bluuebunny/crossref_metadata_2025 huggingface dataset:
Western Flower Thrips, Frankliniella occidentalis (Thysanoptera: Thripidae): Evaluation of Potential Attraction to Vanilla Extract under Laboratory and Greenhouse Conditions
Authors: Herrick Nathan J. , Cloyd Raymond A.
Published: February 2019

Plant-derived essential oils or extracts and their associated volatiles can serve as insect attractants to enhance adult captures when used as whole plants or extracts that are incorporated onto colored sticky traps. In our study, we initially assessed the attractiveness of western flower thrips (WFT) (Frankliniella occidentalis) adults to vanilla extract in the laboratory using choice and no-choice experiments by comparing one (0.05 mL) and two (0.10 mL) drops of vanilla extract (0.029% and 0.059%, respectively). In the choice experiments, a drop of water and drop of vanilla extract were placed on opposite sides of a petri dish. One WFT was placed in the center of the petri dish, and observations were made on whether there was preferential movement to the water or vanilla extract. For the no-choice experiments, one petri dish only contained a drop of water, whereas another petri dish only contained a drop of vanilla extract. One WFT was placed into each petri dish and movement was observed to assess whether the WFT moved toward the water or to the vanilla extract. We then determined if yellow sticky cards containing vanilla extract were more attractive to WFT adults than those with water, by using the number of adults captured on yellow sticky cards as an estimate under greenhouse conditions. Western flower thrips adults were not attracted to vanilla extract based on the results associated with the choice and no-choice tests conducted under laboratory conditions with no differences in selection between vanilla extract and water. In addition, there was no evidence that inoculating yellow sticky cards with vanilla extract enhanced the number of adults captured on yellow sticky cards. Overall, the use of vanilla extract in attracting WFT adults to yellow sticky cards is not justifiable under the parameters of our study.
Ex ante Economic Evaluation of Technologies for Managing Postharvest Physiological Disorders: The Case of ‘Empire’ Apples in New York State
Authors: Rickard Bradley J. , Rudell David R. , Watkins Christopher B.
Published: February 2019

Recently there has been much progress in the development of technologies that use biomarkers to detect and manage postharvest physiological disorders for apples in long-term storage. Such technologies have the capacity to alleviate fruit loss by allowing storage operators to more effectively manage the disorder by adjusting stock distribution. The technology may also reduce costs for storage materials and associated management activities. However, as is common for many new technologies that have not yet been adopted commercially in agriculture, the net economic value of the technology is not well understood and is difficult to assess ex ante. In horticultural markets that include quality (and price) differentiated products, technologies that affect grading are expected to impact revenues in nontrivial ways. Here we develop a framework to assess the likely range of economic implications associated with the adoption of the biomarker technology that allows a greater share of fruit to be marketed in a higher grade and may influence the costs of storing fruit. Results indicate that 10% increases in the share of higher quality fruit lead to increased profits of between 0.99% and 3%. A scenario that leads to a 10% increase in the share of fruit in higher grades and a 10% decrease in material costs for storage would increase profits by ≈4.4%. Our analysis and results are specific to the case of biomarker use to manage postharvest disorders for ‘Empire’ [Malus sylvestris (L.) Mill var. domestica Borkh.] apples, yet the framework can be used with cultivar-specific price and yield information to assess the ex ante economic implications of adopting the technology more generally.
Ascorbic Acid Content in ‘Passe-Crassane’ Winter Pear as Affected by 1-Methylcyclopropene during Cold Storage and Shelf Life
Authors: Cocetta Giacomo , Mignani Ilaria , Spinardi Anna
Published: February 2019

‘Passe-Crassane’ is a winter pear which requires a cold storage period to produce ethylene and properly ripen. In this study, the effects of 1-methylcyclopropene (1-MCP), an ethylene perception inhibitor, were studied during cold storage (30, 60, 90, and 135 days) and shelf life at 20 °C (30 days) of ‘Passe-Crassane’ pears. Ethylene accumulation was monitored and quality parameters were measured. Oxidative stress of fruit was estimated by measuring lipid peroxidation. The cell antioxidant status was assayed determining ascorbic acid (AsA) content and the activities of the enzymes ascorbate peroxidase (APX), monodehyroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR) involved in its oxidation and recycling. AsA content was positively affected by higher temperature (20 °C) and by 1-MCP after 90 days of storage. This effect was more evident after shelf life. Thiobarbituric acid reactive substances (TBARS) increased in pears kept at 20 °C and in treated pears, starting from 60 days of cold storage and remained elevated after shelf life. Although during storage 1-MCP enhanced the activities of APX and DHAR only at 90 days, after shelf life the effect on APX, MDHAR, and DHAR activities was more pronounced and enzyme activities were higher in treated pears sampled after 60 and 90 days of storage. The results indicate that 1-MCP has a beneficial effect on the antioxidant potential of winter pears: it maintained high AsA levels throughout storage and shelf life and improved the enzymatic mechanisms of AsA recycling, especially after shelf life. The effect of 1-MCP on pear ripening may not be solely due to its action on ethylene but also to an increase in antioxidant defense. A stress response linked to lipid peroxidation is triggered by the interaction of cold temperatures and treatment as ‘Passe-Crassane’ pears acquires ripening competence. However, it may be compensated by the high AsA content.
Screening of Lettuce Germplasm for Agronomic Traits under Low Water Conditions
Authors: Eriksen Renée L. , Knepper Caleb , Cahn Michael D. , Mou Beiquan
Published: February 2019

