Browsing by Subject "Plant Production Biology"

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  • Salminen, Annukka (Helsingfors universitet, 2016)
    Kurtturuusun perusmuoto (Rosa rugosa L.) on ollut vuosikymmenten ajan suosittu koristekasvi pitkän kukintakautensa, kestävyytensä ja helppohoitoisuutensa takia. Kuitenkin nykyisin kurtturuusu luokitellaan Suomessa erittäin haitalliseksi vieraslajiksi. Kurtturuusua pidetään haitallisena vieraslajina myös Luoteis- ja Keski-Euroopassa sekä Pohjois-Amerikassa. Risteymätaustansa takia kurtturuusulajikkeiden ja –risteymien lisääntymiskyvyn on oletettu olevan heikompi kuin kurtturuusulla. Tämän tutkimuksen tavoitteena oli tutkia kurtturuusun puutarhamuotojen lisääntymiskykyä ja arvioida niiden leviämisalttiutta luontoon. Tutkimuksen päätavoitteena oli selvittää, mitä lajikkeita tai risteymiä voitaisiin suositella käytettäväksi kurtturuusun sijaan. Leviämisalttiutta arvioitiin vesomisen, kukinnan ja kiulukoiden tuoton runsauden, kiulukkakohtaisen siemenmäärän, siementen elinkyvyn ja siementen itävyyden avulla. Aineistoa kerättiin sekä Etelä- että Pohjois-Suomesta ja mukana oli kurtturuusun perusmuodon lisäksi 12 ruusulajiketta tai –risteymää, joiden vanhempiin kurtturuusu kuuluu. Tutkimuksessa näiden puutarhamuotojen lisääntymiskykyä verrattiin kurtturuusun perusmuodon lisääntymiskykyyn. Kukinta- ja vesomishavainnot tehtiin kesällä 2011 ja kiulukat kerättiin syyskuussa 2011. Siementen elinkyky testattiin tetrazoliumtestin avulla ja kaksivuotinen idätyskoe Helsingin yliopiston Viikin kampuksella kesti syyskuusta 2011 lokakuuhun 2013. Tutkimuksen mukaan puutarhamuotojen lisääntymiskyvyssä on paljon vaihtelua niin taksonien kuin kasvupaikkojen välillä. Osalla puutarhamuodoista oli yhtä hyvä lisääntymiskyky kuin perusmuodolla. Kurtturuusun puutarhamuodot tuottivat kiulukkakohtaisesti vähemmän siemeniä kuin perusmuoto. Niiden siemenet olivat yhtä elinkykyisiä kuin kurtturuusun perusmuodon, mutta keskimääräinen itävyys oli heikompi kuin kurtturuusun perusmuodon siementen. Puutarhamuotojen välillä oli eroja niin siemenmäärissä kuin siementen elävyydessä ja itävyydessä. Tämän tutkimuksen perusteella ei suositella käytettäväksi sellaisia puutarhamuotoja, jotka tekevät paljon siemeniä tai joiden siemenet hyvän elinkyvyn lisäksi itävät keskivertaisesti. Pitkäkestoiselle jatkotutkimukselle on tarvetta, jotta lisääntymiskykyyn liittyvien ominaisuuksien vuotuisesta vaihtelusta voitaisiin varmistua.
  • Rajanen, Hanne (Helsingfors universitet, 2011)
    The forest industry achieves each year large quantities of waste material, such as wood, bark and branches. The waste material is mainly used for energy production, but new applications are being investigated. The bark has been identified as a potential source of numerous bioactive compounds, which would have use, for example, in the pharmaceutical and chemical industries as well as in the pest management of agriculture, forestry and horticulture. The thesis is part of the European Union-funded ForestSpeCs project, which aims to find alternative ways to use the materials of forest industry. The bark extracts of ten economically remarkable northern trees were tested for possibilities as antifeedants for the larvae of the cabbage white (Pieris brassicae L.), the Egyptian cotton leafworm (Spodoptera littoralis Boisduwal), and some of them also for the mustard leaf beetle (Phaedon cochleariae Fabricius) and the alder leaf beetle (Agelastica alni L.). The extracts were prepared in cooperation with the project groups or independently using different methods. Testing was carried out in laboratory conditions by using the dual-choice leaf-disc bioassays for the crude extracts and the individual compounds separated from them. The feeding deterrent indices (FDI) were calculated from the measurements. On the basis of the results, nearly all the tested extracts, at least to some extent, appeared to have an effect on the insect’s eating behavior. Slightly more than half of the 46 extracts tested with the cabbage white caused more than 50% feeding deterrence, in other words the cabbage butterfly preferred the control leaves more often than the treated ones. For Egyptian cotton leafworm larvae over 50% feeding deterrence was caused only by the seven of the tested 56 extracts. In addition, three of the extracts stimulated the consuming of the treated leaves significantly. The alder leaf beetle larvae and adults were deterred by the leaves treated with abietic acid, in particular. The extracts tested on the mustard leaf beetle were also working promisingly. It is possible to extract biologically active compounds from the bark of the tested tree species, but it is necessary, in the context of pest management, to have more research on the correct concentrations of the extracts and effective extracting methods. The quality and quantity of compounds in the bark depend on many factors, such as the impact of the environment and genetics. Tolerance in insects varies a lot by species and there are also differences between individuals. The pesticides manufactured of extracts could be possible to include in the integrated pest management alongside the other methods in the future.
