bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Volatile Reduction on Growth and Development in Closed Atmospheric Chambers
Authors: Stutte G.W. , Wheeler R.M.
Published: January 2019

Plants produce and respond to a broad spectrum of volatile chemical compounds. The concentration and duration of volatile exposure during long-duration space missions will be higher than typically experienced by plants. The effects of using filters to reduce volatile organic compound (VOC) exposure on growth and development of several species has been studied in the Biomass Production Chamber (BPC) at Kennedy Space Center. The VOC composition of the BPC was determined weekly using a modification of EPA Method TO-14 with mass spectrometry. Ethylene concentration was monitored every 8 h using FID gas chromatography. Experiment durations were 84 days for wheat, 105 days for potato, 104 days for rice, and 90 days for tomato. In all cases, non-biological sources including siloxanes, Freon's, solvents and hydrocarbons were the primary VOC constituents. The primary biogeneic compounds detected include ethylene, acetaldehyde, pinene, isoprene, and carbon disulfide. Species-specific compounds detected included various terpenes, esters, furans, alcohols, aldehydes, and ethers. Filtering the atmosphere through activated carbon filters typically reduced the overall VOC concentration by at least 50%. Filtering the atmosphere through potassium permanganate pellets generally maintained ethylene concentrations <25 ppb. Concentration difference between filtered and unfiltered treatments varied according to species, stage of development and specific compound. By reducing the overall VOC exposure, several species-specific morphological and development changes were observed, including: an increase in internode length of wheat, potato and rice, delayed anthesis of wheat and tomato, delayed tuber initiation in potato, delayed ripening of tomato, earlier anthesis of rice, and larger leaf area in potato. No phytotoxicity per se was noted during these experiments.
Canopy Manipulation to Enhance Early Season Cropping of `Arkin' Carambola in South Florida
Authors: Núñez-Elisea Roberto , Crane Jonathan H.
Published: January 2019

Carambola (Averrhoa carambola L.) is a fruit tree that exhibits nearly year-round flowering and fruiting in its natural, tropical habitat. The carambola industry of subtropical south Florida is based almost exclusively on the local cultivar Arkin. `Arkin' is susceptible to harsh winter conditions, which debilitate canopy growth and limit the harvest season to about 7 months (July to February). Crop value increases up to eight-fold during times of scarce production. Less than 10% of total crop volume is produced when fruit value is highest. Strategies to enhance early season cropping of `Arkin' carambola were evaluated during a 3-year period. Under favorable growth conditions, carambola trees readily initiate flowers throughout most of the canopy. Pruning 3- to 4-year-old branches to their main axes (branch length was reduced to about one-half of original size) during early spring caused abundant and synchronous flower initiation on pruned branches, and produced a crop in late June-early July. Fruit from pruned branches had excellent appearance due to lack of wind damage. Fruit from intact portions of the canopy began to be harvested 3 to 4 weeks later. In 9-year-old trees, the fall crop was manually shaken off the tree in November-December, when most fruits were about 50% of their final size. Crop removal resulted in abundant flowering (more than three-fold compared to trees which retained their fruit until harvest) throughout the canopy during early spring and also produced an early crop ((48 kg/tree) in early July. Carambola growers in south Florida have begun to adopt selective pruning and fall crop sacrifice to increase economic returns of their groves.
Effect of Fall/Winter Application of Foliar Urea on Flowering and Yield of `Nour' Clementine Mandarine
Authors: El-Otmani M. , Ait-Oubahou A. , Tadili A. , El-Hila M. , Lovatt C.J.
Published: January 2019

Experiments were established using clementine (Citrus reticulata Blanco) groves to evaluate effect of urea application (at 0%, 0.8%, and 1.6%) during the period from October to February on flowering and yield. Urea significantly promoted flowering when applied during the period from the end of December to early February. October treatment had no effect, but November treatments somewhat increased inflorescence numbers. “Off year” trees (i.e., trees that have a small fruit load resulting from the previous spring flowering) produced more inflorescence than “on year” trees (i.e., trees with heavy fruit load from flowering of the previous spring), and urea enhanced flowering on both tree types. Flower number per inflorescence increased significantly more on “on year” trees irrespective of the type of inflorescence. Fruit set was significantly increased for trees receiving urea treatments from November on, with the greatest increase observed for the December/January treatments. Fruit size was increased significantly more by the January treatment than for the December application, whereas the October and November treatment had no effect on these parameters. Consequently, both earliness and export yield were improved with urea.
Postharvest Control of Botrytis cinerea Infections on Cut Roses Using Fungistatic Storage Atmospheres
Authors: Hammer Philip E. , Yang S.F. , Reid M.S. , Marois J.J.
Published: January 2019

The effectiveness of fungistatic atmospheres for postharvest control of Botrytis cinerea Pers. infections on cut rose flowers (Rosa hybrids L.) was investigated. Storing cut `Sonia', `Royalty', and `Gold Rush' roses at 2.5C with 10% CO2 for 5 days, followed by 2 days of cold storage in air, reduced the number of B. cinerea lesions that developed on inoculated and noninoculated flower petals by 77% and 82%, respectively, compared to cold storage for 7 days in air. Higher CO2 concentrations and longer CO2 treatment times reduced disease severity further, but resulted in unacceptable leaf discoloration on some cultivars. No deleterious effects of CO2-enriched storage atmospheres on flower quality, weight gain, or vase life were observed. Storage at 2.5C for 7 days in 2 μl SO2/liter reduced B. cinerea infections on inoculated and noninoculated flowers by 53% and 43%, respectively. No deleterious effects on flower quality, weight gain, or vase life were observed. Higher SO2 levels reduced disease severity further, but caused bleaching of the petal margins and necrosis around leaf wounds.
Chemical Changes in Developing Seeds of `Independence' Nectarine and `Fay Elberta' Peach
Authors: Bassi Daniele , Ryugo K.
Published: January 2019

