bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutrient Accumulation and Availability in Compost-amended Turfgrass Soil
Authors: Wright Alan L. , Provin Tony L. , Hons Frank M. , Zuberer David A. , White Richard H.
Published: February 2019

Compost application to turfgrasses may contribute to accumulation of macronutrients in soil and eventually pose leaching and runoff hazards. The objectives of this study were to determine the influence of compost on soil-dissolved organic C (DOC) and accumulation of NH4OAc-EDTA-extractable and water-soluble nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S) in St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] turf. Dissolved organic C increased from 3 to 29 months after application for unamended and compost-amended soils, indicating contribution from decomposition of both compost and St. Augustinegrass residues. Dissolved organic C was 75%, 78%, and 101% greater 29 months after application of 0, 80, and 160 mg·ha−1 of compost, respectively, than before application. Dissolved organic C and macronutrients exhibited considerable seasonal variation, because DOC and EDTA-extractable P, Ca, Mg, and S increased after compost application, whereas NO3 declined. Water-soluble K, Ca, and Mg declined, whereas P and S increased from 0 to 29 months. Similar seasonal changes in macronutrient concentrations occurred for unamended and compost-amended soil, indicating that composts, in addition to turfgrass residues, influenced DOC and macronutrient dynamics. Long-term nutrient accumulation occurred in compost-amended turfgrass, but seasonal dynamics were more related to the growth stage of turfgrass than compost. Formation of DOC-cation complexes appeared to contribute to macronutrient mobility, because decreases in DOC and nutrient concentrations occurred during turfgrass dormancy in winter and after high precipitation levels, indicating the potential for leaching of DOC-associated nutrients from soil.
Root to Shoot Relations in an Annual Raspberry (Rubus idaeus L.) Production System
Authors: Alvarado-Raya Horacio E. , Darnell Rebecca L. , Williamson Jeffrey G.
Published: February 2019

Low yields have been observed in annual production systems in raspberry (Rubus idaeus L.) compared with annual yields in perennial systems. This yield reduction could be related to a depletion of root carbohydrates and its consequent detrimental effect on fruit number or size. Additionally, primocanes could play an important role in the carbohydrate dynamics in an annual system and may also affect yield. Two experiments were carried out in 2003 and 2004 to determine the importance of root carbohydrates and primocanes in fruiting and yield components of ‘Tulameen’ red raspberry in an annual production system. In the 2003 experiment, girdled floricanes were compared with nongirdled controls. Girdling before bloom decreased fruits per cane and consequently yield per cane compared with controls, whereas girdling at the end of bloom had no effect. Root dry weight accumulation at the end of the fruiting season was significantly less in both early and late girdled compared with nongirdled plants. In 2004, floricanes were completely girdled or nongirdled at midflowering. Additionally, three primocanes were permitted to grow in one-half of the nongirdled and girdled plants, whereas primocanes were completely removed from the other half. Girdling and removal of all primocanes resulted in 100% plant mortality. In the presence of primocanes, floricane girdling had no effect on yield compared with the nongirdled treatments. There was a reduction in root dry weight in the nongirdled + primocane removal treatment compared with the treatments in which three primocanes were present. In the presence of primocanes, however, root dry weights were similar in both girdled and nongirdled plants. These results suggest that root carbohydrates are important in determining fruit number and yield in the annual system, and reductions in root carbohydrate during early flowering results in decreased yield. However, roots appear to quickly convert from source to sink status, and as the season progresses, both floricanes and primocanes act as sources to replenish root carbohydrate reserves. Carbohydrate dynamics appear to be similar between the annual production system and the traditional perennial system; however, because the annual system begins with limited carbohydrate reserves resulting from root pruning that occurs during removal from the nursery, yields are lower than those seen in perennial systems.
Environmental Influences on Essential Oils in Roots of Anemopsis californica
Authors: Medina-Holguín Andrea L. , Micheletto Sandra , Holguín F. Omar , Rodriguez Jaime , O'Connell Mary A. , Martin Charles
Published: February 2019

The climate conditions and chemical composition of root essential oils for 17 populations of Anemopsis californica in New Mexico were examined. The objective of this study was to observe the effect of environmental conditions and management conditions on essential oil composition in different populations of A. californica. Chemical concentrations of three abundant compounds—methyleugenol, thymol, and piperitone—were determined. Maximum accumulations of each compound were associated with different mean annual temperatures, precipitation, and elevation. Similar chemical profiles were detected in root samples recollected for four populations, suggesting retention of unique chemical profiles in different populations. Vegetative propagation of wild plants under cultivated conditions did not significantly alter the chemical profile of the root essential oil. The chemical concentrations for six essential oil components of A. californica roots were determined under field conditions with varying irrigation and nitrogen (N) fertilizer regimens. The concentration of only two compounds, thymol and piperitone, was increased by increasing irrigation. The concentration of all other compounds, methyeugenol, elemicin, 1,8-cineole, and myrtenol, were independent of the irrigation rates and N fertilizer rates used in the study. These results suggest that the chemical variability observed among different populations of A. californica is primarily genetically controlled and the environmental conditions in New Mexico are conducive to the production of this medicinal plant as a high-value crop.
Effects of Ethephon on Stock Plant Management of Coreopsis verticillata, Dianthus caryophyllus, and Veronica longifolia
Authors: Glady Janelle E. , Lang N. Suzanne , Runkle Erik S.
Published: February 2019

