Master of Science / Department of Grain Science and Industry / Carlos Campabadal Teran / The use of grain aeration as a tool to minimize post-harvest losses requires lower ambient temperature (≤ 20°C) and relative humidity (≤ 70%) conditions than what is usually available during the summer season in temperate climates and throughout the year in some tropical climate regions. Warm and moist conditions contribute to pest problems and increase dependence on chemical control for pest reduction as part of grain management strategies. The grain chilling technology is a non-chemical alternative to cool grain stored under high risk climatic conditions. For this research project, the grain chilling technology was tested in a 1,350-ton low moisture content wheat silo during the 2015 and 2016 summer harvests in Kansas. The grain temperature was lowered from a maximum of 39°C to a minimum of 17°C in less than 250 hours. The results showed that chilled grain maintained at temperatures under 20°C reduced the development rate of insect pests compared to grain stored at temperatures over 25°C and cooled with ambient aeration. However, the cost of grain chilling was calculated to be between 0.26 and 0.32 $/t higher than using ambient aeration. Through computer simulation it was possible to evaluate the performance of the grain chiller against four different ambient aeration strategies for paddy rice stored under the tropical climatic conditions of the North Pacific coast of Costa Rica. After six months of storage, the minimum grain temperature achieved through ambient aeration was 30.8°C using an aeration strategy based on a grain-ambient temperature differential greater than 10°C. Grain chilling lowered the average grain temperature from 35°C to below 15°C in 117 hours and the maximum average temperature it registered after six months of storage was 15.5°C. The economic evaluation of the simulated ambient aeration and chilling strategy determined that the operational costs of grain chilling were between 2 and 4 $/t lower than ambient aeration plus fumigation. However, the initial cost of the grain chiller made the net present cost (NPC) of the chilling strategy between 0.22 and 0.85 $/t higher than the cost of ambient aeration plus fumigation over a 10-year analysis. Several potential financial options were analyzed to make the grain chiller more economically feasible for a rice miller in Costa Rica. It was concluded that the grain chilling technology can reduce grain temperatures below 20°C in a relatively short period of time, which helps control insect populations and maintain grain quality during summer storage in temperate climates and in tropical climates. Utilizing grain chilling reduced operational costs between 78% and 88% when compared to using chemical control of pests. Additionally, it was determined that an initial cost of $74,700 for the grain chiller would require a 16% discount or at least 10,641 t to be chilled annually to make this technology viable for the Costa Rican rice milling industry. Leasing the grain chiller (ten equal payments of $10,926) or adding a premium sell price of 1 $/t to chilled rice would make this technology feasible compared to the traditional grain management strategies utilized in Costa Rica.

Orientador: Nelson Jose Beraquet / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-09T21:19:52Z (GMT). No. of bitstreams: 1 PintoNeto_Manuel_D.pdf: 2243473 bytes, checksum: 6ced89451973439cb8b34ae983a430ed (MD5) Previous issue date: 2008 / Resumo: Estudaram-se parâmetros de qualidade de músculos de 40 bovinos Nelore desossados a quente resfriados ultra rapidamente e também em músculos desossados de carcaças resfriadas por 24 horas em câmara fria a 0 °C, penduradas pela pelve durante tempos diferentes e pelo tendão do músculo gastrocnêmio (tendão de Aquiles). Todas as carcaças foram estimuladas eletricamente. Da metade esquerda de 16 carcaças foram desossados a quente, após 45 min da sangria, os músculos Longissimus dorsi (CF) e o Psoas major (FM). Parte dos músculos foram resfriados em um túnel de congelamento (EQRR) e parte foi resfriada em câmara fria a 0 °C (EQ0). De outras 24 metades esquerdas de carcaças resfriadas, foram desossados os músculos CF, FM e o Semitendinosus (ST). Oito dessas meias-carcaças foram suspensas pelo tendão de Aquiles (tratamento controle EF), oito permaneceram 20 horas penduradas pela pelve e 4 horas pelo tendão de Aquiles (EFP20) e as outras oito penduradas 10 horas pelo osso pélvico e 14 horas pelo tendão de Aquiles (EFP10). Todos os músculos foram subdivididos em três porções, embalados em sacos plásticos a vácuo e maturados em câmara fria a 0 °C durante 14 dias. O comprimento do sarcômero (CS) foi medido logo após a desossa, e após 14 dias de maturação. Após 2, 7 e 14 dias foram medidas a perda por exsudação e capacidade de retenção de água (CRA). Das porções foram feitas fatias