Browsing by department "Department of Agricultural Sciences"
Now showing items 21-40 of 501
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(2014)In this study the economic values for the breeding goal traits for Finnish Ayrshire cattle were determined by the bioeconomical model. Additionally, the economic value was determined for a new trait, feed efficiency, which was modelled as residual feed intake (RFI). Feed efficiency was added to breeding goals because of intrest in reduction of harmful environmental effects of dairy cattle production. The effect of increasing feed costs on the economic weights was also studied. Economic values were determined by the program ECOWEIGHT. The bioeconomical model included 21 traits, which can be divided a few categories: milk production traits, growth and carcass traits and functional traits (calving difficulty, stillbirth, calf mortality in the rearing period, fertility traits, productive lifetime of cows, incidence of clinical mastitis, somatic cell score (SCS) and residual feed intake (RFI)). Economic values and standardized economic weights were defined for the traits. Profitability of the milk production was negative (?13,3%), when the subsidies were not included in the calculations. Adding RFI didn’t have any effect on the economic values of the other traits and it didn’t change the order of the traits in standardized economical weight. The marginal economic values for RFI of cows and heifers were ?55,8 and ?24,9 €/kg/d, respectively. The highest relative economic weights was found for 305-d milk (36%), protein (14%), fat (9%), mature weight (7%) and calving interval (5%). Relative economic weights for RFI of cows and heifers were 4,6% and 1,5%, respectively. An increase in the feeding costs (10, 30 and 50%) changed the order of the traits in standardized economical weights. The weights of milk production traits were decreased and the weights of growth traits, RFI and calving interval were increased. RFI of cows was the fifth important trait when feeding costs increased 30%. According to the results of this study would be beneficial, especially if the relative im-portance of feed efficiency will increase in the future due to increasing feed costs or in-creasing requirements to mitigate the environmental impact of milk production. However, more research will be needed before adding RFI to the breeding goals.
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(2014)Biochar has been proposed to a promising future product as a carbon sink in carbon sequestration and as a soil conditioner. The aim of this master thesis is to clarify, how biochar affects on the crop formation and yield of faba bean Vicia faba in Southern-Finland. The research includes 3 growing seasons (2010-2012), but the biochar was spred in spring 2010. The study was carried out at the fields of the Viikki research farm, owned by the University Of Helsinki. The study was a split plot experiment, in which as the main plot factor was biochar rate (0, 5, 10 t ha?1). As the sub-plot factor was used fertilizing rate (12, 26 and 40 kg ha?1). To analyzing the yield components, the crop mass samples from the vegetation of every experimental plot were taken. The samples were taken at the end of crop maturation, at the development stage of > 85 (BBCH). Then the samples were dried. The yield components from the samples were separated, such as vegetative (leaves, stalks) and generative parts (pods). After that these parts were weighed. Pods were also calculated and seeds were separated from the pods, and then they were weighed. From obtained data, it was then possible to calculate the key number of yield com-ponents. And finally, the statistical analysis were done with these data. Biochar reduced the plant density at dry growing seasons 2010-2011. But at the same time it enhanced the number of pods per plant and number of seeds per pod. At moist year 2012 there were no significant differences in these components. Biochar didn’t affect significantly on the seed yield of faba bean. Fertilizing didn’t affect significantly on any yield component. Biochar and fertilizing affected significantly together only on 1 000 seeds weight on the year 2010. The lack of statistically significant affects was possibly due to the high fertility of the experimental field. There was evidence that biochar may enhance yield formation of faba bean through the ability of plants to compensate the decreased plant density during dry years. In this situation, a plant in-creases the other yield components. Due to biochar, the tolerance of plants to drought stress can become better. As a conclusion, biochar can be remarkable soil conditioner in the future, in particular during dry growing seasons. However, in fertile soils of Southern-Finland, there are no expected big yield increases in the first three years.
