bluuebunny/crossref_metadata_2025 huggingface dataset:
Aeration Criteria and Plant Response in Peat Substrate Amended with Six Sources of Organic Wastes
Authors: Nkongolo Nsalambi , Caron Jean , Gauthier Fabienne
Published: January 2019

Increasing rates (5%, 10%, 25%, and 40%, v/v) of six sources of organic wastes were substituted for peat to assess changes on the physical properties of peat–perlite media and the subsequent plant response. Wastes were both fresh and composted bio-filter, sewage sludge, and de-inked paper sludge. Geranium plants (Pelagornium ×hortum `Orbit Hot Pink') were grown in the media. Saturated hydraulic conductivity (Ksat) and air-filled porosity (AFP) were successively measured with a Cote infiltrometer and by time-domain reflectometry. Pore space tortuosity (PST) and gas relative diffusivity (Dp/Do) were calculated. Both physical and plant growth parameters were significantly affected by the source and rate of application of waste. Ksat (P = 0.0001, r = 0.937), AFP (P = 0.001, r = 0.984), PST (P = 0.0001, r = 0.935), Dp/Do (P = 0.0001, r - 0.872) linearly increased as the rate of waste increased in the media. However, plant height (P = 0.0001, r = 0.856), root dry weight (P = 0.0001, r = 0.994), and shoot dry weight (P = 0.0001, r = 0.963) either linearly or quadratically decreased as the rate of waste increased. Decreases in plant growth parameters were most likely due to high salinity of organic wastes.
Resistance in Tomatoes to Meloidognyne incognita and M. arenaria as Affected by Gene Mi Heterozygosity and Temperature
Authors: Abdul-Baki Aref A. , Haroon Sanaa A. , Chitwood David J.
Published: January 2019

The Mi gene, which is the only source of resistance to the root-knot nematodes M. incognita and M. javanica in tomatoes, is effective only at soil temperatures below 28C. This single dominant gene exists in a homozygous form in certain tomato cultivars, in a heterozygous form in others, and is lacking in others. It has also been introduced into heat-tolerant and heat-sensitive cultivars. The availability of such genotypes allows determining whether a) the homozygous form provides more resistance than the heterozygous form and b) heat tolerance protects the Mi gene at high-temperature stress. The results of in vitro tests using excised roots show that the resistance offered by the Mi gene in the homozygous or the heterozygous form to M. incognita and M. arenaria was the same. The presence of heat tolerance gene did not protect the Mi gene from losing its effectiveness above 28C.
Bacterial Angular Leafspot Disease of Strawberry: Search for Resistance
Authors: Maas John L. , Galletta Gene J.
Published: January 2019

Bacterial angular leafspot disease (BALD) of strawberry, caused by Xanthomonas fragariae, a slow-growing and often difficult pathogen to isolate from infected plants, is most commonly manifested as small discrete, angular, translucent lesions on leaves and sepals. As the bacteria infect systemically, plants may wilt and die. BALD has become increasingly important in North America and other strawberry-growing areas of the world. The systemic nature of the pathogen also is cause for concern with international shipment of strawberry plants, especially because there is no practical method for determining the presence of the bacteria in symptomless, infected plants, nor is there a practical method of chemical control. All cultivars of Fragaria × ananassa (8×) are susceptible to BALD, although a range of susceptibility is often apparent in plantings. Resistant genotypes have been reported among clones of F. virginiana (8×), F. moschata (6×), and F. vesca (2×). A program has been initiated to evaluate native octoploid and diploid strawberry germplasm for resistance to BALD.
Nucleotide Pools in Imbibing Tomato Seeds
Authors: Chohan Shahid N. , Brown Terence A.
Published: January 2019

HPLC was used to measure nucleotide pools in tomato seeds during the 3 h following imbibition in water. In dry seeds, nucleotides were predominantly in the form of monophosphates. During the first 2 h post-imbibition, the monophosphate levels declined and there were sharp increases in the amounts of diphosphates, followed by triphosphates. Between the 2nd and 3rd h, the di- and triphosphate levels continued to increase and the monophosphate levels began to recover, especially in the case of UMP—presumably the result of degradation of unwanted mRNAs left over from the maturation phase of seed development. The adenylate energy charge increased during imbibition and, within 3 h, reached a value close to that of normal active tissue.
Fatty Acid Composition of Plasmalemma Lipids Associated with Cold Tolerance of Sweetpotato (Ipomoea batatas L. Lam.)
Authors: Arambage Abesinghe , Garner James , Silva J.L.
Published: January 2019

Plasmalemma lipid fatty acid changes due to low temperature (12C) were observed in M521-1 and `Travis', chilling-tolerant and -sensitive, respectively, genotypes. Lipid fatty acid changes found in both genotypes after exposure to chilling included decreased palmitic acid (16:0) and an increased unsaturated: saturated fatty acid ratio. Changes detected only in the tolerant genotype were increased linoleic (18:2), linolenic (18:3) and erucic (22:1). Monogalactosyldiglyceride and phosphatidylglycerol were the only lipids with >50% of their fatty acids unsaturated; therefore, it was concluded that these lipids were involved in the chilling tolerance of M521-1. A reduction in arachidonic (20:4) on phosphatidylinositol from `Travis' exposed to 12C resulted in <50% unsaturation of this lipid. This change could be associated with the chilling sensitive response of `Travis'.
Shortening the Dormancy Period and Improving Germination in American Ginseng Seed
Authors: Hovius Marilyn H.Y. , Proctor John T.A. , Reeleder Richard
Published: January 2019