To learn why embryos of early ripening stone fruits abort or fail to germinate, the growth and nutrition of developing seeds of `Independence' nectarine and `Fay Elberta' peach (Prunus persica, Batsch.) were compared. Seeds were collected at weekly intervals, beginning 2 months after full bloom until the fruits were ripe. Fruit diameter, seed and embryo lengths, and fresh weights of nucellus and endosperm were recorded. Parts of the seeds were analyzed for soluble carbohydrates, fats, and total N. At the same phonological stages of fruit development, concentrations of these seed fractions were nearly equal for both cultivars. Percentage composition of all fractions varied with time, but increased on a per-seed basis. Sucrose was the major soluble carbohydrate in embryos of both cultivars. Nitrogen content of the embryos, on a percent dry matter basis, gradually decreased from the 12th week after full bloom to harvest.
Ethylene Production in Debladed Petioles from the Juvenile and Mature Phases of English Ivy in Relation to Adventitious Root Initiation
Authors: Geneve Robert L. , Hackett Wesley P. , Swanson Bert T.
Published: January 2019

Exogenous ethylene could not substitute for NAA to induce adventitious root initiation in juvenile petiole explants of English ivy (Hedera helix L.), indicating that the action of auxin-stimulated root initiation was not directly mediated through ethylene production. Mature petioles did not initiate roots under any auxin or ethylene treatment combination. Ethephon or ACC supplied at 50 or 100 μm was inhibitory to NAA-induced root initiation in juvenile petioles. The pattern of ethylene production stimulated by NAA application was significantly different in juvenile and mature petioles. Ethylene evolution by juvenile petioles declined to near control levels during from 6 to 12 days after NAA application. Reduction in ethylene production was due to reduced availability of ACC in juvenile petioles. Mature petioles continued to produce ethylene at elevated levels throughout the course of the experiment. Ethylene does not appear to play a significant role in the differential root initiation response of juvenile and mature petioles treated with NAA. However, ethylene appeared to have an inhibitory effect during root elongation stages of adventitious root development in juvenile petioles. Chemical names used: 1-aminocyclopropane-1-carboxylic acid (ACC); 1-napthaleneacetic acid (NAA); 2-chloroethylphosphonic acid (ethephon).
Environment Influences Anatomy of Stomata and Epidermal Cells in Tissue-cultured Rosa multiflora
Authors: Capellades M. , Fontarnau R. , Carulla C. , Debergh P.
Published: January 2019

The surface structure of rose (Rosa multiflora L. cv. Montse) leaves formed in vitro under several environmental conditions (light level, relative humidity) and with various growth regulator treatments was studied by light and scanning electron microscopy. The epidermis from leaves developed in cultures grown under a higher light level and a lower relative humidity (80 μmol·s-1·m-2 and 75% RH) than the conditions used in commercial laboratories (25 μmol·s-1·m-2 and 100% RH) showed anatomical modifications of the epicuticular wax, stomata, and epidermal cells similar to that of greenhouse-grown plant leaves. These results indicate that cultured plantlets can resemble greenhouse-grown plants under modified environmental conditions. In vitro pretreatment will reduce transplant losses and shorten the acclimatization period in the greenhouse.
Sweet Potato Canopy Morphology: Leaf Distribution
Authors: Somda Zana C. , Kays Stanley J.
Published: January 2019

Changes in leaf distribution of the sweet potato [Ipomoea batatas (L.) Lam.] cultivar Jewel were assessed bi-weekly for 18 weeks at three plant densities (15, 30, and 45 cm × 96-cm spacing). The distribution of leaves on the branches and the timing at which leaf number stabilized were affected by the plant density. Plant density resulted in significant differences in the number of leaves and percentage of missing leaves during the growing season. Leaf number and total leaf area varied substantially in response to plant density, but individual lamina and petiole lengths and leaf area did not vary. Average petiole and leaf lengths and leaf size increased during the season, with the maximum length and area dependent on the type of branch on which the leaf was formed. Average petiole length per branch and the susceptibility to leaf loss increased with descending branch hierarchy (secondary branch < primary branch < main stem). Leaf losses after the 4th week tended to parallel a progressive increase in petiole length of new leaves, suggesting shading as a primary cause of leaf shedding and the loss of the oldest leaves first.
Nutrient Concentrations and Their Seasonal Patterns in Fraser Fir and Norway Spruce Grown in Seven Vegetation Management Programs
Authors: Warren Stuart L. , Campbell C. Ray , Skroch Walter A.
Published: January 2019

Fraser fir [Abies fraseri (Pursh) Poir.] and Norway spruce [Picea abies (L.) Karst.] were grown in seven vegetation management programs ranging from 100% cover of grass-dominated vegetation to bare soil on opposing north and south aspects. Concentrations of 13 nutrients were determined at three growth stages during 2 years: active terminal growth, cessation of terminal expansion, and dormancy. Aspect did not affect nutrient concentrations. Vegetation management programs bad a significant impact on nutrient concentration for both species. Nitrogen, Ca, B, Fe, and Mn concentrations during dormancy were negatively correlated with herbaceous biomass. In contrast, N during active growth and P and Mg concentrations during all stages were positively correlated with herbaceous biomass. Vegetation management only affected the seasonal trend of Mo. Seasonal trends varied by nutrient in both species.
Autumn Foliage Applications of ZnSO4 Reduced Leaf Nitrogen Remobilization in Peach and Nectarine
Authors: Castagnoli S.P. , DeJong T.M. , Weinbaum S.A. , Johnson R.S.
Published: January 2019

