bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Markers Associated with Morphological Traits in Watermelon
Authors: Hawkins Leigh K. , Dane Fenny , Kubisiak Thomas L.
Published: February 2019

Morphological traits were examined in an F3 generation derived from a cross between C. lanatus var. lanatus [(Thunb.) Matsum. & Nakai] and C. lanatus var. citroides. At least three genes, C (yellow) vs. c (red), i (inhibitory to C) vs. I (non-inhibitory to C), and y (yellow) vs. yw (white), with epistatic and inhibitory actions were found to govern the inheritance of fruit flesh color. The high frequency of yellow-fleshed fruit and low frequencies of white and red fruits can be explained by the presence of a new allele (yw recessive to y) in the multiple allele series at the Y locus. The low frequency of tan colored seeds in segregating populations could be explained by at least three genes governing inheritance of seed-coat color. Single factor analysis of variance was conducted for each pairwise combination of random amplified polymorphic DNA (RAPD) locus and fruit or seed characteristics. Several RAPD loci were identified to be loosely linked to morphological characteristics.
Preculture Conditions Influence Cold Hardiness and Regrowth of Pyrus cordata Shoot Tips After Cryopreservation
Authors: Chang Yongjian , Reed Barbara M.
Published: February 2019

Cold hardiness and cryogenic survival of micropropagated pear (Pyrus cordata Desv.) shoots were evaluated after pretreatments with ABA and sucrose. Shoot cold hardiness increased by 3 °C, and cryopreserved shoot tip growth increased by 17% after a 4-week 150 μm ABA pretreatment. Low temperature (LT) pretreatments improved the recovery of cryopreserved P. cordata shoot tips. Six to 10 weeks of LT were required for reaching high cryopreservation recovery. ABA and LT treatments produced significant synergistic effects on both cold hardiness and cryopreservation recovery. ABA shortened the LT requirement for high cryopreservation growth from 10 to 2 weeks. The optimal treatment for recovery of cryopreserved shoot tips was a 3 week culture on 50 μm ABA followed by 2 weeks of LT, while the maximum cold hardiness (-22.5 °C) was obtained with 150 μm ABA and 2-week LT. A 4 week culture on 150 μm ABA at 25 °C induced dormancy in 74% of shoot tips, but had little effect on cryopreservation growth unless combined with LT. Control and ABA-treated shoot tips, lateral buds, and leaves had similar cold hardiness (-10 to -12 °C), but LT and LT+ABA-treated shoot tips survived the lowest temperatures (-17 to -23 °C), lateral buds next (-15 to -20 °C), and finally leaves (-14 to -18 °C). An increase in the preculture-medium sucrose concentration from 2% to 7% combined with 2-week LT significantly increased cryopreserved shoot tip growth (0% to 75%) and decreased the LT50 from -7.8 to -12.4 °C. The optimal shoot pretreatment for successful recovery of cryopreserved P. cordata shoot tips was a 3 week culture on either 50 μm ABA or 5% to 7% sucrose medium followed by 2 weeks of LT, and increased shoot tip growth from zero to >70%. Chemical name used: abscisic acid (ABA).
Evaluation of an Irrigation Scheduling Model for Drip-irrigated Potato in Southeastern United States
Authors: Simonne Eric , Ouakrim Nadia , Caylor Arnold
Published: February 2019

Potato (Solanum tuberosum L.) is often produced as a nonirrigated crop in the southeastern United States. This practice makes tuber yields dependent on rainfall pattern and amount. An irrigation scheduling method based on a water balance and daily class A pan evaporation (Ep) was evaluated during 1996 and 1998 on a Hartsells fine sandy loam soil for `Red LaSoda' potatoes. Planting dates were 9 and 7 Apr. in 1996 and 1998, respectively, and standard production practices were followed each year. The model tested was (13 DAH + 191) * 0.5 ASW = D DAH-1 + [Ep * (0.12 + 0.023 DAH - 0.00019 DAH2) - RDAH - IDAH], where DAH was days after hilling, ASW was available soil water (0.13 mm/mm), D was soil water deficit (mm), R was rainfall (mm), and I was irrigation (mm). Controlled levels of water application ranging between 0% and 200% of the model rate were created with drip tapes. Four and seven irrigations were scheduled in 1996 and 1998, respectively. For both years, no interaction between irrigation regime and nitrogen rate was observed. Irrigation rate significantly influenced total yield and marketable yield (R2 > 0.88, P < 0.01). Highest total yields occurred at 99% and 86% of the model rate in 1996 and 1998, respectively. These results show that supplementing rainfall with irrigation and controlling the amount of water applied by adjusting irrigation to actual weather conditions increased potato marketable yield. Over the 2-year period of the study, an average additional profit of $563/ha/year was calculated from costs and returns due to irrigation, suggesting that drip-irrigation may be economical for potato production.
Efficacy of the Press Extraction Method for Bedding Plant Plug Nutrient Monitoring
Authors: Scoggins Holly L. , Bailey Douglas A. , Nelson Paul V.
Published: February 2019