American ginseng seed is important as the primary source of propagation. Little is known about ginseng seed stratification and germination. The green seeds are harvested in August/September and stratified in boxes outdoors for 12 to 14 months. Then the after-ripened seeds are field-seeded; they germinate in the spring. Ginseng seeds undergo long dormancy periods caused by embryo dormancy and impermeable seedcoats. The objectives of this research are to shorten the dormancy period, increase the percent germination, and study the changes that occur during stratification using growth regulator and temperature treatments. Seeds stored at 15C from harvest to January and treated with 1000 ppm gibberellic acid (GA3) resulted in the most embryo growth, highest percent germination, and best growth after one growing season compared to 20C and no GA3. Tissue culturing immature zygotic embryos showed a requirement for GA3 (3–5 μM). Radicle growth may need an attached suspensor for development.
Cytological Modifications of Phytotoxicity Induced by Foliar-applied Urea-nitrogen in Citrus
Authors: Bondada B.R. , Romero-Aranda R , Syvertsen J. , Albrigo L.
Published: January 2019

Foliar applications of urea-nitrogen are widely used to alleviate N deficiencies in citrus; however, improper applications can cause serious foliar burn and loss of active green leaf area. Light (LM), transmission (TEM), and scanning (SEM) electron microscopy were used to characterize anatomical and ultrastructural details of foliar burn in citrus. LM examination of the burned leaf area showed collapsed adaxial and abaxial epidermal cells and plasmolysis of mesophyll cells that created large intercellular spaces. SEM showed wrinkling of both the adaxial and abaxial epidermal cells. TEM revealed cytoplasmic vacuolation, disruption of cellular membrane, degradation of grana, and appearance of large plastoglobuli, implying loss of physiological activity. In contrast, control leaves had turgid adaxial and abaxial epidermal cells and compact mesophyll cells with few intercellular air spaces.
The Fertilization of Day-neutral Strawberries in Quebec
Authors: Lamarre M. , Lareau M.J.
Published: January 2019

During 1993 and 1994, the day-neutral strawberry cultivar Tribute was subjected to two rates of N (50 and 100 kg–ha–1), four rates of K (0, 60,120, and 180 kg–ha–1), and three rates of Mg fertilization (0, 25, and 50 kg–ha–1) from June to September through trickle irrigation. The objective of this experiment was to determine the best N, K, and Mg fertilization rates in the production of day-neutral `Tribute' strawberry. The N treatments had no significant influence on yield and fruit size for the two years. We observed the same situation for K as for N. For Mg treatments, fruit size was increased by adding 25 kg–ha–1 during the first picking in 1993, and they had no effect in the second year. For both years, the Mg had no effect on the yield.
NPK Fertilization of Cilantro and Dill
Authors: Ranqappa Muddappa , Bhardwaj Harbans , Showhda Madeha
Published: January 2019

Two experiments, one each with cilantro and dill, were conducted during 1994 to determine optimum rates of N, P, and K fertilizers. In these experiments, `C1410' cilantro and `Bouquet' dill were direct seeded in three-row plots with 0.3-m spacing between rows. A seeding rate of ≈40 seeds per meter of row length was used. Data were recorded, 45 days after planting, on moisture content, chemical composition of foliage (contents of essential oils, protein, and ash), and fresh yield following 25, 50, 75, and 100 kg·ha–1 application of each nutrient (4 × 4 × 4 factorial). Nitrogen rates significantly affected moisture, ash, and fresh yield of cilantro and dill. Phosphorus rates significantly affected moisture content and yield of dill but not cilantro. The effects of K applications were nonsignificant. The optimum N rate for both cilantro and dill was 25 kg/h. The optimum rate of P for dill was 25 kg/h. The data indicated that N and P requirements of cilantro and dill are modest. Further details of these results will be presented and discussed.
Development of a Flavor Profile of `Gala' Apples Using OSME Sensory Technique
Authors: Plotto A. , McDaniel M.R. , Mattheis J.P.
Published: January 2019

`Gala' is an early season apple variety that has a distinctive aroma and flavor. Studies were conducted to identify volatile compounds that contribute to `Gala' aroma. `Gala' apples were harvested at optimum maturity in a commercial orchard. Volatile compounds were trapped on activated charcoal using dynamic headspace sampling and eluted with carbon disulfide. Odor profiles of the samples were determined using OSME, a method developed at Oregon State Univ. that combines gas chromatography and olfactometry with a time-intensity scale. Three trained panelists described odor characteristics of compounds eluted through a sniff port of a gas chromatograph. Compounds were identified by matching Kovats indices with those of standards and also by mass spectrometry. Butyl acetate, 2-methyl butyl acetate, and pentyl acetate were characteristic of `Gala' apple. Methyl-2-methyl butyrate, ethyl-2-methyl butyrate, pentyl acetate, and butyl-2-methyl butyrate carried apple-like descriptors.
Effect of Phosphorus Applied as a Controlled-release Fertilizer or Soluble Fertilizer to a Container Nursery Crop
Authors: Godoy Arleen , Cole Janet C.
Published: January 2019

Thirty commercially propagated bareroot cuttings and 30 cuttings with growing medium around the roots of Halwards' Silver Spiraea were fertilized with various phosphorus fertilizers to determine the effect of fertilizer type on P leaching and on plant quality. The following treatments were applied: 1) 100% controlled-release fertilizer (CRF) consisting of 22N–6P–14K; 2) 50% CRF consisting of 22N–3P–14K plus 50% soluble fertilizer (SF) consisting of 0N–46P–0K, triple superphosphate (TSP); and 3) 100% SF consisting of 22N–0P–14K plus TSP (0N–46P–0K). There was a significant plant by fertilizer interaction for leachate P content. Cuttings with medium and bareroot cuttings receiving 100% SF had a higher concentration of P in leachate; while the cuttings with medium receiving 100% CRF and 50%CRF/50%SF had lowest P concentration in leachate. Plants grown with 50%CRF/50%SF had larger root dry masses compared to the plants grown in 100% CRF and 100% SF. Plants grown in 100% CRF had the smallest stem dry masses compared to the other fertilizer treatments. Plants containing 100% CRF had a lower P concentration in the stems compared to plants containing 100% SF and 50% CRF/50% SF.
Wildflower Seed Source Affects Performance of Six Wildflower Species
Authors: Norcini Jeffrey G. , Aldrich James H. , Lilly John G. , Halsey Lawrence A.
Published: January 2019

