bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Relative Humidity and Root Temperature on Calcium Concentration and Tipburn Development in Lettuce
Authors: Collier G. F. , Tibbitts T. W.
Published: August 2022

Growth chamber studies were undertaken with a tipburn-sensitive cultivar of romaine lettuce (Lactuca sativa L. cv. Lobjoits Green Cos) grown under a photosynthetic photon flux density of 320 μmol s−1m−2 for 16 hours; light and dark temperatures were 26.0° and 12.5°C, respectively. As the relative humidity (RH) during the light period was decreased from 74% to 51%, growth was retarded, Ca concentration increased, and the onset of tipburn delayed. Decreasing RH during the dark period from 95% to 90% reduced growth and resulted in lower CA concentrations and earlier tipburn development. Further decreases from 90% to 65% caused no additional change in growth or tipburn response. Root temperatures of 23.5°, compared with 15.0°, slightly increased Ca concentration but induced earlier tipburn development. Ca concentrations were increased and tipburn delayed by humidity conditions which provided large diurnal fluctuations in water potential in the plant and which encouraged root pressure flow during the dark period. Elevated root temperatures did not provide expected increases in Ca accumulation in young leaves.
Leaf Conductance, Growth, and Survival of Willow and Deciduous Fruit Tree Species under Flooded Soil Conditions
Authors: Andersen P. C. , Lombard P. B. , Westwood M. N.
Published: August 2022

Potted seedlings and cuttings of various tree species were submerged to 5–10 cm above the soil level for up to 20 months in order to determine flood tolerance based on leaf conductance (kl), growth, and survival. Flooding induced a decline in kl at soil oxygen diffusion rates of 30, 22, 20, and 15 × 10−8g cm−2 min−1 for Prunus persica (L.) Batsch, Halford seedlings (peach), Pyrus communis L. cv. Bartlett (Bart), Pyrus calleryana Decne (Call), and Pyrus betulaefolia Bunge (Bet), respectively. The leaves of some species, particularly Pyrus communis L. cv. Old Home × Farmingdale 97 (OH × F 97), abscised shortly after a decline in kl, yet leaves of most other Pyrus species did not abscise despite months of maintaining a kl near zero. Growth rates were reduced for all fruit tree species except Bet and Call after one month of spring flooding. One month of fall flooding reduced the growth of all fruit tree species the following spring. Bet survived 20 months of continuous submergence; however, only Salix discolor Muhl. (willow) grew well under these conditions. Flooding promoted adventitious rooting of willow, Cydonia oblonga Mill. cv. Provence BA 29 (quince) and Malus domestica Borkh. cv. MM 106 (apple); anthocyanin pigmentation in leaves of apple and all Pyrus species; leaf chlorosis of quince, apple, and peach; and hypertrophied lenticels on the submerged stems and roots of all species. The tolerance, based upon kl, growth, and survival, was: willow > Bet > Call = quince > Bart > OH × F 97 = Pyrus pyrifolia (Burm.) Nak. (Pyri) = Pyrus ussuriensis Maxim. (Ussuri) = apple > peach. Although the survival of pear rootstocks with and without a ‘Bartlett’ scion were similar, flooding symptoms often were quite different.
Effects of Nitrapyrin and Nitrogen Fertilizers on Ultrastructure of Mesophyll Chloroplasts of Radish
Authors: Rufner Robyn , Barker A. V. , Boucher J. P. , Kroll W. , Hosmer Trina A.
Published: August 2022

Studies concerning the use of the nitrification inhibitor, 2-chloro-6-(trichloromethyl)pyridine (nitrapyrin), have indicated that at least one site of action of nitrapyrin is associated with leaf chloroplasts. Leaves from radish (Raphanus sativus L. cv. Cherry Belle) grown with 10 ppm nitrapyrin in combination with 6 nitrogen fertilizers exhibited symptoms of nitrapyrin toxicity which ranged from reduced leaf size to marginal chlorosis and chlorotic mottling of leaves. The incorporation of nitrapyrin with nitrogen fertilizers, particularly organic sources of N, significantly reduced the number of chloroplasts per cell and significantly altered the structural integrity of radish chloroplasts relative to mesophyll cells and chloroplasts from plants grown at 0 ppm nitrapyrin.
High-density Polyethylene Wrap Improves Wound Healing and Lengthens Shelf-life of Mechanically Harvested Grapefruit
Authors: Golomb Avinoam , Ben-Yehoshua Shimshon , Sarig Yoav
Published: August 2022

Superficial scratches were a major problem in mechanically harvested ‘Marsh Seedless’ grapefruit (Citrus paradisi Macf.). Sealing individual fruit in 0.015 mm thick high-density polyethylene (HDPE) sheets greatly reduced fruit weight loss under uncontrolled room conditions. HDPE-wrapped fruit retained excellent external and internal qualities for 3 months, but was slightly softer and began to develop an unfresh off-flavor and external yellow-orange color during the 4th month of storage. HDPE wrap did not keep the injury scars invisible but improved active healing and inhibited further softening and spreading of scars, thus partly preserving fruit appearance. Highest phenylalanine ammonia-lyase (PAL) enzyme activity, a key process in lignification and wound healing, occurred in scratched, HDPE-wrapped fruit stored at 30°C. Peak activity was reached 72 hours following injury. Decay of scratched fruit by Penicillium digitatum Sacc. was reduced markedly by storage at low temperature (10°), by disinfection, or by wrapping in HDPE. The beneficial anti-decay effects of HDPE can be attributed both to insulation against secondary contact infections and to provision of a humid atmosphere which at warm temperature enhances lignification and the healing process of superficial flavedo scars.
Storage of Rose and Carnation Flowers
Authors: Staby G. L. , Cunningham M. S. , Holstead C. L. , Kelly J. W. , Konjoian P. S. , Eisenberg B. A. , Dressier B. S.
Published: August 2022

