bluuebunny/crossref_metadata_2025 huggingface dataset:
Adaptability of Selected Half-sib Families of Sycamore to Container and Nursery Production
Authors: Shoemake Larry J. , Arnold Michael A.
Published: February 2019

Ninety seedlings from each of seven half-sib families of sycamore (Platanus occidentalis L.) were grown to marketable size in 9.1-liter containers in College Station, Texas. Dry matter partitioning was assessed with 10 seedlings each of four half-sib families grown in 4.7-liter containers. Half-sib families included selections native to Brazos County, Texas, and Putnam County, Tenn., and four half-sib families from the Westvaco Corp. (WV) or Texas Forest Service (TFS) tree improvement programs. Families could be separated into three groups with TFS-09 attaining a significantly greater height than other families, while Brazos-D, Brazos-C, and TFS-24 were intermediate and WV-10 and WV-14 were shortest. Contrary to previous field production studies, a weak inverse correlation (R2 = –0.19, P > 0.01) was observed between the number of cuts required to remove multiple leaders and plant height, perhaps due to episodic shoot elongation in south Texas conditions vs. a single flush in northern regions. Corrective pruning removed more dry matter from TFS-09 than from Brazos-D, Brazos-C, and Putnam seedlings. Total dry weights of TFS-09 and Brazos-C were greater than WV-14 or Putnam seedlings.
Screening of Deciduous Azalea for Resistance to Azalea Lace Bug
Authors: Wang Yuefang , Robacker Carol D. , Braman S.K.
Published: February 2019

Azalea lace bug is the most serious pest of cultivated azalea. Though deciduous azaleas are generally considered to be more resistant to lace bug than are evergreen azaleas, some variation in resistance has been reported. The identification of the genetic and physiological basis of resistance is important to eventual development of resistant cultivars of both the deciduous and evergreen azaleas. The first step in this program is to evaluate a wide range of deciduous azaleas for level of resistance. Laboratory evaluations were conducted on nine species and two hybrid cultivars of deciduous azalea and a known susceptible cultivar of evergreen azalea, `Delaware Valley White'. Oviposition rate, rate of egg hatch, number of nymphs surviving, and percent damaged leaf area were evaluated for each of the tested genotypes. Results indicated a wide range of susceptibility, with R. canescens and R. periclymenoides plants highly resistant to infection, while R. atlanticum and R. viscosum were highly susceptible.
Plant Introductions from the Mt. Cuba Center
Authors: Lighty Richard W. , Perry Leonard P.
Published: February 2019

Over the past 7 years, eight plants have been introduced from the Mt. Cuba Center for the Study of Piedmont Flora—two woody and six herbaceous ornamentals—which will be illustrated and described. Cornus sericea `Silver and Gold', 1988, is a sport of and similar to `Flaviramea' with white variegated leaves. Aster novae-angliae `Purple Dome', 1989, is a widely known and compact form (50 cm tall) of the species. Heuchera americana `Garnet', 1989, has shiny green foliage of the species mottled garnet-red. Solidago sphacelata `Golden Fleece', 1989, is a compact (50 cm) form of the species with semi-evergreen basal foliage, winning the ISU outstanding plant award in Switzerland in 1994. Leucothoe axillaris `Greensprite', 1991, is easy to propagate and quick to grow, with solid green, narrow leaves with undulating edges and attenuated tips. Pachysandra procumbens `Forest Green', 1992, has larger leaf whorls and a more smoothly undulating surface than the species. Trillium grandiflorum `Quicksilver', 1992, is similar to the species only with 1-year doubling time. Aster laevis `Bluebird', 1995, is similar to the species but has so far been free from foliage diseases.
Cytogenetic Evaluation and Foliage Color Inheritance within Interspecific Begonia Inbreds
Authors: Sun Yue , Ewart Lowell C.
Published: February 2019

A dominant gene, R, is hypothesized to control the red underfoliage color inheritance in tetraploid fibrous-rooted Begonia × semperflorens-cultorum. This dominant gene R is considered to also affect the intensity of the foliage color, with RRRR and RRRr giving dark red color on the underside of the leaves. The combination of RRrr and Rrrr gives intermediate red coloration, and homozygous recessive rrrr gives all green foliage. A homozygous RRRR inbred line is being test-crossed for potential commercial value. Cytological investigations of hybrids and inbreds derived from species crosses are ongoing. The results will be presented.
Identification of Isolated Membrane Major Volatiles of Fresh Tomato
Authors: Lambert Hélène , Willemot Claude , Thompson John E. , Makhlouf Joseph
Published: February 2019

This research is aimed at the identification of volatile compounds from the isolated membranes fractions, microsomes, and deteriosomes. Fractions were isolated from tomato pericarp by ultracentrifugation at 252,000x g during 1 hour, followed by 362,000x g during 12 hours. The supernatant was infiltrated through a membrane of 300,000 D cut off to concentrate the deteriosomes. The volatiles from the fractions were analyzed by dynamic headspace and GC-MS. Our results suggest that the isolated fractions contained most tomato volatiles. Analysis by GC-MS identified two groups: compounds originating from fatty acids [e.g., hexanal and (E)-2-hexenal] and compounds coming from amino acids (e.g., 2 and 3-methyl butanal). Both microsomes and deteriosomes were highly enriched in volatiles on a protein basis. The increase in volatile compounds in these fractions was influenced by fruit maturity and correlate closely with volatile development in the intact fruit. Volatiles may be generated in the microsomes and released from the membranes via deteriosomes.
Seasonal and Geographical Effects on Subsequent Ripening Characteristics of Bananas
Authors: Marin D.H. , Blankenship S.M. , Sutton T.B. , Swallow W.H.
Published: February 2019