Field plantings of six native wildflower species were established at five sites in 1997 from seeds derived from local native populations (local ecotype) and from seeds purchased from commercial sources outside of Florida (nonlocal ecotype). The species were Cassia fasciculata (partridge-pea), Coreopsis lanceolata (lance-leaf coreopsis), Gaillardia pulchella (blanketflower), Ipomopsis rubra (standing cypress), Rudbeckia hirta (black-eyed susan), and Salvia lyrata (lyre-leaf sage; cancer weed). They were evaluated once per month from June to Oct. 1997. Plantings were maintained as follows: no supplemental fertilization; irrigation as needed up until early April to ensure germination; no pesticides except to control fireants and weeds on the perimeter of the plantings; plots were handweeded as necessary. It was clearly evident from these evaluations that the local ecotypes generally were better adapted to north Florida conditions than were the nonlocal ecotypes. The most noteworthy differences were as follows: 1) the local ecotypes of Rudbeckia and Gaillardia had longer flowering periods than their nonlocal counterparts, 2) the local ecotype of Coreopsis flowered profusely while flowering of the nonlocal ecotype was sparse, and 3) the local ecotypes of Coreopsis and Salvia had less disease incidence than their nonlocal counterparts.
“Cold-Trapping” in Retractable Roof Structures To Avoid Spring Frost Damage of Container-grown Nursery Crops
Authors: Svenson S.E. , Bell N. , Henderson A.
Published: January 2019

Compared to film-covered quonset structures typically used for unheated cold protection of nursery crops in Oregon, unheated retractable roof structures can provide cooler day temperatures (lower average daily temperature, ADT) in late winter and early spring. Late winter and spring growth and flowering of six nursery genera (12 replicate blocks), and air temperatures, were studied when crops were cold-protected in a film-covered quonset structure compared to a retractable roof cold protection structure operated using predawn “cold-trapping.” Compared the quonset structures, retractable roof structures had lower daily maximum temperatures, lower ADT, and similar daily minimum temperatures. Shoot growth of all crops was delayed by 2 to 4 weeks, and flowering of Rhododendron `Hino Crimson' was delayed by 4 weeks, in the retractable roof structures. Erica `Irish Bells' had symptoms of cold-damage and did not flower when protected in the quonset structure, compared to no damage and full-flowering when protected in the retractable roof structure. Arctostaphylos had more leaf spots, and less growth in the quonset structures compared to the retractable roof structures. Our hypothesis is that the lower ADT in the retractable roof structures delays de-acclimation to cold temperatures (delaying vegetative and flower budbreak), providing extended protection to frost damage. Higher relative humidity and higher daylight temperatures in the quonset structures may leave the earlier new growth and flowering of nursery crops more susceptible to frost damage and disease infestations compared to the daily vented and cooler retractable roof cold-protection structures.
Effect of Antitranspirant and Fertilization on Flowering, Fruiting, and Biomass Production in `Early Girl' Tomato Plants
Authors: Gu Sanliang , Fuchigami Leslie H. , Cheng Lailiang , Guak Sung H. , Shin Charles C.H.
Published: January 2019

Seedling plugs of `Early Girl' tomato plants (Lycopersicon esculentum Mill.) were potted in peatmoss and perlite (60:40% by volume) medium, fertilized with 8, 16, 24, or 32 g NutriCote Total controlled-release fertilizer (type 100, 13N–5.67P–10.79K plus micronutrients) per pot (2.81 L), and treated with 0%, 2.5%, 5%, or 7.5% antitranspirant GLK-8924 solution, at the four true-leaf stage. Plants were tipped at the second inflorescence and laterals were removed upon emergence. Flowering of both clusters were advanced by higher fertilization rates and depressed by GLK-8924. Increasing rates of fertilization increased flower and fruit number of the lower cluster and fruit set of upper cluster. GLK-8924 had no effect on flower number, fruit number, and fruit set. Fertilization increased the biomass production of all plant parts while GLK-8924 reduced the biomass production of leaves and fruit only. Root and stem biomass was not influenced by GLK-8924. The effect of GLK-8924 on fruit dry weight was dependent on the position of the cluster and GLK-8924 concentration. Fertilization did not interact with GLK-8924 to influence flowering, fruiting, and biomass production.
Quantitative Seasonal Changes in Gross Turfgrass Morphometry
Authors: Wiest Steven C.
Published: January 2019