com 2,54 cm de espessura para o cozimento. As fatias de CF e FM foram cozidas em grelha elétrica a 150 °C até que a temperatura interna da fatia atingisse 74 °C. As fatias do músculo ST foram cozidas dentro de sacos plásticos, em água a 80 °C durante 60 min. Foram medidas as perdas por cocção e as forças de cisalhamento Warner-Bratzler (WBSF). Os atributos de maciez, suculência e sabor de carne maturada foram avaliados sensorialmente por uma equipe de 10 a 15 provadores treinados. As amostras, em cubos de 1,5 cm, eram servidas uma por vez. A análise de variância incluiu o bloco, replicação, tratamento, maturação e suas interações. Foi usado o teste de Duncan para determinar diferenças entre as médias com uma probabilidade de 5%. Os resultados mostraram que a perda por cocção e a suculência dos músculos não foram afetados pela taxa de resfriamento, pendura e maturação. O CS do músculo ST não foi afetado pelos tratamentos e pela maturação. O músculo FM desossado a quente EQ0 teve exsudação significativamente maior que os desossados a frio. As perdas por exsudação dos músculos CF desossados a quente EQ0 não se diferenciaram daquelas dos músculos desossados a frio. O tratamento EQRR diminuiu o CS para o músculo CF e para o FM. Os músculos desossados a quente e resfriados rapidamente EQRR tiveram a maior perda de peso por exsudação e a menor maciez. Não houve diferenças significativas dos valores de WBSF entre os tratamentos para o músculo ST, mas a WBSF diminuiu com o período de maturação, à exceção do tratamento EF. A maciez do músculo ST aumentou com a maturação somente no tratamento com pendura pélvica EFP20. A WBSF do músculo ST e FM não apresentaram correlação significativa com a maciez. A WBSF do músculo FM não foi afetada pela maturação em todos os tratamentos. A maciez do músculo FM desossado a quente (EQ0) e também do desossado a frio (EF) aumentaram com a maturação. Os músculos desossados a quente (EQ0), após os 14 dias de maturação, não foram significativamente diferentes dos desossados a frio. O tratamento EQRR afetou o ¿sabor de carne maturada¿ do músculo FM que apresentou, após 14 dias de maturação, o menor valor para o atributo. A pendura pélvica por 20 horas não apresentou vantagens em relação à pendura por 10 horas post mortem. A pendura pela pelve não diminuiu significativamente a força de cisalhamento nem aumentou a maciez dos músculos LD E ST. Por outro lado a pendura pélvica também não aumentou significativamente a força de cisalhamento nem diminuiu a maciez do músculo Psoas major / Abstract: The objectives of this work were to examine the effects of pre-rigor excision and rapid chilling versus conventional carcass chilling with two forms of carcass suspension on quality attributes of three muscles during the postmortem storage. The Longissimus dorsi (CF), Semitendinosus (ST) and Psoas major (FM) muscles were removed 45 min after exsanguination from the left side of 16 electrically stimulated beef carcasses and vacuum packed. Part of CF and FM muscles were chilled in a freezing tunnel to induce cold shortening (hot boned, rapidly chilled EQRR) and part were chilled in cooling room at 0 °C (EQ0). At 24 hours postmortem, the corresponding muscles plus ST muscle were removed from the left side of 24 electrically stimulated beef carcasses conventionally chilled in a cooling room. Eight of these carcasses were hanged by the Achilles tendon (EF -control treatment) and 16 were hanged by the aitch bone. Eight carcasses were left 20 hours suspended by the aitch bone and 4 hours by the Achilles tendon (EFP20), the other eight were left 10 hours suspended by the aitch bone and 14 hours by the Achilles tendon (EFP10). Sarcomere length (CS) was measured after boning and after ageing. All muscles were cut into three portions, vacuum packed and assigned to ageing in a cooling room at 0 °C during 14 days. After 2, 7 and 14 days, the portions were unpacked to measure drip losses and water holding capacity, then all portions were cut into 2,54 cm-thick steaks and assigned to cooking treatments. CF and FM steaks were cooked at approximately 150 °C in an electric grill to an internal temperature of 74 °C. ST steaks, in plastic bags, were cooked in water bath at 80 °C during 60 min. Cooking losses and Warner-Bratzler shear forces (WBSF) were measured on cooked steaks. From the same cooked steaks were taken 1,5 cm cubes, wrapped in foil and held at 45 °C in a preheated oven as samples for the sensory-panel with 10 to 15 trained panelists that evaluated one cube/steak each time of all muscles from the five treatments. The scores for tenderness, juiciness and aged flavor were evaluated with a 10 cm line scale. Analysis of variance procedure included block, replication, treatment, ageing and their interactions. Means were separated by Duncan test with 5% of significance. The results showed that there was no significant difference related to