There is a need for a substrate testing method suited for plug plant production. Methods currently used by most growers and analytical labs include the saturated media extract (SME) and the 2 water: 1 substrate (v/v) suspension. These methods are not particularly well-adapted to plug production. The press extraction (PE) method has been developed as a simple and quick alternative to these methods. However, interpretive standards for chemical analysis of plug substrates do not exist for PE. This study was designed to provide the necessary correlations between these methods to allow for development of pH, electrical conductivity (EC), and nutrient interpretive ranges for plugs. Plugs of begonia (Begonia ×semperflorens-hybrida Hort.), impatiens (Impatiens walleriana Hook. f.), marigold (Tagetes erecta L.), petunia (Petunia ×hybrida Hort. Vilm.-Andr.), salvia (Salvia splendens F. Sellow ex Roem. & Schult.), and vinca (Catharanthus roseus L.) were collected from commercial greenhouses and the substrate solution extracted with the PE, SME, and 1:2 methods. Plugs of begonia, celosia (Celosia argentea L. var. cristata (L.) Kuntze Plumosa Group), marigold, petunia, and vinca were grown with three fertilizer rates of 50, 150, and 250 mg·L-1 N. Shoots were harvested 30 days after planting and the solution was extracted from each flat using the three methods. For both experiments, PE EC was equal to or higher than the SME EC, and the pH was equal to or lower than the SME pH. The pH from the 1:2 was also similar to the PE. However, 1:2 EC results were consistently the lowest because of the dilution inherent in the 1:2 method. Interpretation ranges for pH and EC relationships were calculated to compare results from the PE with published sufficiency ranges for the SME and 1:2.
Interactive Effects of 1-MCP and Temperature on 'Elberta' Peach Quality
Authors: Fan X. , Argenta L. , Mattheis J.P.
Published: February 2019

'Elberta' peaches (Prunus persica L.) harvested 6 days apart were treated with 0.5 mL·L-1 1-MCP for 4 hours at 20 °C then stored at 0, 5, 10 or 20 °C. Fruit were ripened at 20 °C for 3 days after 1, 3, and 6 weeks of storage at 0, 5, and 10 °C. Treatment with 1-MCP delayed the onset of climacteric ethylene production and reduced respiration in fruit held at 20 °C. 1-MCP-treated fruit were firmer than untreated controls after storage at 0 or 5 °C. 1-MCP-treated fruit also had higher titratable acidity (TA) after 1 week of storage at 0 or 5 °C, but TA was lower compared to controls after 3 or 6 weeks of storage. Fruit stored at 5 °C had more severe internal browning, lower extractable juice and TA than fruit stored at either 0 or 10 °C, however, 1-MCP treated fruit had more severe internal browning than untreated fruit after 3 and 6 weeks of storage at 5 °C. Fruit from harvest 1 treated with 1-MCP and stored at 0 °C for 6 weeks failed to soften after removal from storage. Chemical name used: 1-methylcyclopropene (1-MCP).
Postharvest Handling of Stock (Matthiola incana)
Authors: Çelikel Fisun G. , Reid Michael S.
Published: February 2019

The respiration of flowers of stock [Matthiola incana (L.) R. Br.] had a Q10 of 6.9 between 0 and 10 °C. Simulated transport for 5 days resulted in marked reduction in the vase life of flowers transported at 10 °C and above. Flower opening, water uptake, and vase life of the flowers increased somewhat in a vase solution containing 50 ppm NaOCl, and considerably in a commercial preservative containing glucose and a bactericide. Exposure to exogenous ethylene resulted in rapid desiccation and abscission of the petals, effects that were prevented by pretreatment with 1-methylcyclopropene (1-MCP). Even in the absence of exogenous ethylene, the life of the flowers was significantly increased by inhibiting ethylene action using pretreatment with silver thiosulfate (STS) or 1-MCP. STS was more effective than 1-MCP in maintaining flower quality.
Storage Temperature Affects the Quality of Cut Flowers from the Asteraceae
Authors: Çelikel Fisun G. , Reid Michael S.
Published: February 2019

The respiration of cut flowers of gerbera (Gerbera jamesonii H. Bolus ex Hook.f. `Vesuvio') and sunflower (Helianthus annuus L.) increased exponentially with increasing storage temperature. Poststorage vase life and negatively gravitropic bending of the neck of the flowers were both strongly affected by simulated transport at higher temperatures. Vase life and stem bending after dry storage showed highly significant linear relationships (negative and positive, respectively) with the rate of respiration during storage. The data indicate the importance of maintaining temperatures close to the freezing point during commercial handling and transport of these important commercial cut-flower crops for maximum vase life.
Interspecific Relationships in Pistacia Based on RAPD Fingerprinting
Authors: Kafkas Salih , Perl-Treves Rafael
Published: February 2019

Phylogenetic relationships among nine species in the genus Pistacia were studied by randomly amplified polymorphic DNA (RAPD) analysis. The following species were included: P. atlantica, P. terebinthus, P. eurycarpa, P. vera, P. integerrima, P. mexicana, P. palaestina, P. lentiscus, and P. khinjuk. Genomic DNA was extracted from leaf tissue and RAPD analysis was performed using 20 primers. A total of 242 fragments were generated and 228 bands were polymorphic at the inter-specific level. Subjecting these data to phylogenetic analysis yielded a shortest cladogram that is 338 steps long, featuring two main groups. P. vera, P. khinjuk, P. eurycarpa, P. atlantica, and P. integerrima were included in one group, while P. terebinthus, P. palaestina, P. mexicana, and P. lentiscus formed the second group. The first group included species with single-trunked and big trees, whereas the species included in the second group mostly grow as shrubs or small trees. The cladogram showed that the closest pairs of species were P. terebinthus and P. palaestina, P. eurycarpa and P. atlantica, P. vera and P. khinjuk, and P. mexicana and P. lentiscus. We suggest that P. palaestina is in fact a variety of P. terebinthus in view of the small genetic distance between them. This study also showed that P. eurycarpa (syn. P. atlantica var. kurdica) is a distinct species from P. atlantica, rather than a variety within the same species.
Sequence of the S10 cDNA from 'McIntosh' Apple and a PCR-digestion Identification Method
Authors: Kitahara Kentaro , Matsumoto Shogo
Published: February 2019