Normal refrigeration (NR), low pressure (LP, 10 to 35 mm Hg), and low oxygen (0.5% to 8%) storage trials were conducted using cut flowers of carnation (Dianthus caryophyllus L.) and rose (Rosa sp.). Variables studied were storage time, gas partial pressures, vapor barriers, chemical pretreatments, grower source, cultivars, and stem recutting methods. Low oxygen storage was not beneficial regardless of variables tested. In general, carnations could be stored for 6 weeks under NR and 8 weeks under LP conditions if the flowers were pretreated with silver thiosulfate (STS) and vapor barriers were utilized during NR storage. Roses could be stored up to 2 weeks under NR and up to 4 weeks under LP conditions and still exhibit at least 61% of their nonstored, original vase-life if LP-induced leaf disorders were not considered. Rose vase-life after NR storage was enhanced by utilizing vapor barriers during storage, and visual appearance improved if stems were recut under water upon removal from storage. LP-stored roses did not benefit by these treatments. However, the same cultivars from different growers did not respond equally and great variability was noted among rose cultivars tested regardless of storage method. Of special concern were the LP-induced leaf disorders noted on ‘Forever Yours’, ‘Royalty’, ‘Town Crier’, and ‘Spanish Sun’ roses.
Development of Cyanide-resistant Respiration in Carnation Flower Petals
Authors: Wulster George J. , Sacalis John N. , Janes Harry W.
Published: August 2022

Cyanide-resistant respiration in carnation (Dianthus caryophyllus L.) petal tissue increased daily until 3 days after flowers were harvested. Mitochondria from petals exhibited only cyanide-resistant respiration when malate and pyruvate were provided as substrate. Although intact petals from freshly harvested flowers exhibited little cyanide-resistant respiration, mitochondria isolated from them were highly cyanide-resistant in their respiration if malate and pyruvate were provided as substrate. Pyruvate, in mitochondria, was capable of releasing mitochondria inhibited by cyanide in the presence of malate. Pentose-phosphate pathway activity was significant throughout the postharvest period, but was maximum 5 days after flowers were harvested. The gas exchange quotient (GEQ) was 1 for the first 3 days after harvest, declining on days 4 and 5 and dramatically increasing on day 6 as a result of a climacteric increase in CO2 evolution accompanying flower wilting.
Sensory and Instrument Measurement of Apple Texture
Authors: Abbott Judith A. , Watada Alley E. , Massie David R.
Published: August 2022

The relationships among selected sensory textural attributes and data from modified Instron texture profile analysis (force/deformation curves obtained in compression of tissue cylinders) were examined for ‘Golden Delicious’, ‘Rome Beauty’, ‘York Imperial’, ‘Redspur Delicious’, and ‘Miller Sturdy Spur Delicious’ apples (Malus domestica Borkh.). Sensory crispness, hardness, and toughness were closely related to each other and to Instron texture profile forces at breakpoint (yield), failure, and 75% compression and to work energy in compression and rebound. Correlations of sensory attributes with the best single Instron texture profile variables were similar to those with Magness-Taylor penetration force (measured on an Instron); however, combinations of several texture profile variables in regression equations generally improved prediction of sensory attributes. Experimental Instron texture profile variables, especially force near midcompression, or the experimental variations on the customary variables, such as mean forces around failure and around full compression, were selected for prediction equations more frequently than the customary variables.
Effect of Leaf Number, Leaf Position, and Node Number on Flowering Time in Hybrid Geranium
Authors: Armitage Allan M.
Published: August 2022

Time to flower in Pelargonium Xhortorum Bailey, whether expressed as time to visible flower bud or first anthesis, is most dependent on the first 6-8 true leaves (“critical” leaves). Flowering time was correlated with leaf area of the critical leaves but not with total leaf area. Removal of young leaves did not accelerate flowering but resulted in more flowers on the first inflorescence. If the 6-8 critical leaves occurred within the first 8-10 nodes, then flowering was not inhibited. A minimum of 15 nodes was necessary for flowering, but node number ranged from 15-23. Time from visible bud to anthesis was not affected by defoliation, leaf area, or position of critical leaves.
Effects of Planting Density on Peach and Nectarine Productivity
Authors: Giulivo C. , Ramina A. , Costa G.
Published: August 2022

Productivity (number of fruits/trunk, cross sectional area) of ‘Stark Redgold’ nectarine and ‘Suncrest’ peach [Prunus persica (L.) Batsch], planted at 4 × 1.25, 4 × 1.50, 4 × 1.75, and 4 × 2.00 m, corresponding to 2000, 1666, 1428, and 1250 trees/ha, respectively, was related inversely to tree density; yield per hectare constantly declined as tree density increased. June fruit drop was unrelated to tree density, while the fruit drop pattern peaked at the same date at all the tree densities. Fruit final diameter and weight, yield per tree and per hectare were related inversely to tree density. A significant correlation was found between final fruit size and relative growth rate of fruits (positive) and shoots (negative) during early stage I of fruit development.
Ethylene Production by ‘Flamekist’ Nectarines as Influenced by Exposure to Ethylene and Propylene
Authors: Brecht Jeffrey K. , Kader Adel A.
Published: August 2022