After a preliminary screening of over 3500 cultivars, we selected 200 butterhead, cos, crisphead, leaf, and stem lettuce (Lactuca sativa L.) and wild prickly lettuce (Lactuca serriola L.) varieties to test under high water (150% evapotranspiration [ET]) and low water (50% ET) conditions in the field, and tracked commercially relevant traits related to growth and marketability, maturity, and physiology. Plants typically reduced growth and appeared to reallocate developmental resources to achieve maturity quickly, as indicated by traits such as increased core length. This strategy may allow them to complete their life cycle before severe drought stress proves lethal. Although most cultivars experienced a reduction in growth under low water conditions relative to high water conditions, some cultivars had a significantly reduced yield penalty under stress conditions. Among the different types of lettuce, the fresh weight (FW) of cos cultivars was most affected by drought stress, and the FW of leaf lettuce was least affected. Cos cultivars tended to bolt early. Crisphead cultivars Cal-West 80, Heatmaster, and Marion produced large heads and did not bolt under low water treatments, and butterhead cultivars Buttercrunch and Bibb also produced relatively large heads with very little bolting and no signs of tipburn. The four green leaf cultivars Slobolt, Grand Rapids, Western Green, and Australian showed no statistically significant difference in FW among high and low water treatments in multiple trials, and may be good choices for growers who wish to minimize losses under reduced irrigation. The identification of potentially drought-tolerant varieties and the information from this study may be helpful for cultivar selection by growers under drought conditions, but this study also serves as a step forward in the genetic improvement of lettuce to drought stress.
Characterizing the Frequency Distributions for Fruit Firmness of Sweet Cherry Cultivars
Authors: Stanich Kareen , Cliff Margaret , Hampson Cheryl
Published: February 2019

Fruit firmness is among the most important characteristics for the quality of sweet cherries. However, little has been published on its underlying frequency distribution. This research was undertaken to examine the firmness distributions (n = 48) from six cultivars [Sandra Rose, Summit, Lapins, Skeena, Sumtare (Sweetheart™), and 13S2009 (Staccato™)], two field treatments [with or without gibberellic acid (GA)], two storage times (0 and 7 days), and two growing seasons (2013 and 2014). Fruit was sampled (n = 300) at optimal maturity and firmness was evaluated using the FirmTech2 Fruit Firmness Tester. Firmness distributions were examined using descriptive statistics: mean, median, standard deviation (sd), minimum, maximum, range, skewness, and excess kurtosis. Nonnormality was assessed using skewness and kurtosis test statistics. Exponential models were fitted to the ascending and descending portions of the distributions and the proportion of “too soft” (percentage < 2.56 N·mm−1) and “too hard” (percentage > 4.71 N·mm−1) fruit was determined. A relatively high proportion of distributions were nonnormal (16/24 to 18/24), either skewed, peaked, or both. While most skewed distributions were skewed negatively, with a higher proportion of softer fruit, the distributions for ‘Sandra Rose’ were skewed positively, with a higher proportion of firmer fruit. Principal component analysis (PCA) showed seasonal, cultivar, treatment, and storage effects among three subsets of cultivars with differing characteristic firmness. The softer early-harvest cultivars (Sandra Rose and Summit) had a higher proportion of “too soft” fruit. GA and storage treatments increased mean firmness and reduced the proportion of “too soft” fruit. The firmer late-harvest cultivars (Skeena, Sumtare, and 13S2009) had a small proportion of “too hard” fruit (0% to 19.3%). The work gained insight into the nature of the firmness distributions for sweet cherries and the type of statistics that are most appropriate for analyzing the data.
Growth Analysis and Photosynthesis Measurements of Cucumber Seedlings Grown under Light with Different Red to Far-red Ratios
Authors: Shibuya Toshio , Endo Ryosuke , Kitaya Yoshiaki , Hayashi Saki
Published: February 2019

Light with a higher red to far-red ratio (R:FR) than sunlight reduces plant growth, but the cause has not been firmly established. In the present study, cucumber seedlings were grown under normal light (similar to sunlight; R:FR = 1.4) from metal-halide lamps or high-R:FR light (R:FR = 4.3) created by transmitting their light through FR-absorbing film, and then their growth parameters and photosynthesis were compared. The relative growth rate (RGR) at high R:FR was 92% of that under normal R:FR, although the net assimilation rate (NAR) did not differ between the treatments, indicating that changes in net photosynthesis per unit leaf area did not cause the growth inhibition at high R:FR. The CO2 exchange per unit leaf area did not differ between the treatments, which supports this hypothesis. The leaf area ratio (LAR) of total plant dry weight of high R:FR seedlings to that of normal R:FR seedlings was also 92%. This suggests that growth suppression in the high R:FR seedlings was caused mainly by decreased LAR. The specific leaf area (SLA) and leaf weight ratio (LWR), components of LAR, under high-R:FR light were 89% and 105%, respectively, of those under normal light, indicating that the smaller LAR at high R:FR mainly results from suppressed leaf enlargement per unit leaf dry matter.
Effects of Trunk-shaker Harvester and Ethephon on Plant Water Status, Leaf Gas Exchange, and Yield of Citrus Cultivated under Mediterranean Conditions
Authors: Moreno Rosana , Intrigliolo Diego S. , Ballester Carlos , Garcerá Cruz , Moltó Enrique , Chueca Patricia
Published: February 2019

