Browsing by Subject "Horticulture"

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  • Suomalainen, Sari (Helsingfors universitet, 2009)
    Green areas in cities provide social, ecological, cultural and economical values. Furthermore, the effects and importance of green areas on human well-being in the context of day to day life have been investigated in previous studies. The creation of green structures, and the quality and quantity of green areas are defined at different levels of urban planning in municipalities. The aim of this research was to determine which factors influence the green area planning process. The study compared the planning processes of Tampere in Finland and Stuttgart in Germany. It also analysed the prevailing trends of the cities and the participation of inhabitants. The study utilized qualitative study methods. The material included documents, reports and laws relating to the planning processes. The themed interviews were carried out in the city offices of Tampere and Stuttgart. The results indicated that landscape and green structure planning were compulsory parts of land-use planning processes in Stuttgart, required by laws, and are applicable nation-wide in Germany. The aims of a Landscape Plan and Green Structure Plan were legalized in a Preparatory Land Use Plan and in a Local Development Plan. In Finland, Tampere had good regulations concerning green area planning, but these were not applicable throughout the whole country. The aims of the green area plans could be legalized in Local Development Plans or in Federal Building Code, but there were not as many specified symbols expressing the content of green areas than in Stuttgart (Germany). A special difference was also the compensation method and habitat network planning that influenced the planning process at many levels in Stuttgart, identifying every green space as a part of a green structure. In addition to ecological values, also city parks and gardens were developed in exhibitions and competitions throughout Germany. The aim of Landscape planning is to combine natural elements and values as part of a landscape and a green structure of every city in Finland. It would also provide ecological development. With increasing knowledge about biodiversity and importance for human well-being, different kinds of green areas in the vicinity could also become more familiar and acceptable to citizens. Resulting from this study, future recommendations would be to develop landscape planning, to include more strategic green area planning based on Land Use Act and utilize interaction with citizens. Furthermore, an understanding and consideration of the ecological and physiological aspects of the environment and the using indicators to measure the fruition of the aims should be mandatory during the co-operational planning processes in order to reach the aims.
  • Deng, Xianbao (Helsingfors universitet, 2007)
    Virusinduced gene silencing (VIGS) vectors based on tobacco rattle virus (TRV) are now widely used for characterizing the function of plant genes. However, previous TRV vectors using RNA2 to carry the targeted gene sequence had difficulties to induce gene silencing on some plant species (Gerbera hybrida etc.) due to the obstacle of RNA2 movement. To achieve efficient gene silencing in those species, it is necessary to develop new TRV vectors, in which the targeted gene will be included in TRV RNA1 and the 16K gene will be replaced. Based on TRV RNA1, two new VIGS vectors M1 and M2 were developed through deletion part of 16K gene. Another mutant 16Kstop was also constructed to carry an early terminator in the 4th codon of 16K gene. The infectivity and gene silencing efficiency of the new constructs were assessed through a series of infection experiments. It was found that the infectivity of M1 and M2 was lower than wild TRV RNA1. M1 and M2 could induce PDS gene silencing on Nicotiana benthamiana, but their gene silencing efficiency was limited as compared with previous TRV VIGS vectors in which the PDS gene fragment was contained in RNA2. We also found that the 16K gene sequence, rather than the 16K protein, was required for efficient virus movement and accumulation.
  • Temmes, Outi (Helsingfors universitet, 2008)
    It is known that there are many unique and old plant varieties in the green areas of Helsinki. Especially city gardener Bengt Schalin has been known for his love towards flowering shrubs and trees. During his time (1946-57) many plantations of new and interesting varieties took place. The city of Helsinki has nowadays realised the value of those old plants and has taken part to KESKAS-research at 1980’s. Later during Helsinki KESKAS-project seven crab apples (Malus) were selected for propagation. The purpose of this research was to find hardy and beautiful old crab apple trees among the population found in the parks of Helsinki, and also to find out what species, clones or varieties they represent on the grounds of their morphological marks. The seven tree varieties previously chosen for propagation also needed precise descriptions to avoid name confusions in the market. They were also compared to the rest of the crab apple population to see if they really are unique. Observations were made in summer 2006 and during flowering time 30 trees all over Helsinki were selected for a closer study. 13 characteristics were observed from the flowers, 12 from the leaves and 10 from the fruits. In addition to measured traits a broad collection of photographs was taken to help later comparisons. Descriptions of all research trees were made on the grounds of observations. 24 trees had red flowers, one had red buds which opened to almost white flowers and five had white flowers. Semidouble or double flowers could be found from five trees, and one of them had white flowers. The trees were also grouped on the grounds of their flowers size, fruit size and the remaining of calyx. Hierarchical cluster analysis was also used to help grouping. A couple of the research trees could be categorised as the same species, clones or varieties. Grouping was backed up with the help of ?2-test and comparing the standard deviations of the groups. Species or variety name suggestions for 14 trees were found and two trees were assumed to have the same species in their genotype. However reliable naming could not be done because the descriptions found in the literature were so inaccurate.