‘Flamekist’ nectarine fruit [Prunus persica (L.) Batsch] picked during the slow-growth phase exhibited reduced C2H4 production in response to 1250 and 12,500 ppm C3H6 while fruit picked during the 2nd rapid-growth phase did not. Ethylene production by mature, preclimacteric nectarines during ripening in air at 20°C was stimulated by prior storage in air at 0° or exposure to 100 ppm C2H4 at 0° or 20°. Storage in air + C2H4 at 0° for longer than 4 days, however, nullified the stimulative effect. Subsequent peak-level C2H4 production was reduced by one-half compared to air-stored fruit. Concentration of 1-aminocyclopropane-1-carboxylic acid (ACC) increased along with C2H4 production rates during ripening. In mature fruit showing reduced C2H4 production, ACC accumulated above the expected level relative to control fruit. The data indicates that the inhibition of C2H4 production by C3H6 in developing nectarine fruit during the slow-growth phase is due to low availability of ACC, while in mature fruit the reduction in C2H4 production results from slowed conversion of ACC to C2H4.
Effects of Time of Nitrogen Application and Soil Texture on the Availability of Isotopically Labeled Fertilizer Nitrogen to Reproductive and Vegetative Tissue of Mature Almond Trees
Authors: Weinbaum S. A. , Klein I. , Broadbent F. E. , Micke W. C. , Muraoka T. T.
Published: August 2022

Mature almond [Prunus dulcis (Mill) D.A. Webb] trees growing on light-(Delhi sand) and heavy-textured (Yolo silty clay loam) soils were fertilized with 15N-depleted ammonium sulfate at different times during the year to permit direct measurement of fertilizer N within the trees. The distribution of fertilizer N between vegetative and reproductive organs was monitored during both the year of application, 1980, and the subsequent year. The later that fertilizer N was applied during the season, the less fertilizer N was recovered in the fruit and leaves that year, and the greater its N contribution to these organs was the following year. Isotopic labeling of fruit and leaves appeared to be relatively unaffected by soil texture during the year of fertilizer application. During the subsequent year, however, the recovery of fertilizer N by fruit and leaves was 2-fold greater on the heavy-textured soil than on the light-textured soil. Recovery of labeled N in fruit was relatively low on both soil types following application of fertilizer during the dormant period. Isotopic N was recovered in fruit in both 1980 and 1981 and constituted about 20% to 28% of fruit N at most. About 25% of the applied N was removed in the fruit on the heavy-textured soil over a 2-year period. Up to 1 kg N per tree was removed annually in the harvested fruit.
Peeled Yield and Quality of ‘Delicious’ Apples Peeled by Superheated Steam, Saturated Steam, and Caustic Peeling
Authors: Smith Durward A.
Published: August 2022

Steam peeling resulted in higher, peeled yields and a brighter-colored product than caustic peeling. Efficient peeling was possible using relatively low pressures in conjunction with superheated steam. Peeled yields were 98% for superheated steam-peeled apples with flash cooling, 92% for caustic-peeled fruit which had a prepeel treatment to physically disrupt the cutin layer, 86% for conventionally caustic-peeled fruit, and 83% for the mechanically peeled control.
Effect of High and Low Temperatures on Pollen Germination and Seed Set in Snap Beans
Authors: Dickson M. H. , Boettger M. A.
Published: August 2022

Pollen germination in vivo in beans (Phaseolus vulgaris L.) was less at 8° and 12°C than at 18°. There were large cultivar differences, and germination at 9 am was no different from that at 3 pm. Pollen from bean flowers grown in the greenhouse at 21° Day/18°C Night (D/N) was transferred to plants in bloom at combinations of 8°, 10°, and 12° N, and 20°, 25°, and 30° D. Pollen from plants at the 9 temperature combinations also was used to pollinate plants in the greenhouse. Pollen from plants grown at 30° as compared to 20° and 25°, resulted in reduced seed yields. Conversely, viable pollen transferred to plants at 30° reduced set insignificantly. Thirty/8° D/N combinations resulted in the lowest yields. Low night temperatures appeared to inhibit ovule viability. In contrast, high temperatures reduced pollen viability. NY 5-161 and OSU 1604 were more stable than BBL 47, BBL 92, and PI 165426 at both high and low temperatures.
Ripening Period of Vaccinium Species in Southeastern North Carolina
Authors: Ballington J. R. , Ballinger W. E. , Mainland C. M. , Swallow W. H. , Maness E. P. , Galletta G. J. , Kushman L. J.
Published: August 2022

Vaccinium species collected from the eastern United States were grown and fruited at Castle Hayne, N.C. Harvest season extended from 5 June to 22 Aug. Vaccinium angustifolium Ait. was earliest ripening. Vaccinium myrtilloides Michx., V. elliotti Chap., diploid V. corymbosum L., and tetraploid V. pallidum Ait. populations also contained very early- to early-ripening seedlings. Early-ripening seedlings were not observed in tetraploid V. corymbosum populations and reached peak ripeness around mid-June, about with ‘Bluecrop’. One tetraploid V. corymbosum population continued ripening into early August. Vaccinium ashei Reade populations from Georgia began ripening about 2 weeks earlier than Florida V. ashei or Arkansas V. amoenum Ait. populations. One Georgia V. ashei population was only slightly later than tetraploid V. corymbosum. The Florida V. ashei populations continued ripening into late August. The diploid species V. darrowi Camp, V. tenellum Ait., and V. stamineum L., were all basically late in ripening. The potential utility of these species in breeding for both early- and late-ripening Vaccinium genotypes is discussed.
Reduction of Bacterially Induced Frost Damage to Tender Plants
Authors: Anderson J. A. , Buchanan D. W. , Stall R. E.
Published: August 2022

Strategies for reducing bacterially induced frost damage to tender plants were examined. Introduction of the competitive bacterium, Erwinia herbicola M232A (not active in ice nucleation) did not lower the temperature at which freeze injury of tomato shoots occurred. Streptomycin was effective in reducing freeze damage of tomato shoots only when mixed with the Pseudomonas syringae suspension prior to plant inoculation. Spectinomycin, another aminoglycoside, was effective in reducing frost damage to tomato plants due to P. syringae. Bacteria present intercellularly (within the plant) may play a significant role in bacterial ice nucleation.
Growth, Free Amino Acids, and Mineral Composition of Tomato Plants in Relation to Nitrogen Form and Growing Media
Authors: Magalhaes Jose R. , Wilcox G. E.
Published: August 2022