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(2017)Biokaasulaitos tuottaa biokaasua energiakäyttöön ja mädätettä lannoitteeksi kasvintuotantoon. Biokaasulaitos on täten monipuolinen tuotanto- ja kierrätyslaitos. Tavanomainen energian- ja lannoitteiden tuotanto on hyvin energiaintensiivistä ja uusiutumattomia energianlähteitä käyttävää. Biokaasulaitos mahdollistaa hajautetun energiantuotannon ja lannoitteiden tuottamisen uusiutuvista raaka-aineista, monesti raaka-aineista jotka olisivat muuten jätteeksi luokiteltavaa. Tutkimuksen tarkoitus oli selvittää, mitä Suomessa toimivissa biokasulaitoksissa käytetään syötteinä, kuinka paljon biokaasua saadaan tuotettua, millaisia ovat mädätteen ravinnepitoisuudet ja kuinka viljelijät käyttävät mädätettä pelloilla. Tutkimuksessa selvitettiin myös, millainen olisi ideaali biokaasulaitoksen toiminta kaasuntuoton, mädätteen jatkokäytön ja laitoksen toiminnan kannalta. Kuinka biokaasuntuotantoa voitaisiin Suomessa lisätä ja parantaa energia- ja ravinneomavaraisuutta? Tarkoitus oli kerätä tietoa sekä keskitetysti toimivilta biokaasulaitoksilta että maatilojen omilta biokaasulaitoksilta. Tavoitteena oli vertailla eri laitosten antamia tietoja ja selvittää millaisia eroja laitoksista löytyy. Tutkimus toteutettiin internetpohjaisena kyselynä. Kyselypohjia oli kaksi: toinen biokaasulaitoksille ja toinen maatiloille, joilla joko oli oma biokaasulaitos tai tilalla oli joskus käytetty mädätettä lannoitteena. Yhteensä vastaajia kertyi 14 kappaletta. Mädätteiden pääravinnepitoisuuksissa oli eroja, vaihteluväli oli 2,8-16 ja keskiarvo 6,47 kokonaistypen osalta. Niissä mädätteissä, joissa oli korkea kokonaistyppipitoisuus, oli myös korkea kokonaisfosforipitoisuus (R2=0,56; p=0,013). Tuloksista ei voi tehdä selkeitä johtopäätöksiä sen suhteen, mikä tai mitkä olisivat parhaita syöteaineita. Syöteaineet olivat vaihtelevia, ja samanlaatuisilla syöteaineilla kaasuntuotanto ja mädätteen laatu erosivat kahdella eri laitoksella.
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(2016)The aim of this master thesis was to evaluate suitability of a biogas plant as a manure maintenance method in a kind of a horse village, where many horse businesses are located close to each other. The suitability of the biogas plant was evaluated by ecological and economic effects. For ecological effects the investigation was made concerning nitrogen and phosphorus flows and for economic effects an evaluation was made concerning the total profitability of the biogas plant. Nitrogen and phosphorus flows were investigated by substance flow analysis. The evaluation was made by investigating internal flows, flows inside and outside of the system and the size of the flows of two systems in which one system was a horse village with a biogas plant and the other system was a horse village without a biogas plant. The horse village without the biogas plant was further divided into two options. One option was to spread the manure on fields and the other option was to hand over the manure. The economic profitability was evaluated by gross margin calculation concerning four different options which were a biogas plant producing CHP with and without financial support and a biogas plant producing fuel with and without financial support. Concerning nitrogen and phosphorus flows, the horse village where the manure is spread on fields is as good option as where the manure is being processed on a biogas plant and where the digested sludge is used for fertilizer as well. Handing over the manure outside the horse village is a worse option in relation to the local substances flow cycle. The construction of the biogas plant in horse village was profitable in every options. Although manure processed by biogas plant is evaluated to produce less nutrient loss compared to manure which is spread straight to the field, there still is a need for further investigation about the effects of biogas production on nutrient flows and nutrient losses in order to model the effects of a horse village. However, according to previous investigations it is known that biogas production decrease greenhouse gas effects. The profitability of biogas plant requires that manure maintenance costs of the horse village have been quite high before the biogas plant.
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(2013)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.
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(2018)Tiivistelmä/Referat – Abstract The long period of indoor feeding in Finland emphasizes the importance of good quality silage in dairy cow nutrition. Silage additives are used to ensure successful ensiling. Silage inoculants enhance silage lactic acid fermentation when lactic acid bacteria and sometimes enzymes and other fermentative bacteria are added to silage. Lactic acid content has been higher and pH lower in silages treated with inoculant than in silages without any additive. Aerobic stability of silage and total mixed ration (TMR) has been better with silage treated using inoculant compared to silage without additives. In some studies, the digestibility of dry matter and organic matter has been better with inoculant-treated silage. Silage dry matter intake has been improved with silage treated with inoculants in studies performed with dairy cows, growing beef cattle and sheep. Milk yield has increased in some studies with biological additive when compared to silage without additives. The aim of this study was to examine whether ensiling grass silage with biological additive influences feed intake or milk production of dairy cows in comparison to silage without inoculant. The study was conducted at the research farm of University of Helsinki. First cut timothy – meadow fescue sward was cut and wilted for 46 hours. The grass was harvested in round bales wrapped with 8 film layers either using silage inoculant (treatment B, with lactic acid bacteria and enzymes) or without additive (treatment A). A series of five bales of each silage were prepared one after another. The grass had dry matter of 183 g/kg before wilting and 328 g/kg after wilting. Water soluble carbohydrate concentration was 121 g/kg dry matter (DM). The silages were stored for 174 days before the beginning of the feeding trial. There were no differences in silage fermentation quality. Both silages had high concentration of lactic acid (100 g/kg DM). The dry matter contents were 296 and 294 g/kg and pH 4.25 and 4.31 for the inoculated silage and the silage without additive, respectively. Eight Finnish Ayrshire cows (95 days in milk, standard deviation 25.9) of second or later parity were used. The cows were kept in tie stalls during the trial. A double-reversal design was used with two treatments sequences (ABBA or BAAB) of 21 days each. The cows were fed with total mixed ration consisting of 65% (dry matter basis) of silage (inoculated or without additive), 20% of concentrate mixture, 13% rapeseed meal and 1.5% mineral supplement. Dry matter intake was 1,1 kg/d higher with the inoculated silage (p=0.01) than with untreated silage. Digestibility of dietary dry matter (p=0.02) and organic matter (p=0.02) was lower with inoculated than untreated silage. There was no difference in milk production between treatments (p=0.65). This study indicates that good fermentation quality of wilted (DM 300 g kg) grass silage can be achieved without additives. The increased dry matter intake or the lower digestibility of the diet containing inoculated silage cannot be explained by the silage composition or fermentation profile.