  • Karvonen, Juha (Helsingfors universitet, 2008)
    Experiments with outdoor viticulture were started in Southeast and Southwest Finland in the 1930s. Our rather short growing season and lack of suitable varieties have hindered professional extensive outdoor viticulture. The grapevine varieties bred for northern conditions and the forecasted prolongation of our growing season will likely lead to viticulture in Southern Finland within the next few decades. Soil temperature has an important influence on the survival and growth of the grapevine. Soil temperature is affected by air temperature, cultivation site, soil cultivation, vegetation, soil type and wintertime snow cover. The aim of my Master`s thesis was to measure soil temperatures of grapevine sites and, based on the reults, to estimate the optimal planting depth of a grapevine in Southern Finland. The effect of changes in air and soil temperatures on grapevine growth and development in Tuusula, Vehmersalmi and some Central European localities was also followed. Measurements revealed that soil temperature was at its lowest in March, when in Tuusula at a depth of 20 cm it decreased to -0.7ºC and at a depth of 60 cm to 2.0ºC. Compared with soil temperatures measured by the Finnish Meteorological Institute in other localities, the temperatures at a depth of 20 cm in Maaninka fell to -0.8ºC, in Juva to -0.3ºC and in Jokioinen to -1.6ºC and at a depth of 50 cm in Maaninka to 0.0ºC and in Jokioinen to -0.3ºC. In Tuusula, the annual average soil temperatures at a depth of 20 cm was 6.0ºC and at a depth of 60 cm 7.9ºC. In regression analysis, strong correlations (r2 = 0,497 - 0,684) were obtained between air temperatures measured at grapevine sites at a heigth of 150 cm, ground surface temperatures and soil temperatures measured at a depth of 20-60 cm. In the winter months of December, January, March and April, when the snow cover remained thin, the correlation between snow cover and soil temperatures was weak. The soil temperature during the coldest winter month at a depth of 20 cm fell to slightly below 0.0ºC, at a depth of 40 cm it remained at about 0ºC and at a depth of 60 cm it remained at 2ºC. Based on this, the depth of 40-60 cm can be regarded as the optimal planting depth for grapevines in Southern and Eastern Finland. At this depth, the freezing risk for roots in winter is minor, and in spring solar radiation quickly raises the soil temperature. In 2002-2007, the grapevine growing season had begun in Tuusula as a weeping at the earliest on April 24th. The buds began to swell and break earliest on May 1st. The flowering began earliest on June 16th and lasted for about two weeks. The earliest harvest began on September 14th. From the start of flowering to the start of harvest, the time elapsed was 75-92 days. Growth slackened as the soil temperatures fell and ceased altogether in September. In Central Europe, the weeping of the grapevines starts because of higher air and soil temperatures a couple of months earlier than in Southern Finland, but the flowering begins no more than one month and the harvest only 2-3 weeks earlier. The quicker growth and development in the north can be explained by the quicker warming of the air and soil, the longer days and the abundant supply of light in early summer.
  • Lavonen, Tanja (Helsingfors universitet, 2008)
    Weeds cause hard surfaces and pavements in cities to break down more quickly than they naturally would. Weed control on hard surfaces is mainly based on herbicides, of which glyphosate is the most effective and also most widely used. However, the use of glyphosate on paved areas has been restricted in some countries because of the risk of leaching in to groundwater and watercourse. Alternative methods for weed control on urban areas include mechanical, physical and biological methods and natural product herbicides. Many of the physical methods are based on thermal effect, and the most suitable on hard surfaces are flaming, hot water and hot steam. Vinegar is an alternative herbicide that is commonly in use. Oils have been used as adjuvants in herbicides, but many plant originated oils have phytotoxic effects of their own. Herbicides based on vegetable oils are available in several countries. Steaming and vinegar were tested on hard surface weed control during three growing seasons 2005-2007. The purpose of the study was to investigate whether steaming and vinegar have an effect on the number of weeds on hard surfaces, and how many applications are required to provide adequate control. The aim of the greenhouse experiment was to compare the effects of 12 % vinegar and different concentrations of pine oil and birch oil distillate on two weed species in two different developmental stages. The aim of the third experiment was to test pine oil, birch oil distillate and vinegar for weed control in practice on the bases of ornamental trees. The experiment was carried out during summer 2007. Vinegar and steaming controlled vegetation on hard surfaces, and the best result was obtained by three applications during one growing season. In this experiment vinegar provided better control than steaming. The greenhouse experiment proved the largest concentrations of pine oil and birch oil distillate to control weeds as well as or even better than vinegar. In the field experiment birch oil distillate and pine oil were slightly more effective than vinegar. Reducing the use of herbicides in cities is an important task, and successful weed control requires careful planning. Herbicides should be used only when other means are insufficient.
