bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Sex Type, Season, and other Factors on in Vitro Establishment and Culture of Carica papaya L. Expiants1
Authors: Litz Richard E. , Conover Robert A.
Published: August 2022

Shoot tips were removed from field-grown staminate, pistillate and bisexual selections of Carica papaya L. at intervals during a 21 month period, and were cultured in vitro on a sterile establishment formulation consisting of Murashige and Skoog basal medium (MS) supplemented with 50 μm kinetin and 10 μm naphthaleneacetic acid (NAA) in a growth room at 25°C and with a 16 hr photoperiod at 1.5 klx. Established expiants were transferred to proliferation medium consisting of MS with 2 μm 6-benzylaminopurine (BA) and 1 μm NAA. Establishment of expiants was influenced by season, sex type and degree or type of microbial infection. Proliferation rates varied for different clones and declined sharply after about 13 subcultures. Bacterial contamination was a severe problem; however the nearly ubiquitous Pseudomonas sp. contaminant did not cause mortality. Expiants could not be established from stock plants affected by a disease of unknown etiology that appeared in experimental plantings. Frequency of rooting on MS media with or without auxin declined with increased time in culture.
Sources of Variability in Apple Shoot Selection and Handling for Bud Rest Determinations1
Authors: Latimer Joyce G. , Robitaille Henry A.
Published: August 2022

Many shoot sampling variables were found to influence bud rest of apple (Malus domestica Borkh.). Unlike terminal buds, uppermost lateral buds on decapitated stem pieces were stimulated by wounding and developed throughout the rest period under forcing conditions in a growth chamber and their rate of development was an accurate measure of depth of rest. Neither segment length nor location on the original intact shoot affected bud rest intensity, but single-node segments were avoided because they became desiccated. Rate of development of resting buds in darkness increased with increasing temperature between 20° and 30°C. Bud rest intensity decreased with decreasing shoot length. Shoot location in the tree crown (shaded interior vs. exterior) did not affect bud rest intensity, but there was a significant interaction between crop load and shoot height in the tree. Many interactions were significant between various shoot characteristics and bud rest intensity. Spurs were compared to shoots on the basis of the percent of a population showing terminal budbreak after 28 days of forcing. Terminal buds on spurs entered rest later and emerged earlier than did terminal buds on short, medium or long shoots.
Accumulation of Reducing Sugar and Resistance of Grapefruit Peel to Chilling Injury as Related to Winter Temperatures1
Authors: Purvis A. C. , Grierson W.
Published: August 2022

Resistance of grapefruit (Citrus paradisi Macf.) to chilling injury (CI) was compared with the concentration of reducing sugars in the peel through 3 harvesting seasons. Accumulation of reducing sugars preceded increased resistance to CI. The increase in reducing sugar concentration at mid-season (December – February) resulted from the hydrolysis of sucrose which is regulated by temperature. Accumulation of reducing sugars may be prerequisite to increased resistance of grapefruit to CI, but the role(s) of reducing sugars in the resistance mechanism has not been determined.
Levels of Pectic Substances and Calcium in Gibberellic Acid-treated Sweet Cherry Fruit1
Authors: Facteau T. J.
Published: August 2022

Foliar applications of gibberellic acid (GA3) to mature ‘Lambert’ sweet cherry trees (Prunus avium L.) about 21 days before harvest increased fruit weight (fresh and dry), soluble solids (SS), alcohol-insoluble substances (AIS) (both concentration and per fruit), ash weight, and fruit firmness at harvest. Application of GA3 did not affect concentrations of ethylene diamine-tetraacetic acid (EDTA) or pectinase-soluble pectins and fruit Ca. GA3-treated fruit had lower concentrations of water-soluble pectins and reduced surface pitting. Fruits sampled at 3–7 day intervals (starting about 21 days before harvest) from control and GA3-treated trees showed that as an average response over a 29-day sampling period GA3 increased fruit weight, firmness, AIS concentration, AIS per fruit, pectinase-soluble pectins, and decreased water-soluble pectins. Neither total, residual, or soluble fruit Ca were affected by treatment with GA3. Fruit Ca levels remained constant, on a per fruit basis, during the last 3 weeks of fruit maturation but Ca concentration, expressed as fresh or dry weight, decreased as a result of increased fresh and dry weight. Higher Ca levels were not associated with firmer fruit (comparing GA3 and nontreated fruit), but were correlated positively with firmness in nontreated fruit.
Effects of Magnesium on Tobacco Mosaic Virus-infected Eggplants1
Authors: Seaker E. M. , Bergman E. L. , Romaine C. P.
Published: August 2022

Eggplants (Solanum melongena L. cv. Long Purple) were grown hydroponicajly with 3 levels of Mg, and inoculated with the U-l strain of tobacco mosaic virus (TMV) to determine the influence of host Mg nutrition on concentrations of infectious virus in the leaves. There was a decrease in concentration of infectious TMV in leaves as leaf-Mg increased. Severely Mg-deflcient plants had higher virus concentrations than plants that received adequate or excessive Mg.
Accumulation of 14C-Labelled Material from Foliar-applied 14C Sucrose by Tomato Ovaries during Fruit Set and Initial Development1
Authors: Archbold Douglas D. , Dennis F. G. , Flore J. A.
Published: August 2022

A determinate cherry tomato (Lycopersicon esculentum Mill. cv Farthest North) was used to test whether fruit set involves mobilization of sucrose to the ovary, or whether mobilization occurs only after fruit growth commences. Following auxin treatment, average ovary fresh weight increased 0.4 mg and 3.6 mg during the first 24 and 36 hours, respectively. Radioactivity from foliar-applied 14C-sucrose was not significantly greater in auxin-treated ovaries than in water controls until 48 hours after treatment. Parallel data were obtained following pollination. Labelling with l4CO2 did not alter the response, nor did the time of labelling with 14C-sucrose. Thus, tomato fruit set per se does not appear to involve mobilization.
Ethylene Levels in Flask Atmospheres of Dahlia pin-nata Cav. Leaf Segments and Callus Cultured in Vitro1
Authors: Gavinlertvatana P. , Read Paul E. , Wilkins H. F. , Heins R.
Published: August 2022