Mature-green `Grande Naine' bananas from Costa Rica, Mexico, Ecuador, and Guatemala were harvested in June, Sept., and Dec. 1993 and Mar. 1994. Fruit were treated with ethylene and held at 17C and 80% to 90% relative humidity until they reached color 6 of the standard color scale. Guatemalan bananas had the highest respiration rate, followed by Costa Rican, Mexican, and Ecuadoran fruit. Peel color, ethylene production, and soluble solids content did not differ among the countries. Measurements made at arrival in the United States had a low correlation with days to reach color 5. Prediction equations showed significant linear relationships for most variables; however, correlations were very low. The highest coefficient of determination was observed with respiration rate (r2 = 0.289). Maximum R2 (0.342) was determined using CO2, C2H4, pH, and soluble solids in the model. pH and soluble solids were good variables to determine the physiological stage of the fruit, and they also detected ripening changes earlier than peel color or firmness.
Characterization of Chitinases and β-1,3-glucanases in Grapefruit Flavedo during Fruit Development
Authors: McCollum T.G. , Doostdard Hamed , Mayer Richard T. , McDonald Roy E.
Published: February 2019

Chitinases (EC 3.2.1.14) and β-1,3-endoglucanase (EC 3.2.1.39) are enzymes that are believed to be components of a plant's natural defense against fungal pathogens. We are interested in the potential role of these enzymes in citrus decay resistance. In our preliminary work, we have determined the activities of chitinases and β-1,3-endoglucanases in the flavedo of grapefruit (Citrus paradisi cv. Marsh) at 17 times during the course of fruit development. Chitinase activity is initially high in flavedo, but drops rapidly and is low, although fairly constant, throughout the remainder of fruit development. In contrast to chitinase, β-1,3-endoglucanase activity is lowest in young fruit and increases during development. Western blots of crude flavedo extracts following SDS-PAGE were probed with antibodies raised against purified citrus chitinase and glucanase, and results revealed that changes in the activities of chitinase and β-1,3-endoglucanase were reflected in the amount of chitinase and glucanase protein present in the extracts. Partial purification of flavedo chitinases and glucanases revealed that acidic and basic forms of both enzymes were present in the extracts, although the basic forms were predominant.
Botrytis cinerea Decay in Apples is Inhibited by Postharvest Heat and Calcium Treatments
Authors: Klein Joshua D. , Conway William S. , Whitaker Bruce D. , Sams Carl E.
Published: February 2019

`Golden Delicious' apples (Malus domestica Borkh.) were treated postharvest with heat (38C/4 d or 42C/24 h) or 2% CaCl2 (applied as a dip or pressure-infiltrated) or a combination thereof and then stored. Decay caused by Botrytis cinerea was virtually eliminated in fruit heated at 38C after inoculation prior to storage, regardless of Ca treatment. Apples inoculated upon removal from storage were almost completely protected from decay if they had been previously pressure-infiltrated with Ca, regardless of heat regime. Heating at 42C or Ca dips were only partially effective in preventing decay. Pressure infiltration of Ca (regardless of heat regime) or heating at 38C (regardless of Ca treatment) resulted in firmer fruit (68 N) than Ca dips or heating at 42C (56 N), which were firmer than nontreated fruit (52 N).
Reduction of Microbial Populations on Prunes by Vapor Phase Hydrogen Peroxide
Authors: Simmons Gilbert F. , Smilanick Joseph L. , John Shama , Margosan Dennis A.
Published: February 2019

Moisture is raised in dehydrated prunes to improve palatability before packaging and potassium sorbate is added to inhibit microbial growth. Vapor phase hydrogen peroxide (VPHP) technology uses hydrogen peroxide pulses to disinfect dried prunes. Dried prunes were obtained from dehydrators. The number of colony-forming units per 10 prunes (cfu/p) was compared between untreated and VPHP treated. Three culture media—dichloran rose bengal chloramphenicol agar base (DRBC, Oxoid), aerobic plate count agar (PCA), and potato dextrose agar (PDA)—were used to evaluate cfu/p. Similar mean microbe populations were observed on DRBC (67) and PDA (70); PCA had higher cfu/p (99). Microbes washed from untreated prunes obtained from dehydrators were 58 to 112 cfu/p, depending on the culture medium used. The number of cfu/p assessed on all media on VPHP-treated prunes was near 0 after 100 min exposure. Unlike potassium sorbate, hydrogen peroxide is a microbiocide rather than a microbiostat.
β-Galactosidase II in Ripening Tomatoes
Authors: Pressey Russell , Carrington C.M. Sean
Published: February 2019

Tomatoes contain several isozymes of β-galactosidase, but only one, β-galactosidase II, can hydrolyze the β-1,4-galactans in tomato cell walls. β-galactosidase II has now been highly purified by modification of the original procedure. The molecular weight of this isozyme is ≈62 kDa according to gel infiltration, but SDS-PAGE of the purified enzyme separated three components with molecular weights of 29, 42, and 82 kDa. The 82-kDa peptide may be the intact enzyme and the smallest peptides are subunits as proposed for other β-galactosidases. The N-terminal amino acid sequence of β-galactosidase II showed high homology with amino acid sequences reported for other plant β-galactosidases. A new assay for β-galactosidase II in tomato extracts has been developed using FPLC. This isozyme was not detected in mature-green tomatoes but appeared at about the breaker stage and increased during ripening. The increase in b-galactosidase II was accompanied by a decrease in galactose content of cell wall polysaccharides, suggesting that this enzyme may be involved in the loss of galactose during tomato ripening.
Cell Wall Changes Associated with Normal and Mealy Fruit Softening for a Novel Peach Genotype
Authors: Maness Niels O. , Chrz Donna , Goffreda Joseph C.
Published: February 2019