Photographs of turfgrass canopies were taken throughout Spring, Summer, and Fall 1997 at a height of 1.3 m using a 28-mm lens and film sensitive to either visible or infrared light. The species evaluated were warm-season Bermudagrass, buffalograss, zoysiagrass, and cool-season tall fescue. Color spectra of digitized photographs were obtained by first separating the hue, saturation, and intensity components of the color photo into separate 8-bit (256 gray levels) files. Calculations were then made on the basis of those color components. The infrared photos were scanned as 8-bit files without conversion. Greenup was indicated by a decrease in the frequency of hues between 0 and 50° (reds, browns, and yellows) and an increase in the frequency of hues between 50 and 100° (green and yellow-green). It is well-known that canopy reflectance in the green wavelengths is primarily a function of chlorophyll density, whereas reflectance of near-infrared radiation is indicative more of cell structure. More near-infrared radiation is reflected from leaf surfaces than is green radiation, and less infrared is absorbed by internal leaf structures than is visible radiation. Thus, it is possible to approximate canopy leaf area ratios by using both visible and near-infrared photographic measurements. Quantitative changes in visible and near-infrared canopy reflectances, leaf area ratios, and other morphometric parameters will be presented as a function of time of the year and species. The results demonstrate the utility of using this relatively inexpensive procedure to obtain quantitative measurements as a substitute for, or in conjunction with, subjective visual ratings of turfgrass plots.
Water-absorbent Packet Beneficial to Fresh-cut Honeydews
Authors: Bai Jin-He , Watada Alley E.
Published: January 2019

Fluid accumulation and moisture condensation were of a concern on the quality of fresh-cut honeydews in polymeric film-wrapped containers; thus, the effect of a water-absorbent packet in the container was evaluated. Honeydew cubes were placed in plastic trays with and without water-absorbent packet and sealed with polymeric film, which was either left intact or perforated with a needle. The samples were stored at 5 °C and visual quality score, color, texture (shear force) soluble solids, pH, and microbial count were determined after 4, 8, and 14 days of storage. Honeydew cubes in perforated film packages without the absorbent became unsalable on day 4, while those with a water-absorbent packet had salable quality on day 8 and were unsalable by day 14. Main detriment in salability was development of water-soaked lesions and deteriorated condition. There were less water-soaked lesions in cubes held in sealed film packages with or without an absorbent packet than in perforated film packages with an absorbent packet. Tissue breakdown occurred earlier in sealed packages without an absorbent packet than in packages with an absorbent packet. The absorbent packet retarded the decreasing Hunter `L' value, increasing hue angle (a/b), softening (shear force), and increasing pH. Sealed film retarded changes in color and in mesophilic bacteria, yeast, and mold population.. The oxygen in sealed packages decreased to 10% and carbon dioxide increased to 6% by day 14, which was not harmful to the tissue. These results indicate that the a water-absorbent packet was helpful in maintaining quality of honeydew cubes held in containers with sealed or perforated film.
Strawberry Cultivar Performance and Susceptibility to Tarnished Plant Bug Injury
Authors: Handley D.T. , Schupp M.A. , Dill J.F.
Published: January 2019

Twelve strawberry cultivars established in matted row plots in 1993 were treated with insecticides for tarnished plant bug or left untreated for the 1994, 1995, and 1996 seasons. `Honeoye', `Cavendish', and `Oka' had the highest yields of marketable fruit. `Jewel', `Chambly', and `Kent' had lower, but acceptable, yields. `Lateglow', `Blomidon', `Seneca, NY1424', `Settler', and `Governor Simcoe' had lower yields than other varieties. Tarnished plant bug populations were very low during the 1994 and 1996 seasons, and thus feeding pressure may have been too low for any differences in susceptibility between varieties to be expressed. In 1995, when tarnished plant bug feeding pressure was greatest, `Oka', `Cavendish', and `Honeoye' had the lowest injury levels. `Kent' and `Lateglow' had the highest levels of injury. Insecticide sprays significantly reduced the percent of injured fruit for most cultivars, but did not significantly increase the weight of marketable fruit harvested. This is due to injury being most prevalent on lower order, and thus smaller, fruit. Cultivars that produced high yields, had low injury levels, and had the least difference between sprayed and unsprayed treatments are most likely to have resistance to tarnished plant bug injury. `Oka', `Cavendish', and `Honeoye' were the most promising cultivars in this regard.
Shoot Regeneration and Reduction of Contamination of Date Palm (Phoenix dactylifera L.)
Authors: Mawlood Essam A. , Al-Juboory Karim H.
Published: January 2019

This experiment was conducted at the Zaffarania Experimental Station in Baghdad, Iraq. The seeds of date palm cultivars `Zahdy' and `Khastawy' were cultured on Murashige and Skoog (MS) medium containing 0.5 mg/L NAA and 2.0 mg/L BA. Seeds were treated with 10, 20, 30, and 40 pulses of excimer laser radiation. The results indicate that these seeds exhibited significantly less contamination than control. The highest percentage germination for both cultivars was obtained with explants trerated with 40 pulses excimer laser radiation. Compared to other treatments, the shoot regeneration was greater with seeds from the `Khastawy' cultivar. Scanning electron microscope showed regeneration occurred about 5 months after.
Exogenous Polyamine Application Improves Shoot Elongation In Hazelnut (Corylus avellana L.) Micropropagation
Authors: Nas Mehmet Nuri , Read Paul E.
Published: January 2019

Buds from newly developed shoots obtained from forced outgrowth of mature, unpruned field-grown trees of Corylus avellana L. were cultured in vitro on Murashige and Skoog (1962) medium and a Modified Driver and Kuniyuki (1984) medium containing different levels of N-6 Benzyladenine (BA) (1.5, 2.5, or 3.5 mg/L) supplemented with or without a combination of Putrescine (0.2 mM) + Spermidine (0.2 mM) + Spermine (0.05 mM). Shoot elongation varied among genotypes, media and treatment with/or without polyamines. The best shoot elongation occurred on modified DKW medium containing BA plus polyamines.
Induction and Culture of Apex of Axillary Shoots of Papaya in Vitro from Mature Field-grown Trees
Authors: Guzman S. , Jiménez J. , FarÌas J. , Löpez G.
Published: January 2019