Biologically active levels of ethylene were accumulated in flask atmospheres of leaf segments and callus of dahlia cultured in vitro. The ethylene levels were dependent on concentrations of α-naphthaleneacetic acid (NAA) and 6-fur-furylamino purine (kinetin) in the medium. NAA promoted ethylene levels to a greater degree than kinetin. NAA at 1 mg liter, but not 5 or 10 mg liter, interacted with kinetin to stimulate ethylene synthesis. Reducing ethylene concentrations in the flasks by potassium permanganate absorption had no effect on callus formation from leaf tissue.
Factors Influencing in Vitro Multiplication and Rooting of the Plum Rootstock Myrobalan (Prunus cerasifera Ehrh.)1
Authors: Hammerschlag F.
Published: August 2022

Shoot tips (5 mm) of Myrobalan plum were cultured on Stage I micropropagation medium consisting of liquid modified Murashige and Skoog salts (MS) medium supplemented with 2% sucrose and in mg/liter: 0.4 thiamine HCl, 100 myo-inositol, 0.5 pyridoxine * HCl, 0.5 nicotinic acid, 0.1 p-aminobenzoic acid, 0.01 indolebutyric acid (IBA) and 0.26-benzylamino purine (BA). A 10-fold multiplication rate was achieved every 4–6 weeks when cultured shoots were transferred to Stage II multiplication medium consisting of Stage I medium with 1.0 mg/liter BA and 0.6% agar. Complete rooting (100%) occurred at 4 weeks when in vitro-proliferated shoots were transferred to MS medium supplemented with 2.5 – 5.0 mg/liter indoleacetic acid (IAA) and incubated in the dark for 2 weeks at either 21° or 26°C. Poor rooting occurred in the light (1.0 klx, 16-hr photoperiod). Shoots incubated at 26°C rooted more quickly than those at 21°C. Shoots cultured on MS medium with IAA and incubated in the dark for 2 weeks rooted significantly better than shoots on medium with IBA and incubated under dark or light conditions. Addition of chlorogenic acid to the rooting medium significantly increased rooting in the light. Plantlets were successfully transferred to soil.
Phosphoric Acid Anticrustant Improves Seedling Emergence and P Content1
Authors: Hemphill Delbert D.
Published: August 2022

Phosphoric acid (H3PO4), applied as an over-the-row banded spray to Willamette silt loam, significantly hastened the emergence of seedlings of carrot (Daucus carota L.), cauliflower (Brassica oleracea L. var. botrytis), cucumber (Cucumis sativus L.), lettuce (Lactuca sativa L.), and onion (Allium cepa L.). Final stands were usually improved. The effect was particularly pronounced in early plantings. Banded H3PO4 decreased soil crusting as measured by decreased mechanical resistance to penetration of the soil surface. Phosphorus content of seedlings of carrot, cucumber, lettuce, and onion was significantly increased with H3PO4 anticrustant. Yields were usually greater on soils treated with H3PO4 than on soils treated with either broadcast or subsurface banded applications of concentrated superphosphate (CSP). Subsurface bands of CSP resulted in poorer stands, lower leaf P content, and smaller yields of carrot, lettuce and onion than did banded H3PO4 at the same rate of P application. However, both leaf P content and yield of cucumber tended to be greater with CSP than with H3PO4. Phosphoric acid treatment improved stand of carrot and lettuce at soil pH between 5.0 and 6.1 but decreased stand at pH 6.6.
Heritability of Semi-hard Seed Induced by Low Seed Moisture in Beans (Phaseolus vulgaris L.)1
Authors: Dickson M. H. , Boettger M. A.
Published: August 2022

Semi-hard seed (SHS) in beans is defined as dry seed which does not imbibe water during a 24 hour soak, but which will gain moisture rapidly at high relative humidity within 14 days and then germinate normally. The inheritance of SHS was found to involve several genes. Soft seed was incompletely dominant to SHS. Narrow sense heritability ranged from 20 to 50% in populations studied. SHS was associated with excellent seed quality resulting in unusually vigorous seedlings.
Influence of Seedbed Configuration on Growth, Development, and Yield in Muskmelon
Authors: Dainello Frank J. , Heineman R. R. , Mulkey James
Published: August 2022

Four seedbed configurations, north-sloped, south-sloped, mid-bed trenched, and standard flat-topped beds, were evaluated for influence on plant growth, development, and yield in ‘TAM Uvalde’ muskmelon (Cucumis melo L.). The most desirable growth rate and yield pattern was produced in mid-bed trenches. This configuration significantly increased early yield. Early season yield (June harvest) was 8670 kg/ha or 48% of total yield for the mid-bed trenched treatment as compared with 7170 (38%), 4730 (32%), and 3380 kg/ha (20%), respectively, for the south-sloped, standard, and north-sloped beds.
Effects of Nitrapyrin and Nitrogen Form on Tomato Growth, Water Relations, and Ion Composition1
Authors: Pill Wallace G. , Sparks Donald L.
Published: August 2022