An S-allele cDNA was cloned from pistils of 'McIntosh' apple (Malus ×domestica Borkh.). The allele, designated Si in Japan and S10 in Europe, is an S-RNase that is very similar (94%) to the S3-RNase at the deduced amino acid sequence level. This allele can be detected by amplification using the polymerase chain reaction (PCR) and specific primers, followed by digestion with restriction enzyme EheI. The S10 allele was discovered in 'Empire', 'Maypole', 'Shinano Red', 'Spencer', and 'Vista Bella'. The S-allele cDNAs sequenced to date are listed with their Japanese and European designations.
Bermudagrass Establishment on High Sand-content Soils Using Various N-P-K Ratios
Authors: Rodriguez Ian R. , Miller Grady L. , McCarty L.B.
Published: February 2019

For drainage, turfgrass is often established on sand-based soils, which are typically nutrient-deficient and require supplemental fertilization. The objective of this study was to determine the optimum N-P-K fertilizer ratio for establishing bermudagrass from sprigs in sand. `FloraDwarf' and `Tifdwarf' bermudagrasses [Cynodon dactylon (L.) Pers. × C. transvaalensis Burt-Davy] were sprigged on a United States Golf Association (USGA) green [85 sand: 15 peat (v/v)] in Aug. 1996 at the Univ. of Florida's Envirogreen in Gainesville, Fla. `TifEagle' bermudagrass was sprigged on a USGA green [85 sand: 15 peat (v/v)] and `Tifway' bermudagrass [C. dactylon (L.) Pers.] was sprigged on native soil at Clemson Univ. in Clemson, S.C. in May 1999. Treatments consisted of fertilizer ratios of 1N-0P-0.8K, 1N-0P-1.7K, 1N-0.4P-0.8K, 1N-0.9P-0.8K, and 1N-1.3P-0.8K applied based on a N rate of 49 kg·ha-1/week for 7 weeks. Growth differences were apparent among cultivars. A 1N-0P-0.8K or 1N-0P-1.7K ratio is insufficient for optimum growth of bermudagrass during establishment, even when planted on a soil high in P. Increased coverage rate with additional P was optimized at a ratio of 1N-0.4P at all four sites. Increased coverage with P was greatest on the sand-based greens, probably due to the very low initial P levels of the soils. On two of the sand-based greens, P in excess of a 1N-0.4P ratio decreased coverage rate.
Response of Plasticultured Bell Pepper to Staking, Irrigation Frequency, and Fertigated Nitrogen Rate
Authors: Bowen Pat , Frey Brenda
Published: February 2019

Effects of staking, drip irrigation frequency and fertigated N rate on dry matter partitioning and yield of bell peppers (Capsicum annuum L.), grown using polyethylene mulch and mini-tunnels, were determined in two years. In the second year, which had higher early-season temperatures and more hours of direct sunlight, plants were larger, more productive and had larger fruit with thicker pericarps and a higher water content than in the first year. In both years, staked plants fertigated with 31.5 vs. 63 kg·ha-1 N produced higher yields due to increased fruit size and pericarp thickness. Compared with the response to monthly irrigation plus rainfall, additional irrigation applied when the soil moisture tension averaged below -25 and -20 kPa in the two years, respectively, affected yield only in the second year when it increased yield and the number of fruits produced by staked plants and decreased that of non-staked plants. Patterns of vegetative development and dry matter partitioning indicate that resources were remobilized from leaves to support fruit development.
Seedless Watermelons Produced Via Soft-X-Irradiated Pollen
Authors: Sugiyama Keita , Morishita Masami , Nishino Eisho
Published: February 2019

Watermelon fruit that results from pollination with pollen irradiated with soft-X-ray contains only empty seed, although the fruit develops to a normal size. In this study the processes of fertilization and embryo formation were compared between unirradiated and irradiated pollen in order to reveal the mechanisms by which seedless fruits are generated. The use of soft-X-irradiated pollen resulted in normal pollen tube penetration into the synergid and discharge of sperm cells. Two to three days after pollination, the sperm nucleus was present alongside the egg nucleus before fusion. The polar nuclei divided and the endosperm cell spread in the embryo sac before zygote division. A globular embryo was observed on day 7 to 10 after pollination. Subsequently, the embryo failed to differentiate to organ tissue and degenerated. These results indicate that double fertilization occurred after pollination with the irradiated pollen and that abortion of the embryo results from soft-X-ray induced chromosomal abnormalities in generative nucleus.
Coir as an Alternative to Peat in Media for Tomato Transplant Production
Authors: Arenas M. , Vavrina C.S. , Cornell J.A. , Hanlon E.A. , Hochmuth G.J.
Published: February 2019

Sixteen media prepared from peat, coir, vermiculite, or perlite were used to determine the optimum growing media for tomato (Lycopersicum esculentum Mill.) transplants. Medium composition did not affect tomato seed emergence, although seedling emergence was higher in winter (90%) than summer (85%). Greatest transplant root dry weight, stem diameter, and leaf area were achieved in 50% to 75% peat + 25% to 50% vermiculite in summer. In winter, greatest transplant root dry weight, stem diameter, and leaf area were achieved in eight media: 100% peat, 75% peat + 25% vermiculite, 75% peat + 25% perlite, 50% peat + 50% vermiculite, 50% peat + 50% perlite, 25% peat + 50% coir + 25% vermiculite, 50% peat + 25%coir + 25% vermiculite, and 25% peat +25% coir +25% vermiculite +25% perlite. Transplants grown with >50% coir exhibited reduced plant growth compared to peat-grown transplants, a response that may be associated with high N immobilization by microorganisms and high C:N ratio. Despite transplant growth differences during the summer, fruit yields generally were unaffected by transplant media.
Seasonal Dry Matter, Starch, and Nutrient Distribution in 'Concord' Grapevine Roots
Authors: Bates Terence R. , Dunst Richard M. , Joy Paula
Published: February 2019

