bluuebunny/crossref_metadata_2025 huggingface dataset:
Low Oxygen Delays Budbreak of Apple Trees in Greenhouse and Prolongs Storage Life
Authors: Young Eric , Blankenship S.M.
Published: February 2019

Three percent oxygen significantly delayed and reduced budbreak of fully chilled apple (Malus domestica Borkh.) trees in a greenhouse. When ambient oxygen levels were restored, budbreak occurred normally. Apple trees stored under 3% ± 1% oxygen at 6C for 35 weeks had no detectable bud development in storage. Budbreak and subsequent shoot growth were normal after the trees had been removed from storage.
Isozymes for Cultivar Identification in Kiwifruit
Authors: Messina R. , Testolin R. , Morgante M.
Published: February 2019

The usefulness of isozyme banding patterns as genetic markers in kiwifruit [Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson] was investigated using starch gel electrophoresis. Fifty-four entries putatively belonging to seven female and two male kiwifruit cultivars were examined for 13 enzyme systems (AAT, ACO, GDH, G6PDH, IDH, MDH, ME, MNR, NDH, 6PGD, PGI, PGM, and SKDH). Four enzyme systems, ACO, MDH, NDH, and SKDH, showed identical banding patterns in all clones surveyed. Of the remaining enzymes, AAT, PGI, and PGM had the best discriminating power. Six enzyme systems (GDH, G6PDH, IDH, ME, MNR, and 6PGD), though showing polymorphic banding patterns, were poorly resolved. All the New Zealand cultivars were uniquely identified by the simultaneous comparison of the AAT, PGI, and PGM zymograms. Some enzyme systems were also polymorphic among plants within the same cultivar, thus proving the heterogeneity of kiwifruit material introduced into Europe in the early 1970s.
Epibrassinolide Does Not Enhance Heat Shock Tolerance and Antioxidant Activity in Moth Bean
Authors: Upadhyaya Abha , Davis Tim D. , Sankhla Narendra
Published: February 2019

Moth bean (Vigna aconitifolia Jacqu. Marecbal cv. Jaadia) seeds were germinated in 0, 0.1, 1, or 2 μm EBL. After 72 hours, seedlings were exposed to 22 or 48C for 90 minutes. At 48C, EBL increased total electrolyte, K+, and sugar leakage from the seedlings relative to the control. Following exposure to 48C, EBGtreated seedlings bad higher malondialdebyde concentrations than controls, indicating that EBL enhanced high-temperature-induced lipid peroxidation. At 48C, EBL increased ascorbic acid oxidase activity but decreased superoxide dismutase activity relative to the control. Taken collectively, these data do not support a hypothesis that brassinosteroids confer beat shock tolerance to moth bean. Chemical name used: 24-epibrassinolide (EBL).
Causes of Reduced Pathogen Tolerance in Pelargonium after Application of Silver Thiosulfate
Authors: Whalen Christa Stark , Wulster George J.
Published: February 2019

A silver thiosulfate (STS)-mediated increase in pathogen susceptibility was investigated using shoot cuttings from stock plants of pelargonium (Pelargonium hortorum Bailey cv. Ringo Scarlet) with and without STS treatment. Callusing and rooting were reduced in shoot cuttings from ST&treated plants. The pathogen-tolerant tissue (no STS) was shown to produce enhanced levels of phenolic esters and glycosides during wound healing. Reactivity to the histochemical stain phloroglucinol-HCL was also enhanced during wound healing in cuttings from plants that had not received a silver treatment.
Regeneration of Brassica oleracea from Peduncle Explants
Authors: Christey Mary C. , Earle Elizabeth D.
Published: February 2019

Peduncle explants from 12 Brassica oleracea L. lines representing five varieties [broccoli (italica), cabbage (capitata), cauliflower (botrytis), Chinese broccoli (alboglabra), and rapid-cycling B. oleracea] readily regenerated shoots in vitro. Average regeneration rates of more than 75% were obtained for most lines, with up to 35 shoots per explant. Shoots were visible within 7 to 10 days. Initial regeneration was polarized, occurring mainly from the basal end of explants. Linsmaier-Skoog-based medium containing 1 mg BA/liter was suitable for shoot regeneration from all 12 lines tested. Plants were rooted on hormone-free medium and transferred to soil. Chemical name used: benzyladenine (BA).
Elevated Microsprinklers Improve Protection of Citrus Trees in an Advective Freeze
Authors: Parsons Larry R. , Wheaton T. Adair , Faryna Nick D. , Jackson John L.
Published: February 2019

The severe advective freeze of 23-26 Dec. 1989 killed most nonprotected trees in Florida's northern citrus region. Minimum temperatures reached - 8.3C with >43 hours below freezing. Microsprinklers elevated to a height of 0.6 or 0.9 m and placed inside the canopy of young `Hamlin' and navel orange trees [Citrus sinensis (L.) Osb.] provided excellent protection to heights well above 1 m. Initial survival height of trees with emitters elevated to 0.9 m was higher than has been reported for microsprinklers at a conventional 0.2-m height in earlier severe freezes. Trees rapidly approached prefreeze canopy size from regrowth of the protected scaffold branches. Six months after the freeze, trees protected by microsprinklers elevated to 0.6 m and delivering 26 or 47 liters·hour-1 had regrown to a height of 1.4 or 1.7 m, respectively. Trees with microsprinklers at a height of 0.9 m and delivering 101 liters·hour -1 had regrown to a height of 2.5 m. Trees with no microsprinkler irrigation were killed to the ground. Twelve months after the freeze, trees with elevated microsprinklers were still significantly taller and showed greater recovery than those with microsprinklers near the ground.
Propagation of Peach Cuttings Using Foam Cubes
Authors: Avery John D. , Beyl Caula B.
Published: February 2019