This work was aimed to study whether the application of ethephon as an abscission agent and mechanical harvest using a trunk shaker have any effect on plant water status, leaf gas exchange, and yield of mandarin and orange trees cultivated under Mediterranean conditions. The experiment was performed from 2008 to 2011 in five commercial orchards where parameters related to the plant water status and leaf gas exchange were measured before the application of ethephon, at harvest time and at different occasions after harvest. In addition, the effects of ethephon dose on yield in the current and subsequent seasons were also evaluated. Results showed that ethephon applications and mechanical harvest did not detrimentally affect plant water status in any of the cultivars studied. Furthermore, either had no effect or had a short temporal decrease effect on leaf gas exchange depending on the cultivar studied although with no consequences for the fruit yield obtained during the current season. Increasing ethephon doses led to fruit yield reductions in the mandarin ‘Orogrande’ trees in subsequent seasons. When trunk-shaker and ethephon applications were combined, however, yields from the late-maturing orange significantly decline in subsequent seasons. Overall, results show that using a trunk shaker is a viable technique to mechanically harvest citrus trees destined to both fresh and industry market and can be considered as an alternative to the traditional manual harvest usually performed under Mediterranean conditions. However, its use cannot be recommended for late-maturing oranges, such as the ‘Navel Lane Late’ in which mature fruit and fruitlets coexist in the tree at the time of harvest.
Evapotranspiration-based Irrigation Scheduling of Head Lettuce and Broccoli
Authors: Johnson Lee F. , Cahn Michael , Martin Frank , Melton Forrest , Benzen Sharon , Farrara Barry , Post Kirk
Published: February 2019

Estimation of crop evapotranspiration supports efficient irrigation water management, which in turn supports water conservation, mitigation of groundwater depletion/degradation, energy savings, and crop quality maintenance. Past research in California has revealed strong relationships between fraction of the ground covered by photosynthetically active vegetation (Fc), crop coefficients (Kc), and evapotranspiration (ET) of cool-season vegetables and other specialty crops. Replicated irrigation trials for iceberg lettuce and broccoli were performed during 2012 and 2013 at the USDA Agricultural Research Station in Salinas, CA. The main objective was to compare crop yield and quality from ET-based irrigation scheduling with industry standard practice. Sprinkler irrigation was used to germinate and establish the crops, followed by surface drip irrigation during the treatment period. Each experiment compared three irrigation treatment schedules replicated five times in a randomized block design. Two decision-support models were evaluated as follows: 1) an FAO-56-based algorithm embedded in NASA’s prototype Satellite Information Management System (SIMS) based on observed Fc, and 2) CropManage (CM), an online database-driven irrigation scheduling tool based on modeled Fc. Both methods used daily reference ETo data from the California Irrigation Management Irrigation System (CIMIS) to translate Kc to crop ET, with a target of 100% replacement of water use during the drip irrigation phase. A third treatment followed an irrigation schedule representing grower standard practice (SP) at 150% to 175% ET replacement during the drip irrigation phase. No significant treatment differences were seen in lettuce head weight or total biomass. Marketable yields of lettuce (near 45.4 Mg·ha−1) and broccoli (near 17.4 Mg·ha−1) were in-line with industry averages during both years and all treatments. During 2012, CM yield was below lettuce SP, and above broccoli SP, while in 2013 no treatment differences were detected for either crop. No significant differences were detected between SIMS and SP yields during any trial.
Effect of Forced-air Cooling, Hydrocooling, or their Combination on Fruit Quality of Two Southern Highbush Blueberry Cultivars
Authors: Carnelossi Marcelo A.G. , Sena Edinaldo O.A. , Berry Adrian D. , Sargent Steven A.
Published: February 2019

Blueberry is widely grown around the world, and the United States is the leading producer. A strategy to maintain fruit quality during commercial handling is rapid cooling using the forced-air system. Hydrocooling (HY) is an effective cooling method widely used for many crops and has potential as a cooling method for blueberry. The objective of this study was to compare the cooling efficiency of conventional forced-air cooling (FA), the current commercial method, with immersion HY alone or HY in combination with FA (HY + FA), and to determine effects on blueberry fruit quality during subsequent cold storage. ‘Emerald’ and ‘Farthing’ southern highbush blueberry were commercially harvested and packed into plastic clamshell containers. FA was accomplished by simulating commercial conditions using a small-scale unit within a cold room at 1 °C/80% relative humidity (RH) until 7/8 cooling was achieved (27 minutes). For HY, fruit in clamshells (125 g) were immersed in chlorinated ice water (200 ppm free Cl−1, pH = 7.0) and 7/8 cooling occurred in 4 minutes. For HY + FA, fruit were 7/8 hydrocooled then transferred to FA for 30 minutes to remove free water from the fruit. After the cooling treatments, clamshells were evaluated weekly for selected quality parameters during 21 days storage at 1 °C. For HY treatment, the 1/2 cooling time was 1.13 minutes for ‘Emerald’ and 1.19 minutes for ‘Farthing’, whereas for FA treatment, the 1/2 cooling times were 4.5 and 6.8 minutes, respectively. For ‘Farthing’, cooling method did not affect fruit firmness; after 21 days, there was a slight softening in fruit from all treatments. However, ‘Emerald’ fruit cooled by HY + FA were softer than those from either HY or FA after 14 days of storage. For all cooling methods ‘Emerald’ was less acidic (0.3% citric acid) and was sweeter [10.2% soluble solids content (SSC)] than ‘Farthing’ (0.6% citric acid, 9.4% SSC). There were no differences in bloom among cooling methods. Bloom ratings for ‘Emerald’ remained >4.5 (70% to 80% coverage) whereas that for ‘Farthing’ cooled by HY or HY + FA was 3.7. Anthocyanin concentration in ‘Emerald’ fruit from HY + FA cooling method decreased by 33% during 21 days of storage, whereas that for ‘Farthing’ remained constant (8.3 mg cyanidin-3-Glicoside/g) irrespective of treatment during storage. Compared with ‘Farthing’, ‘Emerald’ was more sensitive to HY, where ≈15% of fruit developed visual skin breaks (split) after 7 days storage. HY shows potential as an alternative method to rapidly and thoroughly cool southern highbush blueberries such as ‘Farthing’, thus, maintaining fruit quality, while introducing a rinsing and sanitizing treatment. HY needs to be tested on commercial cultivars to determine the incidence of fruit splitting.
Investigating the Practices and Challenges for Turfgrass Breeders and Distributors
Authors: Yue Chengyan , Wang Jingjing , Watkins Eric , Bonos Stacy A. , Nelson Kristen C. , Murphy James A. , Meyer William A. , Horgan Brian P.
Published: February 2019