The `Stony Hard' gene of peach conferred a unique ability to manipulate softening and textural properties of the fruit by controlling the concentration and duration of exposure to ethylene. Fruit ripened in ethylene-free air softened very slowly. Exposure of fruit to 1 ppm ethylene continuously for 48 h, or discontinuously at 100 ppm over the same time period, significantly accelerated softening—to a normal texture. Exposure of fruit to 100 ppm ethylene continuously for 48 h induced softening to the same level, but to a mealy texture. We have prepared cell walls and conducted sequential chemical extractions from fruit exposed to the ethylene treatments above. Galacturonic acid content of chelator soluble pectin fractions decreased for mealy fruit, compared to fruit with normal texture, indicating that selective pectin degradation was associated with mealiness. Other differences in polysaccharide sugar composition and apparent molecular size associated with slow, accelerated, and abnormal softening in peach fruit will be addressed.
Postharvest Biological Control of Gray Mold (Botrytis cinerea) on Strawberry Fruit
Authors: Urena A. , Huber D.J. , Bartz J.A. , Chandler C.K.
Published: February 2019

Biological control using antagonistic microorganisms has been the subject of increased interest for postharvest pathogen control. Gray mold is an important factor in the perishability of strawberry fruit, both pre- and postharvest. In view of the specific characteristics of this host–pathogen interaction, strawberry fruit represent a suitable commodity with which to investigate the efficacy of alternative control, including the use of biological measures. During 1994 and 1995, ripe strawberry fruit were harvested from local plantings and endemic microflora were analyzed for potential antagonist modes of action toward B. cinerea. Two bacteria were isolated and these, along with other bacteria and yeast obtained from other sources, were used to inoculate strawberry fruit stored at different temperatures. Effects of storage temperature and interactions of pathogen/antagonist and fruit quality were determined. The results illustrate the potential of using yeast at low temperatures and bacteria at higher, ambient conditions to achieve effective postharvest control of B. cinerea. Microorganisms derived from the fruit and of presumably local origin exhibited significant biocontrol effects and showed a higher capacity for adaptation to the handling practices of strawberry fruit, especially at lower storage temperatures.
Leaching and Persistence of Oxidiazon in Several Organic-based Substrates
Authors: Mentag Rachid , Duchesne Isabelle , Rioux Jacques-André
Published: February 2019

The objective of this study was to determine the persistence and leaching of the herbicide oxadiazon in five substrates. The substrate mixtures consisted of the following: peatmoss, compost, and sand in the following proportions: 1:1:0, 3:3:2, 1:1:2, 1:1:6, and 0:0:1 in 5-liter containers. Rates of oxadiazon used were 4 and 8 kg a.i./ha on two separate split-split plots. Each experimental design had three factors: five substrates, four harvest times (24 h; 1, 2, and 3 months) and five soil depths (0–2, 2–4, 4–6, 6–8, 8– cm). Only herbicide persistence and leaching from the various substrates were investigated in this experiment; therefore, we did not remove plant material. Substrate oxadiazon residues were determined by gas chromatography analysis, and it was shown that leaching was more evident in media with a lower percentage of organic matter. In addition, oxadiazon did not leach below 4 cm in conventional substrate (1 peatmoss: 1 compost: 1 sand, respectively). The persistence of oxadiazon was affected by soil composition and herbicide persisted more in substrates with great percentage of organic matter.
Selectivity of Propane Flamer as a Means of Weed Control
Authors: Leroux G.D. , Douheret J. , Lanouette M. , Martel M.
Published: February 2019

With growing public concern about environmental quality, farmers must turn to new plant protection alternatives that minimize the use of agrochemicals. Flaming has been practiced for several years as a means of weed control in noncropped areas (railroad, ditches, etc.), but its selectivity toward crops has yet to be defined. Experiments were conducted in the ICG-Propane laboratory at Laval Univ. to determine the temperature needed to kill weeds and the temperature that corn could tolerate. Four weed species were studied: Amaranthus retroflexus, Brassica kaber, Chenopodium album, and Setaria viridis and each species was tested at three growth stages: 0–2, 4–6, and >8 leaves. Corn tolerance was tested at four growth stages: coleoptile, 0–2, 4–6, >8 leaves. All plants were grown in the green-house and were submitted to different combinations of operation speeds and of propane pressures, giving 10 temperature intensities ranging from 110 to 390C. The response of each species was evaluated by measuring its height and dry biomass 2 weeks after treatment. The threshold temperature for corn was below 200C; above this temperature, significant corn injury occurred at all growth stages tested. The corn growth stages most tolerant to heat were coleoptile and >8 leaves. While the most sensitive was 4–6 leaves. All weeds tested were sensitive to heat at 0–2 leaf stage. Amaranthus retroflexus and Chenopodium album were controlled until six leaves with temperatures that were not harmful to corn. Weeds with more than eight leaves needed higher temperature, and control rarely reached 60%. Flaming could be a selective method of weed control if operated at a temperature of 170C. Selectivity can be increased by creating a growth differential between corn and weeds.
Antiplatelet Activity, Solids, and Pungency of Four Onion (Allium cepa L.) Genotypes during Cold Storage
Authors: Debaene Jan E.P. , Goldman I.L.
Published: February 2019

