Browsing by discipline "Växtproduktions biologi"

The aim of this study was to look into the possibility of using predatory mites as a biological control agent in the nursery production. This study focuses on the biological control of two phytophagous mites, Tetranychus urticae and Aculus schlectendali that occur as pests in apple seedling production. The directive 2009/128/EY of the European Union obligates the farmers to follow the principles of the integrated pest management and favour other control methods, such as biological control, rather than chemical pesticides. This study is a part of The Finnish Nursery Producers Association’s project that aims to develop biological control practices for the nursery production in Finland and promote integrated pest management in nursery production. The experiments for this study were carried out outdoors in a field and indoors in a seasonal greenhouse, where the population development of T. urticae and A. schlechtendali on apple seedlings was followed. Population density of mites was counted from leaf samples gathered from the seedlings in two week intervals from May until the end of August. Biological control of T. urticae was tested with Phytoseeid mites, Neoseiulus barkeri and Phytoseiulus persimilis. Chemical control was used as a comparison treatment. The effects of the biological control were followed by comparing the population densities of phytophagous mites in the area of biological control to the mite densities in the area of chemical control. N. barkeri and P. persimilis were not able to prevent nor stop T. urticae population growth in the greenhouse where the densities of T. urticae grew higher in the area of biological control than in the area of chemical control. Outdoors the population densities of T. urticae remained low throughout the experiment in both treatment areas. Population densities of A. schlechtendali grew high indoors and outdoors within both treatments. Even though biological control did not succeed in these experiments, the conditions in the greenhouse were suitable for Phytoseeid mites and in theory it should be possible exploit them as control agents in nursery production. The high densities of A. schlechtendali were surprising. In the future it would be important to consider the importance of this species as a pest and find effective means to control it.

This thesis is a Rapid Rural Analysis (RRA) of the farmers’ perceptions of potato production in Nicaragua. The thesis data was collected during the summer of 2011 in the main potato production areas of Nicaragua (Matagalpa, Jinotega and Estelí) through structured interviews. The structured interviews gave consideration to the five different capitals of the Sustainable Rural Livelihood- approach (SRL). These five capitals (social capital, natural capital, human capital, financial capital and physical capital) were incorporated in the study in order to achieve the multidisciplinarity of the RRA- methodology. The thesis data, consisting of 63 individual interviews, was compacted and analysed utilizing cross tabulation. A further statistical analysis was then conducted with Cramer’s V allowing a more detailed view of the dependencies between variables (detected in the cross tabulation). The main finding of this study is that the situation of the potato producers cannot be determined by the size of the production, as has been previously suggested. The size of the farm does not determine yield levels nor perceived financial incentive for production. This study gives a more complex view of potato producers and production in Nicaragua. This study suggests an alternative approach to developmental program planning for the potato production sector in Nicaragua; the production environmental zones. Utilizing the production environmental zones as a basis for planning takes the project to a more practically suitable level that considers the existing variance in yields and access to extension. The main conclusion of this study is that sector development of potato production in Nicaragua is complex. Inclusion of the project beneficiaries in the planning processes may significantly improve development programme planning, outcomes and resilience in time. A development programme, like the one implemented by FAO (United Nations Food- and Agriculture Organization) in Nicaragua, with an overly simplified view of the sector, may lead to severe misjudgements and potentially even cause harm.

The aim of this study was to identify the socio-economic and agro-ecological factors, reflecting the impact of agricultural mitigation actions for food security in Ethiopia and opportunities to develop on the basis of these factors indicators to assess the food security impact of Clean Development Mechanism projects. The study analyzed interviews conducted in three different locations in Ethiopia. The interviews were coded and the encodings were combined in to themes. Different categories of food security impacts were created on the basis of the themes. The CDM projects were analyzed using the themes and categories to form indicators so that the food security impact of the projects could be evaluated. The analyzed mitigation measures were composting, construction of terraces, limited use of areas and the use of agroforestry. Mitigation actions were found to have a positive impact on food security and climate change mitigation. Farmers felt that the mitigation measures were effective and decided to continue their use although the workload of the measures was described great. When developing of mitigation measures attention should be paid to the technical difficulties and feasibility of the action. Based on this analysis it was possible to form indicators for food security impacts of CDM projects. All the evaluated projects were found to have positive effects on food security on the basis of the indicators. Using the indicators directional assessment of food security impacts of CDM project can be made. The projects do not explicitly consider the food safety implications.

Plants absorb water best from fertigation solution with low nutrient concentration. Yet, in intensive greenhouse production high nutrient concentrations are used in fertigation to avoid nutrient deficiencies and decrease in yields. In split-root cultivation the root system of a plant is separated into two growing medium compartments, in which case the other half receives fertigation solution with high EC (electrical conductivity) and the other with low EC. Especially greenhouse cucumber, susceptible to water supply problems caused by salinity of growing medium, is found to benefit from this technique in increased yields. The objective of this study of split-root cultivation of greenhouse cucumber conducted in MTT Agrifood Research Finland was to improve the technique especially in respect of EC of fertigation solutions. In addition to single-root and traditional split-root cultivation there were two split-root treatments in which fertigation solution concentrations were reversed in intervals to improve functioning of root systems. Effects of different EC combinations on vegetative growth between above- and underground parts of greenhouse cucumber and morphology and anatomy of roots were studied in a separate experiment. Results demonstrated that split-root cultivation increased cucumber yields up to 16% but had no effect on uptake of water or nutrients over the whole cultivation period. The most of spiked fruits were formed in single-root cultivation which refers to water supply problems during the highest need for transpiration. The technique didn’t affect plants’ vegetative growth or structure. Petiole sap nitrate and potassium analyses indicated that nutrient concentrations of fertigation solutions had no effect on nutrient uptake of roots. Different EC combinations had a greater effect on root weight than on shoot weight or stem growth in greenhouse cucumber. Petiole sap analyses suggested that nutrients were allocated variously in different EC combinations. The osmotic stress caused by high ECs led to changes in root morphology and anatomy. Results indicated that split-root cultivation enhanced the sink strength of developing fruits in relation to other sinks without affecting vegetative growth. When sides of fertigation solutions of low and high EC were switched during cultivation, the root system was able to take water and nutrients flexibly and economically, in which case significant yield increases were achieved in greenhouse cucumber production. Splitting root system probably affects plants’ hormone metabolism and can impair growth of roots without impairing their functioning, whereupon assimilates are allocated more efficiently to the growth of aboveground plant parts.