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(2011)In recent times climate change, decrease of fossil fuels and increase of their price have greatly increased worldwide interest in renewable energy sources. In Finland, there has been a lot of concentration towards forest industry’s secondary produced wood basis biomass, that forest industry uses for its energy production. Forest industry’s waste water cleaning process creates different kinds of sludge, which are either reused or destroyed by burning or transporting to waste treatment plant. Especially reuse of bio sludge is difficult, and waste area placing in the future is impossible or at least economically too expensive. In practice, sludge is treated by burning, and by drying it becomes a bio fuel. The energy use is the best way to destroy waste sludge. Because of the high water consist of the sludge it must be dried before burning. Drying the sludge with secondary energy flow with waste heat from forest industry processes increases energy income from the burning process and replaces the use of fossil fuels. The goal of this research was to find out the most optimal mixture of bark and sludge by changing different drying parameters. The experimental work was started by building a laboratory size fixed bed dryer for the energy technology experiment hall, where drying was studied by blowing heated air through the fuel layer. The dried fuel material was a mixture of bark and sludge, or just bark or sludge at different masses, different percentage mixtures and different temperatures. Making the drying curves was based on weight changes. In the test rig were probes for controlling and setting the temperature as the experiment expected. The temperature and weight changes were recorded to computer during the experiment. The drying experiments showed that sludge-bark mixture dries well, when the percentage of the sludge mass doesn’t increase over 50 %. When the share of sludge is higher, drying is no longer effective, which is due to channelling of the air through the dried fuel material in the fixed bed dryer. When drying the bark, increase of the temperature from 50 °C to 70 °C was much more effective than from 70 °C to 90 °C, the difference in drying time was about doubled.
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(2015)Brown-heart disorder in rutabaga is a boron deficiency syndrome that renders the inside of the roots brown and makes the crop unfit for market. The connection between boron deficiency and brown-heart was first reported in 1930’s. Brown-heart continues to be a concern for rutabaga growers all over the World, especially in Northern Europe, Canada, United States of America and New Zealand. The aim of this thesis was to compare the effects of various methods of applying boron, in terms of rutabaga yield and brown-heart. The field experiments were done in 2013 and 2014 on Räpi research farm of Apetit Ruoka Oyj in municipality of Köyliö, as part of collaboration between Apetit Ruoka Oyj and Yara Suomi Oyj. The companies aimed to find the best fertilizer solution for the prevention of brown-heart in rutabagas. Treatments were either fertilizer placement or broadcast application. In addition, foliar spraying treatment was used. Nutrient levels of the soil were analysed before planting and after harvest. The nutrient levels of rutabaga leaves before harvest, and nutrient levels of rutabaga roots by the time of harvest, were analysed. Additionally, the yield and number of rutabagas with brown-heart were determined. In experiments done in 2013, the effect of boron treatment on yield was statistically insignificant. In 2014, the fertilizer placement increased the yield as compared to broadcast application. In 2013 the number rutabagas with brown-heart disorder was significantly less within the samples treated with fertilizer placement, as compared to samples treated with broadcast applications. In 2014 the overall number of rutabagas with brown-heart was low, and the differences between treatments were statistically insignificant. Of the rutabaga boron treatments compared in this thesis, the fertilizer placement was more efficient than the broadcast application. Generally, the effect of foliar spraying treatment on yield or quality of the rutabagas was insignificant. In order to achieve high quality rutabaga crop, applying boron with fertilizer placement simultaneous to sowing, is recommended.