Premature defoliation of peach and nectarine (Prunus persica L. Batsch) trees resulting from foliar applications of ZnSO4 reduced N remobilization that typically occurs during leaf senescence. Leaf N remobilization in unsprayed control trees ranged from 45% to 50%, irrespective of tree N status. Leaf N remobilization in trees receiving foliar applications of ZnSO4 ranged from a positive influx of N into the leaf to ≈30% of the N remobilized, depending on ZnSO4 application timing and method of expressing leaf N levels. Early ZnSO4 applications resulted in less N remobilization. Measuring leaf N on an area basis was a more precise indicator of N remobilization than N per unit dry weight, because leaf weight per unit area changes during leaf senescence.
Wound Healing in Cucumber Fruit
Authors: Walter William M. , Randall-Schadel Betsy , Schadel William E.
Published: January 2019

Wound healing in cucumber fruit (Cucumis sativus L., cv. Calypso) was studied using histological and degradative techniques. A thick exudate appeared at the wounded surface shortly after wounding. This material retarded water loss and possibly aided in the formation of sclerified parenchyma observed 24 hours after wounding. The sclerified material was positive to a modified Weisner stain, indicating lignification was occurring. Wound periderm (cork) was initiated directly beneath the sclerified parenchyma cells within 48 hours after wounding. The cork layers were positive to Sudan IV stain, indicating suberin was being formed. The rate of phellem development decreased by 6 days after wounding. By day 7, younger phellem cells and sclerified parenchyma cells were stained by Sudan IV. Degradation of the wound tissue by chemical procedures demonstrated that relatively large amounts of lignin and suberin were deposited during healing. Fragments from the lignin degradation Indicated that lignin was composed mainly of gualacyl and p-hydroxyphenyl residues. Suberin was found to contain mainly 1,16-hexadecane and 1,18-osctadecene decarboxylic acids detected as the silylated diol derivatives.
Gene Transfer of Multiple Flowers and Pubescent Leaf from Capsicum chinense into Capsicum annuum Backgrounds
Authors: Shuh D.M. , Fontenot James F.
Published: January 2019

The inheritance of multiple flowers and leaf pubescence resulting from the crosses between accessions from pepper species Capsicum annuum L. and C. chinense Jacq. was examined. Hand cross- and self-pollinations were made in a glass greenhouse. Only eight normal F1 plants were obtained from crosses between the two species when C. annuum L. was the female parent. F2 and backcross generations obtained from the F, and the two parents were grown in the field. Two field studies indicated that multiple flowers and leaf pubescence were controlled by dominant genes. A three-gene model leading to an F2 segregation ratio of 45:9:10 and a two-gene model leading to an F2 segregation ratio of 13:3 were suggested for the inheritance of multiple flowers and leaf pubescence, respectively. Epistasis was evoked in the interpretation of the data. No linkage was found between the two characters. The inconsistencies between F2 and backcross data might be due to selective elimination of genes from one or the other parent in an Interspecific hybridization. Segregation ratios from intraspecific crosses for leaf pubescence supported a two-gene model and gave an F2 ratio of 13 pubescent leaf : 3 glabrous leaf progeny.
Effect of Glomus fasciculatum on the Growth of Asparagus and the Incidence of Fusarium Root Rot
Authors: Wacker Tracy L. , Safir Gene R. , Stephens Christine T.
Published: January 2019

Asparagus (Asparagus officinalis L.) seedlings inoculated with the sicular-arbuscular mycorrhizal (VAM) fungus Glomus fasciculatum (Thaxt. sensu Gerd.) Gerd. & Trappe (GF) d Fusarium oxysporum (Schlect.) Snyd. & Hans. (FO) were grown under field and greenhouse conditions. In the fi, shoot volumes of GF-inoculated plants were greater than nonGF plants from the 3rd through the 13th month of growth. By the 14th month, GF-inoculated plants grown in high-P soils had significantly lower disease ratings than nonGF plants grown in low-P soils, and rhizosphere populations of FO were lowest in high-P soils, regardless of VAM status. In greenhouse studies, FO inoculation of VAM-infected asparagus plants reduced GF root colonization levels under well-watered (0 MPa), but not under water stress, conditions (- 1.5 MPa). Well-watered plants inoculated with both FO and GF were less diseased and sustained lower rhizosphere populations of FO than plants inoculated with FO alone. The differences in FO populations and disease ratings in these studies were apparently unrelated to final plant tissue P levels.
Ontogenetic Changes in Calcium Concentration and Content in Pickling Cucumber Fruit as Influenced by Genotype and Environment
Authors: Engelkes Cheryl Ann , Widders Irvin , Price Hugh
Published: January 2019

A field experiment was conducted to quantify the ontogenetic changes in Ca concentration and content of pickling cucumber fruits as influenced by environmental conditions and genotype. Pericarp tissue Ca concentrations (1.1% to 0.7% of dry weight) were higher but declined less rapidly during fruit development than endocarp concentrations (0.8% to 0.2% of dry weight). About 90% of net fruit Ca content accumulated within the pericarp of ≈150 g fresh weight fruit, the rest in the endocarp. The rate of Ca accumulation was highly variable during fruit ontogeny but was closely correlated with growth rate (grams fresh weight/day). Environmental conditions had the largest effect on Ca accumulation rate. Fruit tissue Ca concentrations were affected both by genotype and the cultural environment, especially at the later stages of fruit development. Calcium concentrations (1.5 to ≈3.0% of dry weight) in fully expanded leaf tissue were higher than in rapidly growing fruit tissues on the same plants.
Absorption, Translocation, and Metabolism of Sethoxydim in Centipedegrass and Goosegrass
Authors: McCarty Lambert B. , Higgins Jeffery M. , Corbin Frederick T. , Whitwell Ted
Published: January 2019

