaction between apple trees and grass and broadleaf ground covers.
Physiology of Melon Leaf Membrane Thermostability During Heat Conditioning
Authors: Lester G.E.
Published: August 2022

Seedling leaf segments of 2 Cucumis melo L. cultivars were heated for 15 min at 50°C to observe the influence of duration of temperature conditioning on the acclimation and deacclimation of membrane thermostability. The percentage of injury was measured by the increase in solution conductivity due to electrolyte leakage from leaf segments. Leaves from seedlings held for 5 days at 15° had a higher percentage of injury following heat stress then those held 5 days at 35°. Acclimation for 2 to 4 hr at 35° was enough to reduce the percentage of injury to leaves from 15°-grown plants. Deacclimation for 8 hr at 15° increased the percentage of injury to leaves from plants grown at 35°. Heat injury regressed as a function of mean relative leaf-blade growth rate with temperature and leaf age with temperature yielded predictive regression equations suggesting leaf age is better as a predictor of membrane thermostability than is leaf growth rate.
Plant Density and Row Arrangement Effects on Carrot Yields
Authors: McCollum T.G. , Locascio S.J. , White J.M.
Published: August 2022

Experiments were conducted to evaluate the response of carrots (Daucus carota L.) to target plant densities of 39, 59, and 79 plants per meter of band with various row arrangements (2 band/bed with 2, 3, or 4 seeded rows/band with 3.8 to 11.4 cm between rows) on a Landerhill muck soil. Marketable and total carrot yields increased linearly with increased plant density from 24 to 85 plants per square meter. In 2 of 3 experiments, row arrangement significantly influenced yield; greatest yields were obtained when spacing between rows in a band was greater than 3.8 cm, indicating some advantage to increasing the distance between rows. Mean length and diameter of marketable roots decreased linearly with increased plant density. Length and diameter of marketable carrots were influenced by row arrangement in one of the 3 experiments. Carrots grown in rows spaced more than 3.8 cm apart were longer and had a greater diameter than did carrots grown with 3.8 cm between rows.
Growth Responses of Eggplant and Soybean Seedlings to Mechanical Stress in Greenhouse and Outdoor Environments
Authors: Latimer Joyce G. , Pappas Thalia , Mitchell Cary A.
Published: August 2022

Eggplant (Solanum melongena L. var. esculentum ‘Burpee's Black Beauty’) and soybean [Glycine max (L.) Merr. ‘Wells II’] seedlings were assigned to a greenhouse or a windless or windy outdoor environment. Plants within each environment received either periodic seismic (shaking) or thigmic (flexing or rubbing) treatments, or were left undisturbed. Productivity (dry weight) and dimensional (leaf area and stem length) growth parameters generally were reduced more by mechanical stress in the greenhouse (soybean) or outdoor-windless environment (eggplant) than in the outdoor windy environment. Outdoor exposure enhanced both stem and leaf specific weights, whereas mechanical stress enhanced only leaf specific weight. Although both forms of controlled mechanical stress tended to reduce node and internode diameters of soybean, outdoor exposure increased stem diameter.
Relationship of Netted Muskmelon Fruit Water Loss to Postharvest Storage Life
Authors: Lester G.E. , Bruton B.D.
Published: August 2022

‘Magnum 45’ muskmelon fruit, (Cucumis melo L. var. reticulatus Ser.) either shrink-film-wrapped to maintain a water-saturated microatmosphere or non wrapped, were stored in 4°C, 85-95% RH, and were sampled at 10-day intervals for 40 days postharvest. Fruits maintained in a water-saturated microatmosphere via shrinkwrap exhibited no significant change in percentage of dry weight, firmness, soluble sugars, β-carotene, or a loss of membrane integrity throughout 40 days storage. Shrink-wrap fruit had a 1% reduction in fresh weight, and a decline in appearance rating and surface browning by 40 days postharvest but were generally rated as excellent to good salable quality. Unwrapped fruit maintained in 85-95% RH exhibited progressive decline in appearance, surface browning, percentage of dry weight, soluble sugars, mesocarp firmness, and loss of membrane integrity. No change was observed in β-carotene. Non wrapped fruit had a 5.7% reduction in fresh weight within 20 days postharvest and were generally rated as fair to poor salable quality. Mesocarp membrane integrity during postharvest storage was highly dependent on percentage of fresh weight loss over time for both shrink-film-wrapped and non wrapped muskmelon fruit.
Effect of High Temperature on Proline Content in Tomato Floral Buds and Leaves
Authors: Kuo C.G. , Chen H.M. , Ma L.H.
Published: August 2022