Raw onion extract contains organosulfur compounds that prevent aggregation of platelets in human blood plasma and influence onion pungency. Organosulfur compounds are volatile and may change concentration during storage. A study was conducted to determine 1) whether antiplatelet activity of filtered onion extract decreases during time in cold (4C) storage; and 2) correlations among antiplatelet activity, pyruvic acid content, and percent solids during time in cold storage. Two low-pungency genotypes (8155 and Exhibition) and two high-pungency (W420 and W434) genotypes were grown in replicated plots in two Wisconsin and two Oregon locations in 1994. Bulbs were evaluated for antiplatelet activity, percent solids, and pyruvic acid content at 40-day intervals after onion harvest. Significant differences were found for pyruvic acid content, solids, and antiplatelet activity among dates of sampling, genotypes, and locations. Mean pyruvic acid concentrations ranged from 6.4 μm·ml–1 of extract for Exhibition, to 8.0 μm·ml–1 of extract for W420. Mean solids concentrations ranged from 5.8 g/100 g for Exhibition to 11.4 g/100 g for W434. Antiplatelet activity averaged over all genotypes increased over 120 days and was positively correlated with percent solids and pyruvic acid content.
Varietal Improvement of Pepper in Cote d'Ivoire
Authors: Kouamé Christophe N. , Djidji Hortense A. , Goli Koffi
Published: February 2019

Pepper (Capsicum spp.) is an important component of various cropping systems and dishes in Cote d'Ivoire. The need to meet local market demand has prompted the development of high-yielding hot pepper varieties. Three local selections and 20 AVRDC-introduced breeding lines were evaluated in a three-replicate randomized complete block design. Data were collected on fruit and plant characteristics as well as on fruit yield and yield components. Large variations were found in all studied variables. Date of 75% flowering occurred between 52 and 77 days after sowing. First harvest date varied from 99 to 134 days after sowing, while plant height at first harvest ranged from 42 to 92 cm. Fruit size and fruit form were quite diverse. Maximum total fresh fruit weight (5490 g/plot) was about 10 times higher than that of the lowest-yielding (557 g/plot) entry. Selection within those lines has potential to contribute to the improvement of pepper productivity in Cote d'Ivoire.
Effects of Moisture Loss on Water Potential Components and Tissue Deterioration in Carrots during Short-term Storage
Authors: Shibairo S.I. , Upadhyaya M.K. , Toivonen P.M.A.
Published: February 2019

Studies were carried out to understand the effects of moisture loss on water potential and root deterioration in carrot (Daucus carota L. `Eagle') roots during short-term storage. The roots were stored at various temperatures and relative humidities (RH) to provide 0.7 (low), 3 (medium), and 9 mbars (high) of water vapor pressure deficit (WVPD). Carrots at high WVPD lost the most weight, followed by those at medium and lowest WVPD. Water potential and osmotic potential of the carrot tissue at high WVPD did not change significantly up to 6 days, but decreased thereafter. There was no change in water potential and osmotic potential for carrots at medium and low WVPD. A significant quadratic relationship (P = 0.05, r = –0.764) between water potential and carrot root weight loss was observed. Relative electrolyte leakage increased over time in carrots at the high WVPD. At medium WVPD, relative electrolyte leakage did not change up to 6 days, but increased significantly thereafter. Carrots at the low WVPD did not change in relative electrolyte leakage. Relative electrolyte leakage and weight loss correlated positively (P = 0.05, r = 0.789). The results suggest that water stress during short-term storage causes tissue deterioration that may further increase rate of moisture loss and hence reduce the shelf life of carrots.
Inhibition of Galactolipid Biosynthesis in Tomato Pericarp at Chilling Temperature
Authors: Yu Hanling , Willemot Claude
Published: February 2019

We examined the relationship between reduced galactolipid content in tomato fruit at 4C and chilling injury. Galactolipid biosynthesis from 14C-acetate was compared in pericarp discs of cold-tolerant `New York 280' (`NY') and -sensitive `Early Cherry' (`EC') at 4C and 20C. Labeled lipids were separated by 2D-TLC. Labeled monogalactosyldiglyceride (MGDG) molecular species were hydrolyzed using a position-specific lipase; the fatty acids released were hydrogenated and separated according to chain length by reverse-phase TLC. At 4C, the relative amount of radioactivity was reduced in MGDG and enhanced in phosphatidylcholine (PC) in both cultivars, in comparison with labeling at 20C. In discs from fruit chilled for 6 h, labeling was similar in `NY' and `EC'. In fruit held at 4C for 8 days, labeling of MGDG was reduced and that in PC was enhanced to a greater extent in chilling-sensitive `EC' than in `NY'. The proportion of the MGDG label in eukaryotic species (i.e., the ratio in C18/C16 fatty acids in position sn-2), was less in `EC' at 4C than at 20C, even for fruit held at 4C for only 6 h. The ratio was little affected in `NY'. The data indicate that biosynthesis of eukaryotic MGDG was inhibited in tomato fruit at chilling injury-inducing temperatures.
Effects of Carbohydrate Loading on Sugar Profile and Respiration of Asparagus Spears during Storage
Authors: Silva Silvanda , Verlinden Sven , Herner Robert , Beaudry Randolph
Published: February 2019

Asparagus spears (Asparagus officinalis L.) were placed in solutions of six different concentrations of sucrose (0%, 1%, 2%, 4%, 8%, and 16%) plus citric acid at 0C for 24 h following harvest. The profiles of sucrose, fructose, glucose, and respiration rate along the length of the spear were evaluated throughout storage. The effect of carbohydrate loading on the rate of respiration, sucrose loss, and the shelf life of asparagus was determined. For all treatments, sugars decreased and respiration rate increased from the butt to the tip. The 4% sucrose treatment enhanced the sugar level in the tip ≈5-fold relative to the control. For the 8% and 16% treatments, sucrose tended to accumulate in the base. Spears loaded with higher sucrose concentrations had higher respiration rates than controls up to 3 h after loading. After this time, no significant differences were observed between treatments. For all treatments, respiration rates declined rapidly following harvest, stabilizing in ≈24 h. Weight gain and growth increased as the treatment sucrose concentration decreased. Solution uptake was enhanced by loading at lower humidity levels.
Quality Changes and Respiration Rate of Eggplant Fruits Infected with Phytophthora capsici L.
Authors: Garcia R. , Muy M. , Araiza E. , Báez M. , Siller J. , Diaz J.
Published: February 2019