Tomato plants ‘Campbell 1327’ grown in peat with NH4 nutrition had no visible symptoms of NH4 toxicity, while severe symptoms of NH4 toxicity were displayed in solution or sand culture. Growth of plants was much better with NO3-N than NH4-N in sand, vermiculite, or solution culture; but in peat, growth of NH4-treated plants equalled or exceeded that of NO3-treated plants in sand, vermiculite, and peat. The total dry weight of NH4-treated plants grown in peat was 2, 2.5, and 3.4 times higher than plants grown in vermiculite, sand, and solution culture, respectively. Content of uncomplexed ASHS.109.3.406 in NH4-treated plants grown in peat was reduced markedly compared with other media. NH4-treated plants grown in sand, vermiculite, and solution culture, displaying NH4 toxicity symptoms, had a total amino acid:free NH4+ molar ratio < 2, compared to 6-8 with NO3. For NH4-treated plants grown in peat the ratio was similar to that of NO3-treated plants. Asparagine and glutamine in NH4-treated plants grown in peat were 3.5 and 11.3 times higher than with NO3-N, indicating a high efficiency in detoxification of NH4 through incorporation into these amino acids. The medium on which a plant is grown can have a marked influence on the plant response to N form.
The Influence of Gene B on Fruit Development in Cucurbita pepo
Authors: Schaffer Arthur A. , Boyer C. D.
Published: August 2022

The influence of gene B on various growth parameters in 3 genetic backgrounds of Cucurbita pepo L. cultivars ‘Early Prolific’, ‘Small Sugar’, and ‘Fordhook Zucchini’ is reported. While fruit size is smaller in the presence of B in all 3 backgrounds, ‘Early Prolific’ was affected the least. Rind hardness also was lower when B was present in ‘Fordhook Zucchini’ and ‘Small Sugar’ but was not affected in ‘Early Prolific’. Percentage of dry weight of the pigmented rind was unaffected by B in the ‘Early Prolific’ background but was lower due to B in the ‘Fordhook Zucchini’ background. The inconsistent influences of B in these 3 genetic backgrounds are discussed in terms of chloroplast contribution to fruit growth and development.
Peach Rootstock Influence on Foliar and Dormant Stem Nutrient Content
Authors: Knowles J. W. , Dozier W. A. , Evans C. E. , Carlton C. C. , McGuire J. M.
Published: August 2022

Foliar and dormant shoot nutrient content and tree survival of ‘Loring’ and ‘Redhaven’ peach [Prunus persica (L.) Batsch] on 8 seedling rootstocks (Lovell, Halford, Harrow W-208, NA8, Nemagard, Siberian C, NC NRL-4, and NC 152-AI-2) were determined during 2 seasons. Foliar Ca levels of both ‘Loring’ and ‘Redhaven’ peach trees were lower on Siberian C rootstock than on any other rootstock in the study. Dormant stem Ca levels were lower when cultivars were on Siberian C rootstock than when on most other rootstocks. Cultivars on Siberian C had lower foliar K levels than most other scion/rootstock combinations. Some differences in foliar and stem N, P, Mg, and Mn levels were evident; however, these differences generally were small and inconsistent. After 6 years in the orchard, greatest tree loss occurred with ‘Loring’ on Siberian C and ‘Redhaven’ on Siberian C or NA-8. Other rootstocks did not affect tree survival of either cultivar. Tree width was smallest with Siberian C rootstock, but few differences in trunk circumference and tree height were observed.
Inheritance of Glandular Trichomes in Crosses between Lycopersicon esculentum and Lycopersicon pennellii
Authors: Lemke Carol A. , Mutschler Martha A.
Published: August 2022

The absence or presence of type IV trichomes seemed to be simply inherited in crosses of the tomato, Lycopersicon esculentum Mill, and Lycopersicon pennellii Correll. F2 and BC1 data showed a good fit to a 15 : 1 and 3 : 1 ratio, respectively, suggesting that the presence of type IV trichomes is controlled by 2 unlinked genes. Broad sense heritability estimates of type IV trichome density were high. Generation means analysis of type IV trichome density indicated that genic interaction was important in the 3 crosses. All plants examined possessed type VI trichomes. Density of type VI trichomes seemed to be under large environmental influences. Broad sense heritability estimates for the density of type VI trichomes were low to moderate. Correlation coefficients comparing adaxial and abaxial trichome density measurements of both types of trichomes were significant for most of the populations studied. Correlation coefficients comparing type IV and type VI trichomes were not significant in most of the populations studied.
Investigations into the Roles of Fertilizer Level and Irrigation Frequency on Growth, Quality, and Severity of Pythium Root Rot of Peperomia obtusifolia
Authors: Chase A. R. , Poole R. T.
Published: August 2022

Peperomia obtusifolia (L.) A. Dietr. were grown with various fertilizer levels (0.5–3.5 g Osmocote 19-3-10/10-cm pot) and irrigation frequencies (1, 2, or 3 times/week). Plants were inoculated with Pythium splendens Braun 2–6 months after initiation of fertilizer treatments. Top and root quality responses were linear and quadratic with respect to fertilizer level. One month after inoculation, root quality decreased the most for plants with the highest irrigation frequency and the lowest fertilizer level. Plants fertilized at the highest rate did not show a significant decrease in root quality. There was an interaction between fertilizer and irrigation rates as measured by plant height, quality, and disease ratings. Poorest quality plants resulted when watered 3 times/week and fertilized with 0.5 g Osmocote/pot. Highest quality plants resulted when watered 2 or 3 times/week and fertilized with 2.5 g Osmocote/pot.
Summer Pruning of ‘Gala’ Apple: The Relationships between Pruning Time, Radiation Penetration, and Fruit Quality
Authors: Morgan D. C. , Stanley C. J. , Volz R. , Warrington I. J.
Published: August 2022