The papaya (Carica papaya L.) is a tropical fruit tree grown in many coastal region of Colima. The experiments were conducted to optimize cultural requirements for induction and culture of shoot of C. papaya cv. Red Lady in vitro. The crown, fruits, and leaves were removed from 1-year-old trees in the field for stimulate growth of lateral shoots with application of 289 μM gibberellic acid solution along steam surface. Apex (2 × 2 mm) of the shoots induced were established in Drew and Smith (DS) medium containing 1 μM 6-benzylaminopurine (BAP) and 1 μM naphthaleneacetic acid (NAA). After 90 days of establishment, the explants were transferred to a multiplication medium consisting of DS medium containing different concentrations of BAP and NAA (0:0, 2:0.1, 2:0.5, 2.5:0.5 and 3:0.5 μM, respectively). Individual shoots were excised from the proliferating cultures and subcultured onto fresh medium at 30- to 40-day intervals. The shoot number induced of trees in the field was of 47.5 per plant. After three subculture of shoot the best multiplication factor per subculture (6.9) was when 2 or 2.5 uM of BAP and 0.5 μM of NAA were added to DS medium.
Performance of Peach and Nectarine Cultivars in the Gulf Coast Area of Alabama
Authors: Ebel R.C. , Dozier W.A. , Powell A.A. , Caylor A.W. , Nesbitt M.L. , McDaniel N.R. , Okie W.R.
Published: January 2019

There are a limited number of peach and nectarine cultivars available with chilling requirements that perform well in the Gulf Coast area of Alabama. A test planting of 40 peach and 13 nectarine cultivars was established in 1985 at the Gulf Coast Substation at Fairhope, Ala. The plot was prepared and trees grown according to commercial procedures. Blocks of four trees of each cultivar were planted on a 6 × 6-m spacing. Chill hours were calculated each year based on number of hours at or below 7.3 °C starting from and including the first 10 consecutive days a total of 50 h were accumulated to 15 Feb. Data collected included date of full bloom, first harvest date, and total yield. Fruit were measured or rated for skin color, attractiveness, firmness, stone freeness, pubescence, flesh color, dessert quality, shape, weight, percent with split pits, and occurrence of malformed sutures and extended tips. All cultivars were evaluated for 9 years (1987–1995). The peach varieties that performed best in order of harvest date were `Flordaking', `Texstar', `Suzi Q', `Starlite', `Sunbrite', `Junegold', `Bicentennial', `Brighton', `Magnolia', `Sunland', `La Feliciana', `Sam Houston', `Flavorcrest', `La Festival', `La Pecher', `Idlewild', and `Rio Grande'. The nectarine varieties that performed best were `Armking', `Sunlite', `Karla Rose', `Carolina Red', and `Rose-princess'.
Main Physiological Factors Affecting the Germination of Annona muricata L. Seeds
Authors: Corchuelo German , Villamil Hector
Published: January 2019

Dormancy and latency factors such as moisture content, temperature, growth regulators, and seed-coat affecting germination of the Annona muricata L., a tropical fruit, were studied. Three types of fruits were used with presence of stylar residues (medium and big size) and absent of stylar residues. The fruits were taken from 4-year-old trees, which were naturally pollinated. A complete randomized design was used for the study, with 50 seeds per experimental unit and four replications per treatment. The variables measured were days and percent of germination, and average germination velocity. The seed germination was affected by the moisture and oxygen content, because the structure of the seed and their high content of the lipid in there. The length of the germination period was determinated by the concentration of the exogen hormones applied, the temperature range, the kind of scarification used, the substrate utilized and the moisture content present during the assays. Highly significant differences were found among treatments. The optimal conditions for germination (97.5%) were: 30 °C of temperature, no scarification, sand as substrate, and 750 ppm of gibberellic acid. The average of days to germination was 24.5 days. No significant differences were found for the different kind of fruits used in this assay. The results showed that this species presented characteristics of recalcitrant seeds.
The Effect of Field Irrigation Practices on Disease Suppression in Zinnia elegans
Authors: Gombert Linda , Hamilton Susan , Windham Mark
Published: January 2019

The objective of this study was to determine if field irrigation practices affect the development and suppression of three diseases, alternaria blight (Alternaria zinniae), powdery mildew (Erisyphe cichoracearum) and bacterial leaf and flower spot (Xanthomonas campestris pv. zinniae), on Zinnia elegans. Many commercial growers will no longer produce this popular bedding plant and cut flower crop due to high incidence of these three diseases. Plants of 17 different varieties of Z. elegans were started from seed and transplanted into cell-packs to be grown on as bedding plants. They were later transplanted into the field and subjected to one of three watering regimes: natural rainfall plus overhead irrigation, natural rainfall plus sub-irrigation, and natural rainfall only. Weekly evaluations were performed to rate each variety on its susceptibility to disease based upon severity of infection as well as portion of plant affected. Results will be presented on irrigation method and its influence on disease susceptibility and resistance on the 17 varieties evaluated.
Assessing Organic Nitrogen Acquisition of Ericoid Mycorrhizae in Highbush Blueberry (Vaccinium corymbosum L.) Plants by Using an 15N Tracer
Authors: Yang Wei Qiang , Goulart Barbara L. , Demchak K.
Published: January 2019