Classic-type eggplant fruits collected at the packing line were stored at 21C to evaluate respiration, weight loss, and quality characteristics. Fruits were divided on two groups. One group was inoculated with Phytophthora capsici. Fruit size, postharvest changes in color, compositional characteristics, CO2 production, weight loss, and spread area of the disease were monitored daily. Fruit size at harvest ranged between 15 to 17 cm of longitude and 7 to 9 cm of diameter. Seventy two hours after inoculation (HAI) of the fruits with P. capsici, a significant increase on respiration was detected even before the fungus was visually present. After 144 HAI, respiration on infected fruits reached 49 ml CO2/kg per h, while healthy fruits achieved only 15.7 ml CO2/kg per h, reducing quality and shelf-life on rotten fruits. Firmness, titratable acidity, and pH showed a significant difference between healthy and infected fruits. pH on infected fruits change from 4.96 after 96 HAI to 6.91 after 144 HAI, while healthy fruits did not change in the same period. Results were closely related with time after inoculation. Forty-eight HAI, the surface affected was of 2.7 cm by 1.8 cm; while 168 HAI, the affected surface area increased to 12.2 cm by 13.4 cm, representing damage above 60% of the total surface of the fruit.
The Influence of Storage Duration on the Performance of Hydrocooled and Packaged Broccoli under Simulated Shelf Conditions
Authors: Toivonen P.M.A.
Published: February 2019

Broccoli (Brassica oleracea L., cv. Mariner) was harvested and the crop divided into four treatments; 1) “hydrocooled + no wrap”, 2) “hydrocooled + wrap”, 3) “not hydrocooled + no wrap”, and 4) “not hydrocooled + wrap.” Microperforated film (SM60, CryoVac) was used for the wrapped treatments. The broccoli was then placed in 1C storage. On day 3, samples of each of the four treatments were removed from storage and placed into a 13C room to simulate shelf conditions. Visual quality, weight loss, and respiration were monitored over 5 days at 13C. This shelf evaluation was repeated with broccoli samples that had been stored for 10 and 17 days at 1C. Hydrocooling had the greatest effect on shelf performance when broccoli was held in storage for only a few days. However, after a week or more of storage, wrap had the greatest effect on shelf performance. The shelf performance of the “hydrocooled + wrap” treatment was similar for all three shelf evaluations (i.e., after 3, 10, and 17 days of storage). The shelf performance of the other three treatments had significantly deteriorated by the 1st or 2nd week of storage. Broccoli in the “hydrocooled + wrap” treatment maintained the greatest firmness and the lowest respiration and water loss rates. Yellowing was not found to be a problem until a high degree of wilting had occurred. These results show that, with hydrocooling and wrapping, poststorage shelf performance of broccoli is stable for at least 2 weeks of storage at 1C.
Improved Control of the Main Pests in Pome-fruit Orchards of the Forest Steppe Zone in Ukraine
Authors: Khomenko I.I. , Granger Raymond L.
Published: February 2019

The purpose of this research was to develop an improved system of controlling the main pests in pome-fruit plantations without damaging beneficial insects and with a minimal negative effect of pesticides. Current methods of controlling a broad spectrum of pests and diseases were studied. Several variants of spraying regimens were tested. It was established that most of the damage to the fruit is caused by coddling moth and, to a lesser degree, by pear fruit moth on the one hand and mildew and scab on the other. The most-effective and least-harmful spraying regiments were identified.
Development of a Decision Support System for the Management of the Carrot Cercospora Blight
Authors: Riblaire Eric , Gauthier Laurent , Neel Thierry , Bourgeois Gaetan
Published: February 2019

In Quebec, the carrot Cercospora blight represents a major foliar disease. In carrot fields, it causes reductions in yields of up to 30%. The evolution of this disease can be predicted by considering the meteorological and biological parameters and by using expert knowledge. Disease management can be enhanced through the use of a computerized decision support system (DDS). The objectives of the project were: 1) to define a conceptual framework for the operation of a carrot protection module, 2) to integrate a model of Cercospora blight evolution within the framework, 3) to integrate and structure the information needed for the consultation of the DSS, and 5) to validate the recommendations of the module. The various components (knowledge base, database, simulation model) constitute an extension to an existing framework used for agricultural production management (SAGE). The latter is built using an object-oriented programming language (Smalltalk) and an object-oriented database management system. A fully operational version of the system was developed and will be tested during the summer of 1995. The developed system combines a Cercospora blight model and a set of rules that convey the expert's knowledge. These rules were formulated based on interviews with the expert. The nature and organization of the rules will be presented as well as a critical evaluation of the methodology and tools used to build the system.
Leaf Phenolic Variation in Malus sp.
Authors: Garcia M.E. , Rom C.R. , Murphy J.B. , Felton G.W.
Published: February 2019