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(2017)Tämän maisterintutkielman tavoitteena oli selvittää eroja viiden kaupallisen broilerihybridin kävelykyvyssä ja aktiivisuudessa. Hypoteesina oli, että broilerihybridien väliset erot näkyvät kävelytestin ja muunnellun latency to lie- eli LTL-testin tuloksissa, videomateriaalissa ja tuotantotuloksissa. Kukkoja oli viittä kaupallista, yleisesti käytettyä broilerihybridiä, joista yksi oli hitaampikasvuinen, luomu- ja free range -tuotantoon käytetty hybridi. Sukupuolilajitellut 350 kukkoa (65-75 lintua/hybridi) jaettiin satunnaisesti 25 numeroituun karsinaan hybrideittäin (5 karsinaa/hybridi). Lintujen rehunkulutusta ja kasvua seurattiin koko kokeen ajan viikottain. Lintujen kävelykyky arvioitiin teuraspäivinä kävelytestillä ja muunnellulla LTL-testillä (koepäivät 15, 19, 22, 32, 36, 43 ja 49). Kaikille linnuille tehtiin ylimääräinen kävelytesti myös päivinä 27 ja 40. Lintujen käyttäytymistä videoitiin koepäivinä 12, 17, 25, 34 ja 41. Tarkkailtaviksi valittiin satunnaisesti kuusi värjättyä lintua per hybridi (yhteensä 30 lintua). Videoista analysoitiin jokaiselta päivältä kaksi 10 minuutin pituista jaksoa, joista kirjattiin ylös muutokset lintujen aktiivisuudessa (lintujen ryömintä- ja kävelysummat, seisoma- ja makuufrekvenssit ja kokonaismakuu- ja seisoma-aika). Lintujen tuotantotulosten ja kävelykyvyn väliset yhteydet testattiin Kendallin korrelaatiolla. Hybridillä oli erittäin merkitsevä vaikutus kävelykykyyn mitattuna kävelytestillä (p= 0,001). Hybridillä ei ollut merkitsevää vaikutusta lintujen muunnellun LTL-testin tuloksiin (p=0,394). Erittäin merkitsevä negatiivinen korrelaatio LTL-testitulokseen oli elopainolla (p=0,000) ja kävelytestin arvosanalla (p=0,000). Hybridillä oli erittäin merkitsevä vaikutus lintujen elopainoon (p=0,000). Hybridillä ei ollut merkitsevää vaikutusta lintujen videoista mitattuun aktiivisuuteen. Lintujen aktiivisuus korreloi negatiivisesti tarkkailupäivän ja kävelytestin arvosanan kanssa. Lintujen suurempi rintalihasten paino (p=0,001), elopaino (p=0,008) ja rintalihassaanto (p=0,008) huononsivat lintujen kävelytestin arvosanaa.
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(2014)Growing medium and its properties are an important factor affecting plant growth. One can improve the properties of growing medium with different amendments such as lime, nutrients and wetting agents depending on the requirements of the plant. The objective of this study was to examine a soil amendment called BRT EverGreen powder and its effect on white sphagnum peat and on plant growth. The powder has been created by a Finnish company Biomass Refine Technologies BRT ltd Oy. The powder is synthetically made of ureaformaldehyderesin and phosphoric acid includes added water retention lowering surfactants. In cultivation the goal by using BRT powder is to improve water retention and wetting of the growing medium and increase plant available nutrients. This study consisted of three experiments with three different plants or plant mixtures: Lactuca sativa L. ‘Grand Rapids’, Ligularia × hessei and a mixture of lawn (Festuca rubra L., Poa pratensis L. and Agrostis capillaris L.). These plants were expected to benefit from improved water retention of the growing medium. During the experiments the effect of BRT powder on the properties of white sphagnum peat and the speed, amount and quality of plant growth was measured. All plants got the same amount of water by irrigation. Mild nutrient solution was given to Lactuca and Ligularia with irrigation water three times during the experiments and no fertilizers were applied to the grass. The water retention ability of white sphagnum peat was not improved in plantless short term experiments by adding BRT powder. However the results given by direct moisture measurements from the growing medium implied that the BRT powder increased slightly the moisture content of the medium compared to pure peat. From the three different plant types tested only grass grew faster with BRT though the quality wasn’t as good as in pure peat. The improvement in growth was probably due to nutrients in BRT powder because no nutrients were applied to the grass unlike to Lactuca and Ligularia. There were no differences in the growth or quality of Lactuca. Ligularia did not grow as well with powder as in pure peat. Adding lime decreased the negative effect of BRT powder so the very low pH of the powder presumably hampered growth of Ligularia. BRT powder affects the growth of different plants in different ways. This makes its use in cultivation difficult because one does not know what the effect will be. The use of BRT is not recommendable in container cultivation with Lactuca or Ligularia when using peat. BRT powder can increase the growth of grass if additional fertilization is not applied.