Trees of apple cv. Gala (Malus domestica Borkh.), which had previously been dormant pruned, were pruned in mid-December (early summer pruned—73 days after full bloom), mid-January (late summer pruned—108 days after full bloom), or were only dormant pruned (control). On 2 harvest dates (late February and early March) fruit from 4 different regions of the tree canopy were assessed for red blush, background color, soluble solids concentration, and fresh weight. Penetration of photosynthetic photon flux density (PPFD) to each region was measured at the summer pruning times and at the First harvest. Summer pruning increased the percentage of red blush—but not background color—for both pruning dates, decreased fresh weight of fruit from the early pruned trees, and decreased the soluble solids concentration of fruit from the late-pruned trees. The percentage of red blush and fruit fresh weight both showed a highly positive correlation with PPFD penetration, but for fruit fresh weight, the correlation also was dependent on the pruning treatment. The concentration of soluble solids also was related to PPFD penetration although, in comparison with fresh weight, the differences were reduced. Background color was relatively independent of tree position or pruning treatment.
Nutrient Diagnosis of ‘Valencia’ Oranges by DRIS
Authors: Beverly R. B. , Stark J. C. , Ojala J. C. , Embleton T. W.
Published: August 2022

Reference values were derived from field data for use in evaluating the N, P, K, Ca, and Mg status of ‘Valencia’ orange (Citrus sinensis [L.] Osbeck) trees by the Diagnosis and Recommendation Integrated System (DRIS). DRIS diagnoses generally agreed with diagnoses made by the sufficiency range method, with the advantage that DRIS reflects nutrient balance, and identifies the order in which nutrients are likely to become limiting. DRIS diagnoses were affected by the type and age of the tissue sampled. DRIS reflected changes in nutrient concentrations due to alternate bearing or crop load effects and agreed with the sufficiency range method when concentration changes were sufficient to affect the latter method.
Efficiency of Single-harvest Methods for Measurement of Yield in Fresh-market Cucumbers
Authors: Wehner Todd C. , Miller Conrad H.
Published: August 2022

Three rapid methods of measuring yield (small plots harvested at the green stage, and single plants harvested at the green or at the mature stage) were tested for correlation with yield from a replicated multiple-harvest yield trial to determine how well they predicted performance of 10 hybrids in 1981, and 18 lines and cultivars tested in 1982. Only 2 methods of measuring yield were evaluated in 1981, small plots harvested once-over at the green stage and the standard replicated multiple-harvest trial. In that year, the most efficient method for measuring yield, based on capacity of the method to handle lines and to predict multiple-harvest trial performance, was 2 or 3 replications of 3 m plots harvested once-over. Those methods had a calculated advantage (relative capacity × correlation coefficient) of 43% to 80% over the replicated multiple-harvest trial. The most efficient method for measuring yield, of the 4 tested in 1982, was single plots with 1, 2, or 3 replications harvested once-over at the green stage. The tests had a calculated advantage of 102 to 107% over the replicated multiple-harvest trial, respectively. It was concluded that 2 or 3 replications in the test would provide the best results by controlling environmental variability without using an excessive number of seeds per family. In addition, the best correlation with yield in the multiple-harvest test was obtained when all fruit from the plot were counted, rather than just those of marketable size (38 to 60 mm diameter).
Estimates of Heritabilities and Variance Components for Low-temperature Germination Ability in Cucumber
Authors: Wehner Todd C.
Published: August 2022

Variance components for low-temperature germination ability in cucumber (Cucumus sativus) were estimated for 3 germination variables (actual days to germination, days to 50% germination, and percentage of germination) at 17°C using a North Carolina Design I analysis. The estimates were made using the North Carolina Medium Base Pickle (NCMBP) population, which was developed by intercrossing adapted pickling cucumber cultivars with diverse lines for 3 cycles without selection. Estimates of additive and dominance variance for the percentage of germination and days to 50% germination were equal, but additive variance was predominant for actual days to germination. Heritabilities based on half-sib families tested in 2 replications ranged from 0.44 to 0.61 for the 3 germination variables. There were large significant genetic correlations among the 3 germination variables, ranging from 0.61 to 1.03 in absolute value. Selection for either the percentage of germination or for actual days to germination at 17° should result in significant progress in improving low-temperature germination ability of cucumbers in the NCMBP population.
Spent Mushroom Compost as a Soil Amendment for Vegetables
Authors: Wang Sherry Hsiao-lei , Lohr Virginia I. , Coffey David L.
Published: August 2022

Spent mushroom compost (SMC) was used as a soil amendment for field-grown vegetables. Four rates (0, 2, 10, or 20 kg/m2) of SMC were applied to a fine sandy loam in 1981 and 1982. SMC application decreased bulk density and increased the percentage of small pore space, pH, and electrical conductivity. Yields of cucumber and snap bean increased and yield of onion decreased, as the rate of SMC increased in 1981. Yields of cabbage, radish, and tomato were not affected significantly by the addition of SMC. Tomato yield was maximum at 10 kg/m2, then declined as SMC was increased to 20 kg/m2 in 1982. Yield responses of cucumber, fall-planted radish, spinach, and mustard were similar to that of tomato. Salt sensitive crops, such as snap bean, onion, and spring-planted radish, suffered severely reduced plant stands and, consequently, decreased yields. Yield of cabbage, a relatively salt tolerant crop, was not affected by SMC. Concentrations of K in all leaf tissues increased significantly as the level of SMC increased. Mg content in leaf tissue decreased.
Development of the Flower Spike of Bird of Paradise and its Flowering Period in Hawaii
Authors: Criley R. A. , Kawabata O.
Published: August 2022

