Journal articles on the topic 'Annual cold production'
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1
Радченко, Микола Іванович, Євген Іванович Трушляков, Сергій Анатолійович Кантор, Богдан Сергійович Портной, and Анатолій Анатолійович Зубарєв. "МЕТОД ВИЗНАЧЕННЯ ТЕПЛОВОГО НАВАНТАЖЕННЯ СИСТЕМИ КОНДИЦІЮВАННЯ ПОВІТРЯ ЗА МАКСИМАЛЬНИМ ТЕМПОМ ПРИРОЩЕННЯ ХОЛОДОПРОДУКТИВНОСТІ (на прикладі кондиціювання повітря енергетичного призначення)." Aerospace technic and technology, no. 4 (October 14, 2018): 44–48. http://dx.doi.org/10.32620/aktt.2018.4.05.
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It is justified the necessity of taking into consideration changes in thermal loads on the air conditioning system (heat and moisture treatment of air by cooling it with decreasing temperature and moisture content) in accordance with the current climatic conditions of operation. Since the effect of air cooling depends on the duration of its use and the amount of cold consumption, it is suggested that it be determined by the amount of cold spent per year for air conditioning at the GTU inlet, that is, for annual refrigerating capacity. The example of heat-using air conditioning at the inlet of a gas turbine unite (energy–efficient air conditioning systems) analyzes the annual costs of cooling for cooling ambient air to the temperature of 15 °C by an absorption lithium-bromide chiller and two-stage air cooling: to a temperature of 15 °C in an absorption lithium-bromide chiller and down to temperature 10 °С – in a refrigerant ejector chiller as the stages of a two-stage absorption-ejector chiller, depending on the installed (project) refrigerating capacity of waste heat recovery chiller.It is shown that, based on the varying rate of increment in the annual production of cold (annual refrigeration capacity) due to the change in the thermal load in accordance with current climatic conditions, it is necessary to select such a design thermal load for the air conditioning system (installed refrigeration capacity of chillers), which ensures the achievement of maximum or close to it annual production of cold at a relatively high rate of its increment. It is analyzed the dependence of the increment on the annual refrigerated capacity, relative to the installed refrigeration capacity, on the installed refrigeration capacity, in order to determine the installed refrigeration capacity, which provides the maximum rate of increase in the annual refrigerating capacity (annual production of cold). Based on the results of the research, it is proposed the method for determining the rational thermal load of the air conditioning system (installed – the design refrigeration capacity of the chiller) in accordance with the changing climatic conditions of operation during the year, which provides nearby the maximum annual production of cold at relatively high rates of its growth
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Rangarajan, Anusuya, and Betsy A. Ingall. "487 Strategies to Enhance Production of Annual Globe Artichoke." HortScience 35, no. 3 (June 2000): 478B—478. http://dx.doi.org/10.21273/hortsci.35.3.478b.
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Annual production of globe artichokes (Cynara scolymus L.) requires vernalization of the plants, either through cold treatment of transplants or from natural temperature conditions in the spring. Studies were conducted in upstate New York to determine if artificial vernalization treatments could be achieved by earlier planting dates. Initial trials evaluated two cultivars used for annual production in other parts of the country—'Imperial Star' and `Green Globe Improved'. Transplants were set in the field with or without a vernalizing cool treatment, to determine the extent of natural vernalization achieved under New York conditions. `Imperial Star' produced slightly higher marketable yields than `Green Globe Improved' in 2 years of trials. Vernalization treatment increased the number of plants producing buds and the marketable yields, when transplants were set after 15 May. Natural vernalization was achieved and cold treatment prior to transplanting did not improve yields of plants established in early May. At later planting dates, vernalizing transplants increased the number of plants producing apical buds (largest) by about 20%, yet, >57% of non-vernalized plants of each variety produced buds within the season. Average bud sizes did not vary with vernalization treatment. A similar number of days from transplanting to first bud harvest (69 to 75) was noted regardless of planting date and size of transplant.
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Rangarajan, Anusuya, Betsy A. Ingall, and Victoria C. Zeppelin. "Vernalization Strategies to Enhance Production of Annual Globe Artichoke." HortTechnology 10, no. 3 (January 2000): 585–88. http://dx.doi.org/10.21273/horttech.10.3.585.
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Annual production of globe artichokes (Cynara scolymus L.) requires vernalization of the plants, either through cold treatment of transplants or from natural temperature conditions in the spring. Studies were conducted in upstate New York, to determine if artificial vernalization treatments could be achieved by earlier planting dates. Initial trials evaluated two varieties used for annual production in other parts of the country—`Imperial Star' and `Green Globe' Improved. Transplants were set in the field with or without a vernalizing cool treatment, to determine the extent of natural vernalization achieved under New York conditions. `Imperial Star' produced slightly higher marketable yields than `Green Globe Improved' in 2 years of trials. Vernalization treatment increased the number of plants producing buds and the marketable yields, when transplants were set after 15 May. Natural vernalization was achieved and cold treatment before transplanting did not improve yields of plants established in early May. At later planting dates, vernalizing transplants increased the number of plants producing apical buds (largest) by about 20%, yet over 57% of nonvernalized plants of each variety produced buds within the season. Average bud sizes did not vary with vernalization treatment. A similar number of days from transplanting to first bud harvest (69 to 75 days) was noted regardless of planting date and size of tran.
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Wohlfeiler, Josefina, María Soledad Alessandro, Andrés Morales, Pablo Federico Cavagnaro, and Claudio Rómulo Galmarini. "Vernalization Requirement, but Not Post-Vernalization Day Length, Conditions Flowering in Carrot (Daucus carota L.)." Plants 11, no. 8 (April 15, 2022): 1075. http://dx.doi.org/10.3390/plants11081075.
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Carrots require a certain number of cold hours to become vernalized and proceed to the reproductive stage, and this phenomenon is genotype-dependent. Annual carrots require less cold than biennials to flower; however, quantitative variation within annuals and biennials also exists, defining a gradient for vernalization requirement (VR). The flowering response of carrots to day length, after vernalization has occurred, is controversial. This vegetable has been described both as a long-day and a neutral-day species. The objective of this study was to evaluate flowering time and frequency in response to different cold treatments and photoperiod regimes in various carrot genotypes. To this end, three annual genotypes from India, Brazil, and Pakistan, and a biennial carrot from Japan, were exposed to 7.5 °C during 30, 60, 90, or 120 days, and then transferred to either long day (LD) or short day (SD) conditions. Significant variation (p < 0.05) among the carrot genotypes and among cold treatments were found, with increased flowering rates and earlier onset of flowering being associated with longer cold exposures. No significant differences in response to photoperiod were found, suggesting that post-vernalization day length does not influence carrot flowering. These findings will likely impact carrot breeding and production of both root and seed, helping in the selection of adequate genotypes and sowing dates to manage cold exposure and day-length for different production purposes.
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Yaghmaei, L., R. Jafari, and S. Soltani. "Investigating net primary production in climate regions of central Zagros, Iran, using MODIS and meteorological data." Climate Research 83 (May 6, 2021): 173–86. http://dx.doi.org/10.3354/cr01643.
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Rangeland production is sensitive to climate conditions. In this study, we monitored actual and potential production in the climate zones of Chaharmahal and Bakhtiari province in central Zagros, Iran, from 2000-2016. Net primary production (NPP), light use efficiency (LUE) and rain use efficiency (RUE) were extracted from climatic and MODIS satellite data using the Carnegie-Ames-Stanford approach (CASA) and Miami models. The accuracy of the modeled NPP maps was assessed using regression analysis, based on field data collected at 750 sites under different rangeland conditions. The spatial distribution of NPP and RUE indicated that annual production and photosynthetic efficiency in degraded rangelands with poor and very poor conditions have decreased compared to those of moderate-good classes. The highest relationship between the field and modeled NPP was associated with the Astragalus spp.-Ferula spp. (R2 = 0.865, p < 0.001) in the humid and cold climate zone with good rangeland conditions while the lowest was observed in the annual grasses-annual forbs (R2 = 0.198, p < 0.001) vegetation type with very poor rangeland conditions within the semi-arid and cold climate zone. Furthermore, the highest and lowest NPP values were observed in the Daphne mucronata-Prangos ferulacea (48.38 g C m-2 yr-1) and annual grasses-annual forbs (3.42 g C m-2yr-1) vegetation types with LUE values of 0.13 and 0.02 g C MJ-1 within the humid and cold and the semi-humid and cold climate zones, respectively. According to these findings, remote sensing-based differences between actual and potential NPP can be used as a valuable tool for identification of human impacts on broad rangeland ecosystems.
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Stevens, Matthew D., Judith A. Abbott, John D. Lea-Cox, and Brent L. Black. "Consumer Preference among Three Cold-climate Strawberry Production Systems." HortScience 40, no. 4 (July 2005): 1139B—1139. http://dx.doi.org/10.21273/hortsci.40.4.1139b.
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Three cold-climate strawberry production systems, conventional matted row, advanced matted row, and cold-climate annual hill plasticulture, were compared for consumer preference in a pick-your-own (PYO) setting. Replicated 6 × 15 m plots were established in 2002 in Maryland and cropped in 2003 and 2004. To simulate PYO marketing, volunteers were recruited to harvest 3.6-m plots in each of the three production systems and to complete a five-part questionnaire. The questionnaire collected demographic information and allowed volunteers to compare the three systems both prior to and after their harvesting experience. Harvests were carried out twice weekly, with 75 participants in 2003 and 45 participants in 2004. The 2003 season was cool and wet, with frequent rainfall and a high incidence of fruit rot. Spring 2004 was unseasonably hot, resulting in an unusually short harvest season. Consumer preference differed between years and among harvests within a season. The annual hill system was favored early in the 2003 season, with preference shifting to the other systems as the season progressed. The advanced matted row was favored early in the 2004 season. Many of the participants' comments, both positive and negative, were directed at the plastic mulch and raised beds. In several cases, participants indicated that their preferences after picking from each system did not match their initial impressions. Implications of this research to the social components of sustainability will be discussed.
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Takeda, Fumiomi Takeda, Stan Hokanson*, John Enns, Penelope Perkins-Veazie, and Harry Swartz. "Plugging Date and Cold Storage Affect Strawberry Transplant Production and Performance in Annual Plasticulture." HortScience 39, no. 4 (July 2004): 829A—829. http://dx.doi.org/10.21273/hortsci.39.4.829a.