Nitrapyrin (NI) at 10 ppm, compared to water control, added to a soil-sand-peat medium decreased shoot growth of tomatoes (Lycopersicon esculentum Mill. cv. Marglobe) grown with NO3-N nutrition but had no effect on growth with NH4-N nutrition. While plant water stress was decreased by NI compared to the control with NO3-N nutrition, the toxic effect of increased uncombined NH4 concentration in the shoots may have caused the growth reduction. Denitrification suppression by NI with NO3-N nutrition was evidenced by increased media and shoot NO3 concentrations. Nitrification suppression by NI with NH4-N nutrition was evidenced by increased media and shoot NH4 concentrations. Nitrapyrin, irrespective of N form, decreased shoot Ca concentration, increased shoot K and uncombined NH4 concentrations, and had no effect on shoot Mg concentration. Plant water stress was decreased by NI with both N forms at the third and fifth weeks after final transplanting. While NI decreased the differential effect of N form on transpiration rate and leaf diffusive resistance (RL), in NI’s absence, NH4-N nutrition decreased transpiration and increased RL relative to NO3-N. Decreased shoot growth with NH4-N relative to NO3-N nutrition, both in the presence and absence of NI, was associated with increases in plant water stress, root hydraulic resistance, and shoot uncombined NH4 concentration, but a decrease in shoot Ca concentration.
Influence of Cropping on Ca, K, Mg, and Carbohydrate Status of ‘French’ Prune Trees Grown on Potassium Limited Soils1
Authors: Hansen Poul , Ryugo Kay , Ramos David E. , Fitch Larry
Published: August 2022

‘French’ prune (Prunus domestica L.) leaves on nonbearing trees and large scaffold limbs had greater percent dry matter and specific leaf weight than those from bearing ones early in the season. This difference disappeared as the season progressed. Much of the difference could be attributed to the greater accumulation of starch, which displaced water. The demand for photosynthates by the crop was also reflected by lower starch content in 1-year-old shoot, limb bark, and roots, but no difference in the soluble carbohydrate content nor in the ratio of sorbitol + sucrose/glucose + fructose was observed. Leaf K content was influenced by the crop but not Ca and Mg contents. Unlike K contents, Ca contents in fruiting spurs and 1-year-old shoots tended to be greater than those from nonbearing samples; no differences were noted in root samples. These data and those of other workers indicate that K deficiency in this cultivar stems from its strong K demand by the fruit and from the lack of carbohydrates being translocated to the roots, which in turn, limits growth and nutrient uptake, especially K, which is limiting in these soils.
Branching Responses of Young Apple Trees to Applications of 6-Benzylamino purine and Gibberellin A4 + 71
Authors: Forshey C. G.
Published: August 2022

Applications of 6-benzylamino purine (BA) and gibberellin A4 + 7 (GA4 + 7) over a period of 3 years significantly increased primary and secondary branching and total shoot growth of 6 apple cultivars (Malus domestica Borkh.) from the first through the fourth growing seasons in the field. In spur-type ‘Delicious’ and ‘McIntosh’, BA + GA4 + 7 was more effective than deblossoming, pruning, or branch spreading in inducing lateral branching.
Transitional Forms of Hermaphroditic Papaya Flowers Leading to Complete Maleness1
Authors: Nakasone H. Y. , Lamoureux C.
Published: August 2022

Sexual changes in papaya (Carica papaya L.) from the normal hermaphroditic elongata flower toward femaleness by means of stamen carpellody are discussed in relation to the transition from the bisexual elongata flower toward maleness. A series of changes occurs that involves reduction in ovary size and shape, and in numbers of stigmatic rays, dorsal vascular bundles, carpels, and placenta. Placentation is normally parietal in papaya but there is evidence of ancestral axil placentation.
Measurement of Turfgrass Heat Tolerance in Vitro1
Authors: Wallner S. J. , Becwar M. R. , Butler J. D.
Published: August 2022

Injury to turfgrass leaf segments was measured as percent electrolyte leakage as affected by the duration and level of imposed heat stress. Species differences in heat tolerance were most apparent when injury was monitored over time at 50°C, using leaf segments which were obtained from heat-hardened plants and immersed in distilled water during the stress treatment. Quantitative differences in heat tolerance in vitro were consistent with qualitative descriptions of drought resistance for most of the species tested.
Economic Results of Pest Control Intensity for a Multiple Cropping System1
Authors: Epperson J. E. , Dowler C. C. , Chalfant R. B. , Johnson A. W. , Glaze N. C. , Sumner D. R.
Published: August 2022

This study was designed to determine the effect of pest control intensity on net returns in multiple cropping systems. The study is tempered with an evaluation of risk. The cropping system encompasses: turnip greens (Brassica rapa L.) for processing, field corn (Zea mays L.), and southern peas [Vigna unguiculata (L.) Walp. ssp. unguiculata] for processing. Within the ranges of pest control intensities studied, less intensive control resulted in higher net returns. Further, the level of greatest pest control intensity consistently yielded negative net returns. This level, however, was less risky in terms of gross returns. Risk did not differ significantly between the other levels of pest control.
Storage of Pregerminated Seed of Snapdragon (Antirrhinum majus L.) in Hydrophilic Gels1
Authors: Frazier Diamantina C. , Wiest Steven C. , Wootton Richard D.
Published: August 2022

Pregerminated snapdragon seed was damaged to different extents by low-temperature storage for 4 or 8 days in 3 hydrophilic gels or deionized water. Poststorage viability and vigor decreased as a result of storage, but for apparently different reasons. Medium pH was correlated with poststorage vigor, whereas the gas-exchange capacity of the storage media was correlated with poststorage viability. Seed germination and radicle elongation within the gel was also stimulated when the gas-exchange capacity of the storage medium was increased. Enzymatic generation of oxygen within the gel increased both seed germination and radicle elongation, which suggests that the oxygen diffusion rate specifically was limiting these phenomena.
Seasonal Changes and Cultivar Differences in Pigment Concentrations and Percent Dissolved Solids in Roots of Table Beets1
Authors: Watson James F. , Gabelman W. H.
Published: August 2022