cooking loss and juiciness of all muscles from the five treatments and ageing periods. The hot excised and very fast chilled muscles CF and FM had the CS reduced. The CS of muscle ST was not affected by the treatments and ageing. Hot boned and chilled at 0 °C muscles FM had significantly more drip loss than cold boned ones. Hot boned CF muscles, chilled at 0 °C, had no different drip losses from cold boned meats treatments. Hot boned and very fast chilled muscles had the highest drip losses and the lowest tenderness. Drip losses of the muscles Psoas major from carcasses hanged by pelvic bone during 10 hours, were higher than the muscles from carcasses hanged by the Achilles tendon but were not significantly different from hot boned EQ0 treatment. Tenderness of the muscles FM and ST didn¿t have a significant correlation with WBSF. The tenderness of the muscle ST increased with aging for the pelvic hanging treatment (EFP20). There were no significant differences among treatments related to the WBSF of the muscles ST but it decreased with ageing, with the exception of the muscle hanged from the Achilles tendon. WBSF of the muscle FM was not affected by ageing in all treatments. Aged flavor of the muscle Psoas major from treatment EQRR was affected and had the lowest scores after 14 days ageing. There was no advantage of using the pelvic hanging of the carcass by the pelvis during 20 hours over the period of 10 hours. The hot boned and chilled at 0 °C muscles, after 14 days ageing, were not significantly different from cold boned treatments. The tenderness of the muscle Psoas major from hot boned treatment (EQ0) and from Achilles tendon hanged carcass (EF) increased with aging. The pelvic hanging treatments didn¿t increased significantly the tenderness or reduced WBSF of the muscles CF and ST. On the other side, pelvic hanging treatments didn¿t decreased significantly tenderness of the muscle FM / Doutorado / Doutor em Tecnologia de Alimentos

Thesis (M. Sc. (Horticulture)) -- University of Limpopo, 2019 / The South African Avocado Industry is continuously expanding with ‘Hass’ cultivar occupying the largest land and therefore, the most exported cultivar. Expansion of the industry implies an increased demand for irrigation water. However, South Africa is a water scarce country characterised by low and erratic rainfall, where fruit production relies heavily on irrigation. The agricultural sector is under an obligation to reduce water use due to the increasing demand for water by other economic sectors. Therefore, it must find efficient water use techniques to save water and ensure water availability for other economic sectors. Partial root-zone drying (PRD) is an irrigation technique which may lead to 50% reduction in water use, half of the root system is kept wet while the other half is left dry to a predetermined level of soil water depletion, the dry and the moist sides are alternated at regular intervals. During storage and transportation of fresh produce, low temperature is a post-harvest tool used to maintain quality, especially when fruit are destined for long distant export markets. This study investigated the effect of PRD and low temperature storage on post-harvest quality parameters of ‘Hass’ avocado fruit. The experiment was laid as a factorial arranged in randomised complete block design (RCBD). The treatment factors for chilling injury, electrolyte leakage and vascular browning were 2 x irrigation regimes (Full Irrigation (FI) vs. PRD) and 2 x storage temperatures (2.0 and 5.5°C). However, treatment factors for fruit weight loss, respiration rate, fruit firmness, ripening percentage and fruit skin colour were 2 x irrigation regimes (Full Irrigation (FI) vs. PRD), 2 x storage temperatures (2.0 and 5.5°C) and 4 ripening days (0, 2, 4 and 6 days). Mature ‘Hass’ avocado fruit were harvested from PRD and fully irrigated trees and thereafter fruit of each treatment were stored at 2.0 and 5.5°C for 28 days. Each treatment consisted of 6 replicates, with an exception of electrolyte leakage, whereby the experiment was replicated 4 times. After 28 days’ storage at 2.0 and 5.5°C, fruit were ripened at 21°C. The effect of PRD and low temperature storage was determined by evaluating the following physico-chemical fruit parameters during ripening: external chilling injury, electrolyte leakage, fruit weight loss, respiration rate, firmness, fruit skin colour and vascular browning. During ripening, ‘Hass’ avocado fruit stored at 2.0°C showed significantly higher incidences of external chilling injury symptoms compared with xiii 5.5°C, irrespective of irrigation treatment. Furthermore, an interaction between irrigation treatment and low storage temperature had a significant (P<0.05) effect on cell membrane electrolyte leakage. All evaluated fruit showed similar weight loss, irrespective of irrigation and storage treatment. Irrigation, storage