  • Nurmi, Leena (Helsingfors universitet, 2016)
    Kaukasukselta kotoisin oleva köynnöspinaatti on vanha koriste- ja hyötykasvi, joka tunnetaan lähinnä Pohjoismaissa. Suomessa tätä monivuotista köynnöstä on kasvatettu 1800-luvun lopulta lähtien. Siemenestä lisättävä köynnöspinaatti on nykyisin pääasiassa kotipuutarhojen erikoisuus, mutta se voisi olla kaupallisestikin erinomainen varhaisvihannes aikaisen kasvuun lähtönsä takia. Tässä tutkimuksessa selvitettiin kylmäkäsittelyn vaikutusta köynnöspinaatin siementen itävyyteen ja määritettiin tärkeimmät ravinto- ja haitta-aineet. Käsittelyitä oli kolme: 6 viikkoa +5ºC:n tasaisessa lämpötilassa, 6 viikkoa vaihtelevassa ulkolämpötilassa ja suora kylvö kasvihuoneeseen. Ravintoaineanalyysit tehtiin pakkaskuivatuista Herttoniemen, Kaisaniemen ja Tampereen kannan köynnöspinaateista sekä Vantaalla muovihuoneessa kasvaneista lamopinaatin lehdistä. Karotenoidit määritettiin spektrofotometrisesti, folaatit Lactobacillus rhamnosus -bakteerin avulla, tokoferolit ja nitraatti nestekromatografisesti, C-vitamiini ja sokerit entsymattisesti, kivennäisaineet ICP-spektrofotometrisesti, proteiini Dumasin menetelmällä, rasvahapot kaasukromatografisesti ja oksaalihappo ioninvaihto-kromatografisesti. Ravinto- ja haitta-ainepitoisuudet esitetään tuorepainoa kohden. Kylmäkäsittely lisäsi köynnöspinaatin siementen itämistä. Tasaisessa lämpötilassa kylmäkäsittelyn saaneiden siementen itävyys oli 34 % ja vaihtelevassa lämpötilassa 21 %. Ilman kylmäkäsittelyä siementen itävyys oli vain 2 %. Myös viljelykanta vaikutti siementen itävyyteen. Tampereen kannan keskimääräinen itävyys (32 %) oli selvästi suurempi kuin lammilaisten siementen (5 %). Nopeiten itivät Tampereen kannan tasaisessa lämpötilassa käsitellyt siemenet (52 %). Köynnöspinaattien karotenoidi-, folaatti-, tokoferoli-, alfalinoleenihappo-, proteiini-, sakkaroosi- ja kaikkien muiden kivennäis- ja hivenainepitoisuudet, paitsi mangaanin, olivat tuorepainoa kohden suuremmat kuin lamopinaatin. Köynnöspinaatin Herttoniemen kannan lehdissä oli eniten karotenoideja, folaatteja, fosforia, kuparia ja alfalinoleenihappoa. Kaisaniemen kannan lehdissä oli eniten sokereita. Tampereen kannan lehdissä oli suurimmat pitoisuudet tokoferoleja, kaliumia, kalsiumia, rautaa ja sinkkiä. Köynnöspinaatissa oli erityisen runsaasti karotenoideja, folaattia sekä kaliumia, magnesiumia, fosforia ja sinkkiä. Oksaalihappo-, nitraatti-, kadmium ja lyijypitoisuudet pysyivät sallittujen arvojen rajoissa. Köynnöspinaatin siemenet tarvitsevat itääkseen kylmäkäsittelyn joko kylmiössä tai ulkona. Kasvupaikaksi kannattaa tämän tutkimuksen perusteella valita aurinkoinen, melko ravinteikas paikka, jolloin kasveihin muodostuu paljon terveyttä edistäviä ravintoaineita.