The proline contents of anthers, pollen, pistils, and leaves were examined in several tomato (Lycopersicon esculentum Mill.) cultivars under different temperature conditions. The proline content in anthers increased with advancing development of floral buds to a maximum at anthesis. The pistil contained less proline than the anthers and did not accumulate proline with advancement of floral bud development in most cultivars. High temperature reduced proline content in anthers regardless of the stages of floral bud development. It also tended to reduce proline content in pistils of later floral bud stage. The proline content of the leaves was lower than that of anthers or pistils; however, high temperature increased the proline level in the leaves. Pollen collected from the hot-season planting contained less proline than that collected from the cool-season planting. The addition of proline to germination medium enhanced pollen germination rate and increased pollen resistance to heat. These results suggest that the low proline accumulation in anthers and pollen at high temperature may be the result of the high accumulation in the leaves. Also, high proline content in anthers may be necessary to confer heat resistance to pollen germinating at high temperatures.
Boron Use in the Table Beet and the Relation of Short-term Boron Stress to Blackheart Injury
Authors: Halbrooks Mary C. , Peterson Lloyd A.
Published: August 2022

Table beet (Beta vulgaris L.) cultivars (‘Ruby Queen’, ‘Gladiator’, and ‘Mono-King Explorer’) grown with varying B regimens had similar patterns of dry weight and B accumulation. Between 0.1 and 0.4 ppm B in solution, dry weight of leaf blades, petioles, roots, and fibrous roots did not increase. Boron content increased in leaf blades and remained constant in other plant parts. From 0.0005 to 0.011 ppm B in solution, dry weight of whole plants, shoots, and roots increased through 0.007 ppm B. Boron content increased in shoots and leaf blades through 0.011 ppm B. Distribution of dry weight and B content was reversed in these plants compared to those grown in B levels sufficient for normal development. With insufficient B levels, plants accumulated greater dry weight in shoot than root portions, and B content was greatest in root compared to shoot portions. The effect of short-term B stress on dry weight and B content varied with the growth stage at which stress was induced. Severity of B deficiency symptoms was related to length of the B stress interval. Blackheart injury of roots occurred in plants stressed during early secondary growth. Recovery from stress was associated with B stress induced prior to or after this critical developmental period.
Prediction of Lignin and Suberin Deposition in Boundary Zone Tissue of Wounded Tree Bark Using Accumulated Degree Days
Authors: Biggs A.R.
Published: August 2022

The phellogen of cultivated apple, sweet cherry, and peach trees was wounded at regular intervals beginning in early May and ending in late Aug. 1983. Bark tissue supporting the wounds was excised, sectioned, treated with phloroglucinol + HCl, and examined under a bright field to determine the extent of lignification. The same sections were examined under ultraviolet epi-illumination to determine the extent of suberin deposition in the boundary zone tissue formed from cells present at the time of wounding. Mean daily temperature, time post-wounding, and accumulated degree days (base = −5°, 0°, 5°, and 10°C) were used to predict the percentage of wounds lignified and suberized. A segmented quadratic equation incorporating accumulated degree days (base = 0°) was the best model for predicting lignification for the 3 species and for suberin deposition in peach and sweet cherry.
Ethylene and Auxin Transport and Metabolism in Peach Fruit Abscission
Authors: Ramina A. , Masia A. , Vizzotto G.
Published: August 2022

Interaction of exogenous ethylene and embryoctomy with auxin transport and metabolism through the abscission zone located between fruit and receptable (AZ3) was studied in ‘Andross’ peach. At the end of stage I of fruit development, abscission was induced physically by embryoctomy, or chemically be using ethephon as the ethylene releaser, and/or TIBA as an auxin transport inhibitor. Ethephon was applied to the fruit (Ef) or to the pedicel (Ep), and TIBA to the pedicel, alone (TIBAp) or in combination with ethephon to the fruit (TIBAp + Ef). Embryoctomy induced a quick activation of AZ3 cells, with all fruits abscising in one week; Ef, Ef + TIBAp, TIBAp and induced a fruit drop of 80−85%. Ethephon applied to the pedicel was totally ineffective in hastening fruit drop. Abscission was preceded by a reduction of (1−14C)IAA transport through AZ3 cells, an increase of its decarboxylation and changes in partitioning of the radioactivity among the different solvents. Radioactivity in the EtOH fraction declined in those treatments that were effective in promoting abscission, while it decreased in the NaOH and residue fractions. Changes in the H2O fraction were variable. As far as metabolites in the EtOH soluble fraction are concerned, higher levels of (1−14C)IAA and lower amounts of (1−14C)IAASp were detected in explants excised from treatments effective in promoting abscission. Chemical names used: (2-chloroethyl)phosphonic acid (ethephon); and 2,3,5-triiodobenzoic acid (TIBA).
Changes in Extracellular Polysaccharides During Cold Acclimation of Cultured Pear Cells
Authors: Wallner Stephen J. , Wu Min-Tze , Anderson-Krengel Sarah J.
Published: August 2022