Some day-neutral herbaceous perennial species can be difficult to manage as vegetative stock plants because they initiate floral buds under most environmental conditions. Although flowering of many long-day plants can be inhibited by maintaining plants under short days, extension growth is often suppressed, which makes cuttings difficult to harvest. Ethephon (2-chloroethylphosphonic acid) is an ethylene-releasing chemical used to abort flowers, inhibit internode elongation, and promote branching of floriculture crops. The objective of this research was to determine whether ethephon is effective at maintaining vegetative growth and increasing the number of cuttings harvested for three popular perennial species that are difficult to maintain as vegetative plants. Spray applications of ethephon were applied for 10 weeks biweekly (every 2 weeks) or weekly at 0, 400, 600, or 800 mg·L−1. Biweekly applications at 600 mg·L−1 or weekly applications at 400 mg·L−1 increased branching and the number of vegetative cuttings in Coreopsis verticillata L. ‘Moonbeam’ and Veronica longifolia L. ‘Sunny Border Blue’, respectively. Ethephon application increased branching in Dianthus caryophyllus L. ‘Cinnamon Red Hots’, inhibited leaf expansion and stem extension, but did not abort flowers, and induced marginal leaf necrosis at all concentrations tested. Therefore, ethephon application has potential to maintain vegetative stock plants of C. verticillata ‘Moonbeam’ and V. longifolia ‘Sunny Border Blue’ but not D. caryophyllus ‘Cinnamon Red Hots’.
Potential Abscission Agents for Raisin, Table, and Wine Grapes
Authors: Fidelibus Matthew W. , Cathline Kimberley A. , Burns Jacqueline K.
Published: February 2019

Effective abscission agents that decrease fruit detachment force (FDF) are sought by the California raisin industry to improve the continuous tray mechanical harvesting method. Such agents might also enable mechanical harvest of table and wine grapes (Vitis vinifera L.), but few agents are known to be effective for grape. Thus, methyl jasmonate (MeJA) and six other compounds known to stimulate abscission of other fruits were screened for their ability to reduce FDF of mature ‘Thompson Seedless’ grapes. Most compounds tested reduced FDF to some extent, but MeJA was particularly effective. Solutions containing between 45 and 4500 ppm MeJA reduced FDF by at least 50% to 85% compared with nontreated fruits. Application of 2250 and 4500 ppm MeJA to ‘Thompson Seedless’ vines caused 25% to 50% fruit drop, respectively, within 10 d after treatment (DAT). The efficacy of MeJA was verified in a second experiment in which solutions of 0, 1125, 2250, or 4500 ppm MeJA were applied to clusters of ‘Crimson Seedless’ grapes; at 14 DAT, FDF declined as a linear function of MeJA applied. The grapes did not abscise, but berries treated with 2250 to 4500 ppm MeJA had slightly lower soluble solids than nontreated fruits. Solutions of 0 or 4500 ppm MeJA applied to clusters of ‘Cabernet Sauvignon’ and ‘Merlot’ grapevines reduced FDF by 66% and 75%, respectively. Fruit drop was estimated to be less than 10%. Thus, a solution containing up to 4500 ppm MeJA may be an effective abscission agent to facilitate mechanical harvest of ‘Cabernet Sauvignon’ or ‘Merlot’.
Flavor and Other Quality Factors of Enzyme-peeled Oranges Treated with Citric Acid
Authors: Pinnavaia Simona , Senesi Emilio , Plotto Anne , Narciso Jan A. , Baldwin Elizabeth A.
Published: February 2019

Oranges can be satisfactorily processed for fresh slices using a process of enzyme infiltration under vacuum. Scored ‘Valencia’ and ‘Hamlin’ oranges were placed under 90 kPa vacuum in water, 1% citric acid (CA), or 1000 ppm pectinase (Ultrazym) at 30 °C for 2 min followed by 30 min incubation in air. After peeling, fruit were washed, cut, and all but CA-infused slices were dipped in water or 1% CA for 2 min. Drained slices were placed in sealed 454-mL deli containers and stored at 5 °C for up to 21 days. All ‘Valencia’ slices had microbial counts less than 1.0 log cfu·g−1 (cfu = colony-forming units) after 7 days storage, and slices from CA-infused fruit had less than 1.0 log cfu·g−1 after 21 days storage. For ‘Hamlin’, CA dips controlled bacterial growth on slices from water-infused oranges, except at 14 days. Enzyme-infused oranges resulted in slices with lower counts for both cultivars. CA-treated sliced (post enzyme treatment or by infusion) oranges had higher titratable acidity initially (‘Hamlin’) and after 14 days (‘Valencia’). When presented to a taste panel, ‘Valencia’ slices from enzyme-peeled fruit were preferred for texture after 2 days and 8 days in storage. In contrast, slices from fruit infused with water or citric acid were least preferred, were firmer, and had thicker segment membranes. Appearance of enzyme-treated fruit was preferred for ‘Hamlin’ oranges. Enzyme treatments increased levels of aroma volatiles, methanol and methyl butanoate, in ‘Hamlin’ slices, but overall sensory flavor data were unaffected.
Nutrient Treatments Used on Field-harvested Colorado Spruce Trees to Maintain Postharvest Quality
Authors: Tripepi Robert R. , George Mary W. , Linskey K. Amanda , Lloyd John E. , Van Wagoner Jennifer L.
Published: February 2019