Synthetic polyurethane foam cubes were evaluated as an alternative to conventional peat-based media for rooting of expanded nodal, semihardwood, and hardwood cuttings of peach [Prunus persica (L.) Batsch]. Semihardwood cuttings taken in August had higher rooting percentages in foam cubes than in either of two peat-based media. There were no differences in the number of root initials or lengths of roots among the three media. Semihardwood cuttings of 18 cultivars of peach and nectarine had a mean rooting percentage of 58% in the peat-perlite-vermiculite medium compared to 77% for those in foam cubes. There was no difference between rooting percentage or root grade for hardwood cuttings collected in October from either foam cubes or the peat-based medium. Although rooting percentages were lower for expanded nodal cuttings than for semihardwood or hardwood cuttings, there were no differences between the two peat-based media and the foam cubes.
Flower Bud Blast in Easter Lily Is Induced by Ethephon and Inhibited by Silver Thiosulfate
Authors: Mason Michael R. , Miller William B.
Published: February 2019

Interactions of ethephon and irradiance reduction were investigated in terms of flower bud blasting in Easter lily (Lilium longiflorum Thunb. `Nellie White'). Silver thiosulfate (STS) was investigated as an inhibitor of ethylene-induced bud abortion. Fourteen days of 92% irradiance reduction significantly increased bud abortion when plants were exposed to 2.1 mm ethephon. Bud abortion was 39% and 60% for plants grown in ambient and reduced irradiance, respectively. Silver thiosulfate was applied to plants 2 or 3 weeks after the date of the first visible bud, followed by ethephon treatment 2 days later. Bud abortion was significantly reduced by 1 or 2 mm STS, without phytotoxicity. Pretreatment with 1 or 2 mm STS as early as 4 weeks before ethephon exposure significantly reduced ethephon-induced bud abortion. Silver thiosulfate application could inexpensively reduce flower bud abortion during latter stages of greenhouse forcing of Easter lilies.
GA3 and Benzylaminopurine Delay Leaf Yellowing in Cut Alstroemeria Stems
Authors: Hicklenton Peter R.
Published: February 2019

Leaf yellowing of Alstroemeria hybrida L. `Rio' and `Jacqueline', as measured by sphere spectrocolorimetry, was significantly delayed in vase life studies when the ends of cut stems were immersed in solutions of BAP or GA3 immediately following harvest. When BAP or GA3 was used alone at 50 mg·liter-1, foliage color and color intensity did not diminish during 14 days of storage in tap water. BAP and GA3 also showed interaction effects on leaf color, but little was gained by using combinations of chemicals. Chemical names used: 6N-benzylaminopurine (BAP); gibberellin (GA3).
Fluctuations in Leaf Carbon Assimilation as Affected by Root-zone Temperature and Growth Environment
Authors: Ramcharan Christopher , Ingram Dewayne L. , Nell Terril A. , Barrett James E.
Published: February 2019

Short-term effects of root-zone temperatures (RZT) of 28, 33, 38, and 43C for 6 hours daily on container-grown Musa spp. (AAA) `Grande Naine' and Ixora chinensis L. `Maui' were determined under greenhouse and growth room conditions. Diurnal fluctuation of leaf carbon assimilation (LCA) was altered by treatments. In the growth room at 43C, the maximum LCA occurred about midday for banana, but not until afternoon in ixora. LCA was highest (0.53 mg CO2/m2 per sec) in banana with a 33C RZT under greenhouse conditions, while it was equally high (0.74 mg CO2/m2 per sec) at 33 and 38C in a growth room. In ixora, 33C induced the highest LCA (0.40 mg CO2/m2 per sec) in the greenhouse at 1200 hr, but there were no apparent differences in midday LCA between plants with RZT of 28, 33, and 38C in the growth room. Effects of RZT and environment on the daily fluctuations of gaseous exchange processes raise questions about using measurements at only one time during the day to separate treatment effects.
Effect of Ovule Damage on Fruit Development in Three Apple Cultivars
Authors: Proctor John T.A. , Schechter Ido
Published: February 2019

`McIntosh', `Delicious', and `Idared' apple (Malus domestica Borkh.) fruitlet ovaries were artificially damaged with a needle four times after full bloom to assess effects of such damage on fruit growth and development. The damage induced fruit drop, reduced fruit weight, and increased the incidence of fruit deformity, but had no effect on fruit length: diameter ratio. Fruit fresh weight and deformity were correlated with seed per fruit at harvest.
Calcium and Heat Treatments to Improve Storability of `Anna' Apples
Authors: Lurie Susan , Klein Joshua D.
Published: February 2019

Apples (Malus domestica Borkh. cv. Anna) were treated at harvest by a dip in 3% CaCI2 solution, heated for 4 days at 38C, or the two treatments combined, before being placed in OC storage. After removal of the apples from storage and holding them for 1 week at 20C, the combined treatment maintained fruit quality best. The fruit remained firmer than with either treatment separately, and peel yellowing and decreased titratable acidity caused by the heat treatment were less pronounced. Heat treatment alone maintained fruit firmness, while CaCI2 alone had no effect on fruit quality, although it raised the fruit calcium level more than the combined treatment in most experiments. Altering the temperature (0, 20, or 38C) of the CaCl2 dip did not change its efficacy. There was less soluble and more insoluble pectin in cell wall extracts of apples from the combined treatment than from other treatments. In addition, proportionally less Ca was present in the water-soluble pectin fraction of the combined treatment compared to other treatments, indicating different binding properties in the cell wall.
Postharvest Quality and Sensory Attributes of Organically and Conventionally Grown Apples
Authors: DeEll Jennifer R. , Prange Robert K.
Published: February 2019

Postharvest quality and sensory attributes of organically and conventionally grown `McIntosh' and `Cortland' apples (Malus domestica Borkh.) stored at 3C in ambient air or in controlled atmospheres were evaluated. Organically grown apples had higher soluble solids concentration than conventionally grown apples, while there were no significant differences in firmness or titratable acids content. Organically grown `McIntosh' were perceived by sensory panelists as firmer than conventionally grown `McIntosh' at harvest but not after storage, which may have been due to maturity differences. No significant differences were perceived in juiciness, sweetness, tartness, and off-flavor of apples at harvest or after storage.
Sampling Procedures to Estimate Flavor Potential in Onion
Authors: Randle William M.
Published: February 2019