Absorption, translocation, and metabolism of foliar-applied 14C-labeled sethoxydim (14C-sethoxydim) in sethoxydim-tolerant centipedegrass [Eremochloa ophiuroides (Munro) Hack.] and sethoxydim-sensitive goosegrass [Eleusine indica (L.) Gaertn.] were determined. The distribution of 14C in treated leaves indicated that similar amounts (≈ 3%) were found in the epicuticular wax fraction (chloroform wash) of both species after 6 hours. After 2 hours, 16% of the applied 14C-sethoxydim was absorbed in the treated leaf by centipedegrass, but only 2% was absorbed by goosegrass. After 2 hours, centipedegrass also readily translocated greater amounts of 14C than goosegrass (4.3% vs. 0.4%). Six hours after treatment, however, no differences were found in amounts absorbed by the treated leaf and translocated to apical and basal leaves. Because sethoxydim-tolerant centipedegrass absorbed and translocated similar amounts of 14C compared to the sethoxydim-sensitive goosegrass, these two mechanisms do not appear to be a means of tolerance. The major difference found between the two species was in the metabolism of sethoxydim. After 6 hours, 81% to 98% of the 14C in goosegrass extracts remained as 14C-sethoxydim. In contrast, only 1% of the 14C found in apical leaves, basal leaves, and roots of centipedegrass was identified as 14C-sethoxydim. These data indicated that differences in tolerance to sethoxydim between these two species were based on metabolism. Chemical name used: 2-[1-(ethoxyimino) butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2 -cyclohexen-1-one (sethoxydim).
Heat Shock Response in Field-grown, Ripening Papaya Fruit
Authors: Paull Robert E. , Chen Nancy Jung
Published: January 2019

Mesocarp softening during papaya (Carica papaya L.) ripening was impaired by heating at 42C for 30 min followed by 49C for 70 min, with areas of the flesh failing to soften. Disruption of the softening process varied with stage of ripeness and harvest date. The respiratory climacteric and ethylene production were higher and occurred 2 days sooner in the injured fruit than in the noninjured fruit that had been exposed to 49C for only 30 min. Skin degreening and internal carotenoid synthesis were unaffected by the heat treatments. Exposure of ripening fruit to either 42C for 4 hr or 38 to 42C for 1 hr followed by 3 hr at 22C resulted in the development of thermotolerance to exposure to the otherwise injurious heat treatment of 49C for 70 min. Four stainable polypeptide bands increased and seven declined in single-dimensional acrylamide gels following incubation of fruit at the nondamaging temperature of 38C for 2 hr. Three polypeptides showed marked increases when polysomal RNA was translated. These polypeptides had apparent molecular weights of 17, 18, and 70 kDa. Proteins with molecular weights of 46, 54, and 63 kDa had slight increases after heat treatment. The levels of these polypeptides peaked 2 hr after heat treatment and declined within 24 hr. The amount of these polypeptides in the unheated control varied with the batch of fruit. The concentration of three translated polypeptides, with apparent molecular weights of 26, 37, and 46 kDa, declined. Other polypeptides continued to be translated during and after holding papayas for 2 hr at 38C.
Photosynthetic Evaluation of Sweetpotato Germplasm
Authors: Bhagsari Ajmer S.
Published: January 2019

Field experiments were conducted from 1980-1983 to evaluate sweetpotato [Ipomoea batatas (L.) Lam.] germplasm for photosynthetic efficiency, harvest index [HI; (storage root dry matter/total plant dry matter) × 100], and yield. Most genotypes maintained leaf area index (LAI) above five until final harvest, 164 days after planting (DAP). The higher LAI (> 8) for PI 318859, PI 344134, and PI 308205 compared to the other genotypes was maintained at the expense of the storage root development. Single leaf net photosynthesis (Pn) of the genotypes ranged from 0.61 to 1.09 mg CO2/m2 per sec during 1980. Canopy photosynthesis on a ground area (CPn-Ga) basis ranged from 0.95 to 1.56 and 1.04 to 1.30 mg CO2/m2 per sec during July and August 1983, respectively. Canopy photosynthesis expressed on leaf dry-weight (CPn-Dwt) basis was higher for PI 344122 than the other genotypes, except PI 344138, indicating its superior photosynthetic efficiency. Photosynthetic efficiency and stomatal conductance were not related to yield. Stomatal conductance and CPn-Ga were significantly correlated. Harvest index differed significantly at each sampling and ranged from 14.0% to 75.5% at final harvest. Fresh storage root yield for 1983 and 4-year mean yield ranged from 8.6 to 60.1 and 14.1 to 42.2 t·ha-1 respectively. At final harvest, HI correlated significantly with fresh-(r = 0.91) and dry-matter storage root yield (r = 0.95). Despite significant photosynthetic variations among the genotypes, sweetpotato yield was influenced more by HI and storage root sink strength than by photosynthetic efficiency.
Kiwifruit Yield Efficiency, Plant Density, and Bud Number per Surface Unit
Authors: Testolin Raffaele
Published: January 2019