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`Chandler' strawberry plants were propagated in tissue culture and grown from April to August in a protected environment to produce stolons. July-harvested daughter plants were stuck in cell packs with rooting media and placed under mist sprinklers, or cold stored at 2 °C for 42 days. Among the July transplants, some were kept in the greenhouse until field planting (14 Sept.) and others were moved into a cold room on 14 August. Daughter plant size and position on the stolon affected rooting and quality of transplants. July-harvested daughter plants that were plugged and misted after being cold stored for 42 days developed fewer roots than daughter plants plugged immediately after detaching from mother plants in July or August. In the field, transplants produced from daughter plants harvested in July and cold stored for 42 days developed more stolons than transplants from July- and August-harvested daughters that were not exposed to cold storage treatments. Larger daughter plants produced more branch crowns than did smaller daughter plants during the fall. All transplants from daughter plants harvested in July and propagated without cold treatment bloomed by November. Fruit production ranged from 521 to 703 g per plant. `Chandler' plants from daughter plants that weighed 10 g produced 10% greater yield than those that weighed <1.0 g. Plants generated from daughter plants plugged in July produced 26% more fruit than those plants plugged in August. Greenhouse soilless systems can be used to grow `Chandler' mother plants for generating runner tips and transplants for the annual plasticulture in colder climates. `Chandler' plants produced in July can yield a late fall crop under high tunnels and more fruit in the spring than August-plugged transplants
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Jin, Jia Yi, Pavlo Sokolov, and Muhammad S. Virk. "Wind Resource Assessment in Cold Regions - A Numerical Case Study." Applied Mechanics and Materials 875 (January 2018): 94–99. http://dx.doi.org/10.4028/www.scientific.net/amm.875.94.
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This paper describes a case study of wind resource assessment in cold climate region. One-year SCADA data from a wind park has been used to make a comparison with the Computational Fluid Dynamics (CFD) based numerical simulations of wind resource assessment and Annual Energy Production (AEP). To better understand the wind turbine wake flow effects on the energy production, ‘Jessen wake model ‘is used for the numerical simulations. Results show wind resource maps at different elevations, where wind turbine wake flow effects the wind turbine performance and resultant power production. CFD simulations provided a good insight of the flow behavior across each wind turbine, which helped to better understand the wind turbine wake flow effects on wind turbine performance and annual energy production. A good agreement is found between numerical simulations and field SCADA data analysis in this study.
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Трушляков, Євген Іванович, Андрій Миколайович Радченко, Микола Іванович Радченко, Ян Зонмін, Анатолій Анатолійович Зубарєв, and Веніамін Сергійович Ткаченко. "ХОЛОДОПРОДУКТИВНІСТЬ СИСТЕМИ КОНДИЦІЮВАННЯ ЗОВНІШНЬОГО ПОВІТРЯ ЗА ПОТОЧНИМ ТЕПЛОВИМ НАВАНТАЖЕННЯМ." Aerospace technic and technology, no. 2 (April 22, 2019): 51–55. http://dx.doi.org/10.32620/aktt.2019.2.06.
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The efficiency of the outdoor air conditioning systems application depends on how full the installed cooling capacity is applied, that is, with a more complete load and for as long as the possible yearly duration in actual climatic conditions. The production of cold is taken as a criteria of a quantitative evaluation of the efficiency of applying the cooling capacity of air conditioning systems – the amount of cold produced in accordance with its current demand for air conditioning, which in turn depends on the current consumption of cooling capacity and its duration and equals to their multiplication. It is obvious that the maximum value of the current amount of cold produced/consumed indicates an effective application of the installed cooling capacity. However, since the current demands of cooling capacity and their duration, that is, the amount of cold produced/consumed, depending on the changing current climatic conditions, they are characterized by significant fluctuations, which makes it difficult to choose the installed cooling capacity of the air conditioning system. Obviously, if we determine the amount of cold produced/consumed by its current values and summarized during the year, it is possible to significantly simplify the choice of the installed cooling capacity. At the same time, the current amount of cold produced/consumed causes a change in the rate of increment of the annual cold production with a change in the installed cooling capacity, and the maximum rate corresponds to the installed cooling capacity, which provides its efficient use. Proceeding from a different rate of increment of annual cold production with an increase in the installed cooling capacity of the air conditioning system due to a change in heat load in accordance with current climatic conditions during the year, the value of design heat load on the air conditioning system (installed cooling capacity) that provides maximum or close to it the rate of increment of the annual production of cold, and hence the maximum efficient use of installed cooling capacity is chosen
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Ripol-Saragossi, T. L., and I. A. Smychok. "Cold production reducing energy costs using ozone-friendly refrigerants." IOP Conference Series: Earth and Environmental Science 937, no. 2 (December 1, 2021): 022091. http://dx.doi.org/10.1088/1755-1315/937/2/022091.
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Abstract The article considers ways to reduce energy costs in the cold using ozone-safe refrigerants production. In this case, it is necessary to include an air-cooled heat exchanger-pre-condenser in the technological scheme of refrigeration. The conditions for the pre-capacitor for a certain performance selection are formulated. The results of the presented calculations prove a decrease in the annual energy consumption for cold production in comparison with the technological scheme with external cooling and a cascade system. The energy consumption reducing principle of the installation due to the air pre-condenser can also be realized by installing a heat-exchanger on the discharge of low-temperature compressors to heat water for the enterprise needs, receiving free heat energy all year round.
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Masaka, Kazuhiko, and Hajime Sato. "Acorn production by Kashiwa oak in a coastal forest under fluctuating weather conditions." Canadian Journal of Forest Research 32, no. 1 (January 1, 2002): 9–15. http://dx.doi.org/10.1139/x01-159.
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We modeled the annual acorn crops of Kashiwa oak (Quercus dentata Thunb.) in a coastal forest in Hokkaido, northern Japan. Shoots of Kashiwa oak withered away during winter because of sea breeze and cold, and succeeding production of female inflorescences were strongly affected by mortality of buds. Thus, strong sea breeze and cold winters reduced the survival ratio of buds and further resulted in reduction of female flowering. Number of female flowers was related with current acorn crops, however, survival of female flowers after pollination was strongly influenced by warmth in the flowering period. Regression analysis of the annual acorn crop versus weather conditions suggests that acorn crop was decreased by cool conditions in the flowering period. A model equation was constructed to estimate the annual acorn crops by three weather variables: cumulative velocity of sea breeze and mean monthly temperature in winter (DecemberMarch) and maximum monthly temperature in current flowering period (June). This model equation explained 89.2% of observed acorn crops of Kashiwa oak in the coastal forest.
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Weber, C. A. "Strawberry Crown Plugs Provide Flexibility and Improved Performance in Cold Climate Plasticulture Production." Agronomy 11, no. 8 (August 17, 2021): 1635. http://dx.doi.org/10.3390/agronomy11081635.
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Annual plasticulture strawberry production has not been adopted as rapidly in cold climate regions as has occurred in warmer production areas due to uncertainty about potential benefits. Recent trials have demonstrated the potential of regionally adapted varieties in the annual plasticulture system in cold regions, but optimal production practices have not been determined. Summer planting of short-day varieties in these areas would increase flexibility for growers, allowing additional cropping options and improved land use management. The performance of six short-day strawberry varieties (Chandler, Clancy, Jewel, Ovation, Seneca and Ventana) was examined in a series of four annual production trials using cold-stored bare-root crowns for spring planting or a new type of planting stock termed a ‘crown plug’ for two summer plantings. Procedures for producing crown plugs from cold-stored crowns are described. The crown plug summer plantings significantly outperformed the spring planted bare-root plants across all varieties. The July planting established using crown plugs had higher yield and higher mean berry weight across all six varieties compared to the May bare-root planting (623 g/plant—12.5 g mean fruit weight vs. 330 g/plant—10.6 g mean fruit weight, respectively). In the July planting, ‘Seneca’, ‘Ventana’ and ‘Jewel’ exceeded the mean yield per plant for the planting as a whole and the other three varieties also produced more than previously reported for the May planting established with bare-root plants. The August crown plug planting was less productive than the July planting (623 g/plant vs. 498 g/plant, respectively) but was still more productive than both spring plantings. No difference was observed between the April and May plantings across the six varieties. Utilizing crown plugs also reduced the duration of weed control measures needed, improved efficiency of setting plants and limited the need for blossom and runner removal in the field, thus demonstrating labor cost savings that can offset the cost of crown plug production while also producing higher overall yield and mean fruit weight in the varieties in the trial. The summer plantings established with crown plugs demonstrated improved survival through a second winter dormancy period but produced relatively poor yield and berry size in the second harvest season. Crown plugs provide flexibility and improved productivity for growers utilizing annual plasticulture production in cold climate regions.
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Трушляков, Євген Іванович, Андрій Миколайович Радченко, Сергій Георгійович Фордуй, Анатолій Анатолійович Зубарєв, Сергій Анатолійович Кантор, and Веніамін Сергійович Ткаченко. "АНАЛІЗ ЕКОЛОГІЧНОЇ ЕФЕКТИВНОСТІ СИСТЕМ КОНДИЦІЮВАННЯ ПОВІТРЯ КОМБІНОВАНОГО ТИПУ." Aerospace technic and technology, no. 5 (October 22, 2019): 24–29. http://dx.doi.org/10.32620/aktt.2019.5.03.
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Since the supply air conditioning systems operation effect depends on the cooling duration and depth, it is quite justified to estimate it by the value of the specific annual cold production, which is the product of the necessary cooling capacity for cooling the air to the target temperature multiplied by duration of operation at a given cooling capacity and, thus, considers current climatic conditions. Obviously, the realization of the cooling potential (air conditioning) of the ambient air depends on the installed (design) cooling capacity of the air conditioning units, which, in turn, must considering fluctuations in thermal loads by the current variable thermal and humidity parameters of the ambient air. With an increase in the temperature of the ambient air, fuel consumption for the production of a unit capacity (mechanical/electrical energy) increases, and, accordingly, the more harmful substances are removed to the atmosphere with exhaust gases. To reduce the negative impact of unproductive fuel consumption during the operation of air conditioning systems at elevated ambient temperatures, resort to various methods for determining the installed cooling capacity of the installation, to reduce it. In the work, the ecological efficiency of air cooling is studied considering the climatic operating conditions for the Kyiv city that are variable during the year. The annual reduction in emissions of carbon dioxide CO2 and nitric oxide NOX was chosen as indicators for assessing the environmental effect of air cooling. It has been shown that when choosing the installed cooling capacity, by the method of ensuring the maximum growth rate of the annual cold production considering the increase in the installed cooling capacity of the chiller, there is a greater reduction in specific fuel consumption compared to the method of choosing the maximum annual cold production, respectively, and harmful emissions. When comparing the methods for choosing the design cooling capacity, air cooling to 15 °C provides a reduction in carbon dioxide CO2 emissions of more than 34 t for 2017 for the climatic conditions of Kiev, in favor of the method of ensuring the maximum growth rate of annual cold production, and nitric oxide NOX – about 5,8 t.