Twenty bulbs from each of 10 onion (AIlium cepa L.) cultivars and one mass population were harvested from two locations and evaluated for three traits associated with flavor quality. Variance components for soluble solids content (SSC), pyruvic acid concentration (PAC), and percent S were calculated, and sampling schemes required to detect specific differences among treatment means were determined. In general, a five-bulb sample and four replications were sufficient to detect desired differences for SSC and PAC, whereas percent S required a larger sample size and more replications.
MINERAL ORE CO-PRODUCT (IRON OXIDE) AS A GROWTH MEDIUM COMPONENT
Authors: Goyette Garrett , Pill Wallace
Published: February 2019

The utility of Ironrich (IR), a tertiary mineral co-product from TiO2 production, as a growth medium component was investigated. All complementary bulking components (10 to 50% volume) gave reduced shoot fresh weights of tomato, impatiens or perennial ryegrass relative to Fairgrow (FG, co-composted solid waste and sewage sludge). Shoot fresh weights of impatiens and tomato grown in 50% IR with FG were similar to those grown in commercial peat-lites. When provided 200 mg N litre-1 daily, chard shoot fresh weights, beet root fresh weights, and tomato fruit fresh weights from plants grown in 50% IR plus 50% FG were not significantly different from those grown in 50% silt loam plus 50% FG. Tissue Cd, Cr, Ni, and Pb concentrations from plants grown in 50% combinations of FG with IR or silt loam were below the limits of detection. IR plus FG with N-P-K fertilization provided a satisfactory greenhouse growth medium. We project that IR + FG will constitute a satisfactory synthetic topsoil.
LATE PLANTING OF STRAWBERRIES IN THE HILL SYSTEM USING PLUG OR DORMANT BARE ROOT PLANTS
Authors: Lareau M.J. , Lamarre M.
Published: February 2019

Plug or bare root strawberry plants were planted on raised beds with black plastic mulch from mid-June to early-August. The early plantings gave the most developped and productive plants but these required several derunnerings to avoid overcrowding. Due to the unavailability of runners, it was not possible to establish plug plants before mid-July. Field losses of dormant bare root plants were high for the July planting. The use of a perforated polyethylene rowcover from October to May increased yield and fruit size.
SURVEY OF FIELD EXPERIMENTS CONDUCTED TO ESTABLISH MEDICINAL CROPS IN QUEBEC
Authors: Tremblay Nicolas , Michaud Marie-Hélène , Crête René , Gosselin André
Published: February 2019

With the increase in popularity of natural medicine there is an ever growing market for the production of medicinal plants. In the last decade, screening trials of a number of species were conducted. The species currently under study are: angelica (Angelica archangelica; biennial, roots harvested), thyme (Thymus vulgaris; perennial, shoot harvested), German chamomilla (Matricaria recutita; annual, flowers harvested), horehound (Marrubium vulgare; perennial, shoot harvested) and dandelion (Taraxacum officinale; considered as a biennial, roots harvested). In 1990 the species were grown on three soil types (clay-loam, sandy loam and histosol) with different fertilization and irrigation practices. In 1991 two distinct trials were undertaken. The first considered herbicide efficiency and planting density. The second dealt with «organic» management strategies. Depending on the species, treatments of compost amendment, plastic mulch and implantation techniques were compared.
APRT EXPRESSION IN PLANTS
Authors: Schultz David J. , Agarwal Sunita K. , Schaff Dennis A.
Published: February 2019

Adenine Phosphoribosyltransferase (APRT, EC 2.4.2.7) is an enzyme in the adenine salvage pathway. This enzyme is a catalyst for the conversion of adenine and phosphoribosyl pyrophosphate (PRPP) to adenosine monophosphate (AMP) and inorganic phosphate (PPi). We are using the APRT gene to develop a gene transfer selection system in plants because the APRT gene has been shown to be expressed in numerous plant families, the gene is small (approximately 3 kilobases), the enzyme pathway is well characterized, and positive selection systems are readily available for the presence or absence of the functional APRT protein. Additionally, an APRT assay system has been worked out for the detection of the protein product. In order to develop a gene transfer selection system, we are currently isolating the APRT cDNA clone from Glycine max L. (Soybean). The initial step of this research was to show what tissues of soybean the enzyme activity is found in by using the APRT assay. This assay showed that the enzyme is being expressed in the embryo, radicle, and developing seeds. Furthermore, the assay showed that there is no APRT activity found in immature or mature leaves of soybean. This may be due to an inhibitor in the leaf crude extract. When crude extracts of leaves and developing seeds are mixed in equal volumes, no APRT activity was detected in contrast to the half activity of developing seeds which was expected. Currently, our research has focused on isolating a fragment of the APRT gene from genomic DNA using the polymerase chain reaction (PCR). This fragment will then be used to isolate the cDNA clone from a Lambda Zap II cDNA library made from developing seeds.
WINTER-KILLED LEGUMINOUS COVER CROPS FOR SWEET CORN
Authors: Mangan Francis X. , Herbert Stephen J.
Published: February 2019

Field research was conducted in Deerfield, Mass. to study the effects of leguminous cover crops on sweet corn yield. Oat was planted alone and in combination with four leguminous cover crops August 8, 1990. Cover crop residue was disked once and sweet corn seeded April 23, 1991. Each cover crop combination had three rates of nitrogen added in two applications. Sweet corn seeded into stands of hairy vetch (Vicia villosa) yielded the highest of the cover crop combinations. All leguminous cover crop treatments yielded higher than oat alone or no cover crop when no synthetic nitrogen was added. Cover crop combinations were seeded again in the same field plots August 12, 1991. Oat biomass in November was greater where there had been leguminous cover crops or high rates of synthetic nitrogen. Legume growth was retarded in the plots that had previously received high nitrogen. It is thought that legume growth was reduced in the high nitrogen treatments due to increased oat growth and higher soil nitrogen levels which could inhibit root nodulation.
METHOD FOR MEASUREMENT OF GAS PERMEABILITY OF POLYMERIC FILMS
Authors: Gong Sannai , Corey Kenneth A.
Published: February 2019