Kiwifruit [Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson] crop response to variations in plant density and bud number per surface unit of growing area was studied to determine optimum levels of these factors. Five bud numbers per surface unit (50,000, 100,000, 150,000; 200,000, and 250,000 mixed buds/ha) and four plant densities, obtained by varying the in-row spacings (1.5, 3.0, 4.5, and 6.0 m), were combined in a factorial design and tested in a kiwifruit orchard during two growing seasons on the same vines. Kiwifruit yield increased from 7 to 24 t•ha-1 with increasing bud number per hectare according to a 2nd-order polynomial function. Both the reduction in the mean fruit mass as well as the percentage budbreak caused a decrease in orchard efficiency. No differences between 1.5- and 3.0-m in-row spacings were found; spacings wider than 3.0 m reduced crop efficiency principally by decreasing fruit mass.
Yield Responses and Nutrient Uptake of Broccoli as Affected by Lime Type and Fertilizer
Authors: Demchak K.T. , Smith C.B.
Published: January 2019

In a 3-year study with broccoli [Brassica oleracea var. botrytis (L.) Mill. cv. Green Comet], NP or NPK fertilizer at rates of 56N-56P-0K, 56N-56P-56K, and 56N-112P-56K (kg·ha-1) were banded in plots to which three types of lime had been applied—calcitic, calcitic with 3% Mg, or dolomitic. Fertilizer and lime controls were included. Previous liming had raised the soil pH from 5.3 to 7.2-7.4. Effects of lime on yields were greatest when no fertilizer was applied. Dolomitic lime was the most effective, increasing total yield by 49%, terminal weight by 54%, and hastening maturity. Fertilizer effects were most evident when no lime had been applied, with all fertilizer treatments increasing total yield, terminal and plant weight, and hastening maturity. Most changes occurred in the 56N-56P-OK treatment. Effects of lime when fertilizer was applied and effects of fertilizer when lime had been applied were less consistent. Lime alone, especially types containing Mg, increased leaf P, which generally followed the-same trend as total yield. Calcitic lime increased leaf Ca and dolomitic lime increased leaf Mg over other lime treatments. Calcitic lime with 3% Mg increased leaf Ca, but not leaf Mg, compared to the check. All lime treatments decreased leaf Mu, B, and Zn. Fertilizer treatments usually increased leaf N and Mn. Phosphorus uptake was increased by either lime or fertilizer application. Regression analysis strongly suggested that P was the element most responsible for yield increases.
Acidification of Calcareous Soils Improves Zinc Absorption of Pecan Trees
Authors: Fenn L.B. , Malstrom H.L. , Riley T. , Horst G.L.
Published: January 2019

Acidification of < 1% of the effective root zone of a mature pecan tree (Carya illinoensis (Wanghenh.) C. Koch) significantly increased uptake of Zn into the tree and maintained elevated Zn in leaves for 9 years. Sulfuric acid and ZnSO4, applied in a shallow trench, lowered soil pH to a depth of 60 cm and increased volubility of Zn in the acid band. Large concentrations of CaSO4 were formed. Laboratory tests confirmed the movement and volubility of Zn in soils under conditions similar to those in the field. Tree roots did not grow into the acidified band, presumably due to high salinity, but proliferated extensively at the interface of the acidified band and calcareous soil.
Differences of Biochemical Components Between the Skin Tissues of Normal and Black-speckled `d'Anjou' Pears after Prolonged Low-oxygen Storage
Authors: Lee Stephen P. , Chen Paul M. , Chen Tony H.H. , Varga Diane M. , Mielke Eugene A.
Published: January 2019

A proportion of `d'Anjou' pear fruit (Pyrus communis L.) developed a disorder, “black speck” or “skin speckling”, after prolonged controlled atmosphere (CA) storage (1% O2, - 0.5 C). A comparative study of biochemical components revealed that there was no significant difference in succinic, citric, fumaric, and pyruvic acids between the speckled' and normal skin tissues. The content of malic acid in the affected tissue was almost three times lower than that in the normal tissue. The specific activity of NADP-malic enzyme (EC 1.1.1.40) in the affected tissue was also lower, but the total activities were similar. The affected tissue contained higher percentages of dry matter and soluble proteins than the normal tissue. Two-dimensional gel electrophoresis of proteins showed that two groups of novel polypeptides appeared only in the affected skin tissue. This study indicated that a certain proportion of `d'Anjou' pear fruit might have been exposed to unfavorable preharvest environmental stresses, and, therefore, could no longer tolerate the subsequent semi-anaerobic and chilling stresses during prolonged CA storage.
Sucrose Metabolism in Ripening Muskmelon Fruit as Affected by Leaf Area
Authors: Hubbard Natalie L. , Pharr D. Mason , Huber Steven C.
Published: January 2019

Muskmelon (Cucumis melo L.) fruit lack a stored starch reserve and therefore depend on translocated photoassimilate from the leaf canopy for sugar accumulation during ripening. The influence of canopy photosynthesis on sucrose' accumulation within muskmelon fruit mesocarp was examined. Canopy photosynthetic activities were estimated in a sweet and a nonsweet genotype. Photosynthetic rate of the nonsweet genotype, on a per-plant basis, was only 56% of that of the sweet genotype. The effect of limiting leaf area of the sweet genotype on carbohydrate concentrations and sucrose metabolizing enzymes within the fruit was evaluated. A 50% reduction of leaf area 8 days before initiation of fruit sucrose accumulation resulted in canopy photosynthesis similar to that of the nonsweet genotype. Reduced photosynthetic activity resulted in slightly lower soluble-carbohydrate concentration in the fruit; however, fruit sucrose concentration was three times higher than that reported previously for the nonsweet genotype. The extent to which `fruit sucrose phosphate synthase (SPS) activity increased during maturation was diminished by leaf removal. Acid invertase activity declined in all fruit in a similar manner irrespective of defoliation. A reduction of leaf area of a sweet genotype reduced sucrose accumulation within the fruit. Lower fruit sucrose concentration was associated with lower concentration of raffinose saccharides and lower SPS activity within the fruit. Additionally, insufficient assimilate supply was judged not to be the factor responsible for low sucrose accumulation in a nonsweet genotype.
Inheritance of Calcium Use Efficiency in Tomatoes Grown under Low-calcium Stress
Authors: Li Yin-ming , Gabelman W.H.
Published: January 2019