The ability of mycorrhizal highbush blueberry plants to acquire soil organic nitrogen under different organic amendment regimes was investigated in a field experiment by using an 15N tracer. Plants inoculated with an ericoid mycorrhizal isolate from the genus Oidiodendron had lower leaf 15N enrichment than uninoculated plants, indicating mycorrhizal (M) plants absorbed more unlabeled soil nitrogen than nonmycorrhizal (NM) plants. The unlabeled nitrogen was presumably from soil organic N sources which might be less available to NM plants. M plants produced more plant dry weight and larger canopy volume, presumably as a result of improved N acquisition ability. In the study, the effect of pre-plant organic amendments on the growth of highbush blueberry plants was clearly demonstrated. The forest litter amendment produced higher dry mass than either the rotted sawdust amendment or no amendment. The rotted sawdust amendment produced the smallest plants. These results suggested that organic amendments with different C:N ratios might have affected soil N availability by affecting the N mineralization process. The implication of these findings in the production of highbush blueberry in mineral soils will be discussed.
Fruit Volatiles to Control Postharvest Rot of Stone Fruits and Pears
Authors: Skog L.J. , Murr D.P. , Digweed B.E.
Published: January 2019

Volatile compounds are ubiquitous in plants, giving fruits their characteristic aroma and flavor. There is increasing evidence that these compounds can protect plants from pathogenic organisms. In this trial ≈25 volatile compounds were tested for efficacy against Monilinia fructicola and Penicillium expansum. Both in vitro tests on agar plugs of actively growing pathogens and in situ tests on inoculated stone fruits and pears were conducted. The volatile compounds were grouped into three categories based upon fungicidal activity in vitro: highly effective (fungicidal concentration ≤100 M), moderately effective (fungicidal concentration between 100–200 M) and ineffective (fungicidal concentration >200 M). Highly effective compounds included: acetaldehyde, citral, 2-ethyl-1-hexanol, 2,exadienal, E-2-hexenal, 4-hexen-3-one, linalool, (E,E)2,4-nonadienal, E-2-nonenal, E-3-none-2-one, salicylaldehyde, and valeraldehyde. Moderately effective compounds included: (E,Z) 2,6-nonadienal, propionaldehyde, terpinene, butyl acetate, E-cinnamaldehde, hexanal, E-2-hexen-1-ol, Z-3-hexen-1-ol and isoamyl acetate. Ineffective compounds included: butyrolactone, ethanol, ethyl acetate, and methyl acetate. Effectiveness of the compounds varied with both strain and type of microorganism tested. Concentraions required for effective control were much higher when the compounds were tested on inoculated fruit. Phytotoxicity was a problem with some compounds.
Eggplant Variety Evaluation in West Central Florida
Authors: Howe T.K. , Waters W.E.
Published: January 2019

Eggplant (Solanum melongena) varieties and advanced breeding lines were evaluated in a full-bed polyethylene mulch system during Spring and Fall 1997. Yield and horticultural characteristics were assessed for eight entries in the spring and 13 in the fall. Spring: Highest U.S. Fancy yield from the two earliest harvests was 9.6 t·ha–1 from `Kiko' with a mean fruit weight of 0.64 kg and 1% of the total harvested fruit as cull quality. Highest U.S. Fancy yield from all five harvests was 31.2 t·ha–1 from PX 984 with a mean fruit weight of 0.50 kg and 16% cull fruit. Seasonal yields combining U.S. Fancy, U.S. No. 1, and U.S. No. 2 grades ranged from 11.4 t·ha–1 for `Special Hibush' to 47.3 t·ha–1 for `Neon', with four entries not significantly different than `Neon'. Fall: U.S. Fancy yields from the two earliest harvests ranged from 0.5 t·ha–1 for `Oria' to `Agora' (2.7 t·ha–1). Five other entries were not significantly different than `Agora' in early U.S. Fancy yield; `Orient Express', `No. 226', `Neon', `Ghostbuster', and `Vernal'. Greatest U.S. Fancy yield for all six harvests was produced by `Santana' with 25.7 t·ha–1, with a mean fruit weight of 0.45 kg and 14% cull fruit. Seasonal yields combining all grades ranged from 17.1 t·ha–1 for `Machiaw' to 41.2 t·ha–1 for `Santana', with six entries not significantly different than `Santana'.
Artichoke: A New Crop for Northwestern Mexico
Authors: Araiza-Celaya Gerardo , Grijalva-Contreras Raul L. , Lopez-Vilches Francisco , Rivas Victor Salvador
Published: January 2019

Vegetable production in the Caborca area is about 6500 ha ,and the main crops are asparagus, muskmelon, watermelon, and pea. However, our objetive was to evaluate the artichoke as a new crop for this area. We planted one 5-ha plot with `Esmerald'. The planting date was 18 Oct. 1996, and the distance between rows and plants were 1.0 m and 1.6 m (6250 plants/ha). During the first year of production, the first harvest was on 24 Mar. 1997, and the last harvest 10 May. There was a total of seven harvests, with a yields of 400 boxes/ha for table production and 23,000 heads/ha for industrial use. The was 497 dollars/ha, which is very low compared with other vegetables crops.
Tomatoes Remember being Brushed
Authors: Björkman Thomas , Garner L.C.
Published: January 2019

Tomato seedlings grown in close proximity elongate rapidly in a shade-avoidance response. A daily touch stimulus can eliminate the extra growth associated with shade avoidance. Experiments to determine how the touch stimulus is integrated were performed on tomato seedlings grown in plug trays 22 mm apart, starting when two fully expanded leaves overlapped between plants to induce the shade-avoidance response. The standard touch stimulus was applied by brushing the surface of the canopy 10 times each morning with a piece of Styrofoam sheet. This treatment reduced the daily growth rate from 7.7 to 5.8 mm/day, but quadrupling the dose further reduced growth only slightly (J. Amer. Soc. Hort. Sci. 121:894). The ability of the plants to sum individual stimuli was tested by varying the interval between the individual strokes. Intervals of 0.01, 0.1, 1 and 10 min all produced the same growth response. Thus, the individual strokes were perceived as a single stimulus. Had they been perceived as separate stimuli, long intervals would have increased the response. There was no refractory period of insensitivity following the stimulus; that would have reduced the response at longer intervals. The height reduction was directly proportional to the number of days that the treatment was applied, indicating that each day of treatment reduced the growth rate for only 1 day (from 5.9 mm/day to 2.7 mm/day). Thus, brief stimuli are integrated during the day and expressed as a reduction of growth the next diurnal cycle.
Production of Bareroot Roses Using Underground Drip Irrigation
Authors: Schuch U.K. , Karlik J. , Becker J.O.
Published: January 2019