An online survey was conducted to investigate the current practices of and challenges for turfgrass breeders and turfgrass seed distributors (or sales staff) in the United States. We found that turfgrass seed breeders rated producers/growers and consumers as more important parties compared with other interested parties. However, variations in ratings were found for breeders/distributors according to different program characteristics. The volume of seed sales of the species was the most highly rated technical consideration for both breeders and distributors. Compared with distributors, breeders considered the following technical factors more important than others: funding, labor, field trial performance, diversity in working priorities, availability of germplasms, scheduling, and staff training. Costs, followed by resource allocation and resource availability, were rated as the most challenging factors when breeders were implementing priorities. Our findings provide important insight regarding breeding and distribution practices and management in the turfgrass industry.
Virus Movement from Infected Sweetpotato Vines to Roots and Reversion on Root Sprouts
Authors: Adikini Scovia , Mukasa Settumba B. , Mwanga Robert O.M. , Gibson Richard W.
Published: February 2019

Sweetpotato is usually propagated in Uganda by vine cuttings from mature crops, but sometimes sprouts from storage roots are used, especially in drought-prone areas. No information is available on whether the storage of roots of Ugandan cultivars are infected with the viruses and whether the sprouts on them express symptoms so that farmers can eliminate diseased ones. Information on root sprout reversion from virus infection is also lacking. The storage roots of five sweetpotato cultivars was sourced either by random selection of roots from already harvested roots or obtained from symptomless plants selected before harvest at Makerere University Agricultural Research Institute, Kabanyolo (MUARIK), and the National Semi Arid Resources Research Institute (NaSARRI). Roots were also generated in a screenhouse after being inoculated with Sweet potato feathery mottle virus (SPFMV) and/or Sweet potato chlorotic stunt virus (SPCSV). More than 70% of sprouts from roots of all the cultivars selected after harvest at MUARIK and NaSARRI were infected with the viruses. For roots obtained from symptomless plants, 64% and 21% of the sprouted roots from MUARIK and NaSARRI were infected with the viruses, respectively. Most of the root samples from MUARIK had visible virus symptoms on sprouts and tested positive for both SPFMV and SPCSV, whereas those from NaSARRI did not show symptoms and were infected primarily with SPFMV. Plants graft-inoculated with either SPCSV or SPFMV alone produced both infected and noninfected roots, whereas all the root sprouts from dually infected plants showed virus symptoms. Reversion from virus infection was observed on root sprouts infected singly with SPFMV, whereas those infected with SPCSV showed recovery only, and none of the root sprouts infected by both viruses showed recovery. This study proves that roots are good reservoirs for viruses, and reversion occurs only when singly infected with SPFMV. Therefore, there is a need to establish seed channels in which seedstock is cleaned continuously and made available to farmers.
Nitrogen Management for Improving Root and Shoot Components of Young ‘Arbequina’ Olives
Authors: Leskovar Daniel , Othman Yahia A.
Published: February 2019

The impact of nitrogen application on the growth of olive trees has been well studied. However, little is known about the role of levels and forms of N on the development of roots and physiological traits during establishment of young trees. The objective of this 2-year study was to evaluate the influence of N source and level on shoot morphology (tree height, stem diameter, and branch number) and physiology [leaf area and fresh weight, photosynthesis (Pn), transpiration (E), and stomatal conductance (gs)], root components (length, diameter, surface area, and fork number) and N content of young olive (Olea europaea cv. Arbequina) cuttings. Three-month-old olive cuttings were planted in 15-L pots filled with a growing substrate composed of peatmoss + bark + sand (2:1:1/by volume) and placed in a screen house. Two N levels, 2.8 and 5.6 g/tree, and control (0 N) and four N sources, calcium nitrate (CN, 12%N, 17%Ca+2), ammonium nitrate (AN, 35%N), urea (46%N), and the slow-release Osmocote (OSC, 18%N, 6%P, 12%K) were evaluated. Effects of low– (2.8 g/tree) and high N (5.6 g/tree) levels on shoot components (plant height, diameter, branch number, leaf area, and fresh weight) and gas exchange (Pn, gs and E) were similar implying that the low rate of N was adequate for the establishment of young olive cuttings. Nitrogen sources, particularly AN and CN had significant effects on shoot and root morphology, physiology, and leaf and root N concentration. In fact, AN and CN were the best fertilizer sources for olive transplants in term of root and shoot growth. Overall, 2.8 g/tree N level and AN or CN sources were the best treatments for newly established olive ‘Arbequina’ trees. Root components treated with high N rate (5.6 g/tree N) using the slow-release fertilizer (OSC) was similar to those treated with the low AN rate (2.8 g/tree N). Therefore, for nursery containerized olive trees of ‘Arbequina’ or other cultivars with comparable growth rates, we recommend to apply the CN or AN source at 2.8 g/tree N or the controlled-released fertilizer OSC at 5.6 g/tree N.
High Storage Humidity Affects Fruit Quality Attributes and Incidence of Fruit Cracking in Cold-stored ‘Royal Gala’ Apples
Authors: Lee Jinwook , Mattheis James P. , Rudell David R.
Published: February 2019