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(2014)The aim of this study was to investigate the effects of graded amounts of camelina oil on milk fatty acid composition in lactating cows fed diets based on a mixture of grass and red clover silages. The experiment was carried out at the University of Helsinki research farm in Viikki 30th January 2009 – 23th April 2009. Eight multiparous Finnish Ayrshire cows participated in this experiment and four of them were rumen fistulated. Experimental design used was 4 x 4 Latin square. Treatments consisted of concentrate supplements containing various levels of camelina oil (0%, 2%, 4% and 6% on air-dry basis). All concentrates contained camelina expeller (20% on air-dry basis). The cows were offered daily 12 kg of experimental concentrate and silage ad libitum. The experimental periods lasted for 21 days. The first 14 days were adaptation period and the last 7 days formed sampling period. Increase of camelina oil level in the diet linearly decreased forage and whole diet dry matter intake (P?0,002). Camelina oil level did not affect organic matter, NDF and nitrogen whole-tract digestibility (P>0,10). Milk yield and milk protein- and lactose content linearly decreased when camelina oil level increased (P<0,001). Camelina oil level did not affect milk fat yield (P>0,100). Milk fat content (P=0,014) linearly increased and protein content (P=0,032) and urea content (P<0,001) linearly decreased when camelina oil level increased. Camelina oil level did not affect milk lactose content (P>0,100). Increase of camelina oil level linearly worsened milk taste panel scores (P=0,018). Camelina oil level did not affect plasma metabolite concentrations except that of total free fatty acids that linearly increased with camelina oil supplementation (P<0,001). Effects of camelina oil supplementation on rumen pH and rumen fermentation pattern were numerically negligible. Increase of camelina oil level linearly decreased the concentration of saturated fatty acids in milk fat (P<0,001) and linearly increased those of monounsaturated (P<0,001) and polyunsaturated (P<0,002) fatty acids. Increase of camelina oil level linearly decreased the content of mammary de novo synthesised short- and medium-chain 6-14-carbon fatty acid in milk fat (P?0,028). Camelina oil level had no effect on alphalinolenic acid content in milk fat (P>0.100). Increase of camelina oil level linearly increased trans fatty acids and CLA content in milk fat (P?0,008). Camelina oil supplementation did not affect neither the milk fat content of the final product of ruminal biohydrogenation of 18-carbon unsaturates stearic acid nor that of oleic acid (P>0,10). This is possibly due to biohydrogenation not proceeding to the end, ceasing to the last step before stearic acid. Milk fat trans-11 18:1 and cis-9, trans-11 CLA contents linearly increased at remarkably high levels when camelina oil level in the diet increased (P?0,008). This is possibly due to incomplete ruminal biohydrogenation of 18-carbon unsaturated fatty acids. Camelina oil supplement improved milk fat composition by decreasing saturated and increasing the trans-11 18:1 and cis-9,trans-11 CLA content in milk. However, giving camelina oil at high levels decreased silage and whole diet dry matter intake and affected milk production negatively.
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(2015)Porkkana on sekä tuotannollisesti että kotitalouksien kulutuksen kannalta merkittävin avomaanvihannes Suomessa. Porkkanan merkittävin tuholainen on porkkanakemppi (Trioza apicalis), jonka havaittiin vuonna 2009 toimivan myös porkkanaa infektoivan Candidatus Liberibacter solanacearum (CLs) -bakteerin levittäjänä. Merkittävimmät porkkananviljelyalueet sijaitsevat Lounais-Suomessa, joka on myös erityisen kemppiongelmaista aluetta. Alueella on havaittu myös runsaasti CLs-bakteerin aiheuttamaa voimakkaan punaista värittymisoiretta porkkanan lehdissä. Tämän tutkimuksen tavoitteena oli kartoittaa CLs-bakteeritaudin esiintyvyys Lounais-Suomen porkkanaviljelmillä ja määrittää CLs-positiivisten porkkanoiden osuudet eri oireryhmissä: oireettomat, kempinsyömät ja kempinsyömät värittymisoireiset. Tutkimuksen aikana pyrittiin kehittämään edullinen ja toimintavarma PCR-menetelmä CLs-bakteerin laajamittaiseen diagnostiikkaan soveltuvaksi. Lisäksi tutkimuksessa haluttiin tarkastella porkkanakemppien määrien vaihtelua lähekkäisillä porkkanapelloilla Kanta-Hämeessä. Tämän tutkielman CLs-kartoitus oli osa Maa -ja metsätalousministeriön rahoittamaa hanketta kartoittaa taudin levinneisyys Suomessa. Elintarviketurvallisuusviraston näytteeksi keräämät porkkanakasvit käsiteltiin Helsingin yliopiston kasvipatologian laboratoriossa, jossa näytteistä eristettiin DNA:ta ja tehtiin PCR-testit CLs-bakteerin toteamiseksi. Geelissä elektroforeesilla erotellut PCR-tuotteet kuvattiin UV-valossa ja CLs-positiiviset todennettiin vertaamalla PCR-tuotetta molekyylipainostandardiin ja positiiviseen kontrolliin. Toimintavarmimmaksi PCR-menetelmäksi osoittautui kuumassa lämpötilassa toimiva entsyymi ja lyhyt PCR-ohjelma. Kartoitustulokset osoittivat, että tautia esiintyy Lounais-Suomessa runsaasti, sillä suurin osa värittymisoireisista porkkanoista todettiin CLs-positiivisiksi. Sekä taudin että kemppien määrä osoittautui olevan Lounais-Suomessa suurempi kuin vertailualueilla Itä-Suomessa ja Pohjanmaalla. Kemppien määrissä läheisillä pelloilla havaittiin suurta vaihtelevuutta. Tällä hetkellä ainoa keino torjua CLs-bakteeritautia on keskittyä kemppien torjuntaan. Kemppipopulaatiot ovat kuitenkin tulleet viime vuosina kestävämmiksi yleisesti käytetyille torjunta-aineille, mikä luo uusia leviämismahdollisuuksia myös CLs-bakteerille.