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Weber, Courtney A. "Performance of Strawberry Varieties Developed for Perennial Matted-Row Production in Annual Plasticulture in a Cold Climate Region." Agronomy 11, no. 7 (July 14, 2021): 1407. http://dx.doi.org/10.3390/agronomy11071407.
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Annual plasticulture production of strawberries promises superior weed control, fruit quality and yields. However, strawberry varieties adapted for perennial, matted-row production and local markets in cold climate regions have not been widely tested for adaptation to an annual production cycle. Productivity of seven short-day varieties developed for matted-row and/or annual production was examined in an annual plasticulture system in two consecutive trials in central NY (lat. 42.87° N, long. 76.99° W) harvested in 2013 and 2014. ‘Flavorfest’ demonstrated good performance in Trial 1 with high yield (390 g/plant) and large fruit size (13.9 g mean berry weight). ‘Jewel’ was shown to be well adapted to the annual plasticulture system with consistently high yields (330 and 390 g/plant) that equaled or surpassed other varieties and had moderate fruit size. ‘Chandler’ performed similarly to previous trials conducted in warmer regions with yield (340 g/plant) and fruit size (9.8 g mean berry weight) similar to ‘Jewel’. ‘Clancy’ yielded less but was consistent from year to year. The late season varieties Seneca and Ovation showed marked variability between years, possibly due to drastically different temperatures during flowering and fruit development in Trial 1 compared to Trial 2. High temperatures in Trial 1 likely caused higher early fruit yield, a compressed season and a precipitous decline in fruit size in the later season, thus reducing yield in the late season. Survival after a second dormant period was poor resulting in a small second harvest and reduced fruit size. Overall, the system demonstrated many of the expected benefits but may be more sensitive to weather conditions in the region. While many varieties developed for matted-row production may work well in an annual plasticulture system, not all varieties are equally adapted. Performance of each variety should be determined independently before large scale adoption by growers.
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Currey, Christopher J., Roberto G. Lopez, and Neil S. Mattson. "Finishing Bedding Plants: A Comparison of an Unheated High Tunnel versus a Heated Greenhouse in Two Geographic Locations." HortTechnology 24, no. 5 (October 2014): 527–34. http://dx.doi.org/10.21273/horttech.24.5.527.
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Energy accounts for one of the largest costs in commercial greenhouse (GH) production of annual bedding plants. Therefore, many bedding plant producers are searching for energy efficient production methods. Our objectives were to quantify the impact of growing annual bedding plants in an unheated high tunnel (HT) compared with a traditional heated GH environment at two northern latitudes. Ten popular bedding plants [angelonia (Angelonia angustifolia), vinca (Catharanthus roseus), celosia (Celosia argentea), dianthus (Dianthus chinensis), geranium (Pelargonium ×hortorum), petunia (Petunia ×hybrida), french marigold (Tagetes patula), viola (Viola ×cornuta), snapdragon (Antirrhinum majus), and osteospermum (Osteospermum ecklonis)] were grown both in an unheated HT and a glass-glazed GH with an 18 °C temperature set point beginning on 1 Apr. 2011 at both Cornell University (Ithaca, NY) and Purdue University (West Lafayette, IN). Although seven of the species exhibited a delay in flowering in the HT as compared with the heated GH, there were no differences in days to flower (DTF) for geranium, osteospermum, and viola grown at Cornell and viola at Purdue. The remaining species exhibited delays in flowering in the HT environment, which varied based on species. At Purdue, several species were lost because of a cold temperature event necessitating a second planting. For the second planting, osteospermum was the only species grown that flowered significantly later in the HT; 7 days later than the GH-grown plants. Production of cold-tolerant annuals in unheated or minimally heated HTs appears to be a viable alternative for commercial producers aiming to reduce energy costs.
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Yadava, U. L. "STUDIES ON PAPAYA PRODUCTION IN MIDDLE GEORGIA." HortScience 25, no. 9 (September 1990): 1135d—1135. http://dx.doi.org/10.21273/hortsci.25.9.1135d.
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Three exotic lines (Dwarf, L-45, and L-50) of precocious papaya (Carica papaya L.) from India, were grown in nursery rows at the Fort Valley State College Agricultural Research Farm during 1986-1990. Performance of these lines was evaluated for their adaptation and production feasibility under the growing conditions of Middle Georgia. Two lines (L-50 and Dwarf papaya) showed a less satisfactory overall performance than did L-45, which had the highest female to male ratio (7:3) and abundantly produced tree-ripened fruits under cold protection frames during 1989 and 1990. Tree growth and survival for L-45 were greater than those for L-50 and Dwarf papaya lines. Two-month-old greenhouse-grown seedlings when established in the field in April, flowered in 60 to 65 days following transplanting. Under Georgia conditions, fruits ripened on trees in approximately 150 days after fruit set. During 1989-90, the fruit size on L-45 trees varied from 574 g to 2,286 g (mean 1,530 g) with an average of 22.5 fruits per tree. Four years data suggest that papaya can be a successful annual crop if shelter is provided during late fall to protect ripening fruits and trees from frost/cold.
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Stevens, Matthew D., Brent L. Black, John D. Lea-Cox, Ali M. Sadeghi, Jennifer Harman-Fetcho, Emy Pfeil, Peter Downey, Randy Rowland, and Cathleen J. Hapeman. "A Comparison of Three Cold-climate Strawberry Production Systems: Environmental Effects." HortScience 44, no. 2 (April 2009): 298–305. http://dx.doi.org/10.21273/hortsci.44.2.298.
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The environmental effects of the three strawberry (Fragaria ×ananassa) cold-climate production systems were compared: the traditional method of conventional matted row (CMR) and the two more recently developed practices of advanced matted row (AMR) and cold-climate plasticulture (CCP). Side-by-side field plots were instrumented with automated flow meters and samplers to measure and collect runoff, which was filtered and analyzed to determine soil, pesticide, and nitrogen losses. Although annual mean runoff volumes were similar for all three production systems, the soil losses from CMR plots were two to three times greater than the CCP plots throughout the study and two to three times greater than the AMR plots only in the first year of the 3-year study. In general, decreases in erosion and runoff volumes were observed in plots that were disturbed less by machine operations and had less foot traffic as a result of decreased need for hand weeding and in the plots that used straw mulch in the furrows between the beds. Timing and intensity of precipitation events also influenced the amount of soil erosion. Pesticide residues and nitrogen losses were also greatest in the runoff from the CMR plots. The two systems that used drip fertigation, AMR and CCP, also had higher nitrogen uptake efficiencies. Overall, the CCP and AMR systems performed similarly for most criteria; however, considering the nonrenewable nature of the plastic mulch and the need to dispose of the plastic mulch in a landfill, the AMR system was more environmentally sustainable than the CCP system.
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van Noord, Michiel, Tomas Landelius, and Sandra Andersson. "Snow-Induced PV Loss Modeling Using Production-Data Inferred PV System Models." Energies 14, no. 6 (March 12, 2021): 1574. http://dx.doi.org/10.3390/en14061574.
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Snow-induced photovoltaic (PV)-energy losses (snow losses) in snowy and cold locations vary up to 100% monthly and 34% annually, according to literature. Levels that illustrate the need for snow loss estimation using validated models. However, to our knowledge, all these models build on limited numbers of sites and winter seasons, and with limited climate diversity. To overcome this limitation in underlying statistics, we investigate the estimation of snow losses using a PV system’s yield data together with freely available gridded weather datasets. To develop and illustrate this approach, 263 sites in northern Sweden are studied over multiple winters. Firstly, snow-free production is approximated by identifying snow-free days and using corresponding data to infer tilt and azimuth angles and a snow-free performance model incorporating shading effects, etc. This performance model approximates snow-free monthly yields with an average hourly standard deviation of 6.9%, indicating decent agreement. Secondly, snow losses are calculated as the difference between measured and modeled yield, showing annual snow losses up to 20% and means of 1.5–6.2% for winters with data for at least 89 sites. Thirdly, two existing snow loss estimation models are compared to our calculated snow losses, with the best match showing a correlation of 0.73 and less than 1% bias for annual snow losses. Based on these results, we argue that our approach enables studying snow losses for high numbers of PV systems and winter seasons using existing datasets.
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Hokanson, Stan C., Fumiomi Takeda, John M. Enns, and Brent L. Black. "Influence of Plant Storage Duration on Strawberry Runner Tip Viability and Field Performance." HortScience 39, no. 7 (December 2004): 1596–600. http://dx.doi.org/10.21273/hortsci.39.7.1596.
Full textAbstract:
Tissue-culture derived mother plants were established in a greenhouse suspended-gutter, nutrient-film technique growing system to evaluate runner tip productivity in the system. Effects of cultivar (`Allstar', `Chandler', `Latestar', `Northeaster', and USDA selection B 27) and duration (0, 1, or 2 months) of cold storage at 1 °C on tip viability, rooting success, and performance in fruit production were determined. The average number and weight of runner tips produced in the gutter production system, the capacity of runner tips to form cohesively rooted plug plants, and the number and length of adventitious roots produced by runner tips varied significantly among the cultivars and the three storage durations (0, 1, or 2 months). In the field, plants produced from runner tips stored for 2 months produced more runners than plants produced from freshly harvested runner tips. Crown number differed among the cultivars, but was not affected by cold storage treatment. No treatment differences were noted for the fruit harvest parameters evaluated. The results suggest that the transplants derived from mother plants grown in a greenhouse-based soilless system can be useful for annual plasticulture strawberry production in colder climates. Although long periods of cold storage of runner tips resulted in lower tip-to-transplant conversion ratios, field performance of transplants was not adversely affected. Additional research is needed to improve greenhouse strawberry production practices for increasing runner output and storage conditions that maintain the integrity of cold-stored runner tips. Without these improvements it is unlikely that soilless runner tip production will become a widely accepted technique that would replace the field nursery tip production method currently used by commercial strawberry propagators.