‘Royal Gala’ apples can be susceptible to the incidence of fruit cracking and senescent flesh breakdown during cold storage. Because the development of these physiological disorders in other cultivars can be influenced by humidity during storage, the objective of this study was to evaluate the effect of high storage humidity on fruit quality attributes and incidence of physiological disorders in cold-stored ‘Royal Gala’ apples. Fruit obtained from a commercial orchard were kept in cardboard boxes with or without a perforated polyethylene liner during and after cold storage. High storage humidity induced by the perforated polyethylene liner reduced fresh weight loss but enhanced the change of fruit circumference after cold storage. High storage humidity contributed the most reduction of cortex lightness (L*) and hue angle (ho) in stem-end cortex tissues during shelf life. Fruit stored with liners had reduced internal ethylene concentration (IEC) and outer cortex firmness after removal from storage compared with control fruit. Furthermore, high storage humidity prevented shriveling but provoked fruit cracking. The incidence and severity of flesh breakdown were further aggravated during shelf life, compared with cold storage, regardless of a liner application. Overall, maintaining high storage humidity by applying a perforated polyethylene liner can contribute to delaying fresh weight loss, reducing IEC, and preventing fruit shriveling but can enhance cortex tissue browning, loss of flesh firmness, and incidence of fruit cracking during cold storage and shelf life.
Nitrogen Fertilization and Irrigation Frequency Affect Hydrangea Growth and Nutrient Uptake in Two Container Types
Authors: Li Tongyin , Bi Guihong , Harkess Richard L. , Denny Geoffrey C. , Scagel Carolyn
Published: February 2019

Plant growth, water use, photosynthetic performance, and nitrogen (N) uptake of ‘Merritt’s Supreme’ hydrangea (Hydrangea macrophylla) were investigated. Plants were fertilized with one of five N rates (0, 5, 10, 15, or 20 mm from NH4NO3), irrigated once or twice per day with the same total daily amount of water, and grown in either a paper biodegradable container or a traditional plastic container. Greater N rate generally increased plant growth index (PGI) in both plastic and biocontainers. Leaf and total plant dry weight (DW) increased with increasing N rate from 0 to 20 mm and stem and root DW were greatest when fertilized with 15 mm and 20 mm N. Plants fertilized with 20 mm N had the greatest leaf area and chlorophyll content in terms of SPAD reading. Container type had no influence on DW accumulation or leaf area. N concentrations (%) in leaves, roots, and the entire plant increased with increasing N rate. N concentrations in roots and in the entire plant were lower in biocontainers compared with plastic containers. Greater N rate generally increased daily water use (DWU), and biocontainers had greater DWU than plastic containers. The 20 mm N rate resulted in the highest net photosynthetic rate measured on 11 Sept. and 22 Sept. (65 and 76 days after treatment). Net photosynthetic rate (measured on 8 Oct.) and stomatal conductance (gS) (measured on 27 Aug., 22 Sept., and 8 Oct.) were lower in biocontainers compared with plastic containers. Two irrigations per day resulted in higher substrate moisture at 5-cm depth than one irrigation per day, and slightly increased PGI on 19 Aug. However, irrigation frequency did not affect photosynthetic rate, gS, or N uptake of hydrangea plants except in stems. Considering the increased water use of hydrangea plants when grown in the paper biocontainer and lower plant photosynthesis and N uptake, the tested paper biocontainer may not serve as a satisfactory sustainable alternative to traditional plastic containers.
Organic Acids Exuded From Roots Increase the Available Potassium Content in the Rhizosphere Soil: A Rhizobag Experiment in Nicotiana tabacum
Authors: Yang Yongfeng , Yang Zhixiao , Yu Shizhou , Chen Hongli
Published: February 2019

Organic acid secretion from higher plant roots into the rhizosphere soil plays an important role in nutrient acquisition and metal detoxification; however, their precise functions and the related mechanisms in abiotic stress tolerance remain poorly understood. Tobacco is an important crop plant, so thoroughly elucidating these factors in tobacco is of high priority. In the present study, the activation effect on soil potassium (K), contents of exuded organic acids, and physiological changes in the roots of various tobacco varieties under both normal K supply and K-deficiency stress were investigated. Our results showed that one high-K variety (ND202) exhibited a significantly higher total content of organic acids in the root exudates and the highest available K content in the rhizosphere soil, compared with two common ones (K326 and NC89). Moreover, the high-K tobacco variety was less affected in terms of root vigor under K-deficiency stress, and displayed greater increases in the activities of the stress-resistant enzymes consisting of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Taken together, these results provide evidence that tobacco roots exude large amounts of organic acids to increase the available K content in the rhizosphere soil and improve the utilization rate of soil K.
Characterization of Seedling Traits Associated with Early Vigor in Diverse Cotton Genotypes
Authors: Liu Shengjun , Nichols Robert L. , Fritschi Felix B.
Published: February 2019