  • Mäkilä, Riikka (Helsingfors universitet, 2017)
    The aim of this thesis was to study differences between the yields and stability of grass mixtures and pure stands. In addition, the quality of forage was examined. Timothy cultivars which had different growth rhythms were selected for field experiments. The aim was also to examine how species proportions differ in mixtures between years and harvests and what causes observed variation. Moreover, the effect of the effective temperature sum on the quantity and quality of yield was evaluated. A three year field study was carried out in Jokioisinen and Sotkamo. Plots had either pure timothy stands (Phleum pratense L. cultivars Tuure, Rhonia ja Bor 0301) or mixtures that contained 75% timothy and 25% meadow fescue (Festuca pratensis Huds. cultivars Ilmari ja Klaara). Dry yield (kg ka/ha), D-value, iNDF, NDF, protein and lignin content were determined from each harvest. In addition, botanical composition was analysed in Sotkamo. Grass mixtures had higher dry yields and they were more stable than pure stands. The difference in yileds was more significant in Sotkamo than in Jokioinen. Timothy-meadow fescue growths' NDF and iNDF were closer to desired values than pure stands', but with other quality features weren't discovered advantages. In Sotkamo timothy cultivar's and type's (southern or north) dry yield, D-value, NDF, protein content and botanical composition reacted differently with the effective temperature sum. In Jokioinen the yield and quality of varieties reacted similarly with the effectice temperature sum. All timothy cultivars benefited occasionally from adding a meadow fescue to the mixture but not consistently. Year and harvest affected to the species proportions in the mixtures. Also the effective temperature sum had a correlation with yield and quality. According to the results cultivating grass mixtures instead of pure stands is a good way to achieve bigger dry yields that have high quality.
  • Lahtinen, Leena (Helsingfors universitet, 2017)
    The experiences of an individual build and shape his or her personality. Experiences of nature contribute considerably to the development of children’s self-esteem and self-image. It is worth bearing in mind that the children of today will become the builders and decision-makers of tomorrow and, therefore, their education is of great importance. Their attitudes and values will define the development and well-being of our society. Children’s experiences of their daily lives are a key element of this study. The study explored 5–6-year-old kindergarten children’s (n = 98) experiences of garden activities. The garden was examined as a physical, psychological, social and cognitive environment for growth and learning. The study concentrated on the children’s emotional responses that were aroused by garden activities and on the function of the garden as a social meeting place for children. A further aim of the study was to follow the development of the 5–6-year-old participants’ knowledge of the garden and nature. The children’s experiences were assessed with a drawing task, Me as a Gardener, that was supplemented with individual interviews, conducted between 2014–2015. The children’s emotional experiences and knowledge of nature were enhanced as a result of the garden activities. The activities contributed to an increase in positive experiences and self-image, especially in the case of boys, and to the development of an understanding of the effects of gardening. Based on this study can be expected to, an intentional use of the garden as a growth and learning environment encourages the growth of children in early-childhood education settings.
  • Örö, Nelly (Helsingin yliopisto, 2018)
    Meat and bone meal is a by-product of rendering industry. It contains significant amounts of nutrients, for example 2720 tonnes per year phosphorus in Finland. The use of meat and bone meal in agriculture ceased because of the mad cow disease in 1994. Meat and bone meal has been proved to nearly equal mineral fertilizers both economically and in fertilization effect with many crops. The use of high phosphorus content meat and bone meal as fertilizer decreases the need for non-renewable phosphorus resources and closes food system nutrient cycles. The objectives of this thesis were to consider the suitability of meat and bone meal in potato production and to estimate the recycling potential of meat and bone meal in potato production in Finland. The recycling potential was calculated as a ratio between the annual phosphorus demand in potato production and the amount of phosphorus in meat and bone meal produced in Finland. The mean yields of potato as well as the fertilization rates in agri-environment measures and the plant-available proportion of meat and bone meal were used in calculation. The annual phosphorus demand of potato production was estimated as 1100 tonnes and the amount of plant-available phosphorus in meat and bone meal was estimated as 1630 tonnes. This number includes a category 1 disease risk material which must currently be disposed of. The recycling potentials of meat and bone meal were calculated as 67 % and 74 % for all the material and excluding the category 1 material, respectively. Consequently, the amount of phosphorus in meat and bone meal can supply the demand in potato production. Meat and bone meal is a long-term phosphorus fertilizer and suitable for potato production in Finnish conditions if nitrogen and potassium are supplemented to meet the crop’s demand with other fertilizer products. It’s also an advantage that meat and bone meal is accepted in organic production. In a recycling nutrients point of view, the utilization of meat and bone meal as a fertilizer for instance in potato production is a good opportunity to return nutrients to the agroecosystem’s cycle.