The leaf phenolic content of 25 Malus species obtained from the National Germplasm Repository was evaluated. Two methods were utilized for determination of phenolic quantity and form. Total dihydroxy phenolic content was determined by spectrophotometric method using diphenlboric acid 2 aminoethyl ester as the reagent. These phenolics were quantified by using HPLC. Differences in phenolic quantity and type among the species were observed. This variation will be discussed in relation to apple–insect interactions.
Characterization of Rubus Germplasm at the Canadian Clonal Genebank
Authors: Macdonald P.J. , Luffman Margie
Published: February 2019

A collection of indigenous North American red raspberry (Rubus strigosus Michx.) was evaluated in an unreplicated field planting at the Canadian Clonal Genebank, Trenton, Ont. The accessions originated in British Columbia (B.C.) and the United States. Useful characteristics in the collection have been identified under B.C. conditions; however, field performance in Ontario has not been reported. Cultivars originating from B.C., Manitoba, and Ontario were included in the planting as standards. Overwintering injury ranged from slight to severe. Indigenous accessions were vigorous, with cane height comparable to standards; however, in some cases, primocane production was excessive. Most B.C. accessions flowered and fruited equivalent to, or earlier than, the earliest cultivar (`Boyne'), while R. strigosus from other locations were mid-season to late. Primocane fruiting was typical in B.C., but was not consistent in Ontario. Fruit were small, but had good color and structure. Accessions showed resistance to powdery mildew [Sphaerotheca macularis (Wallr.:Fr.)], but were very susceptible to late yellow rust [Pucciniastrum americanum (Farl.) Arth.].
Examination of Apple (Malus × domestica) Fruit Quality and Tree and Fruit Morphology using Molecular Markers
Authors: Conner Patrick J. , Brown Susan K. , Weeden Norman F.
Published: February 2019

Two half-sib populations (cross 1 = `Wijcik McIntosh' (WM) × NY 75441-67, and cross 2 = WM × NY 75441-58) were used to create maps for the parents and to find RAPD or isozyme markers for qualitative and quantitative traits. WM is a sport of `McIntosh' and is heterozygous for the dominant columnar (Co) gene for reduced branching. WM is of great interest in breeding because of the tremendous effect of the Co gene on many aspects of plant form. NY 75441-67 and NY 75441-58 are advanced selections with commercial fruit quality and resistance to scab (Vf resistance from M. floribunda). Traits examined included both tree (plant height, stem diameter, suckering, branching habit, leaf break, burr knot production) and fruit (size, shape, color, stem length, seed number) characters and fruit quality traits (pH, acid content, Brix). The conservation of RAPD markers in these closely related crosses will be examined and the usefulness of molecular markers to preselect for components of plant form and fruit quality will be discussed. Molecular markers will increase the efficiency of the apple breeding program by aiding the understanding and manipulation of complex genetic traits.
Promising Cultivars of Prunus divaricata for the Central Forest-Steppe Zone of Ukraine
Authors: Sydorchuk Larissa V.
Published: February 2019

Prunus divaricata has attracted attention as a commercial culture only recently, but it is in the process of becoming a valuable fruit culture in Ukraine, where it has been planted in an area of >3000 ha. P. divaricata bears fruit earlier during the 2nd or 3rd year after planting. Its fruits ripen earlier than that of plums and are consistently abundant, fairly large, of high-quality, rich in vitamins, and easy to transport. These fruits can be eaten fresh or processed The trees have a short dormancy period, which may account for their relatively poor winter-hardiness. The root system of P. divaricata is shallow and mainly located at a depth of 50 cm from the soil surface. Its vertical roots, however, reach a depth of 2 m or more. The young roots may freeze at ≈12C. However, winter hardiness of the different cultivars varies and is determined by their origin. P. divaricata blooms early, roughly at the time when the flowering of early apricots ends. Its flowers are less susceptible to late frosts than those of apricots. For pollination, three or four different cultivars are needed. Yields ranging from >70 to 80 kg have been reached at the seventh leaf stage with the following cultivars in central Ukraine: `Olen'ka', `Obil'na”, `Raketa', `Zhemchuzhyna', and `Vasylius'ka' (control standard).
Inhibition of Flower Senescence by 2,2'Dipryridyl
Authors: Knee Michael
Published: February 2019

Chelating agents were applied to petunia flowers to test for the involvement of apoplastic metal ions in ethylene-induced senescence. Compounds varying in polarity and charge were applied directly to the corolla prior to a 24-h treatment with 1 ppm ethylene. Charged and polar chelators were inactive. The only compound that inhibited senescence was 2,2'-dipyridyl, and there was evidence of cellular uptake of this compound. Fe2+ and Zn2+ did not reverse the inhibition of senescence by dipyridyl. Cu2+ as low as 0.1 mM reversed the effect of dipyridyl, but the time of senescence was independent of ethylene treatment. Dipyridyl caused a rapid shift in flower color from red to blue, but untreated flowers became more blue than dipyridyl-treated during 9 days. CO2 and ethylene production were stimulated by ethylene, but inhibited by dipyridyl applied before or after a 24-h ethylene treatment. Continuous ethylene treatments did not reverse the delay of senescence by dipyridyl.
Postharvest Ethylene Production and Sensitivity of Eight Specialty Cut Flower Species
Authors: Hedman Paul B. , Dole John M. , Maness Niels O. , Anderson Jeffrey A.
Published: February 2019