A rapid steady state method for measurement of gas permeability of polymeric films was developed. Films were sealed between two equal volume chambers with pure O2 and pure N2 flowing through opposite sides. Oxygen concentration in the N2 cell was measured over time until steady state was reached. The method was used to determine oxygen permeability of two different films. Results from four replications on each film indicated excellent repeatability with coefficients of variation less than 3%. The time required to reach steady state oxygen concentration was dependent upon film type, flow rate, and temperature. The higher the N2 flow rate the shorter the time to reach steady state O2 concentrations. The slowest measurement at the lowest flow rate of 27 ml/min took less than 3 hours to collect the data necessary to achieve steady state. Increasing temperature from 10°C to 20°C resulted in an approximately 40% increase in O2 permeability for both films tested. The technique will be a valuable tool for measuring permeabilities of new films and the same film at different temperatures, and for selecting the appropriate material for modified atmosphere packaging of fresh produce.
Strawberry Cultivar Evaluation In Quebec
Authors: Khanlzadeh Shahrokh , Lareau Michel J. , Buszard Deborah
Published: February 2019

During 1987-90, nineteen strawberry cultivars and one selection from Agriculture Canada/McGill University were evaluated for their fruiting and other plant characteristics. Based upon an index of potential return which Integrates percent yield at each harvest date and total yield, the following cultivars listed in decreasing order of desirability (early productivity) are recommended: `Chambly', `Annapolis', `Honeoye', `Kent' and `Cavendish'. `Lina', `Lester', SJ83OR-2, `Bounty' and `Settler' have the most concentrated ripening period based upon an index of concentration. Highest yields were obtained with `Honeoye', SJ83OR-2, `Chambly', `Kent', Glooscap` and `Oka'. All had large, medium-firm fruit. Because of their tolerance to the herbicide terbacil and their large, medium-firm fruit, `Chambly', `Oka' and SJ830R-2 appear to be potential replacements for the commercial cultivars `Kent', `Honeoye' and `Glooscap' and are recommended for trials in Quebec. `Cornwallis', `Settler', `Midway', `Cavendish' and `Redcoat' had the lowest yield variability of the cultivars on trial.
Strawberry Cultivar Evaluation Using Mathematical Indices
Authors: Khanizadeh Shahrokh , Fanous Mamdouh A. , Lareau Michel J. , Buszard Deborah
Published: February 2019

Three mathematical indices were developed to estimate: a) potential for early dollar return or early ripening (IE), b) concentrated cropping (IC), and deviation or similarity of a genotype to known cultivars (ID). Early ripening genotypes with high yield early in the season will have larger IE values than late genotypes with lower yield early in the season. Genotypes with few harvests will have larger IC values than those requiring several harvests. The ID index helps to identify and group genotypes with similar characteristics. These indices condense large numbers of values or arrays of traits into single index values, thereby simplifying genotype comparisons.
SOUTHERN ROOT—KNOT NEMATODE: THE RACE PROBLEM AS RELATED TO BREEDING FOR RESISTANCE IN SWEETPOTATO
Authors: Dukes P. D. , Bohac Janice R.
Published: February 2019

There are four known physiological races of the southern root-knot nematode [Meloidogyne incognita (Kofoid & White) Chitwood]. Races are designated I through 4 and their identifications are based soley on differential hosts. These race problems as related to breeding sweetpotato for resistance to attack by all races are reviewed and discussed. Data are presented showing the reactions of selected cultivar and breeding clones of sweetpotato to all four races. The reactions of races 1 and 3 are generally well—known. Races 2 and 4 apparently are spreading and becoming more numerous in the southern states where soybean and tobacco are grown. Comparative disease indices are presented showing that generally sweetpotatoes were less susceptible to races 2 and 4. However, there were some notable exceptions, for example, `Sulfur' and `Beauregard' were equally susceptible to all races. High resistances to attack by races 2 and 4 were found in `Sumor', `Nemagold', `Excel', W-241 and others.
INFLUENCE OF CONTAINER SIZE AND TRANSPLANT SEQUENCE ON ROOT DEVELOPMENT OF TWO ILEX SPECIES
Authors: Knight Patricia R. , Eakes D. Joseph , Tilt Kenneth M. , Gilliam Charles H.
Published: February 2019

Stem cuttings of Ilex cornuta `Burfordii Nana' and Ilex × `Nellie R. Stevens', were direct stuck into cell pack, rose pot, quart pot, and trade gallon containers on March 4, 1991. Ten weeks and again at twenty weeks after sticking, rooted liners from cell pack, rose pot, and quart pot containers were transplanted into trade gallon containers. Thirty weeks after sticking, Nellie R. Stevens holly had a greater total root dry weight compared to Dwarf Burford holly. There were no differences in total root dry weight for any transplant treatment, but root distribution was influenced. Cell pack and rose pot liners transplanted twenty weeks after sticking showed a reduction in root growth in the root sector between the radius of a quart pot and a trade gallon pot. Shoot growth was also reduced for cell pack and rose pot liners that were transplanted into trade gallon containers twenty weeks after sticking.
NITROGEN RATE AND TIME OF SAMPLING EFFECTS ON SOIL TEST VALUES CF HIGHBUSH BLUEBERRIES GROWN ON A MINERAL SOIL
Authors: Clark John R. , Irvin Kelly M. , Maples Richard
Published: February 2019