Holding practices for balled and burlapped conifers may inadvertently impact nutrient availability and tree growth. The objective of this study was to examine the effectiveness of several nutrient treatments to maintain or enhance the growth and foliar nutrition of Colorado spruce (Picea pungens Engelm.) trees while they were in a mulch-holding bed. Sixty 1.5 to 1.8-m tall Colorado spruce trees with 61-cm (24 inch) diameter root balls were heeled into a holding bed of fresh pine bark mulch during 2002 and 2003. The treatments applied to the root balls were a control (pine bark without fertilizer), 114.2 g Osmocote (Scotts, Marysville, OH) 15N–3.9P–10K distributed over the top of the ball, one Ross Gro-Stake (Easy Gardener, Waco, TX) 10N–4.3P–8.3K Evergreen fertilizer spike (113 g) per ball, one-half cartridge (≈8.5 g) of Ross Root Feeder (Weatherly Consumer Products, Lexington, KY) 10N–5.2P–10K evergreen fertilizer injected into the root ball at four points, or a 1:1 biosolids-based compost:pine bark mixture (by volume). Trunk diameters and tree heights were measured and foliar samples for nutrient analyses were collected before applying these treatments and at the end of the growing season 20 or 17 weeks later. The 2003 trees were transplanted to a landscape site in 2004, and the height growth of their terminal leaders were measured at the end of the next two growing seasons. Overall, Colorado spruce trees appeared normal while they were held in the mulch beds the first season after nursery harvest. Changes in tree height and trunk diameter by the end of the first season after harvest were unaffected by the nutrient treatments. By fall of both years, needles from trees treated with the mixture of 1:1 compost:bark had the highest levels of foliar N, Mg, Ca, S, and B. Trees treated with the fertilizer spike in 2002 had similar levels of N and S in their needles compared with compost:bark-treated trees, whereas in 2003, spike-treated trees had the second highest levels of foliar N and S, and these levels were significantly higher than those of trees receiving the control or other fertilizer treatments with the exception of N in needles from fertilizer-injected trees in 2002. Plant-available N, however, was highest in the root balls of Osmocote- and fertilizer spike-treated trees only in 2003. Leaders on the 2003 trees that received the compost:bark or fertilizer spike treatments grew at least 70% or 36% taller, respectively, than those trees receiving the other treatments by the end of the second growing season in a managed landscape. Although all nutrient treatments failed to promote increases in tree heights and trunk diameters while the trees were held in a mulch bed for the first growing season after digging, the compost:bark mixture and, to some extent, the fertilizer spike improved foliar nutrition during this time.
Pentas Water Use and Growth in Simulated Landscapes as Affected by Municipal Compost and Mined Field Clay Soil Amendments
Authors: Scheiber S.M. , Beeson Richard C. , Vyapari Sudeep
Published: February 2019

Pentas lanceolata Schum. ‘New Look Red’ plants were grown in compost-amended, mined field clay-amended, or unamended sand soils in drainage lysimeters to evaluate growth, aesthetic quality, and irrigation requirements. Treatments were evaluated with irrigation controlled by tensiometers set to irrigate back to near field capacity when plant-available water in each soil declined to 50%. Compost-amended soils had greater (P < 0.05) mean shoot dry weight, total biomass, shoot-to-root ratios, growth indices, and landscape quality than other amendment treatments. Unamended soils and clay-amended treatments were comparable for all plant parameters. Total irrigation volumes applied were similar among treatments. Compost-amended soils yielded larger canopies, improved quality, and tended toward less cumulative irrigation. Clay amendment was not beneficial.
Application of 1-Methylcyclopropene in Fresh-cut/Minimal Processing Systems
Authors: Toivonen Peter M.A.
Published: February 2019

The application of 1-methylcyclopropene (1-MCP) in fresh-cut processing systems has been approached in three ways: 1) treatment of freshly harvested crop before longer-term storage after which the product is processed, 2) treatment of whole product just before processing, or 3) treatment of fresh-cut product immediately after processing. Results in the literature to date are quite variable in terms of whether 1-MCP treatment provides a benefit, no effect, or a negative effect on shelf life and quality retention of fresh-cut product. There are a number factors that impact the nature and extent of response to 1-MCP by fresh product and these include, but are not limited to, temperature of storage for fresh-cut product, condition of raw product, type of fruit or vegetable, cultivar, harvest maturity, duration of storage before cutting, and the 1-MCP treatment approach. A critical analysis, using existing published and unpublished data, provides a preliminary assessment of the impact of some of these factors. This analysis is intended to provide some insight into important considerations on the use of 1-MCP in fresh-cut processing systems and will guide researchers in considering experimental parameters for future work.
Growth and Photosynthetic Responses of Three Lycoris Species to Levels of Irradiance
Authors: Meng Panpan , Ge Ying , Cao Qianjin , Chang Jie , Pan Peng , Liu Chi , Lu Yijun , Chang Scott X.
Published: February 2019