Changes in betacyanine (red pigment) concentration, betaxanthine (yellow pigment) concentration, and percent dissolved solids associated with growing time and season were studied in roots of 12 cultivars of table beet (Beta vulgaris L.) Differences among cultivars and cultivar × harvest date interactions were detected for each trait. Depending on cultivar and planting date, betacyanine concentration increased, decreased, or remained constant with increased growing time, while betaxanthine concentration and percent dissolved solids invariably increased over the same period. Beets planted on July 12, 1978, had greater pigment concentrations than beets planted on June 9, 1978, when grown the same number of days. At 83 days after planting, root weight was negatively correlated with betacyanine concentration (r = −0.44) and betaxanthine concentration (r = −0.40), but after 136 days, both correlations were reduced in magnitude (r = −0.23).
Emergence of Pregerminated Tomato Seed Stored in Gels up to Twenty Days at Low Temperatures1
Authors: Pill Wallace G. , Fieldhouse Donald J.
Published: August 2022

The effects of storage of pregerminated tomato seed (Lycopersicon esculentum Mill. cv. Marglobe) at 0° and 5°C for 0, 4, 8, 12, 16, and 20 days in 4 gels or in moist cheesecloth on percentage emergence (PE) and emergence rate index (ERI) were examined. The PE and ERI values of freshly germinated (unstored) seeds were statistically equal and high in all gels and much greater than the values of dry seed. After 4 days storage, both PE and ERI were unaffected by storage temperature but were significantly affected by gels in order of emergence magnitude: Moist cheesecloth = Natrosol 250 HHR > Laponite 508 = SGP104K > Vittera II Hydrogel. With ≥ 8-day storage, storage temperature interacted with gels so that 0° compared to 5° storage gave greater PE and ERI in Natrosol 250 HHR and Laponite 508 but lower values in moist cheesecloth. Pregerminated tomato seed storage in Natrosol 250 HHR at 0° is an acceptable alternative to 5° moist storage providing, even after 12 days of storage, a distinctly higher PE and ERI than dry seed. To avoid unacceptably low emergence, chitted seed storage in Vittera II hydrogel should be avoided and storage in Laponite 508 or SGP104K should not exceed 4 days.
Inheritance of Early Flowering in Relation to Breeding Day-neutral Strawberries1
Authors: Barritt Bruce H. , Bringhurst R. S. , Voth V.
Published: August 2022

Strawberry (Fragaria × ananassa Duch.) seedlings from 54 crosses between day-neutral and short-day parents were evaluated in western Washington for the proportion which flowered by September and for the earliness of such flowering when it occurred. The day-neutral progeny of ‘Aptos’, ‘Brighton’, ‘Hecker’, CN5, CN11, CN20, WSU 1714E and SHRI 7020/131, all day-neutral parents, flowered early. The day-neutral progeny of ‘Aiko’,’Linn’, ‘Olympus’ and ‘Tioga’, all short-day parents, flowered late. Crosses producing the highest percentage of day-neutral seedlings also had the highest percentage of day-neutral seedlings which flowered early. Reciprocal crosses produced similar results relative to the proportion of day-neutral seedlings and for the proportion of such seedlings which flowered early. For date of first flowering, general combining ability was found to be more important in these crosses than specific combining ability.
The Effects of Rainfall and Irrigation Management on Citrus Juice Quality in Texas1
Authors: Cruse Robert R. , Wiegand Craig L. , Swanson Wayne A.
Published: August 2022

Juice yield, degrees Brix (soluble solids), citric acid, suspended solids, L-ascorbic acid (Vitamin C), pH, and naringin content in grapefruit were measured from 1969–1975 on 2 sizes of ‘Marrs’ and ‘Valencia’ oranges, Citrus sinensis (L.) Osbeck, and ‘Ruby Red’ grapefruit, C. paradisi Macf., subjected to 4 irrigation management regimes in an area where rainfall contributes about half the annual water requirement. Irrigation main effects in individual years were influenced by variable annual amounts and seasonal distribution of rainfall. Vitamin C, juice yield, pH, and suspended solids were only occasionally affected by irrigation treatment. Citric acid content of ‘Valencia’ orange juice was consistently higher and the citric acid and Brix of grapefruit juice were usually higher in the 2 less frequently irrigated treatments, regardless of rainfall. Among-years analyses of variance showed significant reductions in Brix, citric acid, and suspended solids with increased frequency of irrigation for all cultivars.
Influence of Intensity and Duration of Cool White Fluorescent Lighting and Fertilizer on Growth and Quality of Foliage Plants1
Authors: Conover C. A. , Poole R. T. , Nell T. A.
Published: August 2022

Brassaia actinophylla Endl., Chamaedorea elegans Mart., Dieffenbachia maculata (Lodd.) G. Don ‘Exotica’, Dracaena marginata Lam., and Ficus benjamina L. were grown for 1 year under 13 or 26 μE m−2sec−1 from Cool White fluorescent lamps for 12, 18, or 24 hours daily durations. Increasing light duration to 24 hours daily decreased quality of all plants tested, with Brassaia, Chamaedorea, and Dieffenbachia being most affected. The primary symptoms resulting from constant light were foliar chlorosis and decrease in plant quality, although necrotic spotting appeared at times. By experiment termination, best plants overall were associated with 26 μE m−2sec−1 light for 12 or 18 hours duration and poorest with 26 μE m−2sec−1 light and 24 hours duration. A second factorial experiment with Dieffenbachia and Dracaena tested effects of 3 fertilizer levels (0, 0.67, or 1.30 g Osmocote/3 months per 15-cm pot) under 2 light intensities (13 or 26 μE m−2sec−1) and 2 light durations (12 or 24 hours) on plant quality. Higher fertilizer levels had a limited effect on plant quality, while influence of light intensity and duration was similar to the initial experiment.
Cultivation of in Vitro-propagated Lilium Bulbs in Soil1
Authors: Takayama Shinsaku , Misawa Masanaru , Takashige Yoshiki , Tsumori Hiroshi , Ohkawa Kiyoshi
Published: August 2022