Stand establishment and early growth are important for successful cotton (Gossypium hirstumL.) production, but in comparison with other crops, cotton seedlings develop slowly after emergence. The objectives of this study were to compare and contrast early vigor of diverse cotton genotypes under greenhouse and field conditions. A total of 144 genotypes were grown in a greenhouse and destructively sampled 34 d after planting (DAP). A range of seedling characteristics including areas and weights of the cotyledons and first, second, and third leaves were determined, and leaf weight ratio, specific leaf area, and leaf area ratio were calculated. Of the 144 genotypes that were grown in the greenhouse, a subset of 40 were selected and planted in the field where plant characteristics were assessed at 17, 27, 35, and 48 DAP. Genotypes differed in shoot and stem dry weights, as well as cotyledon, first, second, and third leaf, and total leaf area, as well as dry weight. A positive correlation of seed weight and rapid early growth as indicated by shoot biomass was observed at 34 DAP in the greenhouse through 48 DAP in the field. Shoot biomass of field‐grown plants sampled at 17, 27, 35, and 48 DAP was positively correlated with the size of the cotyledons and the first leaf measured at 17 DAP, as well as with the seed weight. Further characterization of high‐ and low‐seedling‐vigor genotypes identified in this study may provide insights into the physiological and genetic mechanisms associated with early vigor of cotton.
Co‐incorporation of Rice Straw and Green Manure Benefits Rice Yield and Nutrient Uptake
Authors: Yang Lu , Zhou Xing , Liao Yulin , Lu Yanhong , Nie Jun , Cao Weidong
Published: February 2019

Rice (Oryza sativa L.) straw is commonly incorporated into paddy soil after harvest, although it is not fully understood how the straw return strategy and its co‐incorporation with legumes affect soil productivity and rice performance. A 5‐yr experiment was conducted in a rice–rice–fallow or rice–rice–Chinese milk vetch (Mv, Astragalus sinicus L.) rotation in South China. Six treatments were included (i) a control with no fertilization and residue return, (ii) 100% of fertilizer recommendation (F100), (iii) 80% of F100 plus conventional return of rice straw (F80Rs), (iv) F80 plus Mv planting and incorporation (F80Mv), (v) co‐incorporation of F80Rs and F80Mv (F80RsMv), (vi) similar to F80RsMv except late rice straw was retained as high stubble (∼35 cm, F80RhMv). The results showed that, under reduced inorganic fertilizer input, grain yields in treatments with straw and/or Mv return were similar with those of F100. However, N uptake in early and late rice markedly increased by 8 to 14% and 30 to 53% in the co‐incorporation treatment F80RsMv compared with F100, respectively, as well as in the F80RhMv treatment for late rice. Significantly greater fertilizer use efficiency was obtained in the co‐incorporation practices. Although negative cumulative effects were observed for soil organic matter, total N, and available N after 5‐yr rotation, the magnitude of decline in the co‐incorporation treatments was much smaller than in others. Soil available P and K were accumulated in co‐incorporation practice, whereas pH was less affected. Overall, the study suggested that the combination of rice straw and leguminous green manure is a promising practice to produce more grain yield with less fertilizer inputs in subtropical double‐rice production.
Threshold Friction Velocity Influenced by the Crust Cover of Soils in the Columbia Plateau
Authors: Pi Huawei , Sharratt Brenton
Published: February 2019

Core Ideas

Particulate emissions from agricultural lands threaten air quality.

Soil crusts reduce emissions by increasing threshold friction velocity.

Threshold friction velocity was determined from temporal variations in particle concentrations inside a wind tunnel.

Crust cover increased threshold friction velocity, particularly under 60 and 100% crust cover.

Soil crusts provide stability and protection against wind erosion from semiarid and arid lands. Although erosion is initiated when the friction velocity (U*) exceeds the threshold friction velocity (U*t) of soils, there is little information available on the effect of soil crust cover on U*t. The objective of this study was therefore to evaluate the effect of soil crust cover on the U*t of five loessial soils of the Columbia Plateau, United States. Soil samples were sieved and the erodible fraction was placed in 1 by 0.2 by 0.015 m trays. Water drops 4.5 mm in diameter were applied to the soil surface at a known density, which, after drying, created various percentages of crust cover. The trays were placed inside a wind tunnel to assess U*t. which was determined by systematically wind speed until an increase was observed in total suspended particulate concentration inside the tunnel. No significant differences in U*t were found among 0, 15, and 30% cover but significant differences in U*t were found between 60 and 100% cover. The U*t of 100% crust cover was about twice that of 0% cover. Crust crushing energy, which influences abrasion, did not vary across crust cover treatments. The Single‐event Wind Erosion Evaluation Program (SWEEP) revealed the similar influence of crust cover on U*t. The SWEEP adequately simulated U*t for 0, 15, and 30% crust cover but overestimated U*t for 60 and 100% cover. These results suggest that crusts effectively protect the soil from wind erosion by increasing U*t.
A simple mechanism for unconventional superconductivity in a repulsive fermion model
Authors: Slagle Kevin , Kim Yong Baek
Published: February 2019