Lycoris species have appealing characteristics for potting plants, cut flowers, and landscaping decorations, including attractive foliage, which is very similar to that of cymbidium. Lycoris species have been extensively propagated and marketed in Asia. Understanding the response of Lycoris spp. to irradiance intensity will help the horticultural industry improve the production of potting plants of those species. We studied the responses of photosynthesis, growth, and biomass allocation of potted Lycoris spp. (L. chinensis, L. longituba, and L. sprengeri) bulbs grown under three levels of irradiance, i.e., 100%, 70%, and 30% full sunlight. We found that in terms of biomass production L. chinensis can be cultivated under all levels of irradiance studied from full to 30% sunlight. For L. longituba, high irradiance levels increased the rate of net photosynthesis. For both L. chinensis and L. longituba, the full sunlight treatment produced the most attractive plants characterized by shorter, wider, and darker green leaves, features that appeal to consumers. However, none of the growth traits of L. sprengeri were affected by the irradiance treatment over the entire experimental period. It can be concluded that potting plants of L. chinensis and L. longituba are best produced under full sunlight, whereas L. sprengeri can be produced under irradiance levels from 30% to full sunlight.
Effect of Fertigation on the ‘Manzanilla de Sevilla’ Table Olive Quality Before and After “Spanish-style” Green Processing
Authors: Morales-Sillero A. , Jiménez R. , Fernández J.E. , Troncoso A. , Rejano L.
Published: February 2019

Table olive quality was analyzed in adult ‘Manzanilla de Sevilla’ olive trees subjected to different N–P–K fertigation treatments through five years (1999–2003). A randomized block design with four fertigation treatments was established: irrigated without fertilizer (control), and T200, T400, and T600 treatments, in which each tree was respectively fertigated with 200, 400, and 600 g N per irrigation season of a complex 4N–1P–3K fertilizer applied daily. Fruit yield and fruit physical characteristics and chemical composition were studied in 2002 and 2003. Fruit analysis realized in 2002 showed that the fruit pulp/stone ratio and water content increased with the amount of applied fertilizer. In 2003, a similar trend was found for fruit yield, weight, pulp/stone ratio, volume, longitudinal and transversal diameters, and fruit water and potassium concentrations. On the contrary, the concentration of reducing sugars; Ca, Na, and B; and the fruit texture decreased linearly with the fertilizer dose in 2003. No differences between treatments in fruit and stone shape, or stone volume or polyphenols concentration were found. On the other hand, the effect of the treatments on fruit browning damage was studied in 2003, as well as the fruit quality after “Spanish-style” green processing. In spite of the differences in fruit composition and texture, the fertigation treatments did not affect browning damage. After Spanish-style processing, differences between treatments in fruit weight and texture were again observed, but color, brown spots, and blistering incidence were not modified.
In Vitro Regeneration of Castor (Ricinus Communis L.) Using Cotyledon Explants
Authors: Ahn Yeh-Jin , Chen Grace Qianhong
Published: February 2019

An efficient plant regeneration protocol using cotyledon explants was established for castor (Ricinus communis L.), an important oilseed crop. Mature seed-derived cotyledon explants produced adventitious shoots when placed on Murashige and Skoog (MS) medium containing thidiazuron (TDZ). The rate of shoot regeneration was maximal (≈25 shoots per explant) when explants were cultured on shoot induction medium supplemented with 5 μm TDZ and preincubated in the dark for the first 7 days before transferring to the day/night cycle (16/8 h). Only the proximal ends of cotyledon explants produced adventitious shoots, although green calli were observed in cotyledon veins. After 4 weeks in culture, explants with well-developed shoot buds were transferred to MS medium without plant growth regulators for the shoot elongation and development. At ≈4 months after culture initiation, shoots (2 cm in length) were transferred to root induction medium (MS medium supplemented with 5 μm indole-3-butyric acid) where they developed roots in 4 to 6 weeks. Plantlets were transferred to soil and acclimatized to greenhouse conditions. Histological analysis showed the adventitious induction of the shoots originated from the cortical and epidermal cell layers of the cotyledon explants.
Timing the Establishment of Kentucky Bluegrass : Perennial Ryegrass Mixtures for Football Fields
Authors: Stier John C. , Koeritz Eric J. , Garrison Mark
Published: February 2019

Sports field construction contracts in cool-season areas often stipulate a 9- to 12-month period between seeding and opening for play. Seed mixtures are usually dominated by slow-establishing Kentucky bluegrass (KBG; Poa pratensis L.) and contain lower proportions of perennial ryegrass (PRG; Lolium perenne L.) for quick cover. Our objective was to evaluate the effect of planting time on three KBG : PRG mixes, a 100% PRG blend, and their ability to sustain football-type traffic. Field plots were seeded in late summer, as a dormant planting in late fall, and in the following spring. Plots received simulated football traffic, split for one or four weekly games, from mid-August through mid-November of the year in which spring seeding occurred. The experimental design was a strip-split-plot, randomized block with four replications. The study was repeated a second year. All seeding dates provided acceptable turf quality regardless of seed type by September. However, summer seedings of KBG-based mixtures provided better turf quality than mixtures planted in the spring, whereas dormant-seeded mixtures provided the poorest turf quality. Turf seeded with 100% PRG was less sensitive to seeding date, with summer or spring seedings providing similar quality and dormant seedings superior to KBG-based dormant seedings. Summer seedings also resulted in the least amount of broadleaf weeds the next year with dormant seedings having the most weeds, particularly with plots seeded to 95% KBG. All KBG-based seed mixtures provided turf containing ≈50% KBG or more by September, although the amount of KBG remaining after traffic was significantly greatest in plots seeded to 95% KBG and least in plots seeded with 70% KBG. Pure PRG swards provided acceptable turf quality throughout the traffic period but should be used cautiously as a result of winterkill potential and crown rust disease (Puccinia coronata Corda f. sp. agropyri Erikss.). Different amounts of traffic did not affect turf species proportions. The most consistently desirable results may be obtained with a mixture containing 70% to 80% KBG and 30% to 20% PRG, respectively. Mixtures dominated by KBG should be seeded in late summer for best results.
Incidence of Phytophthora and Pythium Infection and the Relation to Cultural Conditions in Commercial Blueberry Fields
Authors: Bryla David R. , Linderman Robert G. , Yang Wei Q.
Published: February 2019