The majority of rose producers in Kern County, Calif., use furrow irrigation to produce ≈50% of the rose plants in the United States. Two experiments were conducted to test the feasibility of producing bareroot roses using underground drip irrigation. Three rose (Rosa hybrida) cultivars, `Dr. Huey', `Manetti', and `Pink Simplicity', were used in both experiments. In the first experiment, drip tape was placed at a depth of 10, 20, 30, or 40 cm. After one growing season, plants irrigated with drip tape at 10-cm depth produced less shoot and total dry weight than plants irrigated with tape placed between 20 and 40 cm. `Manetti' was the most vigorous cultivar and produced ≈70% more shoot and total dry weight than the other two cultivars. In the second experiment, the plants of the three cultivars were spaced 15, 20, or 25 cm apart within the row and irrigated with drip tape placed at 20-cm depth. Total dry weight increased linearly with increased spacing of plants within the row. `Manetti' and `Pink Simplicity' produced higher shoot and total dry weight than `Dr. Huey' plants.
Mulch Type Influences Yield of Fall Tomato
Authors: Sterrett S.B. , Hohlt H.E. , Savage C.P.
Published: January 2019

Because of environmental concerns relating to the potential for surface runoff from plastic culture, the potential of six cover crops [pearl millet (Pennisetum glaucum), sorgham (Sorghum bicolor), cowpea (Vigna sinensis), buckwheat (Fagopyrum esculentum), soybean (Glycine max), and millet/cowpea combination was compared to a plastic mulch for fall tomato production in 1996. All cover crops were chemically desiccated prior to tomato transplanting. The use of plastic mulch significantly increased early marketable yield; soybean or millet/cowpea mulch significantly reduced the production of large fruit. Total marketable yield of cover crop mulches except millet/cowpea was similar to that of plastic mulch. In 1997, full (0.9-m) and narrow (0.45-m) plastic mulched beds were compared to desiccated millet or sorghum mulches or straw mulch applied at planting. Early marketable yield was greatest for straw mulch. Total marketable yield of straw and both plastic mulch treatments was significantly higher than that for desiccated mulches. Width of the plastic mulched bed did not significantly affect total marketable yield.
Enhancing Earliness in Peppers using Rowcovers and Water-filled Tubes
Authors: Rangarajan Anusuya , Ingall Betsy
Published: January 2019

Vegetable growers around New York State are using rowcovers and earlier planting dates to produce early peppers, due to the higher prices received compared to the main season. However, high temperatures often achieved under the tunnels can contribute to blossom abscission of peppers. Water-filled polyethylene tubes, which are placed underneath rowcovers, have been shown to moderate temperatures under low and high tunnels. These tubes of water, placed between or as near to plant rows as possible, under the tunnel, absorb heat during the day and radiate heat during the night. Two tubes, clear and black, were compared for impact on earliness of two varieties of bell pepper. Both tubes were 12″ flat diameter and filled with water to an 8″ flat diameter. Each bed had two rows of peppers, with the water tubes placed down the center. White, perforated plastic was placed over hoops to create row tunnels. Air temperature measurements in the tunnels indicated that both the clear and black tubes decreased the daytime temperatures compared to the tubeless tunnels. The black tubes absorbed more heat during the day. At night, both tubes were equally effective at providing a slight warming of tunnel canopy temperatures. However, clear tubes kept soil temperatures warmer at night and reduced overall soil temperature fluctuations. The black tubes showed no advantage for regulating soil temperature. No significant differences were detected for total yield among different water tubes or cultivars.

However, clear tubes contributed to a 30% increase in early yields, compared to control or black tubes. Economics of water tube use in early pepper production will be presented.
First-year Growth Response of Ornamental Trees to Municipal Wastewater Application
Authors: Jessen Brenda L. , Picchioni Geno , Mexal John G.
Published: January 2019

The U.S.–Mexico border region has experienced rapid population growth in the past 30 years, resulting in natural resource degradation and declining public health. Many U.S.–Mexico border municipalities have inadequate systems for dealing with their waste. A major concern is the threat posed by water pollution, particularly that caused by minimally treated and improperly disposed human wastes. Border wastewater systems need to reduce contaminants, as well as safely recycle nutrients. Existing technology supports the land application of wastewater to tree production for low-cost, low-technology wastewater purification. Chemical analyses of the wastewater has shown that the water possesses an EC of 2.7 to 3.0 dS/m and an SAR of 6 to 7 indicating both high total salinity and sodicity that are potentially damaging to most woody horticultural crops. This project, located in Ojinaga, Mexico, assesses first-year growth characteristics and survival of three fast-growing trees useful for pulpwood production, Eucalyptus camaldulensis (three clones), hybrid Populus spp. (three clones), and Robinia pseudocacia (seedling propagated) following application with saline wastewater. Significant variation in trunk cross-sectional area was exhibited among clones. Eucalyptus clones showing the greatest increase in trunk area growth also exhibited ≈80% dieback during the winter months. Preliminary data indicated that one of the Populus clones may be the best option for effective wastewater treatment and economic sustainability through the sale of pulpwood for Ojinaga and other U.S.–Mexico border communities.
Use of a Backcross Population to Target Genes Controlling Androgenesis in Potato
Authors: Boluarte Tatiana , Veilleux R.E.
Published: January 2019