Time intervals between leaf emergence, flower stalk emergence, and flower cut were determined for 550 Strelitzia reginae Ait. (Bird of Paradise) flowers during 1977–80 at an elevation of 25 m in Hawaii. The interval between leaf emergence and flower stalk emergence averaged 186 days with a range of 173 to 204. The interval between flower stalk emergence and flower cut averaged 64 days with a range of 54 to 74. Seasonal differences in the duration of development did not account for the seasonal differences in yield. Dissection of flowering fans revealed sequences of flower bud abortion which occurred during June to October, and accounted for low flower production during winter and early spring months in Hawaii.
Characterization of Sugar Transport in Storage Tissue of Carrot
Authors: Daie Jaleh
Published: August 2022

Sugars are a major storage carbohydrate and a primary component of carrot root quality. The objective of this study was to determine the characteristics of sugar transport into the storage cells of carrot [Daucus carota (L.)]. Tissue disks were incubated in a buffered solution (pH 6.5) containing various concentrations of sucrose, glucose, or fructose, 1 mm CaCl2, and 100 mm mannitol. Passive uptake was defined as uptake in the presence of 5 μm carbonyl cyanide, - m chlorophenyl hydrazone (CCCP). Active uptake was the difference between total (–CCCP) and passive uptake. Characteristic, biphasic kinetics were observed for all sugars. At sugar concentrations below 10 mm, a saturating active component was operating. Above 10 mm, the influx was a nonsaturating, linear transport system. Active transport was pH dependent, showing high rates of uptake at low pH. Glucose and fructose did not inhibit sucrose influx and vice versa, but they did compete with each other. The kinetics of the hexose competition was noncompetitive inhibition. The competition studies suggested the presence of a separate carrier for each sugar. The evidence indicated that sugar transport across membranes of carrot storage cells is a combination of active and passive transport, consistent with transport kinetics observed in other crops. Active sugar uptake is a significant part of uptake, doubling influx at low apoplastic concentrations. At maturity, sucrose is the major transport and storage sugar. Glucose and fructose however, are transported at considerable rates in vitro, when they are present in the free space.
Responses of Stokes Aster Achenes to Chilling
Authors: Campbell T. A.
Published: August 2022

Stokes aster [Stokesia laevis Hill (Greene)] is a perennial ornamental; achenes are a prospective source of vernolic acid for the chemical industry. Responses of achenes of 6 Stokes aster accessions to temperatures of 0° to 20°C were studied. There was no germination below 11°; germination was near 0 at 11° and reached a maximum at 20°. Achenes equilibrated at 15% moisture generally germinated more rapidly than those at 5% moisture. In hydration-chilling experiments, more than one day of exposure to chilling prior to germination decreased germination and increased the frequency of abnormal seedlings in some entries. Equilibration at 15% moisture prior to chilling reduced damage slightly compared to 5% moisture. There seemed to be a direct relationship between early imbibition rate and susceptibility to chilling damage. Gradual chilling and warming of germinated achenes resulted in a significant reduction in damage compared to abrupt chilling and warming.
Inheritance of Flowering Response in Cucumber
Authors: Vecchia P. T. Della , Peterson C. E.
Published: August 2022

Segregating populations were developed from a cross between 2 parents with distinctly different flowering responses, WI 1606 (P1), a day neutral line of Cucumis sativus L. and PI 215589 (P2), a short-day line from C. sativus ‘hardwickii’ (R.) Alef. Parents (P1, P2) and the F1, F2, BC1P1 and BC1P2 populations were grown in the field at Hancock, Wis., and in the greenhouse under long days (16 hr), and classified as late or early flowering on the basis of the main-stem node at which the 1st flower developed. Segregation within the BC1P2 and F2 populations demonstrated that the short-day requirement for early-flowering in PI 215589 is controlled by a single recessive gene, probably allelic to the previously reported ‘df’ mutant for delayed flowering.
Effects of Delays in Establishing Controlled Atmospheres on Kiwifruit Softening during and Following Storage
Authors: Arpaia M. L. , Mitchell F. G. , Mayer G. , Kader A. A.
Published: August 2022

Establishment of a controlled atmosphere (CA) of 2% O2 + 5% CO2 within one day of harvest (no delay) or after a one-week delay in 0°C air retarded rapid softening of CA-stored kiwifruit (Actinidia chinensis Planch. ‘Hayward’) during the 1st 6 weeks of 0° storage, relative to those kept in air or in CA established after a 2-week delay. Between the 6th and 24th week of storage, further softening in air-stored fruit was suppressed in all CA treatments, and the 2-week delay CA fruit always were significantly softer than those placed in CA within one day of harvest. The one-week delay treatment resulted in an intermediate flesh firmness. The rates of fruit softening at 0°-air after 12, 16, or 24 weeks of CA storage were comparable to those of fruit stored continuously in 0° air.
Improvement and Genetic Control of Partial Resistance in Sweet Corn to Corn Leaf Rust
Authors: Randle W. M. , Davis D. W. , Groth J. V.
Published: August 2022

Evaluation of the progeny populations from crosses between a resistant sweet corn inbred (Zea mays L.) and 3 susceptible inbreds indicated that the variation for partial resistance to corn leaf rust (Puccinia sorghi Schw.) depended on the parents used. Heritability estimates were high with both additive and dominance gene effects important in character expression. Epistasis was shown to influence rust reaction in at least one cross. The ability to improve partial resistance in 2 sweet corn populations was demonstrated by 3 methods of selection.
Coal Cinders with Pine Bark as Azalea Growing Media
Authors: Wagner D. F. , Neal J. C.
Published: August 2022