Fifty-five commercial blueberry (Vaccinium spp.) fields were sampled in northwest Oregon in 2001 to determine the incidence of Phytophthora and Pythium root rot pathogens and identify cultural factors that increase the probability of developing infection. Phytophthora was detected in 24% and Pythium was detected in 85% of the fields sampled. The only species of Phytophthora identified in the study was P. cinnamomi. Root infection by P. cinnamomi was significantly related to cultivar with incidence observed more frequently than expected in ‘Duke’ and ‘Bluecrop’. Both blueberry cultivars are two of the most popular grown in the region, representing 42% of the fields in this survey and ≈46% of the total area planted in Oregon. Two other cultivars found infected by P. cinnamomi were ‘Rubel’ and ‘Briggitta Blue’, together accounting for an additional 24% of the fields surveyed. Phytophthora was not detected in fields planted with ‘Berkeley’, ‘Bluejay’, ‘Bluetta’, ‘Darrow’, ‘Earliblue’, ‘Elliott’, and ‘Powderblue’, each of which represented only 2% to 7% of the fields surveyed. Pythium spp. were identified to genus only, but one or more species of Pythium was found in all 11 cultivars included in the survey. Occurrence of either Phytophthora or Pythium was unrelated to soil type, planting age, or cultural practices such as bed type, cover crop, mulch, irrigation system, fertilizer application, fungicide use, or the source of plant material used in the fields. Overall, most fields with Phytophthora or Pythium remained largely symptomless under good soil drainage conditions and had similar levels of vigor as those without the pathogens.
Production Practices for Satsuma Mandarins in the Southeastern United States
Authors: Nesbitt Monte L. , Ebel Robert C. , Dozier William A.
Published: February 2019

Satsuma mandarin is presently the primary citrus crop for citrus growers in south Alabama, south Mississippi, and for certain new plantings in northwest Florida. Current growth in satsuma mandarin hectarage in Alabama is similar to the historical hectarage expansion that occurred during decades or clusters of years with a low incidence of lethal, freezing temperatures. Commercial groves currently range in size from 100 to 2000 trees and use various freeze protection strategies, including wind breaks, overstory frost protection with pine or pecan trees, under-tree and scaffold branch irrigation, and high tunnel polyethylene-covered greenhouses. The various methods of freeze protection require adjustments in cultural management practices, including spacing, pruning, irrigation, and fertilization. The primary rootstock used and recommended for its cold-hardiness and edaphic adaptation is Poncirus trifoliata. Some groves use ‘Swingle’ citrumelo, mainly because it is grown and propagated in Louisiana, where it is valued for its higher salt tolerance. ‘Owari’ was the original cultivar introduced to the United States from Japan in the late 19th century and is still the main cultivar in Alabama today, although earlier maturing cultivars, including ‘Brown Select’, ‘Early St. Ann’, and ‘LA Early’, are being introduced to extend the marketing season. Cultivars from Japan and China, including ‘Okitsu Wase’, ‘Miyagawa Wase’, and ‘Xie Shan’, are currently being evaluated for suitability in the region. Three general methods of culture with regard to spacing and pruning are discussed. Nitrogen application rates are typically low to moderate, yet leaf nitrogen levels surveyed in groves in 2005 were generally optimal or high with respect to published sufficiency levels for mature citrus in Florida.
Molecular Evidence for Progenitorial Species of Garden Petunias Using Polymerase Chain Reaction—Restriction Fragment Length Polymorphism Analysis of the Chs-j Gene
Authors: Zhang Xinwang , Nakamura Ikuo , Mii Masahiro
Published: February 2019

Wild species and cultivars of Petunia were subjected to analysis for clarifying the historical progenitors of garden petunias (Petunia hybrida) using polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) of Chalcone synthase J (Chs-J) gene. The PCR products for Chs-J intron with adjacent part of exons digested with RsaI enzyme revealed that P. integrifolia and P. inflata (P. integrifolia complex), both with purple flowers, had one large-sized band [650 base pairs (bp)], whereas P. axillaris (P. axillaris complex), a white-flowered species, showed two smaller-sized bands (200 or 280 bp and 350 bp). In P. axillaris, two different band patterns were found among the three subspecies: 200 and 350 bp for P. axillaris subsp. axillaris and 280 and 350 bp for P. axillaris subsp. parodii and subsp. subandina. The 200-bp band was revealed to be specific to P. axillaris subsp. axillaris. P. hybrida cultivars showed four different band patterns, each of which consisted of two to three of the four bands (200, 280, 350, and 650 bp) detected in the wild taxa examined. These results indicate that the wild species analyzed here might partially have contributed to the Chs-J gene of garden petunias analyzed and demonstrate the use of PCR-RFLP in establishing relationships among closely related species and cultivars of Petunia. The puzzling problem related to the possible contribution of more than one subspecies of P. axillaris is discussed.
Photosynthesis of Birch Genotypes (Betula L.) Under Varied Irradiance and CO2 Concentration
Authors: Gu Mengmeng , Robbins James A. , Rom Curt R. , Choi Hyun-Sug
Published: February 2019