The postharvest biosynthesis of ethylene and CO2 was measured at 0, 12, 24, and 48 h after harvest and the effects of exogenous applications of 0.0, 0.2, or 1.0 μl·liter–1 ethylene for 20 h was observed on eight speciality cut flower species. Helianthus maximilliani (Maximillian's sunflower), Penstemon digitalis (penstemon), Achillea fillipendulina [`Coronation Gold' (yarrow)], Celosia plumosa [`Forest Fire' (celosia)], Cosmos bipinnatus [`Sensation' (cosmos)], Buddleia davidii (butterfly bush), and Weigela sp. (weigela) exhibited a climacteric-like pattern of ethylene production followed by a steady rise in CO2 production. Echinacea purpurea (coneflower) ethylene biosynthesis was not significant during the 48-h period after harvest. Vase life of coneflower, yarrow, celosia, cosmos, and butterfly bush was not affected by exogenous ethylene. Exogenous ethylene applications to Maximillian's sunflower, penstemon, and weigela resulted in flower abscission and decreased vase life, indicating that they are probably ethylene-sensitive cut flower species.
Rooting and Drought Resistance of Three Tall Fescue Cultivars
Authors: Fry J.D. , Upham W.S.
Published: February 2019

The relative drought resistance of turf-type tall fescue (Festuca arundinacea Schreb.) cultivars compared to forage-type cultivars has not been well-documented. Greenhouse and field studies were conducted between 1991 and 1994 to determine rooting potential and drought response of a slow-growing, turf-type tall fescue (`MlC18'), a turf-type cultivar with a moderate growth rate (`Mustang'), and a forage-type cultivar (`Kentucky-31'). In the greenhouse, rooting was determined in sand or calcined clay using clear, polyethylene root tubes 4 cm in diameter by 122 cm deep. Root length density (RLD) was measured for 0- to 30-, 30- to 60-, 60- to 90-, and 90- to 120-cm depths. No differences were observed in RLD at the 0- to 30-cm depth. At other depths, RLD of `Mustang” was generally superior to that of `K-31' and `MlC18'. During a 3-week dry-down in the field in 1994, `MlC18' exhibited greater drought stress and a higher canopy minus air temperature than other cultivars. Advantages afforded by reduced mowing of slow-growing tall fescue cultivars may be negated by reduced drought resistance.
Response of `Lisbon' Lemons to Irrigation Frequency in the Arizona Desert
Authors: Wilcox M.A. , Sanchez C.A. , Wright G. , Brown P.
Published: February 2019

The majority of citrus planted in southwestern Arizona are lemons. Lemons are generally more vigorous and usually produce higher yields than other citrus cultivars. However, under water stress, fruit size will be compromised and excessive fruit drop will occur. Limited information is available that addresses the issue of irrigation frequencies and the impact on fruit sizing of lemons. A field study was initiated in 1993 evaluate the response of `'Lisbon' lemons to various flood irrigation intervals. Irrigation intervals were based on soil moisture depletion (SMD), as calculated from frequent neutron probe soil moisture measurements. Individual treatments were irrigated when total SMD was 25%, 40%, 55%, and 70%, respectively. The experiment is a completely random design with four replications. Results indicate that both the most-frequent (25% SMD) and least-frequent (70% SMD) irrigation regimes produced negative results. Overall, the first year's results indicate optimal fruit growth and yield is achieved at 40% SMD.
Heritability of Resistance and Associations of Leaf, Pod, and Seed Reactions to Xanthomonas campestris pv. Phaseoli (DYE) in Common Beans
Authors: Ariyarathne H.M. , Coyne D.P. , Vidaver A.K. , Eskridge K.
Published: February 2019

The inheritance and heritability (H) of leaf and pods reactions and seed infection of common beans (Phaseolus vulgaris L.) to Xanthomonas campestris pv. phaseoli (Smith) Dye (Xcp) were studied in three crosses along with flower and stem color, and the association of reactions to Xcp in the plant organs. Recombinant inbred lines from the crosses `PC 50' × XAN 159, BAC 6 × HT 7719, and BelNeb 1 × A 55 were used. Quantitative inheritance patterns were observed for disease reactions in leaves, pods, and seeds. Stem and flower color were inherited qualitatively. Low to intermediate and intermediate H estimates were found for pod reactions when inoculated on the same time, allowing the infection to occur in a uniform environment. Intermediate to high H estimates were found for leaf and seed reactions to Xcp, respectively. Significant positive intermediate to moderately high correlations were found between the reactions to Xcp of the first trifoliolate with later-developed leaves and pods in all three populations. The moderately high genetic correlations between leaves and pods suggested that some common genes may control the reactions to Xcp in these plant organs. No association was detected between flower or stem color and reactions to Xcp.
Morphological and Biochemical Variability in Two-species Congruity Backcross (CBC) Phaseolus vulgaris × P. coccineus Hybrids
Authors: Anderson Neil O. , Ascher Peter D. , Hoover Emily E.
Published: February 2019

Two-species CBC hybrids between Phaseolus vulgaris and P. acutifolius exhibit transgressive segregation for seed color and patterning, root peroxidases, and seed proteins. CBC pedigrees between P. vulgaris and P. coccineus (differing for species-specific traits) were created to test whether variation would be similar or greater than with P. acutifolius. P. vulgaris `Soldier' (Vermont) × 2- and 4-way intraspecific P. coccineus accessions were used as parents. CBC1 through CBC3 were evaluated for segregation of species-specific genes. Hybrid breakdown was evident in all CBC generations, particularly nonflowering dwarf cripples. Transgressive segregants were found as early as CBC2. One individual was found that had crossovers for species traits: a determinate, red-flowered plant with P. coccineus flowers and P. vulgaris introrse stigmas. By CBC3, all of the variation reported for three-species CBC hybrids (P. coccineus × [P. vulgaris × P. acutifolius]) was evident.
Genetic Variation in Folic Acid Content of Red Beet Genotypes (Beta vulgaris L.)
Authors: Wang Min , Goldman I.L.
Published: February 2019