Suspension-cultured pear (Pyrus communis ‘Bartlett’) cells cold-acclimated during exposure to 2°C. Cold acclimation was accompanied by changes in soluble extracellular polysaccharides and in the deposition of callose in the cell wall. Release of a relatively small neutral polysaccharide into culture medium was increased at 2°. However, low temperature decreased the extracellular accumulation of a larger molecular weight (Mr) pectic polysaccharide. The reduced amount of pectic polysaccharide may have been the result of both a low-temperature-enhanced degradation of existing polysaccharide and an inhibition of new synthesis or secretion. The effect of low temperature on callose deposition was observed using an aniline blue fluorescent staining procedure. Pear cells held at 2° showed far more intense staining than those at 22°, indicating increased deposition of callose or other β-1,3-glucans at the cell surface during cold acclimation.
Inheritance of Fruit Development Interval and Fruit Size in Blueberry Progenies
Authors: Finn Chad E. , Luby J.J.
Published: August 2022

Progenies from crosses among 17 highbush (Vaccinium corymbosum L.), lowbush (V. angustifolium Ait.), and V. corymbosum/V. angustiforium hybrid parents were evaluated in 1983 and 1984 of dates for 50% bloom and 50% ripe fruit, length of the fruit development interval, and berry weight. Additive genetic variance was more important than nonadditive genetic variance, based on general combining ability (GCA) variance components. Heritability estimates were moderately high (0.44-0.78) for all traits. GCA effects were largely dependent on the parents’ ancestry. A long fruit development interval was not necessarily associated with large fruit size. Selection for large fruit size, late bloom period, early ripening, and short fruit development interval in this population should be successful. Parental phenotype should be indicative of relative progeny performance.
Effect of Peat : Vermiculite Mixes Containing Trichoderma harzianum on Increased Growth Response of Radish
Authors: Paulitz T. , Windham M. , Baker R.
Published: August 2022

The effects of peat: vermiculite mixes on increased growth response of radish (Raphanus sativus L. ‘Early Scarlet Globe’) induced by Trichoderma harzianum Rifai (isolate T-12) were investigated. Canadian sphagnum peat and vermiculite were mixed in various ratios to form 0-100% peat mixes. Four levels of T-12 amendment were added to these mixes—0%, 2%, 5%, and 10% (v/v) or 0%, 0.1%, 1%, and 10%. In general, increasing levels of T-12 amendment induced linear increases in radish dry weights after 4 and 5 weeks. Greatest increases were seen in mixes containing 20% peat or 80% peat. The smallest increases were observed when T. harzianum was added to 0% peat or 100% peat mixes. There was no effect on the population densities of T-12 after it was introduced into the mixes. No Pythium spp. or root disease were detected in the mixes, suggesting that T. harzianum, a biological control agent, can increase plant growth independent of any detectable root pathogens.
Adaptability of Blueberry Species to Various Soil Types: II. Leaf and Soil Analysis
Authors: Korcak R.F.
Published: August 2022

A range of soils, with or without the addition of peatmoss, and seedlings of blueberry progenies were used in an outdoor pot study to examine the adaptability of blueberries to upland soil conditions with controlled fertilizer additions and trickle irrigation. Blueberry progenies ranged from essentially pure highbush (Vaccinium corymbosum L.) to interspecific hybrids containing varying amounts of evergreen (V. darrowi Camp), lowbush (V. angustifolium Aiton), black highbush (V. atrococcum Heller), and rabbiteye (V. ashei Reade) blueberry germplasm. The soils represented the 3 physiographic regions of the eastern United States with Berryland sand used as a comparative control. Leaf analysis for N, P, K, Ca, and Mg showed significant effects of soil, but no consistent effect of peatmoss addition or fertilizer source in the 2 years of the experiment. There were significant differences among progenies. Foliar Fe, B, Al, Zn, and Cu concentrations varied independent of soil material, progeny, or fertilizer source. Leaf Mn was significantly increased from solid 10N-4P-8K fertilizer and a significant soil by progeny interaction existed. Those progenies containing some V. angustifolium tended to have increased foliar Mn levels. The reduced vigor of the blueberry progenies grown on soils other than the Berryland sand was tentatively ascribed to induced nutrient imbalances, involving Ca, Fe, and Mn, possibly being governed by soil cation exchange capacity and organic matter reactivity.
Companion Grass and Mulch Influences on Bahiagrass, Centipedegrass, and St. Augustinegrass Establishment
Authors: Dudeck A.E. , Peacock C.H.
Published: August 2022