Three-year-old field-grown 'Concord' (Vitis labruscana Bailey) grapevines were destructively harvested at eight growth stages during 1998 to quantify growth, carbohydrate distribution, and nutrient concentrations of different organs. The roots were the major storage organ for carbohydrates and nutrients, accounting for 84% of the starch and 75% of nitrogen stored in the vines at the beginning of the season. About 78% of the reserve starch in the vine was used for prebloom root and shoot growth. Early-season fine-root growth was a sink for stored vine nitrogen; however, the fine roots quickly became a nitrogen uptake source, providing at least 84% of the spring growth nitrogen. Total root biomass increased from bloom to leaf fall, but reserve carbohydrates and nutrients lost in the prebloom period did not begin to recover in roots until the end of rapid shoot development in late July. Crop removal at harvest, and a late-season root flush, further increased vegetative carbohydrate and nutrient reserves in the short postharvest period.
Temperature, Irradiance, Photoperiod, and Growth Retardants Influence Greenhouse Production of Angelonia angustifolia Benth. Angel Mist Series
Authors: Miller Amanda , Armitage Allan M.
Published: February 2019

The influence of temperature, irradiance, photoperiod and growth retardants on growth and flowering of Angelonia angustifolia Angel Mist series was evaluated. When temperature was increased from 15 to 30 °C, time to visible bud and time to flower decreased in a quadratic manner but total plant height and flower stem dry weight increased linearly. As irradiance increased, time to flower, time to visible bud, and height decreased quadratically. Changes in photoperiod had no effect on growth or flowering, suggesting that A. angustifolia is a day-neutral species with regards to height and flowering time. Daminozide, ancymidol, and paclobutrazol resulted in significant reduction of plant height compared with control plants but did not influence flowering time. Chemical names used: K-cyclopropyl-K-(4-methoxyphenyl)-5-pyrimidinemethanol (ancymidol); butanedioic acid mono (2,2-dimethylhydrazide) (daminozide); K-[(4-chlorophenyl)methyl]-K-(1,1-dimethyethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).
Watermelon Production as Influenced by Lime, Gypsum, and Potassium
Authors: Locascio S.J. , Hochmuth G.J.
Published: February 2019

Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] were grown with three rates each of lime, gypsum, and K during two seasons to evaluate their effects on fruit production and mineral concentration. The first experimental site was a recently cleared Sparr fine sand with an initial water pH of 5.0 and Mehlich I extractable K of 8 mg·kg-1 (very low) and 20 mg·kg-1 Ca (very low). The second site was a virgin Pomona fine sand with a water pH of 4.8, 28 mg·kg-1 K (low), and 612 mg·kg-1 Ca (high). `Crimson Sweet' fruit yields were reduced 10% with an increase in lime rate from 0 to 4.48 t·ha-1 in the first season. In the second season, lime rate had no effect on yield. In both seasons, fruit yields were reduced 14% with an increase in Ca from gypsum from 0 to 1.12 t·ha-1. On the soil testing very low in K, yield increased with an increase in K rate from 90 to 224 kg·ha-1 with no lime or gypsum. On the soil testing low in K, greatest yields were obtained with 90 kg·ha-1 K with no lime and gypsum. Application of lime and gypsum increased Ca and decreased K in seedlings but not consistently in older leaf and fruit tissues. An increase in K application increased leaf K in the first season but not in the second. Fruit firmness and soluble solids content were not consistently affected by treatment during the two seasons. Thus, on soils low in toxic elements (Mn and Al) such as used in this study, watermelon will grow well and tolerate a wide range of soil pH values without additional Ca from lime or gypsum.
Naphthalene Acetic Acid and 2,3,5-triiodobenzoic Acid Affect the Response of Mature Orange Fruit to Abscission Chemicals
Authors: Yuan Rongcai , Hartmond Ulrich , Kender Walter J.
Published: February 2019

Effects of NAA, TIBA, ethephon, and CMN-Pyrazole on fruit detachment force (FDF) of mature `Valencia' and `Hamlin' orange [Citrus sinensis (L.) Osb.] fruit were examined in 2000 and 2001. NAA effectively inhibited the reduction in FDF or fruit abscission caused by ethephon when applied to the abscission zone 24 hours before ethephon application, but had no significant effect when applied to the fruit without contacting the abscission zone, or to the peduncle ≈4 cm above the abscission zone. TIBA, an auxin transport inhibitor, decreased FDF of mature fruit and promoted fruit abscission when applied alone as a spray to the canopy or directly to the fruit peduncle. This response was dependent on TIBA concentration. TIBA was more effective when applied in combination with ethephon or CMN-Pyrazole than alone. These results are consistent with our previous data that endogenous auxin concentration in the abscission zone of mature `Valencia' orange fruit is one of the factors controlling the sensitivity and thus the responsiveness of the abscission zone of mature fruit to abscission chemicals. Chemical names used: 5-chloro-3-methyl-4-nitro-pyrazole (CMN-Pyrazole); 2-chloroethylphosphonic acid (ethephon); naphthalene acetic acid (NAA); 2,3,5-triiodobenzoic acid (TIBA).
Resveratrol Content of Muscadine Berries is Affected by Disease Control Spray Program
Authors: Magee J.B. , Smith B.J. , Rimando Agnes
Published: February 2019