  • Pehkonen, Eero (Helsingfors universitet, 2006)
    Vadelman (Rubus idaeus L.) viljelyala on kasvanut Suomessa voimakkaasti viimeisten viiden vuoden aikana. Vuonna 2005 vadelmaa viljeltiin 473 hehtaarilla. Vadelman satoindeksi on alhainen. Sen pääverso on pitkä, mikä hankaloittaa hoitotoimenpiteitä. Kasvin satoisimmat silmut ovat pääverson kärjessä, joten latvontaa ei kannata tehdä. Suomessakin haluttaisiin kehittää vadelman kasvihuonetuotantoa satokauden pidentämiseksi. Kasvihuonetuotannossa vegetatiivisen kasvun säätäminen on vielä tärkeämpää kuin avomaan viljelyssä. Proheksadioni-kalsium (ProCa) on gibberelliinisynteesi-inhibiittori, jonka on havaittu lyhentävän nivelvälejä sekä lisäävän versojen ja lehtien hiilihydraattipitoisuutta mm. omenalla (Malus domestica Borkh.). Tämän Helsingin yliopiston soveltavan biologian laitoksella toteutetun tutkimuksen tarkoituksena oli selvittää, miten ProCa vaikuttaa kahden kesävadelmalajikkeen ensimmäisen vuoden versojen vegetatiiviseen kasvuun ja edelleen sadontuottokykyyn. Tässä pro gradu -työssä tutkittiin ProCa:n vaikutusta kahden kesävadelmalajikkeen vegetatiiviseen kasvuun, satopotentiaaliin sekä versojen ja silmujen hiilihydraattipitoisuuksiin kesällä 2005 ja talvella 2006. Koetaimina oli 120 Tulameen-lajikkeen ja 150 Glen Ample -lajikkeen tainta. Taimet käsiteltiin kesäkuussa ja käsittely uusittiin osalle taimista neljän viikon kuluttua ensimmäisestä käsittelystä. Koekäsittelyitä oli neljä: ProCa 100 ppm, ProCa 200 ppm, ProCa 100 ppm + ProCa 100 ppm ja ProCa 200 ppm + ProCa 200 ppm. Kontrollikäsittelyitä oli kaksi: vesi sekä vesi + vesi. Kesän aikana havainnoitiin pääverson pituuskasvua ja nivelien määrää. Kesän kasvatuskauden päätyttyä Glen Ample -lajikkeen silmujen ja versojen liukoiset hiilihydraatit ja tärkkelys määritettiin entsymaattisesti. Kylmävarastoinnin jälkeen (71 vrk) tammikuussa 2006 taimet siirrettiin hyötöön kasvihuoneeseen. Hyödön aikana havainnoitiin silmujen puhkeamista ja kukintaa. Hyödön päättyessä hanka- ja pääversojen kuivapaino sekä hankaversojen pituus mitattiin. Kesän 2005 aikana ProCa lyhensi uusien nivelvälien pituuksia väliaikaisesti 1 4 viikon kuluttua käsittelystä. Nivelien lukumäärässä ei tapahtunut suuria muutoksia. Tulameen-lajikkeella kasvu kiihtyi käsittelyn vaikutuksen loputtua. Nivelvälien lyhentymisen takia pääverson kokonaispituus jäi kontrolliin verrattuna 35 % lyhyemmäksi Glen Ample -lajikkeella (ProCa 200 + ProCa 200) ja 14 % lyhyemmäksi Tulameen-lajikkeella samalla käsittelyllä. Myös käsittely ProCa 200 vähensi pääverson pituutta 6 % kontrolliin verrattuna Tulameen-lajikkeella. ProCa-käsittely lisäsi versojen ja silmujen hiilihydraattipitoisuuksia, mutta tuloksissa oli paljon hajontaa. Glen Ample -lajikkeella kaksinkertaiset käsittelyt vähensivät puhjenneiden silmujen osuutta 8 15 päivän kuluttua hyödön aloittamisesta 24 29 %, mutta käsittelyiden väliset erot tasoittuivat hyödön loppuun mennessä. Lisäksi kaksinkertaiset ProCa-käsittelyt vähensivät kukkien määrää 29 44 % 33 65 päivää hyödön alusta, mutta erot tasoittuivat hyödön loppuun mennessä. Käsittelyt eivät vaikuttaneet Tulameen-lajikkeen silmujen puhkeamiseen ja kukintaan. Satopotentiaalissa ei ollut eroa ProCa-käsittelyiden välillä kummallakaan lajikkeella. Glen Ample -lajikkeella hankaversojen kokonaismäärä väheni 27 32 % kasveilla, joita oli käsitelty kaksi kertaa ProCa:lla. Hankaversot olivat kuitenkin vastaavasti 29 43 % pidempiä. Tulameen-lajikkeella ProCa 100 -käsittely vähensi hankaversojen määrää 15 %, mutta hankaversojen pituuteen käsittelyillä ei ollut vaikutusta. Käsittelyillä ei ollut vaikutusta hankaversojen nivelvälien pituuteen kummallakaan lajikkeella. Tutkimuksen perusteella kesällä annetulla ProCa-käsittelyllä voidaan lyhentää pääverson pituutta, mutta satopotentiaaliin käsittelyllä ei ole vaikutusta. Käsittelyajankohta on kriittinen, koska kukkasilmujen kehitys näyttäisi häiriintyvän, jos ruiskutus tehdään loppukesällä.