This study evaluated the influence of companion grasses and mulch on warm-season turfgrass establishment. Vegetative plantings of centipedegrass [Eremochloa ophiuroides (Munro) Hack.] and St. Augustinegrass [Stenotaphrum secundatun (Walt.) Kuntze] and seeded plantings of bahiagrass (Paspalum notatum var. saurae Parodi) and centipedegrass were seeded with nine companion grasses, and they were either mulched or not mulched with grass hay. Data were gathered on seedling stand, rate of ground cover development, and ground cover composition at various intervals after planting. Browntop millet (Panicum ramosum L.) was the most rapid companion grass to establish in all plantings, but it was also most competitive to warm-season turfgrasses. Although ‘FL-501’ oats (Avena sativa L.) had a slower establishment rate than Browntop millet, it was less competitive than the latter as warm-season turfgrass cover 63 days after planting was equal to control plots planted without a companion grass. Mulch had a beneficial effect on establishment rate of seeded bahiagrass that negated the need for a companion grass when establishing bahiagrass from seed. Mulch had no detrimental effect on the slow establishment of vegetatively propagated St. Augustinegrass and centipedegrass or on seeded centipedegrass.
No-tillage Snap Bean Growth in Wheat Stubble of Varied Height
Authors: Mascianica Martin P. , Wilson Henry P. , Walden Ronald F. , Hines Thomas E. , Bellinder Robin R.
Published: August 2022

Bush-type snap beans (Phaseolus vulgaris L.) were seeded by a no-tillage method into standing wheat (Triticum aestivum L.) stubble of 8, 15, 23, 30, and 38 cm in height to evaluate the effects of stubble height on pod mechanical harvest efficiency, plant morphology, and shoot component yield. Basal internode elongation, stem plus leaf yields, pod yields, efficiency of mechanical pod harvest (MH), and height of basal pod set were related in a positive linear or curvilinear fashion to wheat stubble height. Quantity of pods missed during MH was related negatively to height of basal pod set. Harvest efficiency was maximized with 15-30-cm stubble heights, and these notillage systems yielded MH pod levels that equaled or exceeded those of a conventional tillage (plow, disk 2 times) system. Superior MH efficiency was attributed to increased basal internode length and mechanical support of the shoots by the wheat stubble.
Effects of Water Stress and Degree of Ripeness on Rate of Senescence of Harvested Bell Pepper Fruit
Authors: Lurie Susan , Shapiro B. , Ben-Yehoshua S.
Published: August 2022

The physiological changes occurring in green and red bell pepper fruit (Capsicum annuum L. ‘Maor’) before and after harvest were investigated. Red pepper at harvest was less firm and had lower water potential, lower insoluble pectins, and higher water-soluble pectins than green bell pepper. However, the changes occurring in both types of peppers after harvest were similar. Postharvest weight loss was accompanied by a decrease in firmness, decrease in water potential, decrease in insoluble pectin, and an increase in soluble pectin in the cell wall. The production of CO2 showed that there was a slight decrease and a significant but small increase of ethylene after harvest. If weight loss was retarded by holding pepper in a water-saturated atmosphere, then all of these physiological changes were prevented or markedly slowed. It appears that water stress hastens and possibly triggers the onset of senescence in harvested bell pepper fruit.
Application of Flavonoid Glycosides and Phenolic Acids to Suppress Firmness Loss in Apples
Authors: Lidster P.D. , Dick A.J. , DeMarco A. , McRae K.B.
Published: August 2022