Net CO2 assimilation (A) of four birch genotypes (Betula nigra L. ‘Cully’, B. papyrifera Marsh., B. alleghaniensis Britton, and B. davurica Pall.) was studied under varied photosynthetic photon flux density (PPFD) and CO2 concentrations (CO2) as indicators to study their shade tolerance and potential for growth enhancement using CO2 enrichment. Effect of water-deficit stress on assimilation under varied PPFD and (CO2) was also investigated for B. papyrifera. The light saturation point at 350 ppm (CO2) for the four genotypes varied from 743 to 1576 μmol·m−2·s−1 photon, and the CO2 saturation point at 1300 μmol·m−2·s−1 photon varied from 767 to 1251 ppm. Light-saturated assimilation ranged from 10.4 μmol·m−2·s−1 in B. alleghaniensis to 13.1 μmol·m−2·s−1 in B. davurica. CO2-saturated A ranged from 18.8 μmol·m−2·s−1 in B. nigra ‘Cully’ to 33.3 μmol·m−2·s−1 in B. davurica. Water-deficit stress significantly reduced the light saturation point to 366 μmol photon m−2·s−1 but increased the CO2 saturation point in B. papyrifera. Carboxylation efficiency was reduced 46% and quantum efficiency was reduced 30% by water-deficit stress in B. papyrifera.
Vegetative and Reproductive Response of Olive Cultivars to Moderate Saline Water Irrigation
Authors: Weissbein Sebastian , Wiesman Zeev , Ephrath Yhonathan , Silberbush Moshe
Published: February 2019

Selected superior olive cultivars cultivated on a large scale in various countries in the Mediterranean region were tested in a special saline irrigation experimental plot established in 1997 in the center of the semiarid Israeli Negev area. The plot comprised two subplots containing the same 12 olive cultivars in a mirror image design. One subplot was drip-irrigated with tap water (1.2 dS·m−1) and the second with moderate saline water (4.2 dS·m−1). All cultivation practices applied to the two subplots were similar in terms of fertilization, irrigation, soil leaching, and so on. The present study summarizes the vegetative and reproductive response of the tested olive cultivar trees during the 5 years after they reached maturation and full yield. Evaluation of trunk growth, olive yield, oil percentage, olive oil yield, and fatty acid composition of the oil, sodium and chloride leaf levels, and soil fractions up to 90 cm enabled characterization and comparison of the horticultural performance of the various olive cultivars intensively cultivated with the two tested irrigation treatments. The data clearly showed a significant difference between the tested cultivars in terms of growth, yield, and oil parameters. Grouping the tested cultivars in terms of olive oil production yielded the following three groups: Group A—‘Barnea’, ‘Maalot’, and ‘Picholin’—their average oil yield ranged from 8 to 10 kg/tree; Group B—‘Souri’, ‘Frantoio’, ‘Leccino’, ‘Arbequina’, ‘Picual’, ‘Kalamata’, ‘Koroneiki’, and ‘Picholin di Morroco’—their average oil yield ranged from 5 to 8 kg/tree; and Group C—‘Picudo’—ranged from 3 to 4 kg/tree. Saline irrigation treatment at 4.2 dS·m−1 demonstrated only a low rate of retardation effect on growth or yield of olive trees compared with water at 1.2 dS·m−1 of the same cultivar in each subplot. The data obtained from the present study suggest that efficient productive cultivation of mature olive cultivars in Israeli Negev semiarid conditions, irrigated with moderate saline water, is closely related to proper soil leaching methodology and maintaining the soil electrical conductivity level in the root zone in a range lower than 6 dS·m−1.
Nitrogen, Phosphorus, and Potassium Requirements for Optimizing Growth and Flowering of the Nobile Dendrobium as a Potted Orchid
Authors: Bichsel Rebecca G. , Starman Terri W. , Wang Yin-Tung
Published: February 2019

Experiments were conducted to determine how nitrogen (N), phosphorus (P), and potassium (K) rate and fertilizer termination time affect the growth and flowering of a Dendrobium nobile Lindl. hybrid, Dendrobium cv Red Emperor ‘Prince’. Nitrogen, P, and K were tested in separate experiments as a factorial combination of five rates and three termination dates (1 Sept., 1 Oct., and 1 Nov. 2005). Nitrogen and K rates were 0, 50, 100, 200, and 400 mg·L−1. Phosphorus rates were 0, 25, 50, 100, and 200 mg·L−1. Levels of the nutrients not being tested were held constant. For all nutrients, ending fertilization on 1 Sept. resulted in greater or similar pseudobulb thickness compared with ending fertilization on 1 Oct. or 1 Nov. Pseudobulbs grew taller as the N rate increased, peaking at 100 and 200 mg·L−1. There were interactions between the N rate and fertilizer termination time on all reproductive characteristics. For all fertilizer termination times, flower number increased once N was applied. When ended on 1 Nov., 200 and 400 mg·L−1 N caused a delay to reach anthesis. All P rates resulted in taller plants with equally more nodes when compared with 0 mg·L−1. As the K rate increased from 0 to 100 mg·L−1, plant height increased, with no further increase at higher rates. The number of leaves remaining increased as N and K rates increased up to 200 mg·L−1. Total flower number and flowering node number increased as the K rate increased to 100 mg·L−1 (terminated on 1 Sept.) or 50 mg·L−1 (terminated on 1 Oct. or 1 Nov.). In the fourth experiment, only N was ended at four termination times, whereas all other nutrients continued to be supplied until flowering. Control plants received all fertilizer elements until flowering. The duration of N application did not affect vegetative or flowering characteristics. No aerial shoots were observed as a result of prolonged application of N at all rates. In summary, 100 mg·L−1 N, 25 mg·L−1 P, and 100 mg·L−1 K are recommended for optimal vegetative growth and reproductive development of Dendrobium cv Red Emperor ‘Prince’.
The Effects of Flood Initiation Timing and Water Temperature During Flooding on Nonstructural Carbohydrate Concentration and Anatomy of Cranberry
Authors: Vanden Heuvel Justine E. , Goffinet Martin C.
Published: February 2019