The transplanting to soil of bulblets of Lilium longiflorum Thunb., L. × formolongi, L. speciosum Thunb., and L. auratum Lindl., grown on Murashige and Skoog’s medium, was investigated in relation to dormancy. Leaf emergence from tissue-cultured bulblets was inhibited after transplanting into soil without low-temperature treatment. To break dormancy, low temperature (5°C) treatment for 70 days was required when bulblets were produced in the medium with 30 g/liter sucrose, while 120 to 140 days were required when bulblets were produced in the medium with 90 g/liter sucrose. In vitro-produced bulblets of L. longiflorum grew well in soil and about 40% of the bulblets flowered in a year.
Pulse Treatment with Silver Nitrate Extends Vase Life of Anthuriums1
Authors: Paull Robert E. , Goo Theodore
Published: August 2022

Short pretreatments of stems of anthurium flowers (Anthurium andraeanum André) with silver nitrate solutions increased vase life by 40 to 60% after a simulated shipping. Significant improvement was obtained with a single 10-minute treatment with 1 mm silver nitrate. Maximum postharvest life was obtained with flowers treated with silver nitrate within 12 hours of harvest. Silver nitrate treatment was effective on flowers ranging from half to full maturity. No measurable silver was translocated to the spathe or spadix. Silver thiosulfate complex was not as effective as silver nitrate. For response to silver treatment following simulated shipping of 3 days, 2 cm of stem had to be removed before placing in a vase solution. Continuous maintenance of the flower before and after simulated shipping in a commercial preservative was not significantly better than a single pulse with silver nitrate or a combination of silver nitrate pulse and commercial preservative.
Regulation of Growth and Flowering in Chrysanthemum × superbum Bergmans1
Authors: Shedron Karen G. , Weiler Thomas C.
Published: August 2022

Seedlings of Chrysanthemum × superbum shasta daisy varied greatly in their requirements for flowering. Some vegetatively propagated clones of selected seedlings required cold in order to flower, some required long photoperiods, some required both, and some required neither. Flowering bedding plants were produced from seed in 6–8 months.
Microclimate within Open-top Air Pollution Chambers and its Relation to Grapevine Physiology1
Authors: Weinstock Lewis , Render W. J. , Musselman R. C.
Published: August 2022

Performance of open-top chambers used for air pollutant effect studies on mature grapevines (Vitis labruscana Bailey cv. Concord) was evaluated. The chamber environment was characterized by somewhat higher air temperature and dew point and decreased light intensity and wind velocity compared with ambient conditions. Within the chambers, grapevines had slightly increased leaf temperature. No differences due to chambers were detected on vine stomatal resistance, leaf water potential, or the relationship between leaf temperature and incident radiation.
Spine Initiation and Development in Mammillaria Elongata DC1
Authors: Johnson J. L. , Emino E. R.
Published: August 2022

Spine primordia of Mammillaria elongata are initiated in acropetal sequence, beginning on the abaxial side of the spiniferous meristem that occupies the summit of a young tubercle and continuing along either side until a single whorl is completed. If a central spine occurs, it is the last to be initiated and the first to begin elongation. Elongation of the whorled spines follows a basipetal sequence, the inverse of initiation. All elongated spines are at first erect, but the lateral ones become radially oriented as they appraoch maturity. Central spines remain erect and tilted slightly toward the shoot apex. The distal ends of many epidermal cells on developing spines bear conic projections that are most prominent along the median portions.
Volatile Isothiocyanates and Nitriles from Glucosinolates in Rutabaga and Turnip1
Authors: Ju Hak-Yoon , Chong Calvin , Mullin W. J. , Bible Bernard B.
Published: August 2022

Glucosinolates extracted from seeds of 2 rutabaga (Brassica napus L. Napobrassica group) and 2 turnip (B. rapa L. Rapifera group) cultivars, and also from roots sampled at 2-week intervals during growth and development on 2 soil types, were hydrolyzed and the individual volatile products identified by gas chromatography and mass spectrometry. Four isothiocyanates (3-butenyl-, 4-pentenyl-, 4-methylthiobutyl-, and 2-phenylethyl-isothiocyanates), and 2 nitriles (1-cyano-4-methylthiobutane and 2-phenylethylnitrile), were identified. Yields of each constituent varied considerably between cultivars, and also seasonally in root tissue, but generally were quantitatively similar in trend within cultivar grown on loam and organic soils; 2-phenylethyl-isothiocyanate was predominant in roots.
Seasonal Trends of Calcium, Magnesium, and Potassium Fractions in Apple Leaf and Fruit Tissues1
Authors: Himelrick David G. , Walker Candace E.
Published: August 2022

Leaf and fruit tissues of apple (Malus domestica Borkh.) were sequentially fractionated using hot water, sodium nitrate, acetic acid, and hydrochloric acid to extract Ca, Mg, and K in various forms. Water-soluble and sodium nitrate-exchangeable Ca were considered physiologically active forms and increased from 50 to 84% of the total Ca in fruit during the season and decreased from 57 to 45% in leaves. About 90% of the Mg and K concentrations in fruit were physiologically active. Physiologically active forms of Ca, Mg, and K followed changes in total concentrations very closely, so that analyses of physiologically active fractions provide no increased accuracy for predicting physiological disorders.
Cultivar Differences in Ethylene Production by Wounded Sweet Potato Roots1
Authors: Saltveit Mikal E. , Locy Robert D.
Published: August 2022