Vacuum infusion or dipping fruit in solutions of an apple (Malus domestica Borkh.) extract containing chlorogenic acid, catechins, and quercetin glycosides (isolated from ‘Spartan’ apples) suppressed fruit softening of ‘Spartan’ and ‘Golden Delicious’ apples held at 20°C. Quercetin or rutin [0.01% or 0.05% (w/v)], applied by postharvest vacuum infusion or dipping, reduced softening of ‘Golden Delicious’ apples held at 20° and 0°. Structurally related compounds (catechin, coumaric acid, and chlorogenic acid) showed some potential for retarding fruit softening but the effects were inconsistent. Additions of 0.25% (w/v) thickener plus 0.1% surfactant to the dipping solution containing the above compounds further reduced fruit firmness loss in storage. When quercetin or rutin were vacuum-infused either before or after CA storage, fruit were firmer than control fruit over a 25-day period at 20°.
Relative Phosphorus Dependency of Citrus Rootstocks Is Reflected in Leaf Nitrogen Metabolism
Authors: Rabe Etienne , Lovatt Carol J.
Published: August 2022

The relative P dependency obtained for 3 citrus rootstock cultivars was rough lemon [Citrus limon (L)] > Carrizo citrange [Poncirus trifoliate × C. sinensis (L.)] > trifoliate orange [P. trifoliate (L.)]. After only 12 weeks of P deprivation, the youngest, fully expanded leaves of rough lemon (about 21 days old) had amounts of total N, nitrate, and NH3 that exceeded the levels in +P leaves of the same age by 8.4 mg total N, 2.6 mg nitrate, and 0.6 mg NH3 per gram of dry weight. It took 7 months for similar levels of these compounds to accumulate in the youngest, fully expanded leaves of Carrizo citrange (a less P-dependent rootstock) when grown under low P conditions. After 12 weeks of P deficiency, the incorporation of NaH14CO3 into arginine plus urea was 13-, 7.4-, and 4.7-fold greater in P-deficient leaves than P-sufficient leaves for rough lemon, Carrizo citrange, and trifoliate orange, respectively. Concomitantly, arginine accumulated in — P leaves to a concentration 4.2-, 2.1-, and 1.4-fold greater than in +P leaves, respectively, for the same 3 rootstocks. The data clearly demonstrate that relative P dependency of citrus rootstocks influences their N metabolism and support the hypothesis that a more P-dependent rootstock will accumulate total N, nitrate, and NH3 sooner or to a greater extent, exhibit a greater rate of de novo arginine biosynthesis, and accumulate a higher level of arginine than a less P-dependent rootstock. Thus, calculation of the N:P ratio during leaf nutrient analysis may be useful in evaluating the nutritional status of citrus trees. Whenever N:P ratios were >20, de novo arginine biosynthesis and arginine accumulation increased significantly, indicative of ammonia detoxification. The N:P ratio of P-sufficient plants was always <15 when arginine metabolism was normal.
14C-Gibberellic Acid Uptake, Translocation, Persistence, and Metabolism in Grapefruit
Authors: Ferguson L. , Wheaton T.A. , Davies F.S. , Ismail M.A.
Published: August 2022

The uptake, translocation, and metabolism of 14C-gibberellic acid (14C-GA3) was studied in 3-year-old container-grown ‘Marsh’ grapefruit trees (Citrus paradisi Macf.). A total of 1.65 × 105 disintegrations per min (dpm) in 200 μl of solution was applied evenly over the entire fruit surface, or, on both surfaces of 3 to 5 subtending leaves of a fruit. Absorption of 14C-GA3 by leaves and peel began within 1 hr of application and continued for 8 hr. Translocation of labeled material from leaves to peel and the reverse began 4 to 8 hr after application and continued for 4 weeks. No labeled material was recovered from juice or seeds. Labeled material persisted in albedo, flavedo, and leaves for 8 weeks with the highest accumulations in the peel. Separation of 14C-GA3 metabolites from the 95% EtOH extract by reversed-phase HPLC produced 2 14C-labeled peaks. Analysis of these 2 peaks by β-D-glucosidase hydrolysis, n-butanol partitioning, and cochromatography with 14C-GA3 standards suggested that the major component was 14C-GA3 and the other a polar metabolite.
An Evaluation of the DRIS Approach for Identifying Mineral Limitations on Yield in ‘Napolean’ Sweet Cherry
Authors: Davee Douglas E. , Righetti Timothy L. , Fallahi Esmaeil , Robbins Scott
Published: August 2022