Genes for anther culture response (ACR) need to be mapped to enable efficient transfer of the trait to unresponsive but agronomically desirable clones. The objective of this study was to find extremes for ACR in a segregating population to target genes controlling this trait using bulk segregant analysis. Populations resulting from backcrosses (BC) of a diploid interspecific clone [CP2: Solanum chacoense (chc: low ACR) and S. phureja (phu: high ACR)] to both parents were used to characterize two phases of androgenesis in a preliminary study: microspore embryogenesis and embryo regeneration. Among 24 plants from each BC, consistently high- and low-responding genotypes with regard to embryo production were identified. Low ACR clones in each BC produced from 0.0–0.1 embryos per anther (EPA), whereas high ACR clones in the chc and phu BC produced from 1.4–2.9 and 2.8–7.5 EPA, respectively. The frequency of embryos regenerating into plants ranged from 3% to 20% for the chc high EPA clones and 12% to 64% for the phu high EPA clones. Ploidy of regenerated plants was determined by flow cytometry. The frequency of monoploid regenerants among the high EPA clones ranged from 3.6% to 68%. Since these populations showed sufficient genetic variation for ACR, a series of statistically designed experiments were conducted to develop high and low ACR bulks. From four groups of phenotypically characterized PBC plants, a high ACR bulk (–x = 4.9 EPA; n = 14) and a low ACR bulk (–x = 0.12 EPA; n =9) were constructed.
Relationship Between Postharvest Longevity of Cut Flowering Stems and Intact Flowers of Greenhouse-grown Antirrhinum majus L.
Authors: Schroeder Kenneth R. , Stimart Dennis P.
Published: January 2019

Considerable variation exists in Antirrhinum majus L. (snapdragon) for postharvest longevity of cut flowering stems. We have seen a range of 2 to 16 d postharvest life of snapdragon inbreds used in our experiments when evaluated in deionized water. A correlation between longevity of intact flowers and cut flowers has been reported for roses and tulips. In an effort to test this relationship on snapdragons, plants from a short-lived (5 days) and long-lived (16 days) inbred were grown in a greenhouse at the Univ. of Wisconsin, Madison, in Spring 1997. Plants began flowering in Apr.1997. The first three florets on each plant were tagged when fully open and the date of senescence recorded for each individual floret. Results showed a significant difference in longevity of intact florets. Mean floret longevity of the short- and long-lived lines was 13 and 25 days, respectively (LSD0.05 = 1.03 days). This is an indication that selection for postharvest longevity of snapdragons may be done based on intact flower longevity.
Characterization of Glutamate-1-Semialdehyde Aminotransferase and Its Activity Throughout Tomato Fruit Development and Ripening
Authors: Finger Richard E. , Hannapel David J. , Gladon Richard J.
Published: January 2019

Glutamate-1-semialdehyde aminotransferase (GSAT) is a key enzyme in the regulation of chlorophyll biosynthesis and a plausible site to regulate chlorophyll loss during fruit development via a decrease in its activity. The primary objective of this research was to characterize GSAT from tomato fruit by varying substrate concentration and pH and to measure GSAT in various organs of the tomato plant. A secondary objective was to measure GSAT activity and chlorophyll concentration at 5-day intervals from 10 d to 60 d postanthesis during tomato fruit development and ripening. An optimum pH of 7.0 was found, and a maximum velocity (Vmax) of 2.3 nmol·g–1 of tissue and a Km of 119 mmol·L–1 were calculated for GSAT. Activity among organs was greatest at 3.84 nmol·g–1 tissue in leaves of 4-week-old seedlings, 1.67 nmol·g–1 tissue in fruits 15 days postanthesis, and below 0.70 nmol·g–1 tissue in roots, stems, and overripe fruits (65 d postanthesis). During fruit development, GSAT activity was greatest at 10 d postanthesis and declined to day 25. Activity increased from day 25 to a peak at day 40 and then decreased again during ripening to 60 d postanthesis. Total chlorophyll and chlorophyll a concentrations in tomato fruit declined throughout development and ripening with the greatest decrease between 10 d and 25 d postanthesis. Thus, GSAT activity may contribute to the control of chlorophyll concentration in tomato fruit from 10 to 25 d postanthesis when chlorophyll loss mirrors the decline in GSAT activity.
Effect of Potassium Permanganate-based Scrubber on Micro-environment Ethylene Levels and Tomato Ripening
Authors: Cheng Guiwen W. , Sargent Steven A. , Huber Donald J.
Published: January 2019

The effectiveness of a potassium permanganate-based ethylene scrubber on removing simulated package atmospheric ethylene and its effect on ripening of tomato fruit were investigated. In a closed system (glass jars) (fresh wt./container vol. ratio = 0.29) at 12 °C, ethylene released by tomatoes at the turning stage accumulated to 26 ml/L within 2 days [(CO2) = 9%] and 33 ml/L within 6 days [(CO2) = 14%]. Ethylene, however, was undetectable in head space of jars containing 8-g scrubber materials. In the presence of ethylene scrubber, respiration rates were reduced as indicated by the delay in CO2 accumulation. After holding at 20 °C for 6 days following a 16-day, 12 °C storage, deformation under 9.8 N was less in fruit with scrubber (2.9 mm) than fruit without scrubber (3.6 mm). Under a flow-through system, however, fruit surface color and deformation were similar with and without scrubber. The results indicate that an ethylene scrubber can slightly retard ripening of unripened tomato fruit stored in closed environment conditions.