Sixty highly homozygous tomato (Lycopersicon esculentum Mill.) strains, some selected from previous studies and some collected from known low-Ca regions, were screened under a low-Ca culture system (10 mg of Ca per plant). Four strains were selected to represent the extremes for Ca efficiency and used as parents to create a series of F1, F2, and backcross generations for inheritance studies of Ca use under low-Ca stress. Based on total plant dry weight, additive and dominance gene effects were most important for the efficiency of Ca use. Maternal control of efficiency in Ca use was not observed. Estimates of broad-sense heritability ranged from 63% to 79% for total play dry weight. Narrow sense heritabilities, determined in only two of the families, were 47% to 49$ and 68% to 75%.
Enzyme Polymorphism in Mango
Authors: Degani Chemda , El-Batsri Ruth , Gazit Shmuel
Published: January 2019

Forty-one (Mangifera indica L.) cultivars were characterized electrophoretically using the isozyme systems aconitase, isocitrate dehydrogenase, leucine aminopeptidase, phosphoglucose isomerase, phosphoglucomutase, and triosephosphate isomerase. The outcross origin of some of the mango cultivars was supported by the isozymic banding patterns. Reported parentage of some other cultivars was not consistent with their isozymic banding patterns.
Plant Regeneration of `Valencia' Sweet Orange, `Femminello' Lemon, and the Interspecific Somatic Hybrid following Protoplasm Fusion
Authors: Tusa N. , Grosser J.W. , Gmitter F.G.
Published: January 2019

Protoplasm culture following the chemical fusion of `Valencia' sweet orange [Citrus sinensis (L.) Osb.] protoplasts, isolated from an embryogenic suspension culture, with `Femminello' lemon [Citrus limon (L.) Burro. f.] leaf protoplasts resulted in the regeneration of an interspecific allotetraploid somatic hybrid plant, two autotetraploid lemon plants, and diploid plants from both parents. The regeneration of plants from lemon leaf protoplasts is an example of protoplast-to-plant regeneration from non-nucellus-derived tissue for Citrus. Regenerated plants were classified according to leaf morphology, chromosome number, and analyses of phosphohexose isomerase (PHI), peroxidase (PER), and 6-phosphoglucose dehydrogenase (PGD) zymograms. The somatic hybrid plant was vigorous, with leaves morphologically intermediate to the parents. The tetraploid lemon plants were similar to diploids, although less vigorous and with thicker leaves. The tetraploid lemon and somatic hybrid plants, if fertile, could be used in interploid sexual crosses to breed triploid seedless lemon cultivars with tolerance of mal secco disease from sweet orange. Further investigation of plant regeneration from leaf protoplasts could increase the number of totipotent Citrus clones amenable to somatic hybridization and genetic transformation experiments.
Field Response of Peas to Excess Heat during the Reproductive Stage of Growth
Authors: Pumphrey Floyd V. , Ramig Robert E.
Published: January 2019

Regression analysis was used to establish the effect of maximum daily temperatures on fresh pea (Pisum sativum L.) yield during the reproductive stage of growth. Maximum daily temperatures below 25.6C had little influence on pea yield. Temperatures above 25.6C depressed yield; this adverse effect increased exponentially as maximum daily temperature increased linearly. Predicted decrease in fresh pea yield ranged from 16 kg/ha per heat degree day above 27C to 67 kg/ha per heat degree day above 35C.
Seasonal Variation in Polypeptide Profiles and Cellular Structure of Pecan Leaves
Authors: Yates I.E. , Carter E.A. , Wilkins T.A. , Wood B.W.
Published: January 2019

Polypeptides from pecan [Carya illinoensis (Wangenh.) C. .Koch] leaves were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and visualized by silver staining. Pecan leaf protein profiles were similar irrespective of cultivar (Desirable and Stuart), leaflet position, reproductive status of the allied shoot, or seasonal leaf age relative to fruit development. The large subunit of ribulose l,5-bisphosphate carboxylase and the majority of the other polypeptides were consistently present. However, the most striking change in the polypeptide composition was the seasonal decline of a polypeptide with an approximate molecular mass of 24.5 kDa. This leaf polypeptide was present in leaves collected in June and July, coinciding with the periods of initial fruit elongation and rapid increase in fruit volume. A detectable decrease occurred by mid-August, when kernel development was initiated. Changes in the abundance of this polypeptide relative to other polypeptides were observed over two growing seasons. Cells of young leaves collected early in the growing season contained more ribosomes and starch granules, but fewer vesicles and smaller electron-dense osmophilic granules than old leaves collected late in the growing season.
Respiration and C2H4 Production in Various Harvested Crops Held in CO2-enriched Atmospheres
Authors: Kubo Yasutaka , Inaba Akitsugu , Nakamura Reinosuke
Published: January 2019