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(2020)'Candidatus Liberibacter solanacearum' (CLso) is a frequent bacterium in carrot in southern and western Finland but is also occurring in South Savonia. The bacterium is unculturable, lives as a parasite and multiplies in the phloem vessels and is transmitted by the carrot psyllid Trioza apicalis. In Spain, France and Finland the bacterium has also been found in parsnip. The aim of this thesis was to study the occurrence and genetic variation of this bacterium in carrot and parsnip in Satakunda, Southwest Finland and South Savonia from such parsnip and carrot fields where psyllids and discolouration symptoms in foliage have been detected. All the samples were collected based on foliar discolouration symptoms. Four wild plants from the family Polygonaceae were collected from one carrot field and one parsnip field in Satakunda. These plants showed similar foliar discolouration as the carrots. Other criteria for collecting the carrot samples was based on occurrence of psyllids and leaf curling. Samples of parsnips were collected from vegetable farms, where parsnips were grown nearby the carrot fields and where psyllids had been detected. The samples were analysed by real-time PCR with primer combination specific to CLso. Those samples that had high amounts of bacteria were chosen for sequencing and detection of haplotype. CLso was detected in 62,9 % of the carrot samples, in 90,8 % of the parsnip foliage samples and in 76,9 % of the parsnip root samples and in all the samples of symptomatic wild plants. Based on the ftsZ gene sequence, a new haplotype of CLso, named haplotype H, was identified in three of the parsnip samples from Satakunda and in two samples of pale persicaria (Persicaria lapathifolia (L.) Gray). This is the ninth haplotype of CLso identified.
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(2015)Efficient utilization of renewable plant and crop based biomass is one of the main areas of study in industrial biotechnology. Roughly 20-30 % of all plant biomass consists of hemicellulose, a polymer composed of six carbon (hexose) and five carbon (pentose) sugars. This proves a challenge in utilizing all available plant biomass efficiently, since many micro-organisms, which for instance readily ferment glucose (a hexose) into ethanol, will not do so for pentose sugars. Alternative pathways for utilization of pentose sugars are being looked for. Characterization of the Caulobacter crescentus D-xylonate dehydratase (Cc XyDHT) was the aim of this study. Cc XyDHT belongs to the ILVD/EDD protein family, whose members incorporate an iron-sulfur (FeS) cluster into their protein structure coordinated by two to four cysteine amino acids. Removal of the cysteine ligands should disrupt the incorporation of the FeS cluster, and thus presumably the activity of the enzyme. Three cysteines in Cc XyDHT which could act as ligands for the FeS cluster had previously been identified by sequence alignment among the ILVD/EDD family. Accordingly, four single cysteine-to-serine mutants of the Cc XyDHT as expression plasmid constructs were designed, with a non-conserved cysteine residue selected as a control. The wild type and mutated Cc XyDHTs were produced in Escherichia coli and purified with affinity chromatography using Strep-tag. SDS-page and Western blotting with an anti-Strep-tag antibody were used to confirm that the expressed proteins were Cc XyDHTs. The mutations’ effects on the protein fold and to the presence of the FeS cluster were investigated with UV and circular dichroism spectroscopy. Cc XyDHT catalyzes the conversion of D-xylonate into 2-keto-3-deoxy-xylonate. A colorimetric assay using thiobarbituric acid (TBA) as the reactant was used to measure enzymatic activity. The pH and temperature optima, substrate specificity, and enzyme kinetics of the wild type Cc XyDHT were determined. For the two best substrates, kcat/Km = 1220 mM/min for D-xylonate and kcat/Km = 1160 mM/min for D-gluconate were found. All three conserved mutations were found to reduce enzymatic activity more than 99 % with these substrates. Depending on which cysteine was disrupted, differences in the kinetic constants between D-xylonate and D-gluconate were found. The non-conserved mutation reduced activity by approx. 40 %. The spectroscopic results indicate that the three conserved mutants lacked the FeS cluster, while the non-conserved mutant still incorporated it. It can be concluded that the three conserved cysteines are involved in coordinating the FeS cluster, which itself plays an important role in the catalytic activity of Cc XyDHT. These findings should be helpful for follow-up studies in biotechnological application of pentose sugars acids and their derivatives.