Control of muscadine diseases is necessary to minimize yield loss and is especially important for highest quality fresh-market berries. In a systematic disease control spray program, four fungicides registered for grapes were applied sequentially at 10- to 20-day intervals from early bloom until just before harvest to five muscadine cultivars. Objectives of the study were to: 1) determine the effects of the spray schedule on foliage and berry diseases; and 2) study the relationship between disease incidence and resveratrol content of the berries. Resveratrol, a phytoalexin, has shown potential value in prevention and treatment of cardiovascular disease and certain cancer processes. Foliar diseases were rated visually twice during the season. Berry disease ratings were made at harvest. All fungal foliage and berry diseases were significantly reduced by fungicide treatments. Resveratrol was determined separately on berry skins, seed and pulp/juice by gas chromatography/mass spectroscopy (GC/MS). Overall, resveratrol levels in berry skins from unsprayed vines were much higher than those of sprayed vines. Concentrations varied by cultivar and within cultivar by treatment. The relationship between resveratrol concentration in skins and total disease score or scores of specific diseases was not established. Seed resveratrol concentrations differed by cultivar but were not affected by the fungicide treatments. Resveratrol concentration of seed was lower than that of skins. Accumulation of resveratrol in juice/pulp was much lower than in skins and seeds.
Cooler Temperature During Germination Improves the Survival of Embryo Cultured Peach Seed
Authors: Anderson Natalie , Byrne David H. , Sinclair Jonathan , Burrell A. Millie
Published: February 2019

Embryo culture techniques are employed to germinate seed of early ripening peach and nectarine [Prunus persica (L.) Batsch] cultivars. Generally, the embryos in these genotypes do not mature by the time the fruit matures, thus rendering normal stratification procedures ineffective. In 1998 and 1999, immature embryos from multiple peach genotypes were cultured in an embryo rescue medium (Woody Plant Medium, 3% sucrose, 0.065% agar) at 5 °C for 45 days in the dark. Embryos were then placed under lights at either a cool-temperature (18 °C in 1999 and 20 °C in 1998) or a warm-temperature (30 °C in 1999 and 28 °C in 1998) treatment with a photoperiod of 12 hours for germination and initial growth. After 2-4 weeks, embryos were rated for germination, root number, and top growth. The embryos incubated at the cool-temperature regime not only had better germination, but also had a higher rate of greenhouse survival.
Water Status of Garlic Callus under Various Salt and Osmotic Stress Conditions
Authors: Ikeda Takashi , Fujime Yukihiro , Terabayashi Satoshi , Date Shuichi
Published: February 2019

Garlic (Allium sativum L.) calli in vitro were evaluated over a range of salt concentrations and by adding mannitol to culture medium with reduced salt to provide equivalent osmoticum. The water potential of the medium ranged from -0.27 to -0.73 MPa under the various salt and osmotic stress conditions. The percent increase in calli was highest in standard Murashige & Skoog (MS) medium and was reduced when MS salts were reduced but the water potential of medium was adjusted to that of standard MS medium by addition of mannitol. The water potential of callus tissue was similar to that of tissue culture media over a 20-fold range (10% to 200%) of MS concentrations. Turgor of callus tissue was not influenced by any stress conditions. These results indicate that the optimum concentration of salt and water status of medium for formation of garlic calli was provided by standard MS medium.
Using Hairy Vetch to Manage Soil Phosphorus Accumulation from Poultry Litter Applications in a Warm-season Vegetable Rotation
Authors: Alsup Clydette M. , Kahn Brian A. , Payton Mark E.
Published: February 2019

Hairy vetch (Vicia villosa Roth) cover crops were grown in a rotation with sweet corn (Zea mays var. rugosa Bonaf.) and muskmelon (Cucumis melo L. Reticulatus group) to evaluate the legume's ability to remove excess P from soils when poultry litter was used as a fertilizer. Fertilizer treatments were: 1) litter to meet each crop's recommended preplant N requirements (1×); 2) litter at twice the recommended rate (2×); and 3) urea at the 1× rate as the control. Following the vegetable crops, hairy vetch was planted on half of each replication, while the other half was fallowed. The vetch was removed from the field in a simulated haying operation in the spring. Soil samples were taken at 0-15 cm and 15-30 cm depths at the onset of the study and after each crop to monitor plant nutrient concentrations. The vetch sometimes raised soil test N concentrations at the 0-15 cm depth. Soil test P concentrations at the 0-15 cm sampling depth in the vetch system were consistently lower numerically, but not statistically, relative to comparable plots in the fallow system. Soil test P at the 0-15 cm depth was usually increased by litter at the 2× rate relative to the urea control, regardless of cropping system. Yields of both vegetable crops were similar among all cover crop and fertilizer treatments.
Planting Depth Effect on Emergence and Morphology of Buffalograss Seedlings
Authors: Heckman Neil L. , Horst Garald L. , Gaussoin Roch E.
Published: February 2019

Buffalograss [Buchloë dactyloides (Nutt.) Engelm.] is a warm-season perennial grass native to the North American Great Plains region and has been used as a low-maintenance turfgrass. Turf-type buffalograsses are available and are commonly used on nonirrigated land. Our objectives were to determine the deepest planting depth of burrs that would allow acceptable emergence, and to evaluate planting depth effects on buffalograss seedling morphology. Two greenhouse experiments were conducted in Fall 2000. Experimental design was a randomized complete block with 4 replications and a 3 (cultivar) × 6 (planting depth) factorial treatment arrangement. Results showed that buffalograss emergence decreased as planting depth increased. All cultivars had <10% total emergence at planting depths >50 mm. Emergence rate indices were greatest when planting depth was 13 mm and were significantly lower at planting depths of 51 and 76 mm. Average coleoptile length was 11 mm. Coleoptile length was similar between all planting depths except for the 13 mm depth which resulted in 9-mm-long coleoptile. Subcoleoptile internode length increased with planting depth up to 38 mm. Planting depths deeper than 38 mm did not significantly increase subcoleoptile internode length.
Overseeding Strategies for Converting Golf Course Fairways to Creeping Bentgrass
Authors: Reicher Zachary J. , Hardebeck Glenn A.
Published: February 2019