temperature and ripening days did not have effect on respiration during ripening. Fruit reached the respiratory climacteric peak on the same day (day 2). Furthermore, there was no significant interaction effect (P˃0.05) on fruit firmness. However, PRD treated fruit showed slightly low firmness when compared with control fruit. ‘Hass’ avocado fruit harvested from PRD and fully irrigated trees and stored at 5.5°C ripened quicker compared to fruit stored at 2.0°C. There was no significant interaction effect (P˃0.05) on fruit skin lightness (L), chroma (C), hue angle (h°) and fruit eye colour due to irrigation and cold storage treatment. In general, fruit showed skin colour change from emerald green to approximately 75% coloured. Furthermore, irrigation and storage temperature did not have effect on vascular browning, however, there incidence was high on fruit stored at 2.0°C when compared with 5.5°C. The results of this study indicated that ‘Hass’ avocado fruit stored at 2.0°C was negatively affected by low temperature storage and this cold storage temperature is not recommended. PRD reduced water use during irrigation, however, its effect on post-harvest quality of ‘Hass’ avocado fruit subjected to 5.5°C must be further investigated before recommended for export markets. / Agricultural Research Council-Tropical and Subtropical Crops (ARC-TSC) and Agricultural Sector Education Training Authority (AgriSeta)

Thesis (M.Sc.(Agricultural Management )) -- University of Limpopo, 2020 / Avocado fruit ‘Hass’ harvested during early-season and exposed to temperature at 5.5°C for 28 d are susceptible to chilling injury (CI); and therefore, develop poor skin colour during ripening. In ‘Hass’ avocado fruit, skin colour change during ripening is used by European market to indicate fruit ripeness and softness. Therefore, the aim of this study was to evaluate the use of hot water (HW) and methyl jasmonate (MJ) as postharvest treatment dips to mitigate CI; and thereby, enhance ‘Hass’ avocado fruit peel colour during ripening. Fruit were harvested randomly from 5 selected trees treated alike during early season (April 2018); and thereafter, transported to the laboratory. At the laboratory, experiments of this study were divided into 2: experiment (1) fruit were dipped into HW (38, 42 and 46°C for 30, 25 and 20 min, respectively); and experiment (2) fruit were dipped into MJ (10 and 100 µmol/L for 2 min) treatments. In both experiments after these treatments, fruit were allowed to dry for 60 minutes at ambient (±25°C) temperature and untreated fruit were used as control. Thereafter, fruit were stored at commercial shipping temperature (5.5°C) for up to 28 d. After removal from cold storage, fruit were ripened at ambient temperature (±25°C) and evaluated every after 2 d for weight loss, firmness loss, objective colour parameters (lightness-L*, chroma-C* and hue angle-h*), subjective colour (eye colour) and ripening percentage. However, chilling injury (CI) and electrolyte leakage (EL) were evaluated immediately after removal from cold storage. The results showed that HW significantly (P< 0.05) increased weight and firmness loss during ripening. Furthermore, HW reduced EL and external chilling injury (ECI) of ‘Hass’ avocado fruit during cold storage. In addition, the results showed that HW had significant effect (P< 0.05) on colour parameter L* and eye colour rating, but did not affect (P> 0.05) C* and h*. Avocado ‘Hass’ fruit subjected to HW at 42°C/25 and 46°C/20 min developed purple colour (eye colour rating 4.47 and 4.36, respectively) during ripening when compared with HW at 38°C/30 min and control fruit. Moreover, results showed that dipping fruit in 10 µmol/L had a significant effect (P< 0.05) on reducing weight loss during ripening. Methyl jasmonate (10 and 100 µmol/L) treatment reduced EL and alleviated external chilling injury (ECI) of ‘Hass’ fruit during cold storage. The results showed that MJ (10 and 100 µmol/L) treatments had significant effect (P< 0.05) on colour parameter L*, h* and eye colour rating, but did not affect (P> 0.05) C*. Furthermore, ‘Hass’ fruit treated with 10 and 100 µmol/L MJ reached the purple skin colour (eye rating 5.39 and 5.19, respectively) during ripening. Fruit dipped in MJ (10 µmol/L) had low weight loss when compared with fruit treated with MJ (100 µmol/L). In conclusion, the results of this study indicated that HW (42°C/25 minutes) and MJ (10 µmol/L) effectively alleviated external chilling injury; and therefore, improved ‘Hass’ skin colour development during ripening / Agricultural Research Council-Institute (Agriseta) and University of Limpopo

This diploma thesis deals to possibilities lead chilling process with material loss of product and divine to possibilities lead texture final product with chilling process. This work will be base of project for realization chilling tunnel to flow line of proteinic gel.