  • Kämäri, Maria (Helsingin yliopisto, 2014)
    Tämän tutkielman tavoitteena on arvioida Suomen luonnonmukaisen maatalouden fosforivirtojen volyymeja, lähteitä ja kohteita sekä virtoihin vaikuttavia tekijöitä. Tuloksia peilataan luomumaataloudelle asetettuun 20 % tavoitteeseen Suomen peltopinta-alasta. Tutkielman käytännön tavoitteena on tutkia, onko ravinteiden kierrätys suomalaisessa luomumaataloudessa riittävän kestävällä tasolla sekä löytää tarvittaessa käyttökelpoisia ratkaisuja luonnonmukaisen maatalouden kestävämpään ravinnetalouteen tulevaisuudessa. Tutkielman aineisto on kerätty BERAS -hankkeen puitteissa seitsemältä suomalaiselta ERA –tilalta (ecological recycling agriculture –tuotantotapa, ERA). Haastatteluaineiston, kansallisten tilastojen ja kirjallisuuden avulla havainnoista koottiin luomutiloja edustavat fosforitaseet ja tilojen sijainnin perusteella rajatun alueen luomutuotantoa edustava SFA -malli. Kolmen vaihtoehtoisen skenaarion ja tuloksien avulla muodostettiin arviot suomalaisen luomumaatalouden fosforitaseista ja -virroista vuonna 2020. Eteläsuomalainen luomumaatalous ei vaikuta hyödyntävän peltomaan fosforivarantoja, vaan turvautuu ostolannoitteisiin ja tavanomaiseen maatalouden tuottamiin ravinteisiin kuten lantaan ja teurasjätteistä valmistettuihin liha- ja luujauhoihin. Koska kotieläintiloja ei ole riittävästi suhteessa kasvinviljelytiloihin, luomumaatalouden lannantuotto ei riitä kasvintuotannon tarpeisiin. Fosforitaseeseen ei saada merkittävää parannusta vuoteen 2020 mennessä, ellei luomumaatalous ala hyödyntämään peltomaan fosforivarantoja. Samanaikaisesti tulee tukea muita kierrättäviä fosforivirtoja, joista tällä hetkellä potentiaalisimpia ovat vesistöjen biomassat. Elintarviketeollisuuden, yhdyskuntajätteiden ym. biomassojen suhteen tulee kehittää uudenlaisia toimintamalleja ja -tapoja, sekä punnita käytön ekologisia, sosiaalisia, taloudellisia ja terveydellisiä näkökulmia. Jos myös tavanomainen maatalous hyödyntää orgaanisia lannoitteita vuonna 2020, kuten hallituksen tavoitteissa on asetettu, orgaanisista lannoitevalmisteista kuten lannasta tulee entistä kysytympää, mikä voi edelleen heijastua eläintiheyteen, luomukasvien satotasoihin ja tuotannon kannattavuuteen.
  • Kämäräinen, Antti (Helsingfors universitet, 2014)
    Street trees are an important part of a comfortable urban environment. Their beneficial effects in the built environment have been documented in a number of ways around the world. In urban environment tree roots are often grown in limited volumes of soil and competing for space with artificial construction materials and technical structures. Low oxygen concentrations in urban soils are considered as one of the major growth limiting factors, particularly under street pavements. The terrestrial growth conditions are difficult to alter in urban environment. By improving below-ground conditions, tree well-being and sustainability can be significantly increased. Increased ensign of growing conditions and the awareness of the value of urban trees have contributed to the creation of landscaping applications such as structural soil. This study compared gas concentrations in the air of structural and conventional soils, used in roadside tree plantings in the City of Helsinki. Soil air samples were collected during growing seasons 2012 and 2013. Proportions of nitrogen, oxygen, carbon dioxide and methane in soil air were determined by a gas chromatograph. CO?-fluxes were used to evaluate the effect of the soil surfacing material to ground ventilation. Structural soil contained more oxygen in all depths compared to conventional tree soil. A strong correlation existed between oxygen and carbon dioxide concentrations. It seems that cobblestone coating with wide seams does not impair the ground ventilation compared to soil covered with cast-iron grate. Atmospheric growth conditions were more favorable in the structural soil; however the oxygen concentrations in conventional soil were also high.
  • Knuutila, Kati (Helsingfors universitet, 2017)
    The soil mineral nitrogen content is affected by many factors such as nitrogen fertilizer, fertilization and cultivated plant species. The effects of these factors on soil mineral nitrogen content were examined and the research was conducted at the Viikki Research Farm during 2013–2015. The possibility of using soil mineral nitrogen content and nitrogen balance to optimise nitrogen fertilization was also studied as well as the leaching of mineral nitrogen during winter and the factors affecting leaching. The soil type of the experimental area was clay loam in topsoil and sandy loam in subsoil. Soil samples were taken in the spring before tillage and in the autumn before soil freezing from topsoil (0-20 cm) and subsoil (30-50 cm). Ammonium and nitrate were extracted from soil samples with 2 M KCl. Plant species and fertilization changed every year, but fertilization followed the regulations for the subsidies of agricultural environment and all the fertilizers and cultivars were commercially available in Finland. The nitrogen content of the seed and forage samples were determined. The actual nitrogen yield and nitrogen balance were calculated. The expected nitrogen yield and nitrogen balance were calculated with the common nitrogen contents of seeds published by the Finnish Agency for Rural Affairs and compared to the actual nitrogen yield and nitrogen balance, but no differences were found. Soil mineral nitrogen content, nitrogen balance and nitrogen yield varied a lot from year to year which was partly caused by the differences between the growing seasons and winters as well as the changes of cultivated plants and fertilization. The soil mineral nitrogen content was smaller in the spring (33 N kg/ha) than in the autumn (55 N kg/ha). Grass took more nitrogen than the other plant species. The soil nitrate content was smaller under growing grass than harvested plant stand in the autumn and the ammonium content was greater under growing grass than other plant species in the spring. The soil mineral nitrogen content was reduced and differences between treatments were moderated during the winter, which was probably caused by leaching. Fertilization had no direct effect on soil mineral nitrogen content. Increasing nitrogen fertilization increased nitrogen balance, but there was no correlation between nitrogen balance and soil mineral nitrogen content.