Nitrogen rates (using urea) of 22, 67 and 135 kg/ha were applied to mature mulched and unmulched highbush blueberries over a 5 year period. Soil samples were taken each year at budbreak (prior to fertilization) and post-harvest at the suggested time of foliar sampling (approx. Aug.1) to determine N rate effects within and among years. Data analysis revealed that the most common soil test variables affected by N rate and date of sampling were pH, electrical conductivity (EC) and nitrate. For unmulched plants, a significant reduction in soil pH was found each year between budbreak and Aug. 1 for the 67 and 135 kg/ha rates, but not usually for the 22 kg/ha rate. For mulched plants, pH reduction within N rate among sample dates was usually not significant. Overall soil pH reduction was greatest for the 135 kg/ha rate over the 5 years, and the pH reduction for the 67 kg/ha rate was similar to the 135 kg/ha rate for the unmulched plants. For mulched plants, 22 and 67 kg/ha rates had a similar trend of only a slight pH reduction over the 5 years. EC and nitrate trends were very similar, with the highest levels of each on the unmulched plants.
EFFECTS OF BIWEEKLY TOPPING ON NUTRIENT CONTENT OF SHOOT TIPS AND STORAGE ROOT YIELD OF SWEETPOTATO GROWN IN A NFT SYSTEM.
Authors: David P.P. , Almazan A. , Bonsi C.K. , Mortley D.G. , Trotman A.A. , Carver G.W.
Published: February 2019

Studies were conducted in a greenhouse to determine the effects of harvesting sweetpotato (Ipomea batatas L. (Lam.) cv. “TI-82-155”) shoot tips (top 10 cm) at biweekly intervals beginning 42 days after transplanting on yield of storage root and nutrient content of harvested shoot tips. Plants were grown hydroponically from vine cuttings of 15 cm length, planted in 0.15 × 0.15 × 0.12 m growth channels using a closed NFT system. Nutrient was supplied in a modified half-strength Hoagland's solution with a N:K ratio of 1:2.4. Final harvest was at 120 days when shoot biomass and yield of storage roots were measured. Biweekly topping did not affect storage root yield or shoot biomass. However, harvesting time had a significant effect on dry matter and nutrient content of shoot tips.
EFFECT OF INOCULATION WITH AZOSPIRILLUM BRASILENSE ON FOLIAGE AND STORAGE ROOT YIELD OF SWEETPOTATO GROWN HYDROPONICALLY IN AN NFT SYSTEM
Authors: Trotman A.A. , Mortley D. G. , David. P.P. , Carver G.W.
Published: February 2019

The effect of inoculation of sweetpotato (Ipomea batatas L. (Lam.)) cultivar “TI-82-155” with Azospirillum brasilense was investigated in an observational greenhouse experiment. Sweetpotato was grown in a closed hydroponic system and plant nutrients were supplied in a Modified Half-strength Hoagland's solution (N:K 1:2.4) using a nutrient film technique system (NFT). Plants were either supplied with mineral nitrogen (160 ppm) and noninoculated or were supplied mineral nitrogen (160 ppm) and inoculated. Storage root dry matter was higher under inoculation with A. brasilense. Inoculation also increased the percent total nitrogen in the shoot, leaves, and fibrous root. There was a significant difference in fresh fibrous root weight for the inoculated (262.5 g) over the noninoculated (177.1 g) treatments. Mineral nitrogen supplied in the PNS was not limiting because dry matter for plants inoculated with A. brasilense was not significantly higher than for the noninoculated control.
REFLECTIVE PLASTIC MULCHES REDUCE APHID POPULATIONS AND THE SPREAD OF MOSAIC VIRUSES IN SUMMER SQUASH
Authors: Brown J.E. , Yates R.P. , Hogue W.T. , Stevens C. , Khan V.A.
Published: February 2019

Yellow crookneck `Dixie' hybrid summer squash, Cucurbita pepo L. var. melopeop Alef., was evaluated at E.V. Smith Research Center, Shorter, Alabama. Summer squash was grown in single rows spaced 6 feet apart. Plants were seeded 18 inches apart within 20-foot row plots. Treatments were: 1) black plastic mulch (BPM), 2) yellow painted plastic mulch (YPM), 3) white plastic mulch (WPM), 4) bare soil (BS), 5) aluminum painted plastic mulch (APM) and 6) bare soil with Diazinon insecticide (BSI). Aphid traps caught more aphids in BS or BPM plots than those from APM or YPM plots. The onset of mosaic disease incidence of squash infected with the two viruses identified as zucchini yellow mosaic and cucumber mosaic was delayed by as much as three weeks when compared to BSI or BS. Summer squash planted in APM, WPM, YPM and BPM produced 96%, 98%, 75% and 21%, respectively, more total squash yield than that produced on bare soil (control). A higher percentage of green squash (virus infected) was produced from plants grown over BPM (72%), BSI (68%), BS (59%), YPM (57%) or WPM (57%) than from APM (39%)
EPISODIC ROOT AND SHOOT GROWTH IN A WOODY ORNAMENTAL
Authors: Kuehny Jeff S. , Halbrooks Mary C.
Published: February 2019

Episodic growth is a term used to define alternate episodes of root and shoot growth. Fresh weight gain of Ligustrum japonicum roots and shoots was continuous through each episode of shoot elongation. Root:shoot ratio, however varied over time and oscillated with each episode of shoot elongation. During shoot elongation the percent fresh weight (of whole plant weight) allocated to the shoot decreased while the percent allocated to roots increased. During cessation of shoot elongation the percent fresh weight allocated to the shoot increased; while percent allocated to roots decreased. Formation of lateral roots was synchronous with shoot elongation.
PLANT EVALUATION AND INTRODUCTION AT THE TSU-McMINNVILLE NURSERY RESEARCH STATION
Authors: Witte Willard T. , Schlarbaum Scott , Sauve Roger , Flanagan Phillip C.
Published: February 2019