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Olberg, Madeline W., and Roberto G. Lopez. "High Tunnel and Outdoor Production of Containerized Annual Bedding Plants in the Midwestern United States." HortTechnology 26, no. 5 (October 2016): 651–56. http://dx.doi.org/10.21273/horttech03454-16.
Full textAbstract:
Due to the high cost associated with constructing and operating a greenhouse, many growers have begun using alternative, low-input methods for bedding plant production, such as unheated high tunnel and outdoor production. Previous research indicates that bedding plant production in unheated high tunnels may be suitable for cold-tolerant species, but flowering is delayed compared with greenhouse production. To our knowledge, there has been no published research on the effects of outdoor production on bedding plant species. The objectives of this study were therefore to 1) compare the growth and development of 10 cold-tolerant and intermediate annual bedding plant species grown in an unheated high tunnel or in an unprotected outdoor growing area, 2) evaluate the effect of a 1-week acclimation period in the high tunnel before outdoor production, and 3) quantify the effectiveness of these production methods for producing high-quality bedding crops. Seedlings of ‘Antigua Orange’ african marigold (Tagetes erecta), ‘Hot Cakes White’ stock (Matthiola incana), and ‘Lilac Flame’ primula (Primula acaulis), and rooted cuttings of ‘Aloha Kona Hot Pink’ calibrachoa (Calibrachoa ×hybrida), ‘Royal Lavender’ regal geranium (Pelargonium ×domesticum), ‘Bella Oceano’ lobelia (Lobelia erinus), ‘Potunia Plus Red’ petunia (Petunia ×hybrida), ‘Phloxy Lady Purple’ phlox (Phlox maculata), ‘Summertime Pink Charme’ osteospermum (Osteospermum ecklonis), and ‘Empress Purple’ verbena (Verbena ×hybrida) were transplanted on 13 Apr. 2015 (week 16) into an unheated high tunnel or an outdoor growing area, or into an unheated high tunnel for a 1-week acclimation period before being moved outdoors. Average mean daily air temperature was 2.3 °C lower outdoors compared with inside the high tunnel, whereas average daily light integral (DLI) increased by 11.7 mol·m−2·d−1. All plants were delayed when grown outdoors compared with in the high tunnel, and all marigolds grown outdoors died in April when outdoor air temperatures dropped below −4 °C. When plants were acclimated for a 1-week period before outdoor production, all species, with the exception of regal geranium, were delayed by less than 1 week compared with those grown in the high tunnel. Stem length of all species grown outdoors was reduced or similar to those in the high tunnel, whereas biomass accumulation and branch number was unaffected or increased for most species. Overall, high-quality bedding plants could be grown outdoors, although development may be delayed compared with high tunnel production. Growers must be aware of the risk of crop loss due to extreme temperatures and plan for delays when growing annual bedding plant crops outdoors.
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Hamilton, Shane. "Cold Capitalism: The Political Ecology of Frozen Concentrated Orange Juice." Agricultural History 77, no. 4 (October 1, 2003): 557–81. http://dx.doi.org/10.1215/00021482-77.4.557.
Full textAbstract:
Abstract Frozen concentrated orange juice (FCOJ) was invented in 1945 by government researchers. To Florida orange growers beset by surplus production in some years and hard winter freezes in others, FCOJ was a "miracle" technology. Easily stored and transported, concentrate made it possible for orange juice processors to provide consumers with a uniform-quality product year-round. By the mid-1950s constantly rising consumer demand for FCOJ had essentially eliminated Florida orange growers’ constant surplus problem. Furthermore, many oranges that suffered from occasional winter frosts could be transformed into concentrate rather than destroyed. Thus, FCOJ appeared to rationalize the Florida orange industry in the 1950s, eliminating seasonal and annual swings in production and stabilizing prices and profits. However, when severe frosts attacked Florida groves in 1957-58 and again in 1962-63, FCOJ processors responded by doubling prices. Unlike other industrial agriculturists in American history, Florida orange growers and processors did not use technology to control nature in order to increase profits. Instead, they used the environmental limits imposed by Florida’s subtropical climate, along with their oligopolistic market position, to squeeze higher profits out of consumers. They respected the role of nature in limiting their production, not because they were enlightened ecologists, but because their control over orange juice production allowed them to make just as much money from a damaged crop of oranges as from a bumper crop. This case study thus calls into question the meaning of "rationalized" agriculture, showing that the logic of capitalist agriculture is not always straightforward.
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VALERGAKIS (Γ.Ε. ΒΑΛΕΡΓΑΚΗΣ), G. E. "Meteorological conditions affecting cattle production in the area of Thessaloniki, Greece." Journal of the Hellenic Veterinary Medical Society 54, no. 1 (December 19, 2017): 41. http://dx.doi.org/10.12681/jhvms.15218.
Full textAbstract:
This paper presents a study of the climatic factors (temperature, relative humidity, wind, precipitation) affecting catde production in the area of Thessaloniki, the main dairy-farming region of Greece. Data was collected from 1990-1999 and was classified in zones, day-types were created and indexes and scales were used in order to study the annual and seasonal effects of climate. From this study, it was confirmed that high temperatures and high relative humidity are the most important factors affecting cattle productivity in the area. The intensity and duration of such conditions are high. Moreover, it is not low temperature per se, a relatively rare phenomenon, that affects catde performance during winter but the relatively strong and cold, mainly north-northwest winds, combined with high relative humidity.
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Voisin, Nathalie, Alan F. Hamlet, L. Phil Graham, David W. Pierce, Tim P. Barnett, and Dennis P. Lettenmaier. "The Role of Climate Forecasts in Western U.S. Power Planning." Journal of Applied Meteorology and Climatology 45, no. 5 (May 1, 2006): 653–73. http://dx.doi.org/10.1175/jam2361.1.
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Abstract The benefits of potential electric power transfers between the Pacific Northwest (PNW) and California (CA) are evaluated using a linked set of hydrologic, reservoir, and power demand simulation models for the Columbia River and the Sacramento–San Joaquin reservoir systems. The models provide a framework for evaluating climate-related variations and long-range predictability of regional electric power demand, hydropower production, and the benefits of potential electric power transfers between the PNW and CA. The period of analysis is 1917–2002. The study results show that hydropower production and regional electric power demands in the PNW and CA are out of phase seasonally but that hydropower productions in the PNW and CA have strongly covaried on an annual basis in recent decades. Winter electric power demand and spring and annual hydropower production in the PNW are related to both El Niño–Southern Oscillation (ENSO) and the Pacific decadal oscillation (PDO) through variations in winter climate. Summer power demand in CA is related primarily to variations in the PDO in spring. Hydropower production in CA, despite recent covariation with the PNW, is not strongly related to ENSO variability overall. Primarily because of strong variations in supply in the PNW, potential hydropower transfers between the PNW and CA in spring and summer are shown to be correlated to ENSO and PDO, and the conditional probability distributions of these transfers are therefore predictable with long lead times. Such electric power transfers are estimated to have potential average annual benefits of $136 and $79 million for CA and the PNW, respectively, at the year-2000 regional demand level. These benefits are on average 11%–27% larger during cold ENSO/PDO events and are 16%–30% lower during warm ENSO/PDO events. Power transfers from the PNW to CA and hydropower production in CA are comparable in magnitude, on average.
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Brey, Thomas. "Population dynamics of Sterechinus antarcticus (Echinodermata: Echinoidea) on the Weddell Sea shelf and slope, Antarctica." Antarctic Science 3, no. 3 (September 1991): 251–56. http://dx.doi.org/10.1017/s0954102091000305.
Full textAbstract:
Sterechinus antarcticus inhabits the shelf and the slope of the Weddell Sea and is the predominant echinoid between 450 and 1200 m. Growth lines visible in the half pyramids of the Aristotle's lantern were interpreted as annual growth marks. A Von Bertalanffy growth function was fitted to age-diameter data of 217 specimens (D∞ = 82.4 mm, K = 0.017 y−1, t0 = 1.633 y). Based on 92 trawl samples, a representative size-frequency distriution of S. antarcticus was established. From the growth curve, the size-frequency sample and diameter - weight regressions, mortality and somatic productivity of S. antarcticus were calculated by a size-converted catch curve and the weight specific growth rate method. Gonadal productivity was estimated by an average value for reproductive output of cold water echinoderms. Mortality rate Z as'well as somatic P/B ratio amounted to 0.07 y−1. Annual somatic production was estimated as 0.3 mg m−2y−1, and annual gonadal production as 0.25 mg m−2 y−1 between 100 and 1200 m (0.6 and 0.5 mg m−2 y−1 between 450 and 1200 m).
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Zhao, Jinhui, Xuwei Han, and Xuexiu Bai. "Reliability analysis of solar energy and biogas boiler combination warming system." E3S Web of Conferences 260 (2021): 01001. http://dx.doi.org/10.1051/e3sconf/202126001001.
Full textAbstract:
In order to solve the problem of low biogas production caused by low temperature in northern cold area, the solar energy and biogas boiler combination warming system is proposed to raise the temperature of biogas digester. In this paper, under the condition of the optimum area of solar collector, it's obtained that changeable rule of solar energy guarantee rate with month and rule of heating ratio of biogas boiler in the whole year. The solar energy guarantee rate of the system is more than 55.9%, and the combined heating capacity of solar energy and biogas boiler is enough to meet the requirements of annual operation conditions, which is reliable in the northern cold area.
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Reighard, Gregory L., and David R. Ouellette. "Winter Bud Cold-hardiness of Interstem Peach Trees." HortScience 33, no. 3 (June 1998): 541e—541. http://dx.doi.org/10.21273/hortsci.33.3.541e.
Full textAbstract:
Large fluctuations in annual peach production is a chronic problem in the southeastern United States. Winter and spring cold injury to flowers reduces the potential peach crop almost every year in the Southeast. A bloom delaying peach interstem has consistently delayed phenology in the Southeast, but its effect on bud hardiness is unknown. Nine varieties (650–1050 chill hours) budded to `Ta Tao 5' (P.I. 101667) interstems on Lovell rootstock or budded to only Lovell rootstock (i.e., controls) were sampled monthly from November or December to late February in 1996–97 and 1997–98 from an interstem test established in 1993 near Clemson, S.C. High-chill varieties such as `Contender', `Encore', and `Redhaven' were 1 to 2 °C more cold-hardy on interstem trees in late winter. General trends showed that varieties were slightly more cold-hardy on interstems in 1996–97, but no differences were observed from Nov.1997 through early Jan. 1998. Significant varietal differences in cold-hardiness were found on each sampling date, but no trends were observed.