Converting cool-season golf course fairways to creeping bentgrass (Agrostis palustris Huds.) is desirable because it affords excellent playability, enhanced recuperative potential, and enhanced disease tolerance compared to annual bluegrass (Poa annua sp. Timm.) or perennial ryegrass (Lolium perenne), which are common species in fairways. However, converting current golf course fairways to creeping bentgrass with nonselective herbicides is problematic because it disrupts play and decreases revenue, as fairways must be closed for an extended period of time. The objective of our study was to quantify the effect of trinexapac-ethyl (TE), overseeding date, and overseeding rate on the success on the gradual conversion of cool-season fairways to creeping bentgrass over 3 years. `Penneagle' creeping bentgrass was overseeded at 0, 49, or 98 kg·ha-1 in fall, spring, or fall+spring after aerification, and application of TE at 0.0, 0.2, or 0.4 kg·ha-1. Gradual conversion to creeping bentgrass was effective, on perennial ryegrass fairways, with up to 36% cover of creeping bentgrass after 3 years of overseeding. However, only a maximum of 3% creeping bentgrass cover was obtained after the third year of overseeding into primarily annual bluegrass fairways. Fall overseeding with bentgrass at 49 or 98 kg·ha-1 was equally effective and additional spring overseeding did not improve establishment. Applications of TE prior to overseeding did not enhance the conversion. Chemical name used: 4-cyclopropyl-a-hydroxy-methylene-3,5-dioxocyclohexanecarboxylic acid ethyl ester (trinexapac-ethyl).
Thinning 'Golden Delicious' and Spur 'Delicious' with Combinations of Carbamates and NAA
Authors: Marini Richard P.
Published: February 2019

For 2 years, 'Redchief Delicious' apple (Malus ×domestica Borkh.) trees were treated with combinations of NAA and oxamyl and 'Smoothee Golden Delicious' trees were treated with combinations of NAA and carbaryl. Oxamyl, at concentrations of 250 to 750 mg·L-1, but not NAA at concentrations of 1 to 6 mg·L-1, reduced fruit set, yield and crop value. NAA did not consistently affect average fruit weight or the percentage of small fruits on 'Redchief Delicious' trees. Carbaryl reduced fruit set and yield on 'Smoothee Golden Delicious' trees one of the two years. Fruit set and yield were negatively related to NAA concentration both years. In one of the two years the combination of NAA plus carbaryl was more effective than NAA alone. Treatments that provided adequate thinning tended to reduce crop value because the increase in fruit size did not compensate for the reduced yields. Chemical names used: 1-naphthyl-N-methylcarbamate (carbaryl); methyl N′,N′-demethyl-N [(methylcarbomoyl)oxy]-1-thiooxamimidate (oxamyl); 1-naphthaleneacetic acid (NAA).
Hydrogen Cyanamide Accelerates Vegetative Budbreak and Shortens Fruit Development Period of Blueberry
Authors: Williamson Jeffrey G. , Krewer Gerard , Maust Brian E. , Miller E. Paul
Published: February 2019

Experiments were conducted in north Florida and south Georgia to determine the effects of H2CN2 sprays on vegetative and reproductive growth of blueberry. In Florida, mature, field-grown `Misty' southern highbush (Vaccinium corymbosum L. hybrid) blueberry plants were sprayed to drip with 0, 10.2, or 20.4 g·L-1 of H2CN2 [hereafter referred to as 0%, 1.0%, and 2.0% (v/v) H2CN2] on 20 Dec. 1996 and 7 Jan. 1997. During the following winter, mature `Misty' southern highbush and `Climax' rabbiteye (V. ashei Reade) plants were sprayed to drip with 0, 7.6, or 15.3 g·L-1 of H2CN2 [hereafter referred to as 0%, 0.75%, and 1.5% (v/v) H2CN2] on 17 Dec. 1997 and 6 Jan. 1998. For all experiments, plants were dormant and leafless, with slightly swollen flower buds, at the time of spray applications. Generally, H2CN2 sprays increased the extent and earliness of vegetative budbreak and canopy establishment and advanced flowering slightly. The number of vegetative budbreaks usually increased linearly with increasing spray concentrations. In Florida, H2CN2 [0.75% to 1.0% (v/v)] sprays increased mean fruit fresh weight and yield, and shortened the fruit development period (FDP) compared to controls. However, H2CN2 sprays ranging in concentration from 1.5% to 2.0% (v/v) resulted in significant flower bud injury and reduced total fruit yield compared to controls. In south Georgia, 27 of 37 field trials conducted between 1991 and 1998 on several rabbiteye and southern highbush cultivars indicated that leaf development was significantly enhanced by H2CN2. H2CN2 shows potential for increasing early fruit maturity, fruit size, and yield of southern highbush and rabbiteye blueberry cultivars with poor leaf development characteristics in low-chill production regions. Chemical name used: hydrogen cyanamide (H2CN2).
BA and Sucrose Increase Vase Life of Cut Eustoma Flowers
Authors: Huang Kuang-Liang , Chen Wen-Shaw
Published: February 2019