Wounding freshly harvested or cured sweet potato [Ipomoea batatas (L.) Lam.] roots by either breaking, or cutting them in half stimulated C2H4 production in all 13 cultivars and selections examined. Ethylene production was stimulated within 1 day of wounding and generally continued to increase for 7 days before decreasing. At the peak of production, wounded freshly harvested roots produced about 22 times more C2H4 than controls, while C2H4 production from wounded cured roots of the same cultivar or selection increased about 86 times. Wounding stimulated CO2 production by about 72% over the controls. There were marked cultivar differences in the maximum rate of wound-induced C2H4 production.
Salt Tolerance of Two Muskmelon Cultivars under Two Radiation Levels1
Authors: Meiri A. , Hoffman G. J. , Shannon M. C. , Poss J. A.
Published: August 2022

The salt tolerance of cultivars of muskmelon (Cucumis melo, L.) was established under 2 levels of radiation in a glasshouse experiment. ‘Galia’ and ‘Top Mark’ muskmelon differed very little in salt tolerance at either radiation level. The maximum electrical conductivity of a saturated soil extract without yield reduction, the salt tolerance threshold, was 2.0 dS m−1. Beyond the threshold, yield was reduced at a rate of 14.3% per unit increase in soil salinity. Both cultivars were more salt-tolerant at the higher level of solar radiation.
Effect of Spur Defoliation and Ringing during Bloom on Fruiting, Fruit Mineral Level, and Net Photosynthesis of ‘Golden Delicious’ Apple1
Authors: Ferree David C. , Palmer John W.
Published: August 2022

Leaf areas on individual spurs were modified in the pink stage of flower development on ‘Golden Delicious’ apple (Malus domestica Borkh.), and the effects on fruiting, mineral content, and net photosynthesis (Pn), of leaves on those spurs determined. Removal of a 3mm-ring of bark from the spur increased initial fruit set, determined 1 week after petal fall, compared to normal spurs. The combination of ringing and removal of all leaves resulted in a complete loss of fruit. Final fruit set was reduced by any treatment involving ringing, reduction in spur leaf area, or injury to the stigmas. The greatest number and total weight of fruit at harvest were given by undefoliated, unringed spurs where the bourse shoot was allowed to develop. Ringing reduced Pn at petal fall but had no effect later in the season. Presence of the bourse shoot reduced Pn of spur leaves in early June. Spur leaves on fruiting trees had an important localized influence on fruit set, ultimate fruit size, and fruit Ca level of fruit produced on that spur.
Deep Supercooling and Cold Hardiness in Genus Pyrus1
Authors: Rajashekar C. , Westwood M. N. , Burke M. J.
Published: August 2022

Deep supercooling was found in the stem tissues of all the Pyrus species studied. There was more than 1 low temperature exotherm resulting from the freezing of supercooled water in stem tissue, and these exotherms were associated with the tissue injury. The supercooled water in the stems of P. nivalis Jacq., P. cordata (Desv.) Schneider and P. elaeagrifolia Pall, was found in both xylem and bark tissues. The supercooling characteristics of vegetative and flower buds are also described. The hardiest and least hardy species found were P. caucasica Fed. and P. pashia D. Don., respectively.
Phytotoxic Responses of Cherries, Nectarines, Peaches, Pears, and Plums Fumigated with Methyl Bromide for Control of Mediterranean Fruit Fly1
Authors: Harvey John M. , Harris C. M.
Published: August 2022

Cultivars of sweet cherry (Prunus avium L.), nectarine [P. persica (L.) Batsch var. nectarina (Ait.) Maxim.] peach [P. persica (L.) Batsch], pear (Pyrus communis L.) and plum (Prunus salicina Lindl.) differed in their phytotoxic responses to methyl bromide (MB) fumigation treatments designed to control the Mediterranean fruit fly (Ceratitis capitata Wied.) without use of a subsequent cold treatment. Phytotoxic responses were relatively mild or negligible in most cultivars fumigated at 21°C with 48 g MB/m3 for 2 hours, 48 g/m3 for 3 hours, or 32 g/m3 for 4 hours. A few of the cultivars tested were very susceptible to MB injury. In some cultivars, both the control and fumigated lots exhibited symptoms of injury that apparently were not related to the fumigations but were caused by packinghouse handling or orchard practices. The fumigations slowed the ripening of cherries and plums. Decay of nectarines was slightly greater in fumigated than in control lots of fruit.
Effects of Light Intensity and Air Temperature in Simulated Postproduction Environment on Petunia hybrida Vilm.1,2
Authors: Armitage A. M. , Kowalski T.
Published: August 2022

Plants of Petunia hybrida ‘Coral Sea’ were placed in postproduction conditions of low (300 µE m−2s−1), medium (600 µE m−2s−1) or high (900 µE m−2s−1) quantum flux density (QFD) at temperatures of 10, 20, or 30°C after first flower opening. Change in dry weight and number of senesced flowers were determined, and visual quality ratings were given. Plants kept at 20° and 30° had greatest dry weight accumulation and flower number but poorest visual rating at 10 days when kept under high QFD, compared with those kept under medium or low QFD. When plants were kept at 10°, QFD was of little importance to postproduction quality. All plants delined in visual quality by 15 days when kept at 20 or 30° but remained satisfactory when kept at 10°. Plants should be held at either medium or low QFD when placed at 20° or 30° postproduction temperature.
The Influence of Paclobutrozol, a New Growth Regulator, on Sunflowers1
Authors: Wample Robert L. , Culver Elaine B.
Published: August 2022

Paclobutrozol PP333 = (2R,3R + 2S,3S)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl) pentan-3-ol at concentrations of 11.6, 58.0, and 116.0 mg of active ingredient per liter caused significant reductions in water use of sunflowers (Helianthus annuus L.) but there was no significant influence on leaf diffusive resistance. The primary mechanism for reduced water use is by a reduction in leaf expansion. PP333 inhibited internode elongation which causes increased leaf shading. Under nonstress conditions there was no effect on leaf water potential or its components. At the highest concentration, photosynthetic rate was reduced. Fresh and dry weight of shoots was reduced proportional to leaf area. Gibberellic acid reversed the effect of PP333 of shoot height, leaf area, evapotranspiration, and shoot fresh and dry weight.
Postharvest Responses of Chinese Cabbage to High CO2 Treatment or Low O2 Storage1
Authors: Yi Wang Chien
Published: August 2022