The objective of this research was to determine the effect of water temperature during spring and fall floods on nonstructural carbohydrate concentration and anatomy/morphology of ‘Stevens’ and ‘Early Black’ cranberry vines. Potted vines of each cultivar were subjected to either a simulated 1-month late water (LW) flood in the spring at either 11 or 21 °C or a simulated 1-week harvest flood in the fall at either 12 or 20 °C. Higher water temperature resulted in decreased total nonstructural carbohydrate concentration (TNSC) during the LW flood in both uprights (i.e., vertical shoots) and roots of ‘Early Black’ and ‘Stevens’. The effect of water temperature was much less during the harvest flood than during the LW flood, but flooding at either temperature during the harvest flood had an impact on TNSC, whereas for LW floods, high water temperature was more influential than low water temperature. Clumping of chloroplasts in the palisade layer and occlusion of vascular tissues was observed in the leaves of both cultivars as a result of LW flooding. Some epidermal erosion and formation of a fungal mat was apparent on the upper epidermis of some flooded leaves. Senescence in some fine roots was visible after harvest flooding, more so in vines flooded at 20 °C than at 12 °C. Stems and major roots showed no influence of flooding on tissue senescence.
High NO3-N to NH4-N Ratios Promote Growth and Flowering of a Hybrid Phalaenopsis Grown in Two Root Substrates
Authors: Wang Yin-Tung
Published: February 2019

Young, bare-root plants (three leaves, 15 cm in leaf spread) from a vegetatively propagated clone of Phalaenopsis Blume x Taisuco Kochdian were imported in late May and planted in a mix consisting of three parts medium-grade Douglas fir bark and one part each of perlite and coarse peat (by volume) or in pure Chilean sphagnum moss. All plants were given 221 N, 124 P, 515 K, 100 Ca, and 50 Mg (all in mg·L−1) when being irrigated. The total N varied from 0%, 25%, 50%, 75%, to 100% NO3-N with the balance being NH4-N. Plants were fertigated when the substrate became dry. For both substrates, as the percentage of NO3-N increased, plants produced slightly fewer leaves. Regardless of the NO3-N to NH4-N ratio, plants grown in moss produced one extra leaf than those planted in the bark mix during an 8-month period. There was a tendency of increasing top leaf length and width as well as the whole-plant leaf spread as NO3-N increased from 0% to 100% in either substrate. Plants receiving 50% or more NO3-N in either substrate spiked and flowered 2 weeks earlier than those given 25% or 0% NO3-N. When grown in the bark mix, flower count, flower diameter, and inflorescence length all increased as NO3-N increased from 0% to 75%. Flower stem (inflorescence, 5 cm from the base) became progressively thicker as NO3-N increased from 0% to 100%. Only two among the 24 plants grown in moss and receiving 100% NH4-N bloomed. These results suggest that Phalaenopsis does not grow well with 100% NH4-N and must be provided with NO3-N at no less than 50%, preferably 75%, of the total N for improved growth and flowering.
Architectural Development of Inflorescence in Hydrangea macrophylla cv. Hermann Dienemann
Authors: Galopin Gilles , Codarin Sandrine , Viemont Jean-Daniel , Morel Philippe
Published: February 2019

Architectural development of inflorescence in Hydrangea macrophylla cv. Hermann Dienemann was observed using scanning electron microscopy. The study of inflorescence morphogenesis shows that the architecture is of the dichasial type. The first two orders of branching are initiated from a dichasial branching without floral differentiation. The following orders present floral differentiation. They determine the formation of small units through the development of composite dichasium into biparous and uniparous cymes. This research makes it possible to establish a schematic representation of the first phases of inflorescence development and to define early stages of inflorescence morphogenesis.
Effectiveness of Marketing Promotion Programs: The Case of Texas Citrus
Authors: Williams Gary W. , Capps Oral , Palma Marco A.
Published: February 2019

This article analyzes the effectiveness of Marketing Order 906 in promoting Texas grapefruit and oranges and focuses specifically on the answers to two key questions: 1) What have been the effects of the promotion programs funded under Marketing Order 906 on shipments of Texas grapefruit and oranges? 2) What has been the return on the investment made under Marketing Order 906 to promote sales of Texas grapefruit and oranges? The article first provides some background on the Texas citrus promotion program and then develops a seemingly unrelated regression econometric model of Texas grapefruit and orange shipments for the analysis of the effectiveness of the program. The results obtained indicate that the Texas citrus promotion program has been effective in enhancing shipments of Texas grapefruit but not oranges and that the benefits of the promotion efforts have exceeded the costs, at least for grapefruit. Insights are drawn for other commodity promotion programs.
Severity of Verticillium Wilt, Plant Growth, and Spectral Reflectance Indices of Chile Pepper Under Periodic Flooding and No-flooding Conditions
Authors: Sanogo Soumaila , El-Sebai Osama I. , Sanderson Robert
Published: February 2019