An experiment was conducted to measure the effects of pulse treatments of BA, sucrose, and BA before, after, or with sucrose, on the vase life of cut Eustoma flowers. A BA pulse at 50 mg·L-1 before 4% sucrose promoted the longevity of cut Eustoma flowers better than other treatments. Simultaneously, sucrose, glucose, and mannose concentrations in flowers during vase periods were maintained at higher levels in double pulse treatments than in the single pulses. Ethylene production in flowers 2 days after vase treatment was highest in the BA-treated flowers; intermediate in flowers pulsed with BA before, after, or with sucrose; and lowest in sucrose-treated flowers. Although a BA pulse increased ethylene production over that of controls, it inhibited senescence in cut Eustoma flowers. Respiration in flowers pulse-treated with sucrose or with BA before, after, or with sucrose, was significantly higher than that in controls. Results suggest that the vase life of cut Eustoma flowers is improved by either BA or sucrose in vase solution and especially when BA was pulsed before the sucrose pulse. Chemical name used: N6-benzyladenine (BA).
Comparison of Three Nondestructive Methods for Determination of Vegetable Surface Area
Authors: Furness N.H. , Upadhyaya A. , Upadhyaya M.K.
Published: February 2019

Surface areas of differently shaped vegetables, namely beet (Beta vulgaris L.), cucumber (Cucumis sativus L.), carrot (Daucus carota L.), and parsnip (Pastinaca sativa L.) were determined by Baugerod's (a linear) method, a shrink-wrap replica method, and image analysis. Values obtained using these methods did not differ significantly for carrots and beets. Surface area values obtained using image analysis were higher than those obtained by Baugerod's method for parsnips (by 23.5%), and higher than Baugerod's and shrink-wrap replica methods for cucumbers (by 11.3% and 12.6%, respectively). A method was considered reproducible if surface area values from five measurements on the same product did not differ significantly (P ≤ 0.05). Surface area values for an individual product varied in the range of 4.7% for Baugerod's method for parsnips, and 6.6% for the shrink wrap replica method for carrots. No significant variation was observed for any of the vegetables when repeated measurements were made using the image analysis method. Image analysis offers rapidity, lack of adverse effect on produce, and the ability to collect and analyze data simultaneously. However, in absence of the necessary equipment for image analysis, Baugerod's method may be used for a product symmetrical around its central axis, after comparing it with a more direct procedure (e.g., shrink-wrap replica method).
Alternatives to Shellac Coatings Provide Comparable Gloss, Internal Gas Modification, and Quality for 'Delicious' Apple Fruit
Authors: Bai Jinhe , Baldwin Elizabeth A. , Hagenmaier Robert H.
Published: February 2019

Zein, starch, polyvinyl acetate (PVA), carnauba, and carnauba-polysaccharide (CPS) coatings were compared with a commercial shellac coating using controlled atmosphere stored 'Delicious' apples (Malus ×domestica Borkh). Coated apples were stored in air at 2 °C for 2 weeks and then removed to 21 °C for an additional two weeks to simulate marketing conditions. Gloss, internal O2 and CO2 partial pressures, weight loss, flesh firmness, and contents of sugars, acids and volatiles were measured on 0, 2, and 4 weeks after coating treatment. Starch- and carnauba-coated apples had high initial gloss, similar to that found for shellac-coated fruit. Gloss of all coated fruit decreased similarly during the 4-week evaluation period, although all of the coated fruit were glossier than uncoated controls. For uncoated apples, the differences of O2 and CO2 partial pressure between internal and ambient atmosphere were ≈1 kPa at 2 °C, and these increased by a further 2 kPa after transfer to 21 °C. Fruit coated with shellac and starch had >10 kPa CO2, and <10 kPa O2 at 21 °C. Zein-, PVA- and carnauba-coated apples showed a less modified internal atmosphere (6-7 kPa CO2, 11-15 kPa O2). Internal partial pressures of O2 and CO2 were inversely related for most coatings, except for the CPS coating, for which partial pressures of both CO2 and O2 were low. Carnauba-, PVA-, and shellac-coated fruit lost less weight than uncoated fruit. Starch-, shellac-, and CPS-coated fruit were firmer than those from other coating treatments, and all coated fruit were firmer than uncoated control. Titratable acidity was higher in the fruit coated with CPS, starch, and shellac than in uncoated control. Ethyl alcohol and ethyl esters accumulated in starch-, shellac-, and CPS-coated fruit kept at 2 °C, but, levels of these volatiles decreased after transfer of fruit to 21 °C. Carnauba, PVA and zein coatings compared favorably to shellac for gloss and other quality characteristics.
Longan Quality after Hot-water Immersion and X-ray Irradiation Quarantine Treatments
Authors: Follett Peter A. , Sanxter Suzanne S.
Published: February 2019

Hot-water immersion and irradiation quarantine treatments are used to disinfest longan [Dimocarpus longan (Lour.) Steud.] of fruit flies and other pests before export from Hawaii to the U.S. mainland. One day after harvest, longan fruit (cvs. Chompoo and Biew Kiew) were subjected to hot-water immersion at 49 °C for 20 minutes, irradiation treatment at a minimum absorbed dose of 400 Gy, or left untreated as controls. Fruit were then stored at 10 °C in perforated plastic bags, and quality attributes were evaluated after 7, 14, and 21 days. `Chompoo' and `Biew Kiew' fruit treated by hot-water immersion were darker (lower L*) and less intensely colored (lower C*) than irradiated or untreated fruits after 14 days of posttreatment storage. For both cultivars, external appearance of fruit treated by hot-water immersion was rated as unacceptable after 14 and 21 days of posttreatment storage, whereas irradiated and nontreated fruit were rated as acceptable on all days. Penicillium mold contributed to the unacceptable external appearance ratings after 21 days for fruit that were treated by hot-water immersion. With both cultivars, taste of fruit treated with hot-water immersion was rated as unacceptable after 21 days of storage, whereas irradiated fruit remained acceptable. Overall, under these experimental conditions, irradiation was superior to hot-water immersion as a quarantine treatment based upon the maintenance of fruit quality.
Time and Sequence of Inflorescence Initiation and Development of Brunia albiflora (Pillans)
Authors: Poole Caroline J. , Gerber Audrey I. , Jacobs Gerard
Published: February 2019