The outer leaf laminae of Chinese cabbage (Brassica campestris L Pekinensis group) contain higher amounts of ascorbic acid than the outer midribs, inner leaf laminae, or inner midribs. However, the outer leaf laminae lost ascorbic acid at a faster rate than other parts of the Chinese cabbage during storage at 0°C. Quantitative differences in sugars were also found in different parts of the Chinese cabbage. The outer leaf laminae were low in total sugars and had higher amounts of fructose than glucose, whereas outer midribs contained much higher amounts of glucose than fructose. The inner leaf laminae were high in both fructose and glucose and had a higher ratio of glucose to fructose. A similar ratio was also found in inner midribs, but their total sugar content was lower than inner leaf laminae. Relatively low levels of sucrose were found in all parts of Chinese cabbage. Total sugars decreased, but the relative composition of individual sugars did not change during storage. Exposure of Chinese cabbage to 30 or 40% CO2 for 5 or 10 days was detrimental to quality. Short-term exposure to high but noninjurious concentrations of CO2 (10–20%) showed no beneficial effect on quality retention during subsequent storage in air at 0°. However, low O2 (1%) atmosphere was very effective in extending the storage life of Chinese cabbage at 0°. It slowed down the decline of ascorbic acid and sugar contents, delayed the loss of chlorophyll and yellowing of the leaves, and reduced the incidence of decay. The Chinese cabbage was not salable without extensive trimming after 3 months of storage at 0° in air, whereas those in 1% O2 at 0° were still in salable condition after 5 months of storage with only slight trimming. No off-odor, off-flavor, or other symptoms of suboxidation were found at the end of 5 months of storage in 1% O2 at 0°.
Effect of the Fruit-ripening Mutant Genes rin and nor on the Flavor of Tomato Fruit
Authors: Kopeliovitch E. , Mizrahi Y. , Rabinowitch H. D. , Kedar N.
Published: August 2022

The abstract for the paper, “Effect of the Fruit-ripening Mutant Genes rin and nor on the Flavor of Tomato Fruit” by E. Kopeliovitch, Y. Mizrahi, H. D. Rabinowitch, and N. Kedar [J. Amer. Soc. Hort. Sci. 107(3):361–364. 1982.], contains several errors. The correct version of the abstract is as follows: Organoleptic tests of the nonripening tomato mutants rin and nor and their F1 hybrids with the normal-fruit-bearing cultivar ‘Rutgers’ indicated that fruits of the rin heterozygous plants (rin/+) were slightly inferior and that those of heterozygote nor (nor/+) were distinctly inferior in flavor to fruits of the normal genotype (+/+), all sampled 3–5 days after ethylene and CO2 evolution rates attained maximum levels. The flavor of fruits of the double heterozygotes rin/+, nor/+ was poorer than either of the 2 single-gene heterozygotes, while fruits of both homozygous plants, nor/nor and rin/rin, were unpalatable. Analyses of pH, titratable acidity, total soluble solids, and reducing sugars did not indicate that any of these parameters are responsible for the inferior flavor of the genotypes containing the nonripening genes. Comparisons of reciprocal crosses provided no evidence of cytoplasmic inheritance of fruit flavor.
Recurrent Mass Selection for Increased Seed Yield and Seed Protein Percentage in the Common Bean (Phaseolus vulgaris L.) Using a Selection Index1
Authors: Sullivan Joseph G. , Bliss F. A.
Published: August 2022

Recurrent mass selection based on a desired gain index was employed to increase simultaneously seed yield and seed protein percentage in the common bean. Seed protein was increased from 21.9 to 24.6% after 2 cycles of selection. Mean seed yields of selected populations were not significantly greater than the mean of the unselected parents, but high yielding individual families were identified. Of particular interest was the family 2-4-1, with seed yields equal to the highest-yielding parent, and seed protein percentage higher than all parental lines in both years in which the experiments were conducted. Modifications in the selection procedure were proposed which should increase the efficiency of selection for seed yield.
Chilling Injury and Electrolyte Leakage in Fruit of Different Tomato Cultivars1
Authors: King M. M. , Ludford P. M.
Published: August 2022

Mature-green tomato fruit from 2 chilling-sensitive cultivars and 2 chilling-tolerant breeding lines, all derived from Lycopersicon esculentum Mill., were harvested and chilled at 5°C for 0, 2, 7, and 15 days. Mature-green fruit analyzed immediately after chilling showed higher electrolyte leakage in chilling-sensitive than chilling-tolerant lines. However, electrolyte leakage from chilled fruit that were ripened before analysis was higher in normal-sized than in cherry cultivars and seemed to be a function of fruit type rather than of chilling sensitivity. Unchilled field samples of these cultivars harvested at the mature-green, turning, and full-ripe stages and analyzed immediately showed an electrolyte leakage pattern similar to that found for comparable chilled mature-green fruit. No significant differences were found in calcium content (total, bound, or soluble) or in pectinase activity between chilling-sensitive or -tolerant cultivars.
Foliar Sampling of Boston Fern1
Authors: Gilliam C. H. , Evans C. E. , Shumack R. L. , Plank C. O.
Published: August 2022