The ratio-based Diagnosis and Recommendation Integrated System (DRIS) was used to evaluate the mineral status of ‘Royal Ann’ sweet cherry trees. Standard ratios were developed from experimental research plots and then applied to evaluate the nutritional status of a large number of trees in a commercial orchard. DRIS indices for each element were calculated from a formula, which included DRIS standard ratios, their standard deviations, and the observed ratios from the sample being calculated. Nutritional Imbalance Indices (NII) were compared as the sum of DRIS indices irrespective of sign. By selecting a sufficiency range that produced the best agreement with DRIS evaluations, independent sufficiency ranges were derived from the commercial orchard data. Trees with high NII were consistently low-yielding, and, in mulching treatments where unfavorable NIIs were improved, yields were increased. The NII was more strongly correlated with relative yield increases than any other mineral parameter. The data imply that it is possible to develop useful DRIS standards and DRIS-derived sufficiency ranges from survey data, even though conventional statistical approaches do not reveal strong relationships between mineral concentration and yield.
Proportions of Individual Anthocyanins in Fruits of Cranberry Cultivars
Authors: Sapers Gerald M. , Hargrave Donna L.
Published: August 2022

Variation in the proportions of individual anthocyanins in cranberry (Vaccinium macrocarpon Ait.) fruit of different coloration was investigated. Light-, medium-, and dark-red subsamples of ‘Franklin’, ‘McFarlin’, and ‘Searles’ cranberries were analyzed to determine the soluble solids : acidity ratio (SS:A), total anthocyanin, and individual anthocyanins. Qualitative and quantitative differences in the pattern of individual anthocyanins among clones studied over three seasons were not significant. Proportions of individual anthocyanins in fruit subsamples of different coloration within cultivar samples also were similar, indicating constant biosynthetic rates for each anthocyanin during color development. Linear relationships between HPLC peak areas for individual anthocyanins and subsample total anthocyanin or SS:A values were observed.
Factors Affecting Drip Loss from Thawing Thornless Blackberries
Authors: Sapers Gerald M. , Burgher Anita M. , Jones Susan B. , Phillips John G.
Published: August 2022

Fruits from thornless blackberry (Rubus sp.) cultivars were compared to determine causes of variation in drip losses during thawing after frozen storage. Drip was similar in composition to juice obtained by pressing. Drip losses for different cultivars ranged between 1% and 30% in 1984; increased losses in 1983 were attributed to poor fruit condition (e.g., deterioration during postharvest holding). Drip losses were greater in riper samples but did not depend on fruit size. Drip losses were correlated with low insoluble pectin. Microscopic examination revealed an inverse relationship between the tendency to drip and the epidermal cell layer thickness.
Promotion of Floral Longevity by the Ovary in Carnation Flowers
Authors: Sacalis John N. , Lee Jong Suk
Published: August 2022

Cut carnation (Dianthus caryophyllus L.) flowers held in sucrose have a substantially longer vase life than flowers held in water. Excision of the gynoecium does not affect the longevity of flowers in water; however, gynoecia excision did reduce flower longevity when stems were supplied sucrose. Maintenance of cut flower life by the gynoecium was apparently due to the presence of the ovary and not the styles. Excision of gynoecia from buds of intact carnation flowers left to age on the plant also reduced longevity. Gynoecium removal did not result in a significant reduction of total sucrose or glucose in petal content of flowers held in a sucrose solution for 5 days, but absence of the gynoecium did result in a slightly but significantly lower fructose content in petals. It is suggested that the reduction in longevity resulting from gynoecium excision is not due to the failure of petals to take up sugars.
Powdery Mildew Resistance Genes in Muskmelon
Authors: McCreight James D. , Pitrat Michel , Thomas Claude E. , Kishaba Albert N. , Bohn G. Weston
Published: August 2022

Seven previously undescribed genes in muskmelon (Cucumis melo L.) for resistance to powdery mildew [Sphaerotheca fuliginea (Schlecht. ex Fr.) Poll., races 1 and 2] are reported. Progeny 92417 has a recessive gene for resistance to race 1, which is nonallelic to Pm-1. Breeding line WMR 29 has a gene for resistance to race 1 that is allelic to the recessive gene in 92417, but it is not known whether the two genes are identical alleles. Plant introduction 414723, 92417, and WMR 29 differentiated isolates of S. fuliginea race 2 at Montfavet, France, and Riverside, Calif. Comparative responses of F1, F2, and BC progenies from crosses involving 92417, PI 414723, and WMR 29 revealed six new genes for resistance to race 2. Genetic relationships among these seven genes are not fully known. Allelic and linkage relationships of these seven genes with the five previously known genes for powdery mildew resistance are also unknown.