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Sztekler, Karol, Wojciech Kalawa, Wojciech Nowak, Sebastian Stefański, Jarosław Krzywański, Karolina Grabowska, and Łukasz Mika. "Possibility of use adsorption chillers for increase efficiency in conventional power plant." EPJ Web of Conferences 213 (2019): 02082. http://dx.doi.org/10.1051/epjconf/201921302082.
Full textAbstract:
Long-term forecasts indicate that the annual increases in electricity demand by 2030 will be approx. 2 ÷ 3% a year. At present, 40% of the world's electricity is produced using coal-fired power plants. Forecasts indicate that coal will still be the predominant fuel used to produce electricity and thus any actions aimed at increasing the efficiency of electricity production are purposeful. Enormous amounts of waste heat, which is not sufficiently used, are released during the process of electricity production. One of the ways to manage it is to use refrigeration systems based on adsorption chillers which would use waste heat to generate cold that would be employed for air-conditioning or process purposes. In this paper, the cycle of a conventional coal-fired power plant was modelled and then the possibilities of using waste heat for generation of cold as well as the impact of a chiller on the operation of a power unit were analysed using IPSEpro software.
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Scaglia, Guillermo. "PSXI-18 Nitrogen fertilization management of winter pastures for stocker cattle production." Journal of Animal Science 99, Supplement_3 (October 8, 2021): 349–50. http://dx.doi.org/10.1093/jas/skab235.641.
Full textAbstract:
Abstract Bermudagrass is often over-seeded with a cool-season annual grass for grazing purposes. In the Gulf Coast region, summer perennials will not become dormant until there are low soil and ambient temperatures. Nitrogen fertilizer is an expensive input and its split application for winter pastures is recommended. The objective of this experiment was to evaluate the time of application of N fertilizer or its substitution with red clover as a source of N. Three treatments were evaluated in 3 consecutive years (2 replicates per year) on annual ryegrass (cv. Marshall) no-tilled planted (45 kg/ha) on Tifton-85 bermudagrass: 1) Urea in late November and mid-late January; 2) Red clover planted with annual ryegrass; 3) Urea in January only. Thirty crossbred steers (203±24 kg) were blocked by BW and randomly assigned to 1 of 6 groups. Each group were continuously stocked on 1.34 ha pastures for 90 d. Forage mass, botanical composition, and nutritive value of the pastures were determined from the time of the first N application and every 15 d thereafter. There was treatment x year interaction (P = 0.03) in botanical composition. Greater proportions (P = 0.03) of bermudagrass were present on the 2-application treatment on every sampling date until d 15 of the grazing period in Year 1 and 3. This was a result of N absorbed by bermudagrass which impacted its nutritive value (P = 0.01) although not forage production (P = 0.07). In Year 2, annual ryegrass dominated the swards due to a cold artic front in early November. Steers grazing fertilized treatments had greater gains (P = 0.04), while production per ha was greater (P = 0.03) when N was applied in January than when no N was applied. Hay production (kg DM/ha) was similar (P = 0.06) among treatments. Opportunities for improved economics of production and enhanced sustainability appear to be realistic objectives with changes in fertilization strategy.
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Трушляков, Євген Іванович, Андрій Миколайович Радченко, Ян Зонмін, Анатолій Анатолійович Зубарєв, and Веніамін Сергійович Ткаченко. "МЕТОД ВИЗНАЧЕННЯ ХОЛОДОПРОДУКТИВНОСТІ УСТАНОВОК КОНДИЦІЮВАННЯ ПОВІТРЯ КОМФОРТНОГО Й ЕНЕРГЕТИЧНОГО ПРИЗНАЧЕННЯ." Aerospace technic and technology, no. 1 (March 7, 2019): 53–58. http://dx.doi.org/10.32620/aktt.2019.1.06.
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The efficiency of applying air conditioning units for comfort and energetics for a certain period, as well as any power plant, is determined by the effect obtained, primarily in the form of reducing fuel consumption over the year or increasing the production of electrical (mechanical) energy in the case of air conditioning at the heat engine inlet and by annual cold production as an indicator of the efficiency of using the cooling capacity of comfort air-conditioning plants. Since in both cases the effect depends on the duration and depth of cooling, it is quite justified to estimate it in the first approximation by the thermal hourly potential, which is the result of summation hour by hour of air temperature drops multiplied by duration of operation at a lowered temperature and, thus, takes into account current climatic conditions. Obviously, the realization of the cooling potential (air conditioning) of the ambient air depends on the installed (design) cooling capacity of the air conditioning units, which, in turn, must take into account the fluctuations in thermal loads in accordance with the current variable thermal and humidity parameters of the ambient air. Based on the different rates of the increment of the annual thermal hourly cooling potential with an increase in the installed cooling capacity of the air conditioning unit due to a change in the heat load in accordance with current climatic conditions during the year, it is necessary to choose such a design thermal load on the air conditioning unit (its installed cooling capacity) that ensures maximum or close to it the annual thermo-hour cooling potential at a relatively high rate of its increment, respectively, and the effect of cooling in the form of a decrease in fuel consumption per year in the case of air conditioning at the inlet of heat engine and annual cold production of comfort air conditioning units. It is shown that under the same climatic conditions during the year and the depth of ambient air cooling, the rational values of the design cooling capacity of air conditioning units for comfort and energy purposes are the same.
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Creech, J. Earl, Judith B. Santini, Shawn P. Conley, Andreas Westphal, and William G. Johnson. "Purple Deadnettle (Lamium purpureum) and Soybean Cyst Nematode Response to Cold Temperature Regimes." Weed Science 55, no. 6 (December 2007): 592–98. http://dx.doi.org/10.1614/ws-07-040.1.
Full textAbstract:
An experiment was conducted in growth chambers to determine the influence of cold temperature regimes, designed to simulate winter temperature conditions and spring recovery, on the interaction between purple deadnettle and soybean cyst nematode (SCN). The study was a factorial arrangement of treatments with five levels of temperature (20, 15, 10, 5, or 0 C), two levels of exposure time to the temperature (10 or 20 d), and two levels of recovery time at 20 C following exposure (0 or 20 d). In general, purple deadnettle shoot and root growth increased with temperature and time. The ability of purple deadnettle to recover from cold temperatures declined as the length of time that the plant was subjected to the cold temperature increased. SCN juveniles per gram of root at the conclusion of the temperature treatment declined as the temperature increased from 0 to 15 C, likely a result of continued purple deadnettle root growth and the inhibition of SCN hatch, growth, or development at those temperatures. SCN female, cyst, and egg production per gram of root generally increased with temperature and occurred under all temperature regimes. The results of this research indicate that, after hatching, SCN juveniles can survive a period of cold temperature inside the roots of a winter annual and continue development when transferred to warmer temperatures. Therefore, in a field environment, where fall or spring alone may not be sufficient for SCN to complete a reproductive cycle on a winter annual weed, the nematode may be able to reproduce by combining the fall and spring developmental periods.
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Whalen, S. C., and J. C. Cornwell. "Nitrogen, Phosphorus, and Organic Carbon Cycling in an Arctic Lake." Canadian Journal of Fisheries and Aquatic Sciences 42, no. 4 (April 1, 1985): 797–808. http://dx.doi.org/10.1139/f85-102.
Full textAbstract:
Budgets for nitrogen, phosphorus, and organic carbon in Toolik Lake, Alaska, were assembled from data collected during 1977–81. The annual total organic carbon (TOC), total nitrogen (TN), and total phosphorus (TP) loads to the Sake were 8557, 290, and 4.64 mmol∙m−2. Inlet streams were the major source of nutrients to the lake, as direct precipitation provided only 1, 2, and 5%, respectively, of the annual TOC, TN, and TP loads to the lake. Up to 30% of the annual N and P inputs to the lake from riverine sources occurred during the first 10 d of stream flow following breakup when cold water temperatures and snow-covered ice limited primary production. Due to the short water renewal time (0.5 yr), efficiency of nutrient retention was poor and 90, 82, and 70% of the annual TOC, TN, and TP inputs to the lake were discharged at the outlet stream. Regeneration within the water column supplied 40–66% and 68–78% of the N and P necessary for measured primary production. Yearly accumulation rates for C, N, and P in the sediment were about 220, 21.0, and 1.75 mmol∙m−2. Phosphorus remineralized within the sediment was completely retained due to adsorption onto Fe oxide minerals in the oxidizing surface layer. Annual rates of release of C and N to the overlying water column were 110 and 11.5–22.2 mmol∙m2. Mass balance considerations showed no serious errors in estimates of any terms of the annual sediment and water column N, P, and organic C budgets.
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Black, Brent L. "Prohexadione-calcium Decreases Fall Runners and Advances Branch Crowns of `Chandler' Strawberry in a Cold-climate Annual Production System." Journal of the American Society for Horticultural Science 129, no. 4 (July 2004): 479–85. http://dx.doi.org/10.21273/jashs.129.4.0479.
Full textAbstract:
Balancing vegetative growth with fruiting is a primary concern in strawberry (Fragaria ×ananassa Duch.) production. Where nursery plant selection and preconditioning are inadequate for runner control, additional approaches are needed. The gibberellin biosynthesis inhibitor prohexadione-Ca (commercial formulation Apogee) was tested over two seasons for suppressing fall runners of `Chandler' plug plants in a cold-climate annual hill production system. Prohexadione-Ca was applied as a foliar spray at active ingredient concentrations ranging from 60 to 480 mg·L-1, either as a single application 1 week after planting, or repeated at 3-week intervals. The lowest rate resulted in inadequate runner control, with some runners producing malformed daughter plants. Higher rates resulted in 57% to 93% reductions in fall runner numbers, with a concomitant increase in fall branch crown formation. There were no effects of the prohexadione-Ca treatments on plant morphology the following spring, and no adverse effects on fruit characteristics or yield. Chemical names used: prohexadione-calcium, calcium 3-oxido-4-propionyl-5-oxo-3-cyclohexene-carboxylate.
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Koenig, Walter D., Johannes M. H. Knops, and William J. Carmen. "Intraspecific variation in the relationship between weather and masting behavior in valley oak, Quercus lobata." Canadian Journal of Forest Research 50, no. 12 (December 2020): 1299–306. http://dx.doi.org/10.1139/cjfr-2020-0098.