Boston fern [Nephrolepis exaltata (L.) Schott ‘Rooseveltii’] was grown with sufficient and insufficient levels of N and K and leaf nutrient concentrations were determined periodically from 4 frond sections: frond tips, 10–12 cm; frond midsections, 10–12 cm; frond bases, 10–12 cm; and whole fronds, 30–40 cm. Both the frond midsection and the whole frond were found to be acceptable for foliar analysis. Frond tips had the lowest nutrient concentrations for most elements. Foliar N was similar for all frond sections sampled. Nitrogen deficiency symptoms occurred after 2 to 4 weeks of minus N conditions. When three N sources were added to plants grown under minus N conditions, N source had a limited influence on N uptake as measured by foliar analysis. One and 2 weeks after N treatment was restored to N-deficient ferns, foliar N had increased 55 and 100%, respectively.
Chlorflurenol as a Fruit-setting Hormone for Gynoecious Pickling Cucumber Production Under Open-field Conditions1
Authors: Ells James E.
Published: August 2022

Curbiset, a commercial formulation of methyl-2-chloro-hydroxy fluorene-9-carboxylate (chlorflurenol), induced more parthenocarpic fruit on plants of cucumber (Cucumis sativus L.) from which developing fruits were removed than from plants from which fruit were not removed. Planting at closer spacings yielded more fruit per hectare when chlorflurenol was applied to young plants. However, when sprayed on older plants, spacing did not affect yield. Fruit quality (shape and color) deteriorated when harvesting was delayed beyond 10 days after spraying. Chlorflurenol set a higher percentage of pre-anthesis blossoms early in the season and a greater percentage of post-anthesis blossoms late in the season. Mature blossoms produced larger fruit at harvest than immature blossoms when set with chlorflurenol. Chlorflurenol could be used repetitively to induce a successive fruit set on the same plants for hand-harvest, or sprayed once for a once-over mechanical harvest.
Influence of Varying Soil Lead Levels on Lead Uptake of Leafy and Root Vegetables1
Authors: Nicklow C. W. , Comas-Haezebrouck P. H. , Feder W. A.
Published: August 2022

Six crops [lettuce, Lactuca sativa L.; collard and kale, Brassica oleracea L. (Acephala group); carrot, Daucus carota L.; beet, Beta vulgaris L.; and turnip, Brassica campestris L. (Rapifera group)] were grown in soils that contained 3 ranges of available Pb: 0–5, 225–300, and 450–600 ppm. Pb concentration in crop tissue was directly proportional to the Pb concentration in the soil. Turnip and lettuce leaf tissues accumulated the highest Pb concentrations of leafy vegetables tested, while collard and kale accumulated the lowest concentrations. The beet root peel contained elevated Pb concentrations relative to the beet root. The distribution of Pb accumulated in various parts of the plant differed between crops studied.
The Interaction of Fertilizers and Vesicular-arbuscular Mycorrhizae in Composted Plant Residues1
Authors: Guttay A. J. R.
Published: August 2022

Composted plant residues of corn (Zea mays L.), eastern hemlock [Tsuga canadensis (L.) Carr.], and sugar maple (Acer saccharum Marsh.) were used as the growing media for corn in a pot experiment. Fertilizer components were an added variable. The vesicular-arbuscular mycorrhizae (VAM) of corn were quantitatively low in the corn and hemlock composts and high in the maple compost. Dry-matter production was related to media fertility and independent of VAM quantity. The incidence of VAM in maple compost was negatively affected by added super-phosphate and positively affected by added ammonium nitrate, muriate of potash, and limestone. The incidence of VAM was found to be negatively correlated with extractable phosphorus in the maple compost and positively correlated with extractable potassium.
Response of Crops to Sorghum Residues1
Authors: Ruiz-Sifre Gerardo V. , Ries Stanley K.
Published: August 2022

Vegetable and field crops were grown on young residues of several cultivars of sorghum (Sorghum vulgare Pers.) in the greenhouse and field. Seedling growth of field corn (Zea mays L.) in the greenhouse was increased by residues of sorghum shoots, but not by residues of sorghum roots. In contrast the growth of sweet corn in the field was always decreased by residues of ‘Bird-a-Boo’ sorghum roots and whole plants. The growth and yield of snap beans (Phaseolus vulgaris L.) in the field was increased or decreased by sorghum residues depending on the sorghum plant part, quantity, cultivar, and soil environment. Although sorghum residues may stimulate crop growth in some instances, this stimulation was not easily controlled because the optimal range of sorghum residues and soil environment is too narrow and unpredictable.
The Effect of Shading and Nutrient Supply on Variegation and Nutrient Content of Variegated Cultivars of Peperomia obtusifolia
Authors: Shen Gloria Wei-hsin , Seeley John G.
Published: August 2022

A reduction in light intensity by 27%, 47%, or 73% shading significantly increased percent variegation (relative amount of nongreen area per leaf) and significantly decreased fresh and dry weight, but did not appreciably affect leaf nutrient content of Peperomia obtusifolia L. Nutrient treatments had no consistent effect on variegation or fresh and dry weight.
Cherry Fruit Development: Changes in Seed IAA Oxidase Activity
Authors: Valpuesta Victoriano , Bukovac Martin J.
Published: August 2022

Indoleacetic acid (IAA) oxidase activity was measured in seeds of Prunus cerasus L. cv. Montmorency from full bloom to maturity. IAA oxidase activity reached a maximum at early Stage II of fruit development and decreased to trace levels during Stage III. The peak of IAA oxidase activity coincided with the time that the seed approached full size and endosperm was at a maximum volume and just prior to the rapid growth phase of the embryo. Inhibitors of IAA oxidase were coextracted (acetate buffer, 0.2 m, pH 4.0) with the enzyme. Low molecular weight compounds, which modified IAA oxidase activity, were separated from the enzyme extract with Sephadex G-25. The compounds from seeds of fruits in Stages I and III inhibited and from Stage II enhanced IAA oxidase activity. The possible role of IAA oxidase and the effectors in cherry fruit development are discussed.