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(2015)Yeasts have huge agricultural, medical and economic importance, and consequently, their isolation and identification are needed for more potential microbe resources. Studies of plant-microbe interaction have revealed many molecular mechanisms using mostly filamentous fungi, bacteria and viruses. However, our knowledge of yeast-plant interactions is lagging behind and there is a lack of yeasts known to interact with the model plant Arabidopsis. There were two major aims of this study: isolating and identifying the yeasts from wild growing Arabidopsis, as well as screening possible immunity modulation patterns of the strains against Arabidopsis. More than 70 yeast strains were isolated and identified belonging to 6 genera, suggesting the huge abundance of yeast diversity on plant surface. With the help of phylogenetic analysis of sequences from the internal transcription spacer (ITS) and D1/D2 region of 28S ribosomal DNA large subunit, one strain within the genus of Protomyces is proposed to be a novel species. Further carbon assimilation tests confirmed this, demonstrating differences of assimilation patterns between the new strain and all well described species in this genus. Another interesting finding was the possible pathogenicity of several yeast strains. Significant disease-like symptoms appeared on Arabidopsis five days after infiltration. Additionally, two strains synthesized auxin or related compounds in culture. Although more infections are necessary to confirm the pathogenicity, these have potential for development of new systems to study plant-yeast interactions with the genetic model plant Arabidopsis. The mechanism of yeast pathogenesis will provide new knowledge about plant defense and further assists plant breeding to produce crops with more durable resistance.
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(2015)The present work was based on the analysis of glyphosate concentrations in six soil layers after continuous multiple applications of herbicide products and various sampling times during the study period of 2010?2012, and aimed to contribute to a better recognition of the glyphosate persistence in clay soil. Two tillage methods (conventional tillage and no-till) were carried out in two replicates on the experimental field located in Jokioinen, South-Western Finland. This experiment was important for the identification of glyphosate amounts in soil profile and for planning a better field management in the future on the larger scale. Results of the study demonstrated that glyphosate and its metabolite AMPA remained on the field a year after the spraying of the herbicide. Calculated reference degradation rate constants and half-lives were proved to be in a range with literature review. While the impact of tillage methods on the glyphosate retention in soil was not possible to assess by the present study due to the quite sparse nature of the data, the residuals of glyphosate and AMPA at deep layers were almost non-detectable. Study clearly showed that accumulation of glyphosate happens mostly in topsoil, and the leaching potential into deeper layers was quite limited.
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(2016)Conifers are used for forest plantations and as landscape trees. Norway spruce is the main softwood species in Finland and can occasionally be observed in urban areas. However, root rots of conifer trees caused by Heterobasidion annosum leads to huge economic losses not only in Finland but also in other European countries. Due to the availability of complete genome sequence for both host and pathogen, in this study using Norway spruce and its root rot pathogen (Heterobasidion annosum) as an experimental model, the host-pathogen interaction was investigated. Conifer trees have established a variety of defense mechanisms to repel microbial infections, including constitutive barriers, accumulation of antimicrobial chemicals, activation of signaling pathways and induction of defense-related compounds resulted from an intra-organismic response including cell death. In the conifer pathosystem, cell death associated necrotic browning reactions promote tissue colonization by necrotrophic pathogens such as Heterobasidion annosum. By contrast, in crop plants, cell death associated hypersensitive response (HR) is known to inhibit invasive growth of biotrophic pathogens. However, not much is known about the chemical and molecular characteristics of necrotic cell death responses observed in different developmental stages of conifers from seedlings to mature trees. In addition, the term reaction zone is often used to describe responses of tree tissues bordering the heartwood to pathogenic infections, but nothing is known on whether there are any similarities between the necrosis response and reaction zone. To investigate this, Norway spruce at different developmental stages (seedlings, young trees and mature trees) were challenged with Heterobasidion parviporum. Six major indicators were assayed: necrosis lesions, cell death, pH, reaction zone, reactive oxygen species (ROS) and expressions of defense-related genes (Per1, Per2, LAC, JAZ1, OPR, and STS2). Increased transcript levels of the following genes Per1, Per2, LAC and JAZ1 were documented in seedlings but higher expression of Per2 and LAC was recorded in mature trees. Results revealed that all infected tissues were strongly necrotic or had increased lesion size. This is accompanied by increasing pH units up to 6.0 similar to levels documented in the reaction zone. Furthermore, ROS-generating peroxidase activity increased in infected tissues compared to the control. All these changes were found to be similar to observations in the reaction zone of woody trees. However, cell death was only measured in seedling roots and the method needs to be optimized for woody tissues. Further tests are therefore required for the clarification of relationship between necrotic cell death in seedling plants and reaction zone responses in mature woody tissues.