Full textAbstract:
Masting behavior — variable and synchronized reproduction by a population of plants — has long been recognized as correlating with weather. How and why weather conditions influence seed production is, however, poorly understood. We investigated the relationships between acorn production and both local weather and long-term climate in 10 populations across the geographic range of the valley oak (Quercus lobata Née), a California endemic that matures acorns in a single season. Acorn production was larger following a cold spring in the prior year and dry conditions in the winter and spring immediately preceding acorn maturation; similar patterns were also found, with minor differences, at all 10 individual sites. The strength of the relationships varied geographically in the case of the correlation between winter rainfall and annual acorn production, which was stronger (more negative) at wetter sites. Thus, in contrast to a recent study in Quercus petraea (Matt.) Liebl., weather had generally similar effects on acorn production throughout the range of Q. lobata. Similar to Q. petraea, however, the strength of the relationship between site-level annual acorn production and one of the weather factors affecting acorn production (winter rainfall in the case of Q. lobata) varied geographically in ways that may be related to differences among sites in the degree of pollen limitation. Understanding the mechanisms by which weather affects seed production is challenging but critical if we are to understand how climate change will affect masting behavior in the future.
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Giraud, X. "Modelling an alkenone-like proxy record in the NW African upwelling." Biogeosciences Discussions 3, no. 1 (January 27, 2006): 71–121. http://dx.doi.org/10.5194/bgd-3-71-2006.
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Abstract. A regional biogeochemical model is applied to the NW African coastal upwelling between 19° N and 27° N to investigate how a water temperature proxy is produced at the sea surface and recorded in the slope sediments. The biological model has two phytoplankton groups, to distinguish an alkenone producer group (considered as coccolithophores) from other phytoplankton. The Regional Ocean Modelling System (ROMS) is used to simulate the ocean circulation, and takes advantage of the Adaptive Grid Refinement in Fortran (AGRIF) package to set up an embedded griding system. The results show that the alkenone-like temperature records in the sediments are between 1.1 and 2.1°C colder compared to the annual mean SSTs. Despite the seasonality of the coccolithophorid production, this temperature difference is not mainly due to a seasonal bias, nor to the lateral advection of phytoplankton and phytodetritus from the cold water domain to most offshore locations, but to the production depth of the coccolithophores. If core-top sediment alkenone-derived temperatures are effectively recording the annual mean SSTs, the quantitative alkenone production in the water column must be inhomogeneous among the coccolithophore population and depend on physiological factors (growth rate, nutrient stress).
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Pan, Caleb G., John S. Kimball, Munkhdavaa Munkhjargal, Nathaniel P. Robinson, Erik Tijdeman, Lucas Menzel, and Peter B. Kirchner. "Role of Surface Melt and Icing Events in Livestock Mortality across Mongolia’s Semi-Arid Landscape." Remote Sensing 11, no. 20 (October 16, 2019): 2392. http://dx.doi.org/10.3390/rs11202392.
Full textAbstract:
Livestock production is a socioeconomic linchpin in Mongolia and is affected by large-scale livestock die-offs. Colloquially known as dzuds, these die-offs are driven by anomalous climatic events, including extreme cold temperatures, extended snow cover duration (SCD) and drought. As average temperatures across Mongolia have increased at roughly twice the global rate, we hypothesized that increasing cold season surface melt including soil freeze/thaw (FT), snowmelt, and icing events associated with regional warming have become increasingly important drivers of dzud events as they can reduce pasture productivity and inhibit access to grazing. Here, we use daily brightness temperature (Tb) observations to identify anomalous surface melt and icing events across Mongolia from 2003–2016 and their contribution to dzuds relative to other climatic drivers, including winter temperatures, SCD, and drought. We find a positive relationship between surface melt and icing events and livestock mortality during the fall in southern Mongolia and during the spring in the central and western regions. Further, anomalous seasonal surface melt and icing events explain 17–34% of the total variance in annual livestock mortality, with cold temperatures as the leading contributor of dzuds (20–37%). Summer drought showed the greatest explanatory power (43%) but overall had less statistically significant relationships relative to winter temperatures. Our results indicate that surface melt and icing events will become an increasingly important driver of dzuds as annual temperatures and livestock populations are projected to increase in Mongolia.
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Pestiné Nagy, Orsolya, Attila Ombódi, Tamás Kassai, and Judit Dimény. "Possibilities of Growing Artichoke (Cynara scolymus L.) in Hungary." Acta Agraria Debreceniensis, no. 9 (December 10, 2002): 126–30. http://dx.doi.org/10.34101/actaagrar/9/3572.
Full textAbstract:
The domestication of choice broadening, special vegetable species offers new market possibilities in Hungary. The production of artichokes has good perspectives due to its high protein, vitamin and mineral contents and its wide usability. According to the literature, in Hungary it is worth examining the annual production technology, which has yet to be researched in our country. The basic aim of our work was to establish the annual production of artichoke in Hungary with scientific research.In the experiment, 5 Italian sorts (Valetta di Roma, Gobbo di Nizza, Violetto di Romagna, Violetto S. Francesino and Precoce di Romagna), 1 American sort (Green Globe) and 1 Egyptian sort (Balady) were used. For one half of the plants, we tried to bring on bud-production appearing in the first year only with early planting, while we used also a gibberellic acid hormone treatment for the other half.Only the sort Green Globe had yields in appropriate quantity (21.4 t/ha) and quality. The low yield and inequable quality of buds of the Italian and Egyptian sorts refers to the fact that these sorts are not applicable for annual production in Hungary. Although the gibberellic acid treatment resulted an earlier harvest, increased the equality of buds and increased the proportion of stems producing buds except for the sort Green Globe, overall it did not have a positive effect. The hormone treatment fastened the physiological processes of the plants, thereby it induced early insenescence and lignifying of the buds. The high temperatures during the bud-formation period largely increased the ratio of flabby, over-blowing buds, so the planting must be timed in the future that the harvest period is in early automn or late spring, early summer months.According to our results, globe artichoke can become a perspective culture by applying cold-resistant sorts with short growing seasons, which can be produced as annual crops without hormone treatment by the appropriate timing of bud-formation.
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Smoła, Zofia T., Agnieszka Tatarek, Józef M. Wiktor, Józef M. W. Wiktor, Anna Kubiszyn, and Jan M. Węsławski. "Primary producers and production in Hornsund and Kongsfjorden – comparison of two fjord systems." Polish Polar Research 38, no. 3 (September 1, 2017): 351–73. http://dx.doi.org/10.1515/popore-2017-0013.
Full textAbstract:
Abstract Hornsund and Kongsfjorden are two similar-sized Arctic fjords on the West coast of Spitsbergen. They are influenced by cold coastal Arctic water (Hornsund) and warmer Atlantic water (Kongsfjorden). Environmental conditions affect the timing, quantity, spatial distribution (horizontal and vertical) of spring and summer blooms of protists as well as the taxonomic composition of those assemblages. Here, we compile published data and unpublished own measurement from the past two decades to compare the environmental factors and primary production in two fjord systems. Kongsfjorden is characterized by a deeper euphotic zone, higher biomass and greater proportion of autotrophic species. Hornsund seems to obtain more nutrients due to the extensive seabird colonies and exhibits higher turbidity compared to Kongsfjorden. The annual primary production in the analysed fjords ranges from 48 g C m−2 y−1 in Kongsfjorden to 216 g C m−2 y−1 in Hornsund, with a dominant component of microplankton (90%) followed by macrophytes and microphytobenthos.
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Howard, Dean, Yannick Agnan, Detlev Helmig, Yu Yang, and Daniel Obrist. "Environmental controls on ecosystem-scale cold-season methane and carbon dioxide fluxes in an Arctic tundra ecosystem." Biogeosciences 17, no. 15 (August 10, 2020): 4025–42. http://dx.doi.org/10.5194/bg-17-4025-2020.
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Abstract. Understanding the processes that influence and control carbon cycling in Arctic tundra ecosystems is essential for making accurate predictions about what role these ecosystems will play in potential future climate change scenarios. Particularly, air–surface fluxes of methane and carbon dioxide are of interest as recent observations suggest that the vast stores of soil carbon found in the Arctic tundra are becoming more available to release to the atmosphere in the form of these greenhouse gases. Further, harsh wintertime conditions and complex logistics have limited the number of year-round and cold-season studies and hence too our understanding of carbon cycle processes during these periods. We present here a two-year micrometeorological data set of methane and carbon dioxide fluxes, along with supporting soil pore gas profiles, that provide near-continuous data throughout the active summer and cold winter seasons. Net emission of methane and carbon dioxide in one of the study years totalled 3.7 and 89 g C m−2 a−1 respectively, with cold-season methane emission representing 54 % of the annual total. In the other year, net emission totals of methane and carbon dioxide were 4.9 and 485 g C m−2 a−1 respectively, with cold-season methane emission here representing 82 % of the annual total – a larger proportion than has been previously reported in the Arctic tundra. Regression tree analysis suggests that, due to relatively warmer air temperatures and deeper snow depths, deeper soil horizons – where most microbial methanogenic activity takes place – remained warm enough to maintain efficient methane production whilst surface soil temperatures were simultaneously cold enough to limit microbial methanotrophic activity. These results provide valuable insight into how a changing Arctic climate may impact methane emission, and highlight a need to focus on soil temperatures throughout the entire active soil profile, rather than rely on air temperature as a proxy for modelling temperature–methane flux dynamics.
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Giraud, X. "Modelling an alkenone-like proxy record in the NW African upwelling." Biogeosciences 3, no. 3 (June 21, 2006): 251–69. http://dx.doi.org/10.5194/bg-3-251-2006.
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Abstract. A regional biogeochemical model is applied to the NW African coastal upwelling between 19° N and 27° N to investigate how a water temperature proxy, alkenones, are produced at the sea surface and recorded in the slope sediments. The biogeochemical model has two phytoplankton groups: an alkenone producer group, considered to be coccolithophores, and a group comprising other phytoplankton. The Regional Ocean Modelling System (ROMS) is used to simulate the ocean circulation and takes advantage of the Adaptive Grid Refinement in Fortran (AGRIF) package to set up an embedded griding system. In the simulations the alkenone temperature records in the sediments are between 1.1 and 2.3°C colder than the annual mean SSTs. Despite the seasonality of the coccolithophore production, this temperature difference is not mainly due to a seasonal bias, nor to the lateral advection of phytoplankton and phytodetritus seaward from the cold near-shore waters, but to the production depth of the coccolithophores. If coretop alkenone temperatures are effectively recording the annual mean SSTs, the amount of alkenone produced must vary among the coccolithophores in the water column and depend on physiological factors (e.g. growth rate, nutrient stress).