Denna studie undersöker hur trans representeras i tv-serien Chilling Adventures of Sabrina, med syftet att undersöka vad för mening serien skapar om trans i stort. Detta undersöks genom att titta närmare på en karaktär i serien, transpersonen Theo Putnam, och hur han och andra förhåller sig till hans kropp och kön. Studiens metoder är en tematisk analys samt en transläsning och fyra teman av transrepresentation har identifierats i materialet: mobbning i relation till kropp och kön, kroppen som hinder, kroppen som accepterad samt sexualitet och kärlek i relation till trans. Dessa teman visar att trans i serien representeras som något som tidvis gör att en blir utsatt och mobbad, men som till största del inte är så problematiskt. Kroppen och könet är i serien frånkopplade, och serien visar att en inte måste korrigera sin kropp som transperson. Studien kommer fram till att trans i serien framställs som något bra, och att kön, kropp, relationer samt sexualitet ses som flytande och föränderliga.

Sub-zero saline solutions were evaluated for the improvement of chilling efficiency and product quality of broiler carcasses. In this study, four experiments were conducted to chill broiler carcasses using different saline solutions and chilling temperatures in the Meat Processing Center at California Polytechnic State University (Cal Poly, San Luis Obispo, CA) or in the processing plant at Foster Farms (Livingston, CA). In Experiment I, three salt concentrations and solution temperatures (0% NaCl/0.5°C, 4% NaCl/-2.41°C, and 8% NaCl/-5.08°C) were used to chill carcasses. The fillets in brine chilling at sub-zero temperatures showed lower shear forces than the fillets in 0% NaCl control solution. In Experiment II, three salt concentrations (0% NaCl/0.5°C, 4% NaCl/-2.41°C, and 8% NaCl/-5.08°C) were used to chill carcasses with/without pre-chilling in 0% NaCl/0.5ºC or 0% NaCl/14°C. Fillets from the carcasses in 4% NaCl/-2.41°C significantly improved tenderness (P < 0.05), with no significant difference observed for the shear force of 8% NaCl/-5.08°C, regardless of pre-chilling. In Experiment III, four salt concentrations (0% NaCl/0.5°C, 1% NaCl/-0.6°C, 2% NaCl/-1.2°C, and 3% NaCl/-1.8°C) were used to chill carcasses. The shear force of fillets decreased as the salt content increased and chilling temperature decreased from 0%NaCl/0.5°C to 3%NaCl/-1.8°C, with the lowest shear force observed in 3% NaCl brine at -1.8°C (P < 0.05). The chilling time (90 min) of 3% NaCl was reduced by 25 min (or 22%) compared to water control (115 min), with an intermediate reduction (13 - 17%) v seen for other NaCl solutions (95 – 100 min). Breast fillets showed no significant difference in chilling yield, pH, R-value, and sarcomere length for raw meats as well as in cooking yield and salt content for cooked fillets across all treatments (P > 0.05). In Experiment IV, three salt concentrations (0% NaCl/0.5°C, 3% NaCl/-1.8°C, and 4% NaCl/-2.41°C) were used to chill carcasses. The chilling time (55 min) of 4% NaCl was reduced by 35 min (or 39%) compared to the time (90 min) of water control, with an intermediate reduction (11%) seen for 3% NaCl solution. Control fillets in 0% NaCl showed a higher shear force than the fillets in sub-zero brine chilling (P < 0.05). Based on these results, broiler carcasses chilled in 4% NaCl/-2.41°C appears to be ideal to improve both chilling efficiency and meat tenderness compared to the carcasses chilled in 0% NaCl/0.5°C.