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(2010)Protein-energy malnutrition and mineral deficiencies are two of the three forms of nutritional deficiencies that affect most developing countries due to inadequate access to food and diets based on a sole crop. Common bean (Phaseolus vulgaris L.) is the staple crop of Nicaragua and it has the potential to improve the nutritional status of the poorest group of the nation. Its high content of both protein and nonhaem iron provides many nutrients, but inhibitors also may prevent absorption of iron and zinc by the human consumer. A proper production chain must be followed to ensure the best grain quality for the consumer. To achieve food security, both production and high nutritional content must be maintained. Four nationally important accessions of common bean, with different harvesting dates, were selected to be submitted to two treatments: to evaluate the impact of storage conditions on the end quality of the grain. The duration of the study was six months with sampling every six weeks, and the two treatments were controlled one stored at 40°C and 75 RH %, and the other was stored in in-situ conditions. Proximate and mineral composition was evaluated as well as tannin, phytate and bioavailability. Significant differences among different accessions were found, being the most significant in protein, Fe and Zn content, tannins and phytate. Protein values ranged from 21-23%. Iron content was 61-81 mg/kg but only 3-4% was bioavailable. Zinc content was 21-25 mg/kg and 10-12% was bioavailable. The concentration of phytate ranged from 8.6-9.6 mg/g while tannin values ranged within 37.7-43.8 mg/g. Storage at high temperatures was demonstrated to have an impact on certain nutritional compounds and proved detrimental to final grain quality. Soluble sugar content and tannin content decreased after six months in both storage conditions, IDF decreased in the in-situ and SDF in the stress. The iron content and bioavailability in INTA Biofortificado were not as outstanding as expected, so experiments should be conducted to compare its iron uptake and delivery with other cultivars.
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(2015)Need for higher productivity motivates and forces farmers to adapt new technological solutions. Global Navigation Satellite Systems (GNSS) have enabled several solutions to increase efficiency specially in field operations in terms of assisted or automatic steering, yield monitoring and precision farming. Accuracy of raw GNSS-data is poor and not suitable for any field operation. Methods to minimize error caused by different sources are in conclusive role to adapt positioning solutions to agriculture and to field operations. Aim of this study was to compare different GNSS correction methods by means of static and dynamic measurements. Results of the measurements occurred that high precision is achievable. Ground Based Augmentation Systems (GBAS) were more precise (RTK base station, AgriVRS and Centerpoint RTX) than Space Based Augmentation Systems (SBAS) (Omnistar G2 and Egnos). RMS values in 8 hour static measurements were between 0.004 and 0.406 m. Autonomic positioning RMS value was 1.014 m. In dynamic measurements scale was from 1.610 m to 0.015 m. Correction methods performed better in relative positioning than in repeating same position in subsequent days. Automatic steering is possible with every correction method. When using paid license corrections accuracy rises. Accuracy should be chosen by need of the field work, for example seeding needs higher accuracy than broadcasting of fertilizer. Due to Northern location of Finland SBAS are not available everywhere. Correction sent from satellite can be blocked for example by tree line. Also radio signal is hard to utilise in data transfer due to scattered field structure. Finland has excellent cellular network. Corrections loaded via cellular to receiver were available in test sites most practically.
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(2020)The research of this thesis was focused on anaerobic digestion of cow manure mixed with different types of biowaste, especially those material that are available in Finland. The research was conducted by search, collection, and analysis of different data in literature. Topic of the thesis was predetermined by the Co-Creation Lab project of Helsinki Institute of Sustainability Science (HELSUS), which was seeking solution to achieve carbon neutral cow milk production. The solution was co-approached by three participants conducting thesis from technological, economical, and legislative points of view, in which I was responsible for writing mainly the technological part, and general findings in economic efficiency and legislative terms by the other two co-creators were also included in this thesis. The research was mainly related with the whole cycle of biogas production, including basics about anaerobic digestion (AD), applications of the biogas and digestate as a product and by-product of AD. Substrates for AD were researched with a focus to find the best combination of cow manure (CM) and biowaste in regard with methane yield outcome, especially a mixture of CM and silage waste that suits the cow farming situation in Finland. Methane yields for mono-digestion of various types of biowaste and co-digestion of CM with different biomass were collected and analyzed. Premises for biogas plant establishment were researched briefly, including facility composition, and consideration of feasibility and raw material availability. CM with grass containing 75% timothy and 25% meadow fescue grass at 70%:30% mixing ratio could be the best combination of CM: grass co-digestion, followed by 0.5:0.5 mixed CM and perennial ryegrass. Furthermore, CM mixed with food waste at 52:48% ratio could be the best combination among co-digestion of CM with biowaste other than grass, followed by CM and food waste mixed with 68%:32% ratio, and CM with oat straw mixed at 1:2 ratio could be a considerable combination of CM and crop waste.
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