  • Valin, Marjo (Helsingfors universitet, 2014)
    Suomenlinna is a sea fortress that consists of eight islands and it is a very popular tourist attraction in Helsinki. The vegetation of Suomenlinna has been influenced by its location in the outer archipelago and by the previous military use. The primary aim of this study was to explore the composition and abundance of plant species in soil seed banks of dry meadows at Kustaanmiekka. The established vegetation of the dry meadows was studied in 2009. Soil seed samples were collected in April 2011 from ten dry meadows located around Kustaanmiekka. The samples were taken from two different soil layers: 0-4,5 cm and 4,5-9 cm. Seedling emergence method was chosen to study the seed banks. It was carried out from May to October 2011 in the Viikki campus greenhouse at the University of Helsinki. A total of 5887 seeds from 83 taxa germinated from the soil seed bank samples. The most common species were Berteroa incana (L.) DC., Festuca rubra L. and Potentilla argentea var. argentea. The seed banks contained a few polemochorous species (Berteroa incana, Epilobium hirsutum L. and Silene latifolia Poir. ssp. alba (Mill.) Greuter & Burdet which were brought in Finland with military troops. Noteworthy species found only in the seed bank were Descurainia sophia (L.) Webb ex Prantl and Matricaria recutita L.. The seed density varied from 5030 to17600 seeds/m2. Compared to the short-lived species, the amount of perennial species and their seeds was greater in the seed banks. The number of species and seeds differed between the dry meadows. A 2 luonnonalue had the highest number of species while Makeavesialtaiden luonnonalue and Kustaanmiekan sisäosan hiekkataso had the highest number of seeds. The total number of species and the average number of seeds didn´t correlate with the content of the main nutrients or humus in the soil, nor with soil pH or soil type. The soil seed banks could be utilized in the maintenance of the dry meadows in Kustaanmiekka by uncovering and breaking the soil. Rare meadow species that reproduce from seeds and that are still present in the vegetation would also benefit from this. More research is needed to determine the best method to utilize the soil seed banks when seeking to recruit as many species from the seed bank as possible.
  • Niemelä, Aki (Helsingfors universitet, 2016)
    Atmospheric concentration of greenhouse gases has increased significantly since the pre-industrial era. Global warming is a major issue in the modern world and it has been predicted that climate will change dramatically in the next few decades due to the growing GHG concentrations. Agriculture is a major source of GHG emissions and the EU has set a target for the agricultural sector to reduce GHG emissions. The aim of this study was to calculate GHG emissions for the plant and animal production of studied Finnish farms for the year 2013. The aim was also to analyse the effects of reduced synthetic nitrogen fertilizer use to agricultural GHG emissions with help of two co-operation model for the farms. Another goal was to develop an Excel-based calculator to calculate GHG emissions from farms. Data for this study was collected from 9 actual Finnish farms. The farms were paired and simulated co-operation models were applied. GHG emissions were calculated with developed FarmCALC 2.1 – calculator for the farm pairs before and after co-operation. Co-operation models reduced the GHG emissions from plant production exiting the farms (11–23 %) and pig meat production (13–20 %). But there was no significant effects in milk and beef production. All effects of the co-operation models to the GHG emissions of animal production were based on the changes in feeding and in GHG emissions of feed production. Joint effect of these two were the reason that no changes in GHG emissions of milk and beef production were observed. There was also some uncertainties in calculation method and the method was sensitive to yield changes so there are some uncertainties in calculated GHG emissions. Despite of these uncertainties, results of this study correlate well with previous studies and results were encouraging. It is recommended to study more about the effects of co-operation and reduced synthetic nitrogen fertilizer use to agricultural GHG emission. This study was part of Sustainable Intensification –project, ”Kasvinviljely- ja kotieläintilojen yhteistyö – avain tuotannon kestävään tehostamiseen” (KESTE).
  • Poutanen, Jari (Helsingfors universitet, 2014)
    Gray mold (Botrytis cinerea) is an important disease of strawberry. The pathogen is spread by spores to strawberry flowers, from where the disease spreads to the developing berries. It progresses fast especially in high humidity and without any control. It can destroy even half of the crop. In conventional production, the strawberries have been sprayed by fungicides several times in beginning of summer. Only approved biological fungicides in Finland are Prestop- ja Prestop mix (Verdera Oy), and those can be spread to strawberries by honey bees (Apis mellifera), witch visits in the flowers of strawberry. For this task, the special additional equipment must been installed to hives. Inquiry survey have been made for the strawberry growers, witch have used the entomovectoring control method. The survey clarifies the problems of beginning to use the method, laboured and profitability, problems relating to bees and the needs of develop. Result of the survey is, that the growers have quite committed to use entomovectoring control method, even that many growers told that it was laboured and the efficency could not been seen clearly. The main reasons for the use of method were control of gray mold, reduce of chemical control and safety for user and environment. In addition to method gave image benefit to grower and improved pollination of strawberry. Getting started and use of method were more often trouble-free. The main development points were to extent the time between the addition of pesticide to the spreader equipment and to develop the method for commercial bumble-bee (Bombus terrestris) hives.