Brunia albiflora (Pillans) is harvested commercially in South Africa as a cut flower for export to European markets. To compete with European cut flowers high quality and continuity of product during the marketing period are essential. Optimizing the cut-flower potential of B. albiflora requires an understanding of the flowering process and selection of clonal material. We present a series of scanning electron micrographs which show three-dimensional images of the developmental stages of the shoot apex during the transition from the vegetative to the reproductive state. In B. albiflora the inflorescence consists of more than 15 individual rotund inflorescences arising from lateral positions on the terminal portion of the shoot. Development of the apical meristem of axillary shoots was studied to determine the time and sequence of inflorescence initiation and development. These observations identified that flower initiation occurs in October, followed by flower development through summer, with anthesis being reached from February to March.
Heading Fruiting Shoots before Bloom Is Equally Effective as Blossom Removal in Peach Crop Load Management
Authors: Marini Richard P.
Published: February 2019

Three experiments were performed to determine if pruning treatments could reduce the need for peach [Prunus persica (L.) Batsch] fruit thinning without reducing average fruit weight. To determine if dormant shoot heading affected fruit size simply by reducing the number of flowers per tree, all 1-year-old shoots on `Cresthaven' trees were headed by 50% or blossoms were removed from the terminal half of each shoot. At 45 days after full bloom, all trees were hand-thinned to obtain predetermined crop densities. Average fruit weight was highest on trees with blossom removal, but crop value and net profit were highest for nontreated trees. To determine the influence of treatment severity on fruit weight, all shoots on `Cresthaven' trees were blossom-thinned or headed to remove blossoms on varying proportions of each shoot. Fruit set and the number of fruit removed during postbloom thinning decreased as the percentage of a shoot that was headed or blossom-thinned increased. Average fruit weight at harvest and crop value were higher for trees with blossom removal than for trees with headed shoots. Fruit weight and crop value were not affected by the percentage of the shoot treated. In the final experiment, all shoots on `Cresthaven' trees were headed by 50% or were not headed. Heading of shoots reduced fruit set, number of fruits removed at thinning, and thinning time per tree, but yield, crop density, and average fruit weight were not affected by heading. Profit was increased by shoot heading one of the 3 years. Results from this study indicate that heading peach shoots by 50% while dormant pruning can reduce thinning costs without reducing fruit size, but a similar level of labor-intensive blossom removal may reduce postbloom thinning costs and improve fruit size.
Digital Image Analysis of Sweetpotato Storage Roots in Herbicide Trials
Authors: Villordon Arthur , Carroll Heather
Published: February 2019

Digital image analysis (DIA) was evaluated for use in assessing size and shape attributes of sweetpotato [Ipomoea batatas (L.) Lam.] storage roots in herbicide studies. Digital image files of U.S. no. 1 storage roots were taken using a digital camera. Image analysis was performed using a publicly available software package. Eight size and shape attributes were measured and subjected to univariate and multivariate procedures. DIA revealed differences for storage root width and roundness attributes. Principal component analysis suggested that storage root length, width, and roundness best described the variability of the storage root sample. The results demonstrate the potential use of DIA in augmenting data from sweetpotato herbicide trials as well as other investigations that require information about storage root size and shape responses.
Seasonal Variation in Cuticular Waxes on Hosta Genotypes Differing in Leaf Surface Glaucousness
Authors: Jenks Matthew A. , Gaston Carole H. , Goodwin Mark S. , Keith Jessie A. , Teusink Rebecca S. , Wood Karl V.
Published: February 2019

Cuticular waxes were analyzed on abaxial and adaxial leaf surfaces of three Hosta genotypes differing in leaf surface glaucousness; the glossy-leaved Hosta plantaginea, the glossy-leaved Hosta lancifolia, and the glaucous-leaved Hosta `Krossa Regal'. All three hosta had their highest total leaf wax quantity in the spring soon after full leaf expansion. The major wax constituent class on these hosta was primary alcohols, comprising up to 84.6% of the total wax. Many hosta leaves had unusually high C24 length primary alcohols, especially in the spring. However, the dominant chain length in this alcohol class varied with development and genotype. A unique class of ß-diketones were present on the glaucous `Krossa Regal', comprising as much as 28.7% of the total waxes on abaxial leaf surfaces in the summer. Interestingly, these ß-diketones were only 0.9% of total waxes on adaxial leaf surfaces of `Krossa Regal' in the summer. Studies are under way to determine whether the dramatic seasonal changes in the waxy leaf coatings described in this report are associated with biotic and abiotic stress resistance in hosta.
Effect of Red Light Treatment of Seedlings of Pepper, Pumpkin, and Tomato on the Occurrence of Phytophthora Damping-off
Authors: Islam S.Z. , Babadoost M. , Honda Y.
Published: February 2019

A study was conducted in the greenhouse to investigate the effects of red light (600-700 nm) on the subsequent occurrence of seedling infection of bell pepper, pumpkin, and tomato caused by Phytophthora capsici. Three- or 4-week-old seedlings were inoculated with zoospores or transplanted into pots filled with artificially infested soil mix. Red light treatment of seedlings reduced Phytophthora damping-off by up to 79%. Only 21% to 36% of red light-treated seedlings became infected, whereas 78% to 100% of the control seedlings, grown either in natural daylight (NDL) or under white light (WL), became infected and died. The height, and fresh and dry weight of seedlings treated with red light were significantly higher than those grown under NDL or WL.