Conservation biological control is a strategy of biological control that aims to support natural enemies of pests. One of the potential ways to support natural enemies is to enhance diversity in agricultural landscapes. By establishing non-cultivated areas near crop fields natural enemies can be provided with many resources including food, shelter and overwintering sites. The availability of these resources potentially enhances the abundance and diversity of natural enemies and their efficiency to reduce pest populations. The goal of this study was to compare the effects of two different fallow strip types – meadow strip and grassland strip – on the abundance and species composition of predatory arthropods. To examine the differences between the strip types, data were collected from the strips and adjoining cereal fields. An experiment was conducted on two barley fields in Helsinki in summer 2014. Two fallow strips were established in the middle of each field. The strips were composed of four 3 m * 60 m-sized plots. Every other plot was sown with meadow seed mixture and every other with grassland mixture. Data on predatory arthropods were collected during June-July using pitfall traps. There were more predatory arthropods on the fallow strips than on the barley fields. However, there were no differences in the abundance of predatory arthropods between the fallow strip types. Moreover, the abundance of predatory arthropods on adjoining cereal field did not differ between the strip types. The species composition of predatory arthropods differed statistically significantly between barley fields and the fallow strips, and almost significantly between the strip types. The results indicate that the fallow strips succeeded to provide favorable habitats for predatory arthropods, which may be due to food or shelter that they provide. The lack of clear differences on the abundance and species composition of predatory arthropods between the strip types can be explained by the fact that the vegetation of the strips was not yet fully established in the first year. Other reasons include the substantial differences between the two study fields. However, it seems that fallow strips have potential to provide biodiversity benefits, which have previously been observed in environmental fallow fields, and to enhance ecosystem services such as biological control.

Tämä maisterintutkielma perustuu tekijän julkaisemaan projektiraporttiin Kestävämpi maatalous Uudellemaalle (Lamminparras 2013, Elinkeino-, liikenne- ja ympäristökeskus Raportteja 38/2013). Kestävämpi maatalous Uudellemaalle -projekti toteutettiin talvella 2012–2013 Uudenmaan elinkeino-, liikenne ja ympäristökeskuksessa (ELY-keskus). Tutkielma tarkastelee maatalouden kestävyyttä ja sen määrittymistä aineistonaan projektin yhteydessä koottu aineisto. Lisäksi tutkielma tarkastelee projektissa käytettyä Delfoi-metodia. Aineisto muodostuu projektinaikaisista muistiinpanoista, jotka koskevat projektiin osallisten keskusteluja ja palavereja. Kestävälle kehitykselle on olemassa vakiintunut määritelmä, jonka mukaan sen tarkoituksena on turvata tulevien sukupolvien tarpeet siten, että niin ekologinen, taloudellinen kuin sosiokulttuurinen kestävyys toteutuvat. Kestävän kehityksen termiä käytetään paljon niin tieteessä, politiikassa kuin yritysten markkinoinnissakin. Kuitenkin todellisen kaikki osaset huomioon ottavan kestävän kehityksen ymmärtäminen ja toteuttaminen on äärimmäisen hankalaa. Näin ollen kestävällä kehityksellä voidaankin tilanteesta riippuen tarkoittaa hyvin eri asioita ja sitä tulkitaan eri puolilla maailmaa ja eri instansseissa hyvin erilaisilla tavoilla. Delfoi-metodi on tulevaisuudentutkimuksessa käytetty haastattelu- ja kyselymenetelmä, jolla pyritään saamaan asiantuntijatietoa tulevaisuuden kysymyksistä. Delfoi-menetelmän erityspiirteitä ovat kyselyn toistuminen, palautteen anto sekä anonyymius. Kestävä kehitys määrittyi Uudenmaan ELY-keskuksessa melko suppeasti, pysyen Uudenmaan tiukkojen maantieteellisten rajojen sisäpuolella. Kestävyyden eri osa-alueista suurin paino arvo oli ekologisella kestävyydellä, mutta usein myös taloudellinen kestävyys ohjasi projektia. Projektissa käytetty Delfoi-metodi tuotti todella paljon tietoa viranomaisryhmän käyttöön. Se ei ehkä onnistunut tuottamaan selkeitä tulevaisuudenpolkuja, mutta tuotti runsaasti tietoa siitä mitkä seikat tulevaisuudessa taritsevat erityishuomiota ja mihin suuntaan maatalouden ympäristönsuojelu on Uudellamaalla menossa.

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.

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.

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.

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.