  • Mustalahti, Aino-Maija (Helsingfors universitet, 2011)
    Insect pollination increases seed production and improves the quality of the yield of various crop plants. In berry plants, such as strawberry and raspberry, the size and the quality of the fruits increase by successful insect pollination. Strawberry flowers are mainly not attractive to honeybees but raspberry is one of the main yield crops for honeybees. The aim of the study was to find out, how efficiently honeybees visit strawberry and raspberry flowers, concentrating on the honey bee visits on a single flower during one hour. Honey bees can be used as vectors of Gliocladium catenulatum to control Botrytis cinerea in strawberry and raspberry. The success of vector dissemination and its sufficiency to control Botrytis cinerea is evaluated based on flower visits. The data was collected from six farms in Eastern-Finland near to Suonenjoki, in the summer 2007. The flower visits were calculated during the flowering season of strawberry and raspberry in different weather conditions, times of the day and distances from the bee hives. Flowers were chosen randomly and they had to be open to be selected for observation. The observation time varied according to bee activity on the field. In average, honeybees visited on single strawberry flower 1.75 times per hour, and on single raspberry flower 4.27 times per hour. In both plants there were no significant differences in the flower visits according to the stage of the flowering. Time of the day (hour) correlated negatively with flower visits in both plants and temperature correlated positively to flower visits in both plants. Challenging weather conditions restricted the collecting of the data and the summer was rainy. Despite of that, honeybees visited the flowers of the both plants so that the pollination was proper and the control of Botrytis cinerea was sufficient. When planning the vector dissemination, especially in strawberry, the placement and the adequate number of bee hives should be taken into consideration. The need of nutrition should be great in the hives, to maximize the flower visits. Open brood can be inserted to hives or pollen storages can be removed from the hives to stimulate pollen collection. More information is needed on the effect of hive placement, competing plants and attractiveness of different Finnish strawberry cultivars to flower visits. It could be necessary to determine the nectar and pollen secretion of Finnish strawberry and raspberry cultivars.
  • Kemppinen, Johanna (Helsingfors universitet, 2017)
    Blackcurrant (Ribes nigrum L.) is a woody plant in cold regions and it adapts well for the Finland’s boreal zone. There were less than 600 companies farming blackcurrant and green currant in 2014 and the acreage was 1449 ha and the level of yield was over 1000 kg/ha. In year 2016, the number of companies were 544 and the acreage was 1435 ha and the level of yield less than 1000 kg/ha. There has been a pressure to reduce the high price of domestic blackcurrant, due to that the inexpensive imported berries have been taken more position in industry. The global warming can be a serious threat for the cultivation of blackcurrant in the future. There is a need for new cultivars of blackcurrant in Finland and the objective of this research was to examine the depth and reversal of on dormancy on various points of time and the resilience of winter. For the results the bud burst was monitored in quantity and temporal on forcing. The processing of release of dormancy in various temperatures and light conditions before the forcing was also included to the research. The cold hardiness was tested in temperatures, which was descending step by step in controlled sub-zero experiment. The results demonstrated that the bud burst was the lowest during the deepest dormancy in OctoberNovember and the largest in February, when the dormancy was already released. ‘Almiai’ and ‘Gagatai’ were the best cultivars, which were able to maintain the dormancy; in first forcing in October, bud burst 0 %. The bud burst was particularly substantial in February and ‘Ben Tron’ the bud burst was even 80 %. In October-November the time elapsed for bud burst was highest and least was in February with average of 10 days. The most optimal temperature in dormancy release was 0 ⁰C. On the cultivar ‘Mikael’ the bud burst was quicken in +18 ⁰C . The longer the processing time was, the shorter was the time for bud burst. The temperatures +12 ⁰C and +18⁰C were too high for dormancy release. In cold hardiness, the cultivars didn’t differ much from each other. The results demonstrate that the cultivars differ from each other in the depth of dormancy and release. ‘Almiai’ and ‘Gagatai’ maintained best their dormancy. These cultivars could be suitable options for farming in Finland. They were also winter hardiness. In the future, there should be breeding of blackcurrant cultivars, which adjust different kind of environments. Additionally, we should discover and breed cultivars, which have good resistant for winter and maintain dormancy, even though the temperatures are varying in winter.