Since 1988, efforts have been underway to establish a nursery research station in McMinnville, Warren County, Tennessee. Approximately 80 acres of farm property adjacent to the Collins scenic river has been conveyed to Tennessee State University (TSU) for this purpose. Scientists at TSU, Tennessee Technological University, University of Tennessee, and USDA's National Arboretum and Shade Tree Laboratory have cooperated in obtaining grant funds via the Capacity Building Grants Program to initiate a plant evaluation and introduction program. Replicated trials of woody genera include Acer, Castanea, Cornus, Lagerstroemia, Quercus, Syringa, Ulmus. Herbaceous genera are Echinacea, Hemerocallis, Hosta. Plantings will be made over a three year period as infrastructure at the new station develops. Additional grant proposals have been recently submitted.
BETTERGRO BLACKEYE: A NEW PEST AND DISEASE RESISTANT HIGH YIELDING SOUTHERNPEA
Authors: Fery R. L. , Dukes P. D.
Published: February 2019

The Agricultural Research Service of the United States Department of Agriculture announced the release of `Bettergro Blackeye' southernpea on 24 July 1991. The new cultivar is well adapted for production throughout the southern United States where it can be expected to produce excellent yields of high quality, blackeye-type peas. `Bettergro Blackeye' outyielded the `Pinkeye Purple Hull-BVR' check in the 1986, 1987, 1988, and 1989 Regional Southernpea Cooperative Trials by 34.8, 14.3, 12.6, and 20.9%, respectively. Canned samples of fresh `Bettergro Blackeye' peas scored well in three years of quality evaluation tests. The new cultivar is resistant to the cowpea curculio, the major insect pest of the southernpea in southeastern production areas, and root knot, a severe root disease incited by several species of the root-knot nematode. `Bettergro Blackeye' plants have a greater tendency to produce a second crop than plants of most southernpea cultivars.
NITROGEN FERTILIZATION AFFECTS MUSCADINE GRAPES
Authors: Spiers James M. , Braswell John H.
Published: February 2019

Leaf concentrations of N, P, K, Fe, and Mn in `Sterling' muscadine grapes (Vitis rotundifolia Michaux) grown for 2 years in sand culture were not influenced by different N fertilizer sources. Leaf Zn and Cu were higher in plants receiving N as NH4NO3 rather than as (NH4)2SO4. Growth was greatest in plants fertilized with NH4NO3 compared to those with either (NH4)2SO4 or NaNO3 fertilization. Leaf Ca, Mg, Mn, and Cu content decreased linearly and leaf N increased linearly as N fertilizer rates were raised from 1.8 to 16.1 mM. Plant growth was a positively correlated with leaf N but was negatively correlated with leaf Ca, Mg, and Mn content. Percent Mg in the leaves was reduced when N levels, regardless of N source, were raised from the low (1.8 mM) to middle (5.4 mM) rate. High leaf N levels were correlated with lower Ca and Mg in the leaves, indicating a possible relationship between N fertilization and the late-season Mg deficiency often observed in muscadine grapes.
EFFECT OF MODIFIED ATMOSPHERE PACKAGING ON CARNATION
Authors: Pertuit A.J. , Vergano P.J.
Published: February 2019

Cut carnation (Dianthus caryophyllus) `White Sim' flowers from Columbia (South America), nontreated or dipped for three seconds in water or 9.5 g/1 benlate (DuPont) or 3336 (Cleary), were placed in “orchid tubes” and remained in air or were packaged in barrier bags of air or 10% CO2/10%O2 (80%N2). Postharvest life (days) was recorded, and the CO2, O2, and CH2=CH2 concentrations within the bags were monitored with gas chromatographs. Controls, nonsealed and in air, did not differ in postharvest life, indicating no benefit from a fungicide dip (P= 0.05). Botrytis was not observed in this test. Flowers sealed in bags did not differ in postharvest life (P= 0.05); however, when a single degree of freedom comparison was made (PR>F: 0.0001), their postharvest life was longer than controls (5.8 vs. 3.1 days). In bags, CO2 increased and O2 decreased over time, CO2 remaining higher and O2 lower with the 10%CO2/10% O2 treatment. CH2=CH2 increased to 4 ppm over 10 days, but ppm within bag treatments did not vary on any day (P= 0.05).
Phytotoxicity of Bentazon to Woody and Herbaceous Landscape Plants
Authors: Norcini J.G. , Aldrich J.H.
Published: February 2019

Eight species of low-growing woody and herbaceous landscape plants were evaluated for tolerance to 1.1 or 2.2 kg a.i. bentazon/ha (plus a crop oil) applied over the top twice 7 days apart. Raphiolepis indica L. Lindl. `Alba' was the only species tolerant to bentazon in either of two experiments. Bentazon injury to Liriope muscari (Decne.) L.H. Bailey `Evergreen Giant' was minor (slight chlorosis) and would probably be tolerable under most landscape situations. Injury (primarily chlorosis/necrosis) to Carissa macrocarpa `Emerald Blanket', Juniperus horizontalis Moench `Bar Harbor', Pittosporum tobira (Thunb.) Ait. `Compacta Green', Trachelospermum asiaticum (Sie-bold & Zucc.) Nakai `Aslo', Ophiopogon japonicus (Thunb.) Ker-Gawl., and Hemerocallis × `Aztec Gold' was significant and therefore unacceptable. Chemical name used: 3-isopropyl-1H-2,1,3-benzothiadiazin-(4)-3H-one 2,2-dioxide (bentazon).
Sodium Ameliorates the Effect of Potassium Deficiency in Cauliflower Leaves
Authors: Sharma C.P. , Singh Sandhya
Published: February 2019