The respiration rate (O2 uptake) and the rate of C2H4. production were measured before, during, and after 24 hours of treatment with 60% CO2 (20% O2) in 18 kinds of fruits and vegetables by use of an automated system connected to a microcomputer. High CO2 decreased respiration only in climacteric fruit and broccoli, which were producing C2H4. Ethylene production decreased with CO, treatment of peaches, tomatoes, and broccoli, but that of bananas increased. In five nonclimacteric fruits (three citrus species, grapes, and Japanese pears) and several vegetables (carrots, onions, cauliflower, and cabbage), in which C2H4 production was not detected, high CO2 affected respiration little, if at all. When eggplants, cucumbers, podded peas, spinach, and lettuce were treated with high CO2, C2H4 production began and respiration increased. These results indicate that the respiratory responses of harvested horticultural crops to high CO2 might be mediated by the effects of CO2 on the action and/or synthesis of C2H4.
Dormancy Effects on Supercooling in Deacclimated `Meteor' Tart Cherry Flower Buds
Authors: Callan Nancy W.
Published: January 2019

Exposure of `Meteor' tart cherry (Prunus cerasus L.) flower buds to deacclimating conditions resulted in an increase in the temperature of the low-temperature exotherms (LTEs) produced by the flower primordia during controlled freezing. Primordium supercooling temperature was related to chill unit accumulation, an indicator of depth of flower bud endodormancy. LTEs ceased to be detected after deacclimation earlier in 1986-87, a season of more rapid chill unit accumulation, than in 1987-88. Before deacclimation, the range of primordium LTE temperatures within a flower bud was normally ≤1C, but in deacclimated buds considerable variability in LTE temperatures was observed. However, primordia within a flower bud lost the ability to supercool simultaneously. This change was generally concurrent with the appearance of mature xylem vessel elements (XVE) in the upper bud axis and in the flower primordium but did not entirely depend on vessel element maturation.
Seasonal Variation in Intensity of Bud Dormancy in Apple Cultivars and Related Malus Species
Authors: Hauagge Roberto , Cummins James N.
Published: January 2019

Dormancy patterns throughout the season were studied in more than 90 apple (Malus ×domestica Borkh.) cultivars and related Malus spp. The seasonal apple bud dormancy pattern resembles a normal curve: it starts to intensify soon after bud formation and reaches maximum intensity by the time of leaf fall/senescence. Genotypes were grouped into three general classes based on maximum dormancy intensity. Maximum intensity of bud dormancy measured in cold winters is inversely related to adaptation to the subtropics. Low-chilling requirement (CR) cultivars have a shallow depth of dormancy with very little alteration throughout the year. High-CR cultivars have intense bud dormancy, the first stage of which can be induced by growing these cultivars at temperatures above 20C. Genotypes differed in their rates of dormancy dissipation. The efficiency of chilling unit (CU) accumulation to break dormancy was negatively correlated with CR, which indicates the importance of factors other than CU accumulation in terminating bud dormancy in low-CR cultivars. The inherent length of bud dormancy plays a major role in determining the time of budbreak in the spring. Deviations may be related to the genotypic efficiency in which chilling modifies dormancy and possibly the basal temperatures to which buds respond. Chill unit requirement and heat unit requirement are dependent factors. Heat requirement comparisons may be meaningless if the dormancy intensities of the genotypes are not taken into consideration.
Description of Florists' Cognitive Structure and Perceived Performance of Supplier Services through Second-order Factor Analysis
Authors: Prince Thomas L. , Tayama Harry K. , Grabner John R.
Published: January 2019

Retail florists' performance ratings of services provided by wholesale growers, wholesale florists, and grower-shippers/brokers were factor-analyzed to yield a hierarchical classification of customer service in floral distribution. Nine customer service factors were identified and three major independent classes of customer service were defined, including 1) physical distribution, 2) marketing, and 3) product quality services. Florists rated the performance of suppliers' physical distribution services higher than marketing and product quality services. Florists' perception of physical distribution and product quality services did not vary across type of supplier, but for marketing services, florists rated wholesale growers higher in performance than wholesale florists. The hierarchical classification of customer service and service performance profiles provide the floral industry with relevant market information for the successful development and effective implementation of customer service programs.
Bases of Yield and Production Efficiency in Apple Orchard Systems
Authors: Robinson Terence L. , Lakso Alan N.
Published: January 2019

Bases of orchard productivity were evaluated in four 10-year-old apple orchard systems (`Empire' and `Redchief Delicious' Malus domestics Borkh. on slender spindle/M.9, Y-trellis/M.26, central leader/M.9/MM.111, and central leader/M.7a). Trunk cross-sectional areas (TCA), canopy dimension and volume, and light interception were measured. Canopy dimension and canopy volume were found to be relatively poor estimators of orchard light interception or yield, especially for the restricted canopy of the Y-trellis. TCA was correlated to both percentage of photosynthetically active radiation (PAR) intercepted and yields. Total light interception during the 7th to the 10th years showed the best correlation with yields of the different systems and explained most of the yield variations among systems. Average light interception was highest with the Y-trellis/M.26 system of both cultivars and approached 70% of available PAR with `Empire'. The higher light interception of this system was the result of canopy architecture that allowed the tree canopy to grow over the tractor alleys. The central leader/M.7a had the lowest light interception with both cultivars. The efficiency of converting light energy into fruit (conversion efficiency = fruit yield/light intercepted) was significantly higher for the Y-trellis/M.26 system than for the slender spindle/M.9 or central leader/M.9/MM.111 systems. The central leader/M.7a system bad the lowest conversion efficiency. An index of partitioning was calculated as the kilograms of fruit per square centimeter increase in TCA. The slender spindle/M.9 system had significantly higher partitioning index than the Y-trellis/M.26 or central leader/M.9/MM.111. The central leader/M.7a system had the lowest partitioning index. The higher conversion efficiency of the Y/M.26 system was not due to increased partitioning to the fruit; however, the basis for the greater efficiency is unknown. The poor conversion efficiency of the central leader/M.7a was mostly due to low partitioning to the fruit. The Y-trellis/M.26 system was found to be the most efficient in both intercepting PAR and converting that energy into fruit.
Tomato Flowering and Early Yield Response to Heat Buildup under Rowcovers
Authors: Peterson Roy H. , Taber Henry G.
Published: January 2019