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Zhou, Chunshan, Rongrong Zhang, Xiaoju Ning, and Zhicheng Zheng. "Spatial-Temporal Characteristics in Grain Production and Its Influencing Factors in the Huang-Huai-Hai Plain from 1995 to 2018." International Journal of Environmental Research and Public Health 17, no. 24 (December 9, 2020): 9193. http://dx.doi.org/10.3390/ijerph17249193.
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The Huang-Huai-Hai Plain is the major crop-producing region in China. Based on the climate and socio-economic data from 1995 to 2018, we analyzed the spatial–temporal characteristics in grain production and its influencing factors by using exploratory spatial data analysis, a gravity center model, a spatial panel data model, and a geographically weighted regression model. The results indicated the following: (1) The grain production of eastern and southern areas was higher, while that of western and northern areas was lower; (2) The grain production center in the Huang-Huai-Hai Plain shifted from the southeast to northwest in Tai’an, and was distributed stably at the border between Jining and Tai’an; (3) The global spatial autocorrelation experienced a changing process of “decline–growth–decline”, and the area of hot and cold spots was gradually reduced and stabilized, which indicated that the polarization of grain production in local areas gradually weakened and the spatial difference gradually decreased in the Huang-Huai-Hai Plain; (4) The impact of socio-economic factors has been continuously enhanced while the role of climate factors in grain production has been gradually weakened. The ratio of the effective irrigated area, the amount of fertilizer applied per unit sown area, and the average per capita annual income of rural residents were conducive to the increase in grain production in the Huang-Huai-Hai Plain; however, the effect of the annual precipitation on grain production has become weaker. More importantly, the association between the three factors and grain production was found to be spatially heterogeneous at the local geographic level.
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Трушляков, Євген Іванович, Андрій Миколайович Радченко, Микола Іванович Радченко, Сергій Анатолійович Кантор, and Веніамін Сергійович Ткаченко. "ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ КОНДИЦІЮВАННЯ ЗОВНІШНЬОГО ПОВІТРЯ СИСТЕМИ КОМБІНОВАНОГО ТИПУ." Aerospace technic and technology, no. 4 (August 31, 2019): 9–14. http://dx.doi.org/10.32620/aktt.2019.4.02.
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One of the most attractive reserves of enhancing the energetic efficiency of air conditioning systems is to provide the operation of refrigeration compressors in nominal or close to nominal modes by choosing rational design cooling loads (cooling capacities) and their distribution according to a cooling load behaviour within the overall design (installed) cooling load band to match current changeable climatic conditions and provide close to maximum annual cooling capacity generation according to cooling duties. The direction of increasing the efficiency of outdoor air conditioning in combined central-local type systems by rationally distributing the heat load - cooling capacity of the central air conditioner into zones of variable heat load in accordance with current climatic conditions and its relatively stable value, i.e. cooling capacity required for further air cooling at the entrance to the indoor recirculation air conditioning system is justified. By comparing the values of the excessive production of cold and its deficit within every 3 days for a rational design heat load of the air conditioning system (cooling capacity of the installed refrigeration machine), which provides close to maximum annual production of cold, and the corresponding values of the excess and deficit of cooling capacity in accordance with current climatic conditions during July substantiated the feasibility of accumulating the excess of cooling capacity of a central air conditioner at low current loads and its use for covering cooling deficit at elevated heat loads through pre-cooling the outdoor air. It is developed a scheme of a combined central-local air conditioning system, which includes the subsystems for the outdoor air conditioning in a central air conditioner and the local indoor recirculated air conditioning.
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Parks, Timothy P., and Andrew L. Rypel. "Predator–prey dynamics mediate long-term production trends of cisco (Coregonus artedi) in a northern Wisconsin lake." Canadian Journal of Fisheries and Aquatic Sciences 75, no. 11 (November 2018): 1969–76. http://dx.doi.org/10.1139/cjfas-2017-0302.
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We quantified production, biomass, and production to biomass (P/B) ratios for cisco (Coregonus artedi) in Trout Lake, Wisconsin, USA (2001–2015). Across all years, annual production, biomass, and P/B were variable ranging 0.6–30.2 kg·ha−1·year−1, 1.2–39.7 kg·ha−1, and 0.4–0.9·year−1, respectively. Cisco production exhibited obvious decline. However, neither biomass nor P/B changed significantly over time. Long-term patterns of environmental conditions remained unchanged during the study and were unrelated to cisco production. However, lake trout (Salvelinus namaycush) relative abundance showed a strong inverse relationship with cisco production and biomass. Intense lake trout stocking has occurred in this lake over time to conserve a genetically unique strain of the species. These management efforts may have had the unintended consequence of amplifying top-down predation on cisco. Since cisco P/B has gone largely unchanged, cisco production would be predicted to rebound quickly to adaptive reductions in lake trout stocking. Further increases in lake trout numbers could place both populations at risk of collapse. This study provides an example of a fisheries production approach for understanding and conserving cold-water fisheries, especially in lakes dominated by ciscoes.
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FOWLER, D. B., M. L. GRAHAM, and R. ASHFORD. "INFLUENCE OF FALL APPLIED 2,4-D AMINE AND MCPA ON COLD HARDINESS AND OTHER AGRONOMIC CHARACTERS OF WINTER WHEAT AND RYE." Canadian Journal of Plant Science 66, no. 4 (October 1, 1986): 837–43. http://dx.doi.org/10.4141/cjps86-105.
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The effects of 2,4-D and MCPA amine treatments on cold tolerance and other agronomic characters of winter wheat (Triticum aestivum L.) and rye (Secale cereale L.) were studied in controlled environment and field trails. For both species, the level of cold tolerance achieved in controlled environments was reduced following exposure to 2,4-D and MCPA at rates up to 2.24 kg ha−1. In contrast, similar rates of fall applied 2,4-D and MCPA did not affect the cold tolerance of wheat and rye growing in the field. Treatment of plants from different seeding dates indicated that the observed field herbicide tolerance was not influenced by large differences in plant growth stage. Yield and other agronomic characters were also unaffected by fall 2,4-D and MCPA treatment. In contrast, broadleaf weed control was obtained with rates as low as 0.28 kg ha−1 for both herbicides, emphasizing the large safety margin between rates required for effective winter annual weed control and crop tolerance levels. From a practical standpoint, the influence of other management practices, such as delayed seeding, were of much greater importance in winter cereal production than the effects of commerical rates of 2,4-D or MCPA applied in the fall for broadleaf weed control.Key words: Wheat (winter), rye, 2,4-D amine, MCPA amine, cold tolerance
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Schrader, James A., Diana R. Cochran, Paul A. Domoto, and Gail R. Nonnecke. "Phenology and Winter Hardiness of Cold-climate Grape Cultivars and Advanced Selections in Iowa Climate." HortTechnology 29, no. 6 (December 2019): 906–22. http://dx.doi.org/10.21273/horttech04475-19.
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The popularity of grape (Vitis sp.) and wine production in the upper midwest region of the United States is increasing steadily. The development of several cold-climate, interspecific-hybrid grape cultivars (northern hybrids) since the 1980s has improved the probability of success for both new and established vineyards in this area of the country, but long-term data describing the performance of these cultivars in midwestern U.S. climates are needed to both aid growers in their choice of cultivars and to provide them with information about factors important in their management. We characterized the long-term winterhardiness and annual phenology of 12 cold-climate northern hybrid grape cultivars (two established cultivars, five newer cultivars, and five advanced selections) grown in a randomized and replicated field plot in central Iowa, an area that offers a warm growing season and very cold dormant season for grape culture. The established cultivars included in the study were Frontenac and St. Croix. The newer cultivars evaluated were Arandell, Corot noir, La Crescent, Marquette, and Petit Ami, and the advanced selections were MN 1189, MN 1200, MN 1220, MN 1235, and MN 1258. The grape trial was established in 2008, and vines were evaluated from 2011 through 2017 for annual timing of budbreak, bloom, veraison, and harvest, as well as winter survival of vines and primary buds. As a group, the northern hybrids in our trial showed good winterhardiness of vines but variable hardiness of primary buds across the six winters, which ranged from warmer than average to much colder than average. In Iowa climate, buds of northern hybrids were generally most vulnerable to cold temperature damage from late-winter (March) low-temperature events or from extreme midwinter low-temperature events. The bud hardiness of individual cultivars ranged from very hardy (Frontenac, Marquette, and MN 1235) to poor hardiness (Arandell, Corot noir, Petit Ami, and MN 1189), with all 12 cultivars showing good bud survival during Iowa winters that were warmer than average, but the less-hardy cultivars showing poor bud survival during winters that were colder than average. Evaluations of phenology revealed that heat accumulation measured in growing degree days with a threshold of 50 °F was not a reliable index for predicting the timing of annual developmental stages for the cultivars we tested. Our results indicate that northern hybrids rely on other factors in addition to heat accumulation for guiding annual development, and that factors such as photoperiod likely have a strong influence on phenological timing during seasons with unusual weather patterns. We determined that none of the cultivars were vulnerable to cold temperature damage to fruit before harvest in Iowa’s climate, but that three of the cultivars (Arandell, Marquette, and MN 1235) were highly vulnerable to shoot damage from spring freeze events, and four others (Corot noir, La Crescent, MN 1200, and MN 1220) were moderately vulnerable to cold damage to shoots in spring. An itemized summary of the relative hardiness, vulnerabilities, and timing of phenological stages of the 12 cultivars is provided to aid growers in selection and management of grape cultivars for Iowa climate. Based on hardiness and phenology, four of these cultivars (Frontenac, MN 1258, MN 1220, and MN 1200) have the lowest risk of issues related to cold temperatures.
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Þrastarson, Sindri, Björn Marteinsson, and Hrund Ólöf Andradóttir. "Fýsileiki virkjunar sólarorku á norðurslóðum: Reynsla af sólarpanelum IKEA á Íslandi." Icelandic Journal of Engineering 25 (December 7, 2019): 1–19. http://dx.doi.org/10.33112/ije.25.1.