Motivated by a scarcity of simple and analytically tractable models
of superconductivity from strong repulsive interactions, we introduce a
simple tight-binding lattice model of fermions with repulsive
interactions that exhibits unconventional superconductivity (beyond BCS
theory). The model resembles an idealized trilayer. The Cooper pair
consists of electrons on opposite sides of the dielectric, which
mediates the attraction. In the strong coupling limit, we use degenerate
perturbation theory to show that the model reduces to a superconducting
hard-core Bose-Hubbard model. Above the superconducting critical
temperature, an analog of pseudo-gap physics results where the fermions
remain Cooper paired with a large single-particle energy gap.
The Feeling of Thinking: Stories and Animations on the Experience of Reading Theory
Authors: Reichl Veronika
Published: February 2019

In this set of stories I investigate in the experience of reading philosophical texts. Reading is one of the most central activities of engaging with philosophy. But how is it done? How is it perceived? Which aesthetic and emotional experiences take place?I conducted 50 confidential interviews with dedicated readers of theory / philosophy (students, professors, and others) on their personal reading practise and experience. Based on these interviews I am writing a series of stories. Some of the stories are true to their interviews, others take motifs of the interviews only as a starting point for investigating in reading.The stories explore in the embodied process of reading. They describe, why readers take on the task of reading philosophy, how they struggle to understand and how they deal with the authority of the authors. They also investigate in how reading influences the lives of the readers.
Institutional support for the organic farming development – a conceptual framework
Authors: Dobrovolska Olena , Manuel Recio Espejo José
Published: February 2019

Realization of agricultural production complying with the sustainable development principles has resulted in a separate direction – organic farming. Its big difference from all other economy sectors is in its dependence on the natural and climatic conditions. Therefore, agricultural production has a dual nature, namely it depends on the environment health on the one hand, and, on the other hand, directly affects this health through the use of technologies that can both improve and substantially worsen the environmental situation. The institutional support for the organic farming is of great importance. This issue is relevant for scientists from countries, where organic farming is actively developing. In Ukraine, this is also a topical issue. The paper presents a conceptual framework of institutional support for the organic farming development, which includes elements such as state regulation, self-regulation, objects and subjects of organic farming, as well as an organic product market. Legal, informational, infrastructure and financial directions of ensuring the development of organic farming are also defined. The essence of each element is revealed. The main indicators of the organic farming development in Ukraine are analyzed, i.e. the organic farming areas, their proportion in agricultural lands, the number of producers, the volume of the organic market, the volume of organic consumption per capita, as well as the share of domestic organic land in the world's territory. A correlation analysis based on data from the largest world market of the USA made it possible to determine the factors that have the greatest impact on the development of the organic agricultural sector. The number of organic producers is statistically significant, and the share of land in the organic farming does not have a significant impact on the organic product consumption. At the same time, this can be seen from the point of view that the more producers will offer their products, the more saturated the market will be, and therefore the level of the organic products coverage can be greater.
Molecular characterization of nontuberculous mycobacteria in hospital waters: a two-year surveillance study in Tehran, Iran
Authors: Moradi Somayeh , Nasiri Mohammad Javad , Pourahmad Fazel , Darban-Sarokhalil Davood
Published: February 2019

Microbiological control of hospital waters as one of the main sources of nontuberculous mycobacteria (NTM) is important for the prevention of NTM-associated illness. This study aimed to investigate the prevalence of NTM in the hospital water systems of Tehran, Iran. A total of 218 samples from different hospital waters (i.e., tap water and medical devices such as humidifying cup of oxygen manometer, dialysis devices, nebulizers, and dental units) were included in this study. Phenotypic and molecular tests were used to identify the isolated organisms to species level. Of 218, 85 (39.0%) samples at 37 °C and 87 (40.0%) samples at 25 °C were identified as NTM. Using hsp65-sequencing method, Mycobacterium lentiflavum was the most frequently encountered, followed by M. gordonae and M. paragordonae. No significant difference was seen in frequency and species in mycobacteria isolated at 37 °C and 25 °C temperatures. Humidifying cup of oxygen manometer had the most contaminated water among the investigated water distribution systems in hospitals. Isolation of NTM from hospital water sources is a serious public health problem in Iran and merits further attention by health authorities. Establishment of microbiological monitoring systems for hospital waters and expanding the number of facilitated laboratories are strongly recommended.
Pareceristas Ad-Hoc
Authors: Araujo Marta Maria
Published: February 2019

Pareceristas Ad-Hoc
O ensino de filosofia nas perspectivas inter e transdisciplinar: uma análise da problemática ontológica
Authors: Silva Gilson Malta
Published: February 2019

Este artigo tem por objetivo divulgar os resultados de uma pesquisa de mestrado. Investigou-se como um ensino de filosofia, proposto nas perspectivas inter e transdisciplinar, estava sendo organizado numa unidade educacional? Assim sendo, realizou-se uma pesquisa descritiva de natureza qualitativa tendo por referenciais teóricos Edgar Morin e Basarab Nicolescu. A metodologia foi composta por investigação teórica e incursão a campo. A primeira constituiu-se de pesquisa bibliográfica e análise documental. A segunda consistiu em observar a organização do ensino em sala de aula. Como técnica de análise de dados utilizou-se a análise de conteúdo. As questões discutidas nesse artigo referem-se ao conjunto das aulas nas quais foi abordada a problemática ontológica, ou seja, temas, problemas, conceitos relacionados à organização, às percepções e às significações sobre o Real, Realidade ou Natureza. Concluiu-se que as características do ensino observado, no que se refere à problemática em questão, permitem considerá-lo uma multidisciplinaridade escolar “modesta”.
A produção de textos científicos explicativos na formação inicial de professores de Química
Authors: Núñez Isauro Beltrán , Bezerra de Barros Sandra Cristina
Published: February 2019