Coal cinders with pine bark were evaluated as containerized plant growing medium. Rhododendron obtusum Lindl. ‘Hinodegiri’ liners were grown in several combinations of media composed of pine bark mixed with an aged and a recently combusted source of cinders. Measurements of media pH, soluble salts, NO3− –N, NH4+ –N, and 19 extractable nutrient and metallic ions were obtained. Leaf tissue samples were analyzed for 19 elements. Top dry weight, visual growth and chlorosis ratings, and root visual ratings constituted the plant growth parameters measured. Satisfactory growth was generated in pine bark amended with up to 50% cinders from either source.
Quality of Euvitis Hybrid Bunch Grapes after low Temperature Storage with Sulfur Dioxide Generators
Authors: Ballinger W. E. , Nesbitt W. B.
Published: August 2022

Eighteen lines of Euvitis grapes in 1980, and 30 in 1981, were stored for 9 weeks at 0°C in 5.7-liter telescoping, corrugated cardboard shipping containers with polyethylene liners, with and without commercially available sulfur dioxide (SO2) generators (1 in 1980; 2 in 1981). Decay during storage without SO2 varied greatly among lines (2% to 81% in 1980 and 0% to 62% in 1981). The generator producing SO2 for the entire 9 weeks in 1981 eliminated decay of most grape lots. By comparison, the generators producing SO2 for only 2 weeks permitted 4 times as much decay. Two weeks of SO2, however, permitted only one-fifth as much decay as that associated with no SO2 during storage. Both generators reduced degradation of appearance and flavor of the grapes. The long-term generator was associated with more SO2 damage to the fruit than was the short-term generator. The lines varied widely in tolerance to SO2. SO2 damaged the fruit by entering openings in their surfaces caused by stem tears and cracks.
Quality of Citrus Fruit Following Cold Treatment as a Method of Disinfestation against the Caribbean Fruit Fly
Authors: Adsule P. G. , Ismail M. A. , Fellers P. J.
Published: August 2022

Fruit of ‘Valencia’ orange (Citrus sinensis Osbeck) and ‘Murcott’ tangerine (Citrus reticulata Blanco) were subjected to cold treatment at 1.1°C for 17 days as prescribed for the disinfestation of citrus of the Caribbean fruit fly (Anastrepha suspensa (Loew) in the plant protection and quarantine treatment manual. Fruit quality was evaluated during subsequent storage at 4.4°C for one week followed by 2 weeks at 21.1°. Fruit under cold treatment did not develop any physiological disorders. Fruit color and general appearance remained unaffected. Loss due to decay was 2.3% for ‘Murcott’ tangerine and 7.2% for ‘Valencia’ orange. Moisture loss for both varieties was about 5%. Fruit quality, including flavor, was found to be acceptable in ‘Murcott’ during subsequent storage. Yet the quality of ‘Valencia’ remained acceptable for one week only at 4.4°. Cartons used for packing fruit and stored at 1.1° absorbed more moisture when transferred to 21.1° than the cartons at 4.4° or 21.1° because of moisture condensation on fruit.
Development of Drought-stressed Poinsettias
Authors: Gilbertz David A. , Barrett James E. , Nell Terril A.
Published: August 2022

Single stem Euphorbia pulcherrima Willd. cv. Eckespoint C-1 Red were exposed to single or repeated episodes of drought stress to leaf water potentials of −1.0 or −1.3 MPa at different times during crop development. Decreased plant height and delayed flowering generally were caused by treatments including stress prior to time of initial bract coloration. Plant quality was reduced by those treatments that inhibited bract development and caused leaf abscission. Inflorescence diameter was reduced the most by stress after bract coloration. Bract dry weight was sensitive to stress and was reduced by stress between the time of initiating long nights and bract coloration. Leaf abscission resulted from a single exposure to −1.3 MPa after flower initiation. Stress prior to start of long nights had little effect on plant development.
Reversal of Nematode-induced Growth Retardation in Tomato Plants by Inhibition of Ethylene Action
Authors: Glazer Itamar , Apelbaum Akiva , Orion Daniel
Published: August 2022

Tomato plants (Lycopersicon esculentum) infected with root-knot nematodes, Meloidogyne javanica, contain 2.2 to 2.6-times higher levels of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) in the roots and leaves compared with uninfected plants. The nematode-induced increase in the ACC coincides with increased ethylene production in the infected plants. Foliar spray with aminoethoxyvivyl-glycine (AVG), which inhibits ethylene production or with silver thiosulfate (STS) which inhibited ethylene action, partially or completely eliminated the pathogenic symptoms displayed by a nematode-infected plant, indicating that the ethylene induced by the nematode infection plays a major role in the pathogenic symptoms infliced by the nematode. Foliar spray with 3 mM STS 4 to 8 days after the nematode inoculation was found to be the most effective treatment for reversing the nematode infection symptoms.
Sweetpotato Population Changes During Six Random Crossing Generations1
Authors: Jones Alfred
Published: August 2022

Twenty-four traits in generations 2 to 7 of a randomly intercrossing sweetpotato [(Ipomoea batatas (L.) Lam.] population were studied. Mean changes detected were: increased flowering, reduced leaf whorl purpling, increased vine purpling, decreased vine diam, decreased root wt, fewer smooth skinned types and some increase in vine length. Changes in the fusarium wilt index were not significant but distributional changes were important; fewer plants with high levels of resistance occurred in the later generation. Reductions in vine diam and in root wt were considered independent of each other. There was no indication that the natural selection for increased flowering was responsible for either vine diam or root wt reductions.
Influence of Fertilizer Placement and Micronutrient Rate on Watermelon Composition and Yield1
Authors: Locascio S. J. , Fiskell J. G. A. , Martin F. G.
Published: August 2022