  • Schulz, Torsti (Helsingin yliopisto, 2014)
    In this thesis I study the end of meadow-based agriculture in the village of Nummenpää in the municipality Nurmijärvi from the 19th century to the mid 20th century. My primary source materials are historical maps of the region and the original survey forms of past agricultural censuses. I also appraise the utility of these materials for historical ecological research and the study of long term changes. I digitized agricultural land use from historical maps and analyzed changes in land use by comparing maps from different time periods. The agricultural census records were analyzed with logistic regression to determine characteristics of farms relating to the presence of meadows. Meadows had lost their role in agricultural production in Nummenpää before 1920, somewhat earlier than in Nurmijärvi on average. Between 1870 and 1930 most of the meadows had been ploughed into fields. Of meado land that had been meadow already at the turn of the century only a few percent remained in 1930. Farms in Nummenpää had not yet differentiated into specialized crop production or animal husbandry during the study period, but mechanization proceeded and more emphasis was placed on cattle and dairy production. There was insufficient variability between farms to determine properties that could be associated with the end of the agricultural use of meadows. It is also possible, that meadows lost their role so early that there was no longer a clear link to the agricultural economy. The census records and maps used in the study did not have sufficient temporal coverage and resolution to permit me to determine the dynamics of landscape change associated with the end of the meadow-based agriculture nor the factors driving the change. The separate analysis of map and census data was not conducive to linking socioeconomic change to landscape change. Nonetheless, I maintain that the source materials used in the study, and other similar materials, are well suited for historical ecological research. The materials must be evaluated critically from a historical perspective and the analysis should integrate the distinct sources. By utilizing appropriate spatiotemporal models it should be possible to reach more interesting conclusions and reduce the impact of uncertainty and imprecision inherent in the materials.
  • Andersson, Johanna (Helsingin yliopisto, 2014)
    Bacterial soft rot and blackleg are amongst the major diseases of potato (Solanum tu-berosum L.). In Finland Pectobacterium atrosepticum, Pectobacterium carotovorum subsp. carotovorum, Pectobacterium wasabiae and Dickeya-species cause rotting of the tuber and softening of stems on potato. These diseases cause major postharvest losses and weaken the quality of the crop, which is a problem in seed potato production. The aim of this study was to determine whether the antagonistic bacteria are toxic to in vitro plants, as well as to study the ability of the antagonistic bacteria to spread inside or on the in vitro plants. It was also investigated if the antagonistic bacteria can prevent soft rot of potato in in vitro plants, as well as the ability of the antagonistic bacteria to prevent the spreading of soft rot bacteria from soil to the plants. This study was carried out in laboratory and in greenhouse conditions in the University of Helsinki at the Department of Agricultural Sciences. As potato material cultivar Melody was used and as antagonistic bacteria 10 different bacteria were chosen: Serratia plymuthica A30 (NR), Flavobacterium sp. strain B17 (A3), Agrobacterium sp. (A6), unsequensed bacteria isolated from potato root (A4), Serratia j5h9 (S1), Alcaligenes faecalis (R8), Bacillus M1ju27 (BC1), Bacillus S3H53 (BC2), Burkholderia M1423 (BK3) and Pseudomonas S2h50 (PS3). Dickeya solani and Pectobacterium carotovorum were used as pathogens. Although BC1, BC2, S1 and BK3 antagonists did not influence negatively the potato in vitro seedling growth they did not, however, properly prevent soft rot of in vitro plants. Further studies on preventing soft rot of in vitro plants is needed.
  • Aho, Jenna (Helsingfors universitet, 2017)
    In a previous study, Pectobacterium strains were isolated from rotten potato tubers and stems. Strains were identified as P. carotovorum subspecies carotovorum by their biochemical properties. In acnA gene sequence analysis the strains isolated from diseased potato stems were different from P. carotovorum subspecies carotovorum type strain and also from strains isolated from rotten potato tubers. However, the strains isolated from rotten potato stems were not able to cause typical blackleg symptoms, like rotting of stems, when inoculated in potato plants. The focus of this master’s thesis was to further study if the new strains are pathogenic in nature or whether they could have arrived to already rotten potato tissue as secondary infection. One goal was to find out if the strains can produce compounds that inhibit growth of known blackleg pathogens, and could they make already contaminated potatoes disease free in a field. This was tested in vitro as well as in a field trial with two potato varieties. As a result the strains isolated from stems were able to produce toxic compounds that inhibited the growth of several common soft rot and blackleg pathogens, whereas compounds produced by the strains isolated from tubers had no effect on the growth of the other bacteria. This suggests that the strains present in stems have properties that make it possible for them to spread from the environment to already infected stem lesions and compete with blackleg and soft rot bacteria already present in the tissue. Blackleg symptoms were absent during the field trial, but in some cases the inoculations caused soft rot of tubers and stunted growth of the inoculated plants. The two potato varieties used in the field trial, Rikea and Fontane, had a different response against the used strains. Although the in vitro results suggested that some of the strains that were originally isolated from stems could act as biological control agents, the results from the field trial contradicted this indicating that the strains might have pathogenic properties, which makes them unsuitable as biological control organisms.