Several warm winter events have occurred across the Southeast in the past decade, including 2 major events in 2017 and 2018 in Georgia and South Carolina. Plants will begin their spring growth sooner than climatology would suggest and then be damaged by early spring frosts in what is commonly known as a "false spring" event. Some species of plants, like peaches and blueberries, which produce buds early in the season, are just an example of some of the agricultural products more at risk than others. As an important measure of dormancy time in plants, chill hours present a measurement capable of tracking phenological shifts in plants. While a lack of required chill hours can delay spring emergence, intense warm periods can override the chilling hour requirement and induce spring emergence. This project involves training self-organizing maps (SOMs) to identify periods of anomalous winter warming based on a reduced number of chill hours within a 5-day temporal period compared to the period's climatological average. A second SOM is nested in the node that produced the most anomalous events to identify the range of warming that occurs in the most anomalous events, the synoptic setups of these events, and when these occurred. Hourly 2-meter temperature from ERA5 is used to conduct this analysis over a domain centered primarily over South Carolina and Georgia with a temporal period of 1980-2020. Climatological examination of chill hour accumulations in the past 4 decades show an overall decrease in chill hour accumulation across the past decade (2011-2020) Results indicated that periods of higher-than-average temperatures are increasing with time while periods of average or lower than average temperatures are decreasing with time. Both results were statistically significant by Mann-Kendall test. The results of the nested SOMs suggest that an increase in patterns of southerly flow (a common pattern for warmer temperatures) is occurring through time. A third SOM investigating early spring hard freezes was inconclusive but illustrated that some years had more early spring frosts than others independent of how many warmer than average periods occurred in the main winter. The use of SOMs for investigating climatological and synoptic changes in winter and early spring proved successful and effective. Future modifications to these SOMs could be used to identify more trends that exist within these seasons. / Master of Science / Several warm winter events have occurred across the Southeast in the past decade, including 2 major events in 2017 and 2018 in Georgia and South Carolina. Plants will begin their spring growth sooner than climatology would suggest and then be damaged by early spring frosts in what is commonly known as a "false spring" event. Some species of plants, like peaches and blueberries, which produce buds early in the season, are just an example of some of the agricultural products more at risk than others. As an important measure of dormancy time in plants, chill hours present a measurement capable of tracking shifts from normal winter to spring transition in plants. While a lack of required chill hours can delay leaf emergence and spring blooms, intense warm periods can override the chilling hour requirement and induce this spring emergence. This project involves training self-organizing maps (SOMs), a machine learning model, to identify periods of anomalous winter warming based on a reduced number of chill hours within a 5-day temporal period compared to the period's climatological average. A second SOM is nested in the node that produced the most anomalously warm events to identify the range of warming that occurs in the most anomalous events, the large-scale meteorological setups of these events, and when these occurred. Hourly 2-meter temperature from ERA5, a climatological dataset, is used to conduct this analysis over a domain centered primarily over South Carolina and Georgia with a temporal period of 1980-2020. Climatological examination of chill hour accumulations in the past 4 decades show an overall decrease in chill hour accumulation across the past decade (2011-2020) Results indicated that periods of higher-than-average temperatures are increasing with time while periods of average or lower than average temperatures are decreasing with time. Both of these trend findings were statistically significant by Mann-Kendall test. The results of the nested SOMs suggest that an increase in patterns of southerly flow (a common pattern for warmer temperatures) is occurring through time. A third SOM investigating early spring hard freezes (temperatures low enough to cause damage to plant cellular structures) was inconclusive but illustrated that some years had more early spring frosts than others independent of how many warmer than average periods occurred in the main winter. The use of SOMs for investigating climatological and synoptic changes in winter and early spring proved successful and effective. Future modifications to these SOMs could be used to identify more trends that exist within these seasons.

No description available.