A explicação científica é essencial para a produção dos conhecimentos científicos e para a compreensão dos fenômenos e processos das ciências. Consequentemente, é um conhecimento profissional necessário para a atividade docente, e o professor de química precisa dominá-lo para obter êxito em sua prática pedagógica, na educação básica. Este artigo objetiva caracterizar o conhecimento de estudantes do curso de licenciatura em Química sobre a explicação científica e a escrita de textos explicativos. O estudo foi realizado com 24 estudantes da disciplina Estágio e Prática de Ensino de Química II. Foi aplicada uma prova pedagógica com perguntas de conteúdo, relacionadas com as questões do estudo. Os resultados evidenciam um baixo domínio desse conhecimento docente assim como a necessidade de se atribuir importância à formação inicial dos graduandos quanto aos processos de comunicação da ciência, para que possam pensar sobre esses processos e aprender a ensiná-los no contexto da educação científica.
Avaliação em larga escala no Brasil
Authors: Costa Anderson Gonçalves , Vidal Eloisa Maia , Vieira Sofia Lerche
Published: February 2019

O artigo analisa a relação entre a coordenação federativa e o Estado-avaliador e os modos como o governo central tem utilizado de pactos colaborativos para promover medidas de avaliação e responsabilização sobre as unidades subnacionais. De abordagem qualitativa, caracteriza-se como uma pesquisa exploratória utilizando como procedimentos o levantamento bibliográfico e documental. Numa leitura da legislação educacional apresenta os pactos e as estratégias da União para com estados e municípios que tornaram a avaliação um demarcador das relações intergovernamentais. Conclui que a relação Estado-avaliador e coordenação federativa vai sendo forjada na medida em que os sistemas de avaliação são significados pelas características próprias a uma nova função do Estado, num cenário de descentralização em que o controle da União possibilita a coordenação federativa a partir de pactuações em torno de resultados, avaliações em larga escala, qualidade da educação, transparência pública e prestação de contas.
Decreto nº 20.529, de 16 de outubro de 1931
Authors: Araújo Marta Maria de
Published: February 2019

No governo Provisório de Getúlio Dornelles Vargas (1930-1934), foi criado o Serviço Nacional de Intercâmbio Bibliográfico, bem como regulada a sua execução (Decreto nº 20.529, de 16 de outubro de 1931). A sua institucionalização visou atender ao pedido do Diretor-Geral da União Pan Americana devido à divulgação das publicações oficias e autorais tanto no Brasil como no estrangeiro em cumprimento da Convenção de Bruxelas, de 15 de março de 1886, assinada pelo Brasil. A publicação desse Decreto nº 20.529, de 16 de outubro de 1931, nesta Seção de Documentos, constitui uma fonte inestimável para os trabalhos de História da Educação do Brasil.
Festa Literária no Colégio Estadual do Rio Grande do Norte
Authors: Araújo Marta Maria de , Oliveira Neto Fabio Marques de , Fernandes Raquel Duarte
Published: February 2019

CONFERÊNCIAS no Colégio Estadual. Natal: Sebo Vermelho Edições, 2012 (1ª série).
Las nociones aristotélicas de naturaleza y de fin en Sobre la filosofía y en Física II
Authors: Seggiaro Claudia
Published: February 2019

En el presente trabajo nos interesa analizar la relación entre naturaleza y fin, poniendo principal énfasis en el libro II de la Física y en Sobre la filosofía. Para ellos dividiremos el trabajo en tres partes. En la primera, examinaremos los posibles motivos por los cuales Aristóteles en Física II realiza la remisión a Sobre la filosofía. En la segunda parte y en la tercera, nos centraremos en dos fragmentos de Sobre la filosofía que creemos centrales para analizar las nociones de naturaleza y finalidad: el 8b y el 16. El objetivo de este análisis es establecer qué tipo de continuidad doctrinal hay entre la Física y Sobre la filosofía.
A processão do Absoluto: notas sobre Merleau-Ponty e Schelling
Authors: Zambonelli Nogueira Rafael
Published: February 2019

O presente artigo busca analisar as relações entre Merleau-Ponty e Schelling a partir de um ângulo diferente dos (poucos) trabalhos dedicados a essa questão, os quais costumam se limitar à retomada por parte de Merleau-Ponty da primeira filosofia da natureza de Schelling. Analisaremos tais relações tomando como fio condutor a ideia schellinguiana de Absoluto e como ela é retomada por Merleau-Ponty na medida em que implica uma concepção não-separada do Absoluto e, ipso facto, sua temporalização e historicização — o que não significa, é claro, uma recaída no relativismo, mas uma elaboração ontológica (e “dialética”, se se quiser, mas em um sentido a ser precisado no texto) que supera as dicotomias clássicas entre universalidade e singularidade, infinitude e finitude, temporalidade e eternidade etc., articulando-as dinamicamente no interior do Absoluto como unidade que exige a diferenciação e a multiplicidade.