  • Kotkavuori, Juulia (Helsingfors universitet, 2016)
    The common lilac is one of the oldest cultivated ornamentals in Finland. The basic form of common lilac spread here in the beginning of the 18th century and lilac cultivars came in the mid-19th century. The aim of this study was to create DNA fingerprints for selected un-named common lilac individuals found in parks of Helsinki. The second objective was to find out the spread and cultivation history of common lilac in Finland. The hypothesis was that the common lilac was introduced and dispersed via Turku and Viapori. This was tested by comparing the DNA fingerprints of old lilac shrubs growing in historical sites with each other. DNA fingerprints were created for 88 samples using nine microsatellite markers The diversity of the microsatellite markers and the lilacs were evaluated by the effective number of alleles, expected heterozygosity and PIC values and AMOVA, respectively. Cluster analysis and a UPGMA dendrogram allowed the detection of identical samples. A total of 35 alleles were found and each of the nine loci was polymorphic. The effective number of alleles ranged from 1.17 to 4.83. The expected heterozygosity ranged from 0.14 to 0.79. The markers SV2, SV4 and SV1 had the highest PIC-values, more than 0.5. The analysis of molecular variance (AMOVA) showed significant level of differentiation between the clustered groups. The variation is explained by differences between and among the groups. The common lilac material studied was diverse. Microsatellite markers proved to be suitable for the study of Syringa vulgaris –species. Cultivar identification was complicated by missing amplification products. One local shrub was identified as the old French cultivar 'Congo'. The samples from historical sites connected to Turku and Viapori did not show any consistent differences, so the data do not support the hypothesis of two old lilac populations.
  • Laine, Ida (Helsingin yliopisto, 2015)
    Pihlajalla (Sorbus aucuparia L.) on vankat perinteet suomalaisessa maisemassa niin suosituimpana pihapuuna kuin puistoissa ja viherrakentamisessakin. Se on vaatimaton ja kestävä laji, joka kasvaa lähes missä vain ja valtaa nopeasti alaa vesojensa ja siementensä avulla. Metsätaloudellisesti sitä pidetään yleensä roskapuuna. Pihlajasta on jalostettu myös marjantuotantoon sopivia lajikkeita, makeapihlajia. Pihlajan taudeista tiedetään melko vähän, sillä se ei lajina ole taloudellisesti kovin merkittävä. Sen tiedetään sietävän hyvin latvuston ja juuriston tuhoja. Kuitenkin jo 50-luvulta lähtien on ympäri Eurooppaa raportoitu kloroottisista rengaslaikkuoireista pihlajan lehdissä, ja oireiden on todettu siirtyvän oksastuksessa sairaasta kasvista terveeseen. Vasta 2000-luvulla oireiden aiheuttajaksi varmistui aiemmin tuntematon, neljästä yksijuosteisesta RNA-rihmasta koostuva pihlajanrengaslaikkuvirus, EMARAV.Tässä tutkimuksessa haluttiin selvittää löytyykö suomalaisista rengaslaikkuoireisista ja oireettomista pihlajista EMARAV-sekvenssi ja testata RT-PCR:ää sekä dot blot -hybridisaatiota viruksen tunnistamisessa.Eri puolilta Suomea kesäkuussa 2007 kerätyistä 73 lehtinäytteestä jokainen antoi positiivisen tuloksen dot blot -hybridisaatiossa. Näistä 17 näytettä oli peräisin täysin oireettomista puista. RT-PCR:ssä virussekvenssiä saatiin monistetuksi 54 näytteestä. Ongelmia aiheuttivat eristettyjen RNA-näytteiden epäpuhtaudet.Tulosten mukaan EMARAV on Suomessa erittäin yleinen virus pihlajalla ja esiintyy yleisesti myös latenttina infektiona.
  • Laamanen, Tuija-Liina (Helsingfors universitet, 2015)
    Carrot production is very specialized and professional in Finland. Long term storage of the yield is necessary during winter. In storage, the resistance of carrots to diseases decreases even with optimized storage conditions. Diseases can cause huge losses during long storage periods, but the severity of losses varies between years and fields. One of the most harmful diseases of carrots during storage is Mycocentrospora acerina. It is a soil borne fungus that cannot be controlled by fungicides. This is a study of the test method to evaluate the risk of M. acerina in a field. In this test slices of carrots were placed in a container with collected soil samples from a test field. The containers with soil samples and carrot slices were kept six weeks in the dark at +15 °C temperature. After that it was possible to see if M. acerina had grown up from the soil and infected the carrots by forming dark colored patches to the carrot slices. By calculating and comparing the amount of patches on each soil sample it was possible to evaluate the risk of M. acerina in a test field. Results from the test were compared to amount of M. acerina infection found in stored carrots harvested from the same fields. The study showed that it is possible to evaluate the risk of M. acerina. Soil samples can be collected in different times of the year, and the test can be made with fresh or storage carrots. The test samples need to be comparable, so they must be collected the same way and the amount of samples in each container must be sufficient to minimize variation. This study will introduce simple guidelines that farmers can use to test fields and evaluate the risk of M. acerina.