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The efficiency and production costs of solar panels have improved dramatically in the past decades. The Nordic countries have taken steps in instigating photovoltaic (PV) systems into energy production despite limited incoming solar radiation in winter. IKEA installed the first major PV system in Iceland with 65 solar panels with 17.55 kW of production capacity in the summer of 2018. The purpose of this research was to assess the feasibility of PV systems in Reykjavík based on solar irradiation measurements, energy production of a PV array located at IKEA and theory. Results suggests that net irradiation in Reykjavík (64°N, 21° V) was on average about 780 kWh/m2 per year (based on years 2008-2018), highest 140 kWh/m2 in July and lowest 1,8 kWh/m2 in December. Maximum annual solar power is generated by solar panels installed at a 40° fixed angle. PV panels at a lower angle produce more energy during summer. Conversely, higher angles maximize production in the winter. The PV system produced over 12 MWh over a one-year period and annual specific yield was 712 kWh/kW and performance ratio 69% which is about 10% lower than in similar studies in cold climates. That difference can be explained by snow cover, shadow falling on the panels and panels not being fixed at optimal slope. Payback time for the IKEA PV system was calculated 24 years which considers low electricity prices in Reykjavik and unforeseen high installation costs. Solar energy could be a feasible option in the future if production- and installation costs were to decrease and if the solar PV output could be sold to the electric grid in Iceland.
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Wang, Zhilei, Ying Wang, Dong Wu, Miao Hui, Xing Han, Tingting Xue, Fei Yao, et al. "Identification and Regionalization of Cold Resistance of Wine Grape Germplasms (V. vinifera)." Agriculture 11, no. 11 (November 9, 2021): 1117. http://dx.doi.org/10.3390/agriculture11111117.
Full textAbstract:
With the extreme changes of the global climate, winter freezing injury has become an important limiting factor for the development of the global grape industry. Therefore, there is a significant need for the screening of cold-resistant wine grape germplasms and cold regionalization for cold-resistant breeding and the development of grapevine cultivation in cold regions. In this study, the low-temperature half-lethal temperature (LT50) values were determined for the annual dormant branches of 124 wine grape germplasms (V. vinifera) to evaluate their cold resistance. The LT50 values of the 124 tested germplasms ranged from −22.01 °C to −13.18 °C, with six cold-resistant germplasms below −20 °C. Based on the LT50 values, the 124 germplasms were clustered into four types, with cold resistance from strong to weak in the order of type Ⅱ > type Ⅰ > type Ⅳ > type Ⅲ, corresponding to the four cold hardiness zones. Zones 1, 2, 3, and 4 included 6, 22, 68, and 28 germplasms, respectively, with decreasing cold resistance. The number of germplasms in different hardiness zones followed a normal distribution, with the most in zone 3. In Type Ⅱ, the fruit skin color of germplasms was positively correlated with cold hardiness, while the temperature of origin was negatively correlated with cold hardiness. The average LT50 of germplasms in different origin regions ranged from −17.44 °C to −16.26 °C, with differences among some regions. The cold regionalization analysis resulted in the distribution of 124 germplasms in four temperature regions in China with six germplasms in region A (−22 °C ≤ LT50 ≤ −20 °C), 30 germplasms in region B (−20°C ≤ LT50 ≤ −18°C), 71 germplasms in region C (−18 °C ≤ LT50 ≤ −15 °C), and 17 germplasms in region D (−15 °C ≤ LT50 ≤ −13 °C). Strong cold-resistant wine grape germplasms (V. vinifera) were identified, and these could be used as parental material for cold-resistant breeding. In some areas in China, soil-burial over-wintering strategies are used, but our results suggest that some wine grapes could be cultivated without requiring winter burial during overwintering. The results of this study should provide guidance for the selection of promising strains for cold-resistant breeding for expanded cultivation of improved varieties for wine grape production in China.
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Agyekum, Ephraim Bonah, Usman Mehmood, Salah Kamel, Mokhtar Shouran, Elmazeg Elgamli, and Tomiwa Sunday Adebayo. "Technical Performance Prediction and Employment Potential of Solar PV Systems in Cold Countries—A Case Study of the Sverdlovsk Region of Russia." Sustainability 14, no. 6 (March 17, 2022): 3546. http://dx.doi.org/10.3390/su14063546.
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Power distribution to decentralized and remote communities secluded from centralized grid connections has always been a problem for utilities and governments worldwide. This situation is even more critical for the isolated communities in Russia due to the vast nature of the country. Therefore, the Russian government is formulating and implementing several strategies to develop its renewable energy sector. However, very little information is available on the possible performance of solar photovoltaic (PV) modules under Russian weather conditions for all year round. Thus, this study has been designed to fill that research gap by assessing the performance ratio (PR), degradation, energy loss prediction, and employment potential of PV modules in the Sverdlovsk region of Russia using the PVsyst simulation model. A side-by-side comparison of the fixed tilted plane and tracking horizontal axis East–West were analyzed. According to the results, the annual production probability (P) for the fixed PV module for a P50, P75, and P90 is 39.68 MWh, 37.72 MWh, and 35.94 MWh, respectively, with a variability of 2.91 MWh. In the case of the tracking PV module, the annual production probability for the P50, P75, and P90 is 43.18 MWh, 41.05 MWh, and 39.12 MWh, respectively, with a variability of 3.17 MWh. A PR of 82.3% and 82.6% is obtained for the fixed and tracking systems, respectively, while the PV array losses for the fixed and tracking orientations are 15.1% and 14.9%, respectively. The months of May to August recorded the highest array losses due to the high temperatures that are usually recorded within that period.
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McDonald*, Mary Ruth, Kevin Vander Kooi, Cathy Bakker, and Alan McKeown. "Crop Diversification In Ontario: Adaptation of Annual Globe Artichokes." HortScience 39, no. 4 (July 2004): 802B—802. http://dx.doi.org/10.21273/hortsci.39.4.802b.
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Globe artichoke (Cynara scolymus L.) is a high value cool season crop which requires vernalization to induce flower formation. The climate in Ontario does not allow for survival of perennial cultivars or for consistent natural vernalization of annuals. Three methods of vernalization were tested: a controlled environment chamber, a lighted cold storage, or GA3 application in the field. Plants, cv. Green Globe Improved, were grown in a greenhouse set at 25 °C day temperature in 72-cell Styro-foam trays in a peat mix. At 4 weeks, plants receiving vernalization were transferred to growth chambers, or lighted coolers (four standard 8 foot cool white fluorescent lamps) at 10 °C for two weeks. The others stayed in the greenhouse. GA3 treatments (PROGIB, 15 g ai/ha) were applied at 2, 4 and 6 weeks after transplanting. Cultivars Green Globe Improved, Imperial Star, Emerald, and Large Green Globe were evaluated in separate trials. Trials were conducted at Simcoe, on coarse sand in a high heat area, and Kettleby, on organic soils in a cooler area of Ontario. Shortly after planting at Simcoe several 30 °C days occurred which devernalized and injured the crop. Artichokes grew well at the Kettleby site. Vernalization in the growth chamber was most effective and resulted in the earliest bud formation and highest total yield (1503 cases/ha). Large Green Globe was not well adapted to Ontario conditions. Imperial Star and Emerald produced the highest yields, 2180 and 1779 cases/ha, respectively. Globe artichokes can be grown successfully as an annual crop in cool production areas of Ontario.
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Zhang, W. J., H. M. Wang, F. T. Yang, Y. H. Yi, X. F. Wen, G. R. Yu, Y. D. Wang, and J. C. Ning. "Underestimated effects of low temperature during early growing season on carbon sequestration of a subtropical coniferous plantation." Biogeosciences Discussions 8, no. 1 (February 15, 2011): 1411–44. http://dx.doi.org/10.5194/bgd-8-1411-2011.
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Abstract. The impact of air temperature in early months on the carbon sequestration of a subtropical coniferous plantation was discussed by analyzing the eddy flux observations at Qianyanzhou (QYZ) site located in southern China from 2003 to 2008. This site experienced two cold early growing seasons (with temperature anomalies of 2–5° C) in 2005 and 2008, and also a severe summer drought in 2003. Results indicated that the low air temperature from January to March was the major factor controlling the inter-annual variations in net carbon uptake at this site, rather than the previously thought summer drought. The accumulative air temperature from January to February showed high correlation (R2 = 0.970, p < 0.001) with the annual net ecosystem production (NEP). This was due to the controls of early-months temperature on the plant phenology developing and the growing season length at this subtropical site. The cold spring greatly shortened the growing season length and therefore reduced the carbon uptake period. The eddy flux observations showed a carbon loss of 4.04 g C m−2 per growing-season day at this coniferous forest site. On the other hand, the summer drought also reduced the net carbon uptake strength because the photosynthesis was more sensitive to water deficit stress than the ecosystem respiration. However, the impact of summer drought occurred within a relatively shorter period and the carbon sequestration went back to the normal level once the drought was relieved.
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Zhang, W. J., H. M. Wang, F. T. Yang, Y. H. Yi, X. F. Wen, X. M. Sun, G. R. Yu, Y. D. Wang, and J. C. Ning. "Underestimated effects of low temperature during early growing season on carbon sequestration of a subtropical coniferous plantation." Biogeosciences 8, no. 6 (June 23, 2011): 1667–78. http://dx.doi.org/10.5194/bg-8-1667-2011.
Full textAbstract:
Abstract. The impact of air temperature in early growing season on the carbon sequestration of a subtropical coniferous plantation was discussed through analyzing the eddy flux observations at Qianyanzhou (QYZ) site in southern China from 2003 to 2008. This site experienced two cold early growing seasons (with temperature anomalies of 2–5 °C) in 2005 and 2008, and a severe summer drought in 2003. Results indicated that the low air temperature from January to March was the major factor controlling the inter-annual variations in net carbon uptake at this site, rather than the previously thought summer drought. The accumulative air temperature from January to February showed high correlation (R2=0.970, p<0.001) with the annual net ecosystem production (NEP). This was due to the controls of early-month temperature on the plant phenology developing and the growing season length at this subtropical site. The cold spring greatly shortened the growing season length and therefore reduced the carbon uptake period. The eddy flux observations showed a carbon loss of 4.04 g C m−2 per growing-season day at this coniferous forest site. On the other hand, the summer drought also reduced the net carbon uptake strength because the photosynthesis was more sensitive to water deficit stress than the ecosystem respiration. However, the impact of summer drought occurred within a relatively shorter period and the carbon sequestration went back to the normal level once the drought was relieved.