Am Beispiel von Aster alpinus 'Happy End' wird der Entwicklungsverlauf vom Zeitpunkt der Vermehrung bis zur Ausbildung von Infloreszenzen beschrieben, um daraus Empfehlungen für die Kultur als blühende Topfstaude abzuleiten. Dazu wurden über einen Zeitraum von drei Jahren Versuche mit unterschiedlich vermehrten Pflanzen durchgeführt. Verwendet wurden hierbei Pflanzen aus generativer und vegetativer Vermehrung (Stecklinge, in vitro). Untersucht wurde der Verlauf der vegetativen und generativen Entwicklung unter spezieller Berücksichtigung der Dormanz und der Differenzierung der Blütenanlagen. Die Umstimmung des vegetativen Meristems in ein generatives wurde durch die Transplantation von Sproßknospen in die Invitro-Kultur und durch histologische Untersuchungen erfaßt. Während der juvenilen Entwicklungsphase und vor dem Eintritt in die Endodormanz erfolgt die Blüteninduktion. Der früheste Zeitpunkt der Blütendifferenzierung konnte bei Aster alpinus Ende September festgestellt werden. Die Endodormanz beginnt ab Mitte Oktober und dauert bis Mitte-Ende Dezember an. Erst danach ist eine weitere Entwicklung der Infloreszenz möglich. Anschließend wurde der Einfluß der exogenen Applikation mit dem Cytokinin 6-Benzylaminopurin und der Einfluß der Kühlung auf die vegetative und generative Entwicklung untersucht. Dazu wurden die Pflanzen während der juvenilen Phase über einen Zeitraum von 6 Wochen mit BAP-Lösungen in unterschiedlichen Konzentrationen (15, 20 und 25 mg/l) besprüht. Der Einfluß der Kühlung wurde durch die Erfassung von Freiland temperaturen und durch eine zeitweise Aufstellung der Pflanzen im Kühlraum ermittelt. Erfaßt wurden dabei alle Temperaturen unter 2ø C und die Dauer der Kühlung. Die Applikation von BAP in einer Konzentration von 20 und 25 mg/l bewirkte eine signifikant höhere Anzahl gestreckter, vegetativer Sproßknospen. Der Einfluß der Cytokininbehandlung auf die Anzahl der gestreckten Infloreszenzen war dagegen nicht signifikant. Die Wirkung der Kühlung auf die Streckung von Infloreszenzen erwies sich gegenüber der Cytokininbehandlung als wesentlich stärker. Die Dauer der Kühlung korreliert positiv mit der Anzahl gestreckter Infloreszenzen. Das Vernalisationsbedürfnis ist jedoch nicht obligat. Beide Faktoren (Cytokininapplikation und Kühlung) zusammen, haben eine synergistische Wirkung auf die Anzahl gestreckter Infloreszenzen. / A study was made on the development rhythm of perennials on Aster alpinus 'Happy End' from the beginning of propagation until flowering, to give recommondation for cultivation as a flowering potplant. Approximately three years of examinations with different propagated plants were carried out. Plants from generative and vegetative propagation (cuttings, in vitro) were used. The course of vegetative and generative development was examined especially taking into account the dormant stages and the differentation of flowering plants. The change of the vegetative to the generative meristem was recorded by the transplantation of shoots to the invitro-culture and by histological examinations. The flower initiation took place during the juvenile development phase and before the beginning of endodormancy. The earliest flower differentation was observed at the end of September. The endodormancy started in the middle of october and lasted until mid to late December. Only afterwards was a further development of the inflorescence possible. In the second part the influence of exogen application with the cytokinin 6-Benzylaminopurin (BAP) and the influence of chilling at the vegetative and generative development were examined. In addition the plants were sprayed with BAP-solutions with different concentrations during the juvenile phase of about 6 weeks. The influence of chilling was measured under outdoor conditions and with temporary artificial chilling. All temperatures under 2 øC and the length of time they were chilled, were recorded. Afterwards the plants were maintained in the greenhouse until flowering. The application of BAP with concentrations of 20 and 25 mg/l caused significantly longer vegetative shoots. The influence of the cytokinin treatment on the number of elongated inflorescences was non-significant in contrast. The rate of progress to generative development improved with increased chilling time. The vernalisation response is not obligatory. Both factors (cytokinin application and chilling) together have a synergistic effect on the number of elongated inflorescences.