Verticillium wilt, caused by Verticillium dahliae, is an economically important disease on chile pepper (Capsicum annuum L.), which is grown primarily under furrow and drip irrigation in New Mexico. Field observations by producers indicate that Verticillium wilt is more prevalent on chile pepper grown under drip irrigation than under furrow irrigation. To test these observations, chile pepper plants at the six- to eight-leaf stage inoculated or noninoculated with V. dahliae were subjected to either periodic flooding or no-flooding conditions in the greenhouse. Plants under periodic flooding were subjected to three events of 7 day flooding and two events of no flooding over a period of 5 weeks. Differences among treatments were assessed using disease severity, plant dry weight, and spectral reflectance-based physiological indices such as moisture stress index (MSI), chlorophyll-based difference index, water band index, and photochemical reflectance index (PRI). There was a significant interaction between flooding and inoculation with respect to disease severity (P < 0.003). In plants inoculated with V. dahliae and subjected to periodic flooding, the relative treatment effect (RTE) based on disease severity was increased from 40% to 130% relative to noninoculated plants subjected to no flooding. However, under conditions of no flooding, RTE increased by ≈200% to 286% when plants were inoculated with V. dahliae relative to noninoculated plants. In general, periodic flooding and inoculation with V. dahliae were accompanied by a decrease in plant dry weight as well as in the level of spectral reflectance-based physiological indices. In noninoculated plants subjected to periodic flooding, plant dry weight was reduced by ≈45% to 50% relative to noninoculated plants subjected to no flooding. In plants inoculated with V. dahliae and subjected to periodic flooding, reduction in plant dry weight was ≈46% to 60% relative to noninoculated plants subjected to no flooding. Under conditions of no flooding, plant dry weight was reduced by ≈33% to 52% when plants were inoculated with V. dahliae relative to noninoculated plants. Of all the spectral reflectance-based physiological indices, PRI was the most affected by flooding and inoculation. For noninoculated plants, the mean area under the curve for PRI (AUC-PRI) was decreased by ≈90% under periodic flooding relative to no flooding. In plants inoculated with V. dahliae and subjected to periodic flooding, reduction in AUC-PRI was ≈93% relative to noninoculated plants subjected to no flooding. Under conditions of no flooding, AUC-PRI was reduced by ≈93% when plants were inoculated with V. dahliae relative to noninoculated plants. These results showed that chile pepper growth and physiology were affected similarly by flooding and inoculation with V. dahliae. However, severity of Verticillium wilt was greater under no-flooding than under periodic flooding conditions.
Effect of Style of Cut and Storage on Phenolic Composition and Antioxidant Activity of Fresh-cut Sweetpotatoes
Authors: Padda Malkeet S. , Picha David H.
Published: February 2019

Three different style fresh-cut (shredded, French fry, and sliced) sweetpotatoes [Ipomoea batatas (L.) Lam.] were stored at 0 and 5 °C for 4 and 8 days. At specified storage intervals, the fresh-cut sweetpotatoes were analyzed for total phenolics, individual phenolic acids, and antioxidant activity. Sweetpotato tissue analyzed immediately after cutting was considered the control. Storage at 5 °C resulted in an increase in total phenolics in all types of fresh-cut sweetpotatoes, except in shredded tissue analyzed after 4 days of storage. However, at 0 °C, only sliced tissue accumulated higher total phenolics than the control. In general, antioxidant activity in all fresh-cut sweetpotatoes held at 5 °C was higher than in the control. No significant increase in antioxidant activity was observed in shredded sweetpotatoes stored at 0 °C. Chlorogenic acid followed by 3,5-dicaffeoylquinic acid were the predominant phenolic acids present in fresh-cut sweetpotatoes. The highest content of chlorogenic acid (539.9 μg·g−1 dry weight) in sliced tissue stored for 8 days at 5 °C was ≈6-fold higher than in the control (88.3 μg·g−1 dry weight). No significant development of tissue browning, off-odors, or off-flavors were observed after 8 days of storage and the products were considered to be marketable.
Effects of Reclaimed Municipal Waste Water on Horticultural Characteristics, Fruit Quality, and Soil and Leaf Mineral Concentration of Citrus
Authors: Morgan Kelly T. , Wheaton T. Adair , Parsons Larry R. , Castle William S.
Published: February 2019

Water Conserv II is a municipal reclaimed water project operated by the city of Orlando and Orange county, FL. The Water Conserv II project has been supplying high-quality reclaimed water for irrigation of citrus orchards, nurseries, greenhouse operations, golf courses, and residential landscapes in Orange and Lake counties since 1986. Selected commercial citrus orchards in the Water Conserv II service area receiving either groundwater or reclaimed water have been monitored quarterly since the project began. This yearly monitoring was undertaken to determine any adverse long-term effects on citrus tree growth or production associated with irrigation using this reclaimed water. Citrus blocks were rated for horticultural condition quarterly, fruit quality was determined before harvest, and soil and leaf samples were analyzed yearly from 1994 to 2004. Citrus growers irrigating with reclaimed water were encouraged to use higher-than-recommended amounts of water as a means of disposal of this reclaimed water resulting in increased weed growth and dilution of juice solids per box of fruit. Leaf boron and magnesium were significantly higher after irrigation with reclaimed water. Calcium and boron from the reclaimed water have eliminated the need in orchards receiving reclaimed water for liming of the soil and applying annual foliar sprays containing boron.