Cauliflower [Brassica oleracea (Botrytis Group) cv. Pusi] grown in refined sand with 0.01 normal K supply had lower dry matter and tissue concentration of K than the controls and developed visible symptoms characteristic of K deficiency. Compared with control plants, the laminae of K-deficient plants contained significantly higher concentrations of sugars and nonprotein N and significantly lower concentrations of starch and protein N. However, the midribs of K-deficient leaves contained more protein N than leaves of control plants. Substitution of K by Na resulted in increased Na concentrations in leaves and recovery from the K-deficiency effect on the carbohydrate and N fractions. Maximum response to sodium was found in the intercoastal-lamina of K-deficient plants.
Interpretation of Light Quality Measurements and Plant Response in Spectral Filter Research
Authors: Rajapakse Nihal C. , Pollock Robert K. , McMahon Margaret J. , Kelly John W. , Young Roy E.
Published: February 2019

Experiments were conducted to correlate the response of chrysanthemum [Dendrathema ×grandiflorum (Ramat.) Kitamura] plants to light environment based on various quantitative light quality parameters by growing plants under 6% or 40% CuSO4 and water spectral filters. Using a narrow band width (R = 655-665 and FR = 725-735 nm) or a broad band width (R = 600-700 and FR = 700-800 nm) for R: FR ratio calculation, 6% CuSO4 filter transmitted light with a higher R: FR ratio than 40% CuSO4 or water filters. Light transmitted through 40% CuSO4 and water filters had similar narrow band R: FR ratios (≈1.2), but the broad band R: FR ratio (2.0) of 40% CuSO4 filter was higher than that of water filters. The estimated phytochrome photoequilibrium (ϕ) value varied considerably with the photochemical properties of phytochrome used for estimations. Final height and internode length of plants grown in 6% or 40% CuSO4 chambers was ≈30% less than of plants in corresponding control chambers. Leaf and stem dry weights were reduced by light transmitted through CuSO4 filters. The results suggest that broad band R: FR ratio correlated more closely to above plant responses than the narrow band R: FR ratio. Blue (B): R and B: FR ratios (not absolute amount of blue wavelengths) correlated well with plant response, suggesting that involvement of blue light should not be ignored in expressing plant response to light transmitted through CuSO4 filters. At present, the presentation of complete spectral data would be the most useful in explaining plant response to light environment.
PHOTOSYNTHETIC INHIBITION OF MAGNOLIA GRANDIFLORA `ST. MARY' LEAVES BY SUPRAOPTIMAL ROOT-ZONE TEMPERATURES
Authors: Martin Chris A. , Ingram Dewayne L.
Published: February 2019

Leaf photosynthesis of Magnolia grandiflora `St. Mary' (13-month-old rooted cuttings) was studied when tree roots were exposed to 28, 35, or 42 ± 0.8C for 8 weeks. Root-zone temperature (RZT) treatments were sustained for 6 hours per day by an electronically controlled root-heating system. The experiment was conducted in a 3×7.5-m walk-in growth room. Growth room irradiance was supplied by eighteen 1000-W, phosphor-coated metal-arc HID lamps (photosynthetic photon flux = 600 μpmol-2·-1 at canopy height) for 13 hours daily augmented with 3 hours of incandescent light during the dark period. Leaf C assimilation (A) at an RZT of 42C decreased linearly over 8 weeks compared to leaf A at RZTs of 35 and 28C. Leaf A was similar for all trees at week 1; however, leaf A at an RZT of 42C was 30% and 34% less than at RZTs of 3.5 and 28C, respectively, at week 8. Stomatal conductance at RZTs of 28 and 35C increased linearly over 8 weeks compared to conductance at a RZT of 42C. Intercellular CO2 levels were not affected by RZT treatments. This finding suggests that reductions in leaf A were nonstomatal. Photosynthetic inhibition resulted in reduced shoot and root growth. Operators of outdoor container production nurseries should implement cultural practices that minimize exposure of tree roots to RZTs >35C.
VIABILITY AND GERMINATION TESTS OF FRINGED GENTIAN, GENTIANA THERMALIS (O. KUNTZE) ILTIS
Authors: Cochrane Joan , Hughes Harrison , Zizz James D.
Published: February 2019

Fringed gentian, Gentiana thermalis (O. Kuntze) Iltis is an attractive wildflower, that may be used as a fall flowering ornamental. This species has received limited attention in terms of seed viability and germination. Seeds were subjected to a tetrazolium viability test that involved imbibition for 24 hours at 22C. No embryos in any line tested were stained. However, imbibition at 3C for up to 4 weeks followed by staining at 22C resulted in significant levels of positive viability, as indicated by embryo staining. A germination study indicated that stratification was necessary for germination, with 6 weeks chilling giving better results than 0 or 3 weeks. However, the number of seeds germinated was less than expected, given the results of the tetrazolium test.
ENDOGENOUS PRODUCTION OF RAFFINOSE FAMILY OLIGOSACCHARIDES INCREASES DURING THE FIRST STAGES OF COLD ACCLIMATION IN SEVERAL WOODY PLANTS
Authors: Esensee V. , Remmele R. , Stushnoff C. , McNeil M.
Published: February 2019

Woody plants can be induced to cold-acclimate by exposure to sublethal low temperatures, but only after the onset of vegetative maturity. We monitored seven woody plant taxa, at monthly intervals, to determine the date of vegetative maturity, freeze-killing temperature, cell membrane electrolyte leakage, and the quantity and diversity of endogenous oligosaccharides. The freeze-killing temperature changed from -5 to -7C before vegetative maturity to -15 to -20C after vegetative maturity. There was a 10-fold increase in raffinose and about a 3-fold increase in endogenous stachyose in samples that were cold-acclimated under controlled conditions. In field samples, endogenous raffinose increased from <0.02% in August to 2% to 11% in cortical stem tissues of all cold-acclimated taxa. The tetrasaccharide stachyose increased from <0.02% to 0.25% to 2.5% for similar comparisons. None of the other sugars or polyols showed similar, consistent patterns during the onset of cold acclimation. In response to low temperature, raffinose family oligosaccharides (RFOs) have previously been shown to increase substantially in cabbage, soybean, kidney bean, and Chlorella. RFOs also possess high water-binding characteristics and tend to enhance aqueous glass transitions. Accordingly, we hypothesize that the endogenous production of these oligosaccharides may play an important role in metabolic events associated with cryoprotection of critical cellular functions during low-temperature stress.
RELATIONSHIP BETWEEN PUNGENCY, SOLUBLE SOLIDS, AND SUSCEPTIBILITY TO NECK ROT IN ONIONS
Authors: Thornton Michael , Torell James , Richardson Daryl
Published: February 2019