Five polyethylene rowcover treatments (none, slitted white, slitted clear, chimney, and perforated) were combined factorially with four tomato [Lycopersicon esculentum (Mill)] cultivars (`PikRed', `Jetstar', `Supersonic B', and `Heinz 1810') in a 2-year experiment. Clear or white rowcovers more than doubled early yield in 1986, from 1.2 to 2.9 t·ha-1. This early yield advantage resulted from an advancement of flowering rather than an increase in fruit number or size. In Spring 1987, high temperature caused increased fruit abortion with all rowcovers, resulting in early yield reduction. Flower production on the first two clusters for either year was not reduced by high temperatures and was increased for `Heinz 1810'. Tomatoes under slitted, white covers, the best-yielding treatment in 1987, yielded only 72% of those without rowcovers. Sustained high temperature, ≈ 40C for 3 consecutive hours or more, occurred with all rowcovers and correlated with early yield loss.
Relationship between Nodal Position and Plant Age on the Nutrient Composition of Vegetative Poinsettia Leaves
Authors: Dole John M. , Wilkins Harold F.
Published: January 2019

Vegetative, single-stem poinsettia plants (Euphorbia pulcherrima Willd. `Gutbier V-14 Glory') were allowed to develop 10, 15, or 20 nodes (nodal groups). Within each nodal group, blades from the same node position were removed, combined into one sample per node, and analyzed for nutrient content. Nutrient concentrations were found to be distributed within the plant in one of three patterns: 1) N, P, and K concentrations were higher in upper than in lower leaves; 2) Ca, Mg, Fe, Mn, and B concentrations were higher in lower than in upper leaves; and 3) Cu and Zn concentrations were higher in upper and lower leaves than in middle leaves. When 10, 15, and 20 noded groups were compared, the distributional patterns were similar, but actual nutrient concentrations between groups differed. Leaf P, Ca, Mg, Fe, Mn, Zn, and B concentrations increased over time. However, concentrations of N, K, and Cu were highest in 43-day-old leaves and lowest in 19-day-old leaves for N and Cu and lowest in 67-day-old leaves for K.
Water Stress and Storage-protein Degradation during Germination of Impatiens Seed
Authors: Khademi Mehrassa , Koranski David S. , Hannapel David J. , Knapp Allen D. , Gladon Richard J.
Published: January 2019

Water uptake by impatiens (Impatiens wallerana Hook. f. cv. Super Elfin Coral) seeds was measured as an increase in fresh weight every 24 hours during 144 hours of germination. Seeds absorbed most of the water required for germination within 3 hours of imbibition and germinated at 60% to 67% moisture on a dry-weight basis. Germination started at 48 hours and was complete by 96 hours at 25C. Water stress of -0.1, -0.2, -0.4, and -0.6 MPa, induced by polyethylene glycol 8000, reduced germination by 13%, 49%, 91%, and 100%, respectively, at 96 hours. Under the same water-stress conditions, increases in fresh weight were inhibited by 53%, 89%, 107%, and 106%, respectively. Three distinct groups of storage proteins were present in dry seed; their estimated molecular weights were 1) 35, 33, and 31 kDa; 2) 26, 23, and 21 kDa; and 3) two bands <14 kDa. Major depletion of storage proteins coincided with the completion of germination. Water potentials that inhibited germination also inhibited degradation of storage proteins. During germination under optimum conditions, the soluble protein fraction increased, coinciding with a decrease in the insoluble fraction.
Vegetative and Reproductive Characteristics of Poinsettia Altered by a Graft-transmissible Agent
Authors: Dole John M. , Wilkins Harold F.
Published: January 2019

Poinsettia (Euphorbia pulcherrima Wind. ex. Klotzsch) cultivars were divided into free-branching and restricted-branching groups. Auto and reciprocal grafts were made among three free-branching cultivars, Annette Hegg Brilliant Diamond (BD), Annette Hegg Topwhite (TW), and Annette Hegg Hot Pink (HP), and two restricted-branching cultivars, Eckespoint C-1 Red (CR) and Eckespoint C-1 White (CW). when CR scions were grafted onto BD stocks, vegetative characteristics of branching pattern and leaf morphology of CR plants were altered when compared to the control graft combination CR/CR (scion/stock). Branching pattern was determined by pinching the scion above the 12th node and measuring axillary shoot length, diameter, and node number 30 days later. CR scions grafted onto BD stocks produced a plant very similar to BD plants when axillary shoot length and node number were compared. However, axillary shoot diameter and leaf morphology were intermediate between CR and BD plants. Changes were retained after two generations of serial vegetative propagation and are considered permanent. The reproductive characteristics of anthesis date, bract color, and cyathia cluster diameter were not influenced by the stock. CR/BD plants produced twice as many axillary inflorescences as BD/BD or BD/CR plants, while CR/CR plants did not produce any. All of the free-branching cultivars were able to alter the vegetative characteristics of all of the restricted-branching cultivars.