Plant growth and fruit yield were enhanced by broadcast as compared with band applications of either N-P-K fertilizer or micronutrients. Plant dry wt were similar with applications of either CuSO4-5H2O at 4 and 8 lb./acre Cu or complete micronutrient frit (FTE 503) at 30 and 60 lb./acre in 2 seasons. In 1 season, fruit yields were significantly higher where CUSO4 was used. Increases in rate of either micronutrient source resulted in increased fruit yields where applications were broadcast but a decrease where banded. These responses to increased micronutrient rates were related to an increase in micronutrient efficiency with the broadcast placement and to a toxicity with the band placement.
Solution Culture Investigations of the Influence of Manganese, Calcium, Boron, and pH on Internal Bark Necrosis of ‘Delicious’ Apple Trees1
Authors: Cooper Richard E. , Thompson Arthur H.
Published: August 2022

Manganese toxicity was expressed as leaf chlorosis, early leaf abscission, reduced flower bud number, reduced growth, and internal bark necrosis (IBN). Increasing Ca or decreasing Mn in the solution were effective in correcting IBN, while increasing B or pH were ineffective. High solution Mn was associated with a decrease in bark Ca, and high solution Ca was associated with decreased Mn accumulation. Severe IBN was observed on the ‘Delicious’ scion, but no bark symptoms were visible on the EM IX clonal stock. Manganese concn were similar in both stock and scion bark, but Ca levels in the stock bark were substantially higher than those in the scion.
The Effect of Temperature and Daylength on Shoot Growth and Bud Formation in Azaleas1
Authors: Pettersen Harold
Published: August 2022

Preliminary experiments showed that flower bud initiation took place 3-4 weeks earlier after a “soft” than after a “hard” pinch. The effect of daylength was more pronounced in young than in older plants. In temp/daylength experiments with young plants, bud initiation was stimulated to a varying extent in all 8 cultivars investigated. A critical daylength could not be shown. Optimal daylength for flower bud formation was about 12 hr whereas a 24-hr day inhibited flowering to the greatest extent. The effect of daylength depends on temp. At 15-16°C the plants were nearly day neutral, but they reacted as facultative short day plants above 20°C. Optimum conditions for growth were about 24°C, with continuous light.
Indole-3-Acetic Acid Oxidase Activity from Developing Peach Seeds and Its Inhibition by Extractable Catechin1
Authors: Ritzert R. W. , Hemphill D. D. , Sell H. M. , Bukovac M. J.
Published: August 2022

An indole-3-acetic acid oxidase system was detected and characterized in extracts of immature peach seed (Prunus persica (L) Batsch, cv. Redhaven). The enzyme had a pH optimum of 4.5 to 5.0 and required Mn2+ and 2,4-dichlorophenol for optimum activity. The reaction product appeared to be 3-methyleneoxindole. Catechin, a natural polyphenol, was isolated from peach seed. It inhibited the IAA oxidase system and had a synergistic effect on IAA activity in the Avena coleoptile straight growth assay. Kinetic studies demonstrated that the catechin inhibition was non-competitive with substrate.
The Movement and Fate of (2-Chloroethyl)phosphonic Acid in Walnut1
Authors: Martin George C. , Abdel-Gawad Hesham A. , Weaver R. J.
Published: August 2022

14C-ethephon applied to a walnut leaflet penetrated and translocated rapidly in young plants, but more slowly in older plants. The compound translocated to the kernel at higher levels when applied to a leaflet than when applied to the hull but in both cases levels of activity were low. Between 5 and 7 days after application the radioactivity in the kernel decreased markedly, 14C-ethephon in the leaves, hull, shell, and kernel was metabolized, but no side products remained in the plant tissue that could be detected by the techniques employed.
The Quality of ‘Red Delicious’ Apples As Affected By Overtree Sprinkler Irrigation1
Authors: Unrath C. R.
Published: August 2022

Irrigation and evaporative cooling of ‘Red Delicious’ apple trees over 2 growing seasons resulted in a reduction in environmental stress as evidenced by plant and air temp reductions (8). The trees were spot-picked weekly, based on acceptable color to meet grade standards. Harvesting was completed one week earlier on trees receiving overtree sprinkler irrigation as compared to those with undertree or no irrigation. Fruit from trees which received overtree irrigation had greater surface coloration and nearly twice as much surface area with good solid red color as fruit which received undertree or no irrigation. Overtree irrigation improved fruit size and shape during 1969 but not 1970; increased soluble solids, and reduced cork spot and bitter pit in 1970. Lower firmness of overtree irrigated apples in 1969 was attributed to their greater size. Irrigation (over and undertree) had no influence upon internal breakdown measured after 4 months of storage at 32°F.
Incidence of Cork Spot as Related to Calcium in the Leaves and Fruit of ‘York Imperial’ Apples
Authors: Shear C. B.
Published: August 2022

In a controlled nutritional experiment, the percentage of fruit showing cork spot was significantly negatively correlated with the concn of Ca in leaves and in the flesh of the fruit. With NO-3 N, fruit Ca increased more rapidly in proportion to leaf Ca than with 3/4 of the N supplied as NH4. To assure commercial control of cork spot, flesh Ca must be above 200 ppm dry wt. To consistently attain this level in the fruit, leaf Ca in late August must be above 1.90 percent dry wt. The wide range in incidence of cork spot at a given level of fruit Ca indicates that high Ca in the fruit may decrease or prevent this disorder but the causal factor is not the lack of Ca.