A field study was conducted to determine the relationship between pungency, soluble solids content, and susceptibility to neck rot in onions. `Golden Cascade', `Sweet Amber', `Valdez', and `Vega' onions were planted in a field with low soil S content. Sulfur, as coarse-ground calcium sulfate, was applied as a band before planting. After harvest, yield was determined and a sample of jumbo onions was taken from each plot to determine pungency, dry matter content, and soluble solids content. Healthy bulbs were returned to storage and evaluated for neck rot after 4 months. Yield, grade, and neck rot incidence after storage were not affected by S treatments. However, there was a trend toward lower neck rot incidence at the highest S application rate (160 lb/acre). Pungency of jumbo onions increased after the application of S as gypsum. `Sweet Amber' and `Valdez' were less pungent than `Golden Cascade' or `Vega'. Neck rot susceptibility was evaluated with an inoculation test of detached bulb scales. Growth and sporulation of the neck rot pathogen Botrytis allii were reduced by S application. Pungency and neck rot susceptibility were negatively correlated.
Effect of Nitrogen Source and Timing on Highbush Blueberry Performance
Authors: Hanson Eric J. , Retamales Jorge B.
Published: February 2019

`Bluecrop' highbush blueberries (Vaccinium corymbosum L.) received various N fertilizer treatments for 5 years. Treatments were evaluated by measuring berry yields and leaf N levels annually and bush size after 5 years. Nitrogen fertilizers increased yields and leaf N levels compared with nonfertilized controls. Split applications of urea (half applied at budbreak, half at petal fall) resulted in 10% higher yields than the same amount in a single application at budbreak. Urea and two controlled-release fertilizers (CRF) with different dissolution rates (3 to 4 months, 8 to 9 months) resulted in similar yields and leaf N levels when compared at the same rate of N. The dissolution rate of the CRF materials did not affect yields or leaf N levels.
A Rapid Method for Determining Physical Properties of Undisturbed Substrate
Authors: Niedziela Carl E. , Nelson Paul V.
Published: February 2019

A new tube method for determining physical properties in container substrates was compared to an existing system. While both offer the advantages of undisturbed substrate and measurement of properties without altering the geometry of the substrate in the container, the tube method is easier to conduct. Both methods proved equally effective for determining air-tilled porosity, container capacity, total porosity, bulk density, and particle density.
Fresh Nectarine Quality and Methyl Bromide Residues after In-package Quarantine Treatments
Authors: Hinsch R.T. , Harris C.M. , Hartsell P.L. , Tebbets J.C.
Published: February 2019

California nectarines [Prunus persica (L.) Batsch. var. nectarina (Ait) Maxim.] packed in single-layer corrugated fiberboard boxes were fumigated with methyl bromide (MB) at a rate of 48 g·m-3 for 21 hours at 21C and normal atmospheric pressure and a 50% load (v/v) as a quarantine treatment for codling moth (Cydia pomonella L.). When the boxes were loosely stacked with spaces between them or tightly stacked and forced-air fumigated, concentration multiplied by time (C × T) relationships were > 68 g·m-3·h-1, which is recommended for efficacy. Tightly stacked boxes that were not forced-air fumigated had C × T products <68 g·m-3·h-1. Organic bromide residues were <0.001 μg·g-1 and inorganic bromide residues were < 7.0 μg·g-1 after 3 days. A trace to slightly phytotoxic response was observed in `Summer Grand' and `Fantasia' nectarines in 1989 but not in 1990.
Application of Dormant Oil to Peach Trees Modifies Bud-Twig Internal Atmosphere
Authors: Deyton Dennis E. , Sams Carl E. , Cummins John C.
Published: February 2019

Treatments of single applications of 0%, 3%, 6%, 9%, or 12% dormant oil were sprayed on peach (Prunus persica L. Batsch) trees on 6 Feb. 1990. A repeat application of 6% oil plus 6% oil applied 6 days later was also made. Internal CO 2 concentrations of oil-treated buds and twigs were higher than the control the day after treatment and continued to be higher for 6 days. The second application of 10% oil prolonged the elevated CO2 concentration. Applications of 9% or 12% oil delayed flower bud development and bloom. The repeated application of 6% oil delayed bud development and bloom more than a single application of 6% oil. Damage to fruit buds increased as oil concentration increased, but repeated application of 6% oil resulted in less damage than a single application of 12% oil.
Improved Production Procedures for Somatic Embryos of Sweetpotato for a Synthetic Seed System
Authors: Chée Raymond P. , Cantliffe Daniel J.
Published: February 2019

Embryogenic callus of sweetpotato [Ipomoea batatas (L.) Lam.] disassociates in liquid medium to form a heterogeneous population of embryogenic and nonembryogenic cell aggregates of varying sizes. To improve embryo production, such cell aggregate populations were obtained by manually fragmenting calli 5 to 10 mm in size into liquid medium. The resulting suspensions were analyzed and the embryogenic fraction identified. The percentage of embryogenic aggregates and the percentage of aggregates forming embryos decreased with decreasing aggregate size. Thus, 76% of the 710- to 1000-μm-diameter aggregates but only 14% of the 180- to 250-μm aggregates had embryogenic potential. However, only 20% of the 710- to 1000-μm aggregates and only 2% of the 180- to 250-μm aggregates actually formed embryos. Conversely, embryogenic callus and embryo production per milligram of cultured embryogenic callus increased quadratically with decreasing aggregate size. Individual torpedo-stage embryos were produced from cell aggregates 180 to 250 μm in size.