Governmental recommended allowances for folic acid have increased dramatically in recent years, especially for pregnant women. Red beet is an important vegetable source of folic acid; however, little is known about the extent of variation for native folic acid content in red beet genotypes. The objective of this investigation was to evaluate variation in folic acid content (FAC) among red beet hybrids (F1), inbred lines (IL), plant introductions (PI), and open-pollinated cultivars (OP). Eighteen genotypes, including 12 F1 and six OP, were evaluated in field experiments during both years. Averaged over years, highly significant differences among genotypes and between F1 and OP were detected. FAC ranged from 3.7 mg to 15.2 mg per gram dry weight. The FAC in OP was 13% higher than in F1. Thirty genotypes, including 13 IL and 17 PI, were evaluated in greenhouse experiments during 1993 and 1994. Highly significant differences among genotypes and between IL and PI were detected. FAC varied from 1.54 mg to 11.13 mg per gram dry weight. The FAC in IL was 43% higher than in PI. These results demonstrate an approximate 10-fold variation among red beet genotypes for FAC.
Preliminary Performance of Six Scab-resistant Apple Cultivars in Northwestern New Jersey
Authors: Cowgill Winfred P. , Maletta M.H. , Tietjen W.H. , Compton J. , Polk D. , Goffreda J.F.
Published: February 2019

Six scab-resistant apple cultivars, Enterprise (CO-OP 30), CO-OP 36, Liberty, Freedom, Nova-Ez-Grow, and NY-754 were propagated on M.26 EMLA. Trees were planted in 1990 in a randomized complete-block design with six replications, five trees per replication. `Empire'/M.26 EMLA was the control cultivar. Tree spacing was 3 m apart in the row and 6 m between rows. Trees were individually staked and trained to a modified spindle bush. Precocity, bloom counts, tree height and width, TCA, cumulative yield efficiency, and fruit quality have been determined annually. `CO-OP 36', `Enterprise', and `Liberty' had significantly higher cumulative yields in 1993–94 than the other cultivars. The same three also had significantly superior fruit quality characteristics. `Liberty' was the most precocious of the scab-resistant cultivars, very similar to `Empire'. `Liberty' was also the weakest-growing cultivar, followed by `Empire'.
Early Growth and Yields of Scab-resistamt Apple Cultivars
Authors: Crassweller R.M. , Greene G.M.
Published: February 2019

Apple scab is the primary disease that drives commercial pesticide recommendations; therefore, the use of cultivars that are resistant to this disease would help in reducing chemical inputs in apple production. To date, there has been only limited information on the performance of the scab-resistant apple cultivars. In 1990 and 1991, apple cultivars that are resistant to apple scab were planted at two sites in Pennsylvania, one site was the Fruit Research and Extension Center (FREC) in south-central Pennsylvania, and the other was the Horticulture Research Farm (HRF) in central Pennsylvania. Horticultural characteristics measured were trunk cross-sectional area (TCSA), flowering characteristics, yields, and fruit maturity. Trees at the FREC produced fruit 1 year earlier than those at HRF. `Enterprise'/M.26 has been the most-productive cultivar at FREC, as measured by average total weight of fruit per tree. At HRF, `CO-OP 26'/M.26 had been the most-productive cultivar. At the end of the 1994 growing season, `CO-OP 26' and `Williams Pride', both on M.26, are the largest trees as measured by TCSA at HRF. At the FREC, `Enterprise' was the largest cultivar.
Effects of Municipal Solid Waste (MSW) Compost Mulch on Growth, Yield, and Soil Analysis of Papaya (Carica papaya L.)
Authors: Ozores-Hampton Monica , Bryan Herbert H
Published: February 2019

Municipal solid waste compost was applied with a side delivery applicator on top of the bed as a mulch in May 1993, 6 months after transplanting at Homestead, Fla. Papaya (`Know You No 1') was grown with and without compost mulch. Compost was distributed on the surface of the bed ≈90 cm wide and 5 cm thick. There were no mulch effects on trunk diameter nor plant height. Plant height was affected by papaya sex 4 and 6 months after transplanting. Hermaphroditic plants were taller than female plants. There were no mulch effects on marketable yield per plant, marketable size, or number of cull fruit. Sex, however, influenced papaya size and total cull number. Hermaphroditic plants produced larger marketable fruit and more cull fruits than female plants. Lower plant mortality rates were found after 1.5 years in the mulched plants compared to unmulched plants. Soil and tissue analysis showed no differences in N, P, K, Mg, S, Mn, Fe, Cu, and B, except for Zn. Zinc contents in soil and tissue were higher in the mulched areas than unmulched areas.
Effect of Yield and Mite Infestation in Four Strawberry Cultivars due to Rowcover Application in a Subtropical Region
Authors: Rubeiz I.G. , Nadi K.M. , Farran M.T. , Freiwat M.M.
Published: February 2019

Yield and mite infestation were studied in `Chandler', `Milcin', `Milsei', and `Oso Grande' strawberry, as affected by floating rowcover application (R) inside a greenhouse in Beirut. Results showed that R reduced yield of all cultivars in comparison to noncovered (C) plants, primarily by the reduction in fruit number (P ≤ 0.05), during the winter and spring harvests. Cultivars varied in yield, irrespective of the cover treatment (P ≤ 0.05) and in yield distribution over the 4 months of harvest (P ≤ 0.05). The shading effect of R offset the slight rise in soil temperature it caused. Air temperature did not drop to a level that would stop plant growth. Red spider mite infestation started after rowcover removal. Mite adult, larva, and egg populations were comparable between the R and C treatments (P > 0.05). Miticide sprays were the effective way to control mites. It is recommended from this study not to use rowcovers on greenhouse-grown strawberries in the Mediterranean region.