Browsing by discipline "Växtproduktionsvetenskap"

Four different Bradyrhizobium sp. (lupin) inoculants were investigated in both greenhouse and field experiments to compare their effects on growth, yield and biological nitrogen fixation. Narrow-leafed and white lupin of the greenhouse experiment compared the strains test in different potting media in a controlled environment, while field experiment tested their performance in field conditions. The greenhouse experiment was conducted with 3 narrow-leafed lupin cultivars (Haags Blaue, Boruta and Sonet) and 1 white lupin cultivar (Ludic). Plants were grown in 3 different potting media (soil, 2 peat : 1 sand and 1 peat : 2 sand) with 5 Bradyrhizobium treatments (uninoculated control, commercial peat inoculant of HAMBI 3118 and liquid cultures of HAMBI 3115, HAMBI 3116 and HAMBI 3118). Plants were grown in a greenhouse unit with average day and night temperature of 22°C and 18°C. Plants were illuminated by using cool white fluorescent tubes maintaining 18 hours day and 6 hours night. In the greenhouse experiment, inoculation significantly increased shoot (117.1-141.9%), root (45.8-64.4%) and nodule (237.0-266.6%) dry weight, plant height (38.3-46%), nodule number (620-659%) and chlorophyll content (29.0-38.5%) over the values found in uninoculated controls. Soil type or potting medium also influenced lupin growth and yield, with better results observed in soil, poorer in 2 peat : 1 sand and poorest in 1 peat : 2 sand. Best performaces were obtaind by inoculating with HAMBI 3115 strain in soil. Uninoculated plants and even inoculated plants grown in peat-sand potting medium, showed relatively poor results, which was more obvious in high-yielding cultivars, Boruta and Ludic, than in low-yielding cultivars, Haags Blaue and Sonet. Inoculation treatments also showed significantly higher shoot (3.15-3.39% N) and root (1.96-2.54% N) nitrogen content. Biological nitrogen fixation rate, measured by the nitrogen difference method, ranged between 87.9 and 90.8% depending on both bacterial strain and host cultivar. The field experiment showed significant increases in shoot (14.4-47.9%), root (11.9-29.1%) and seed (13.8-68.6%) dry weight, plant height (3.6-10.7%), pod plant-1 (10.7-50.6%) and chlorophyll content (5.7-20.7%) following inoculation of the three narrow-leafed lupin cultivars. Uninoculated plants grown in soil in the greenhouse experiment and in the field experiment both produced some nodules, which showed the evidence of presence of indigenous nodule-forming and nitrogen-fixing bacteria. Among the 3 liquid cultures, HAMBI 3115 performed best in terms of lupin growth, yield and biological nitrogen fixation in both greenhouse and field experiments. The performance of the peat-based commercial inoculant of HAMBI 3118 strain exceeded all other inoculants in the field experiment but not in the greenhouse experiment, showing the importance of the carrier. The results indicated that lupin growth and yield are strongly affected by Bradyrhizobium inoculation and soil characteristics. Selection of a suitable Bradyrhizobium strain for inoculation and growing cultivars according to their soil preferences can maximize lupin yield. The suitability of HAMI 3115 for making peatbased inoculants should be tested.

Research on phosphorus (P) fertilization of white cabbage has been limited even though white cabbage is an important field vegetable in Finland. The quantities of phosphorus recommended in Finland when cultivating white cabbage are relatively large and excessive fertilization increases the risk of runoff to water systems. Scientific research is needed to determine fertilization levels that ensure good yields while reducing risks to the environment. The effects of P fertilization on yield, phosphorus uptake and phosphorus balance of white cabbage were studied in two soils of different P status in Piikkiö, Finland. The experiment on soil with loamy sand texture and high P status consisted of four fertilization treatments between 0-32 kg P ha-1 while the experiment on clay parcel with relatively low P status consisted of five treatments between 0-100 kg P ha-1, including a starter treatment. Yield, plant P content and P uptake were unaffected by the treatments. Yield was 83-87 t ha-1 on high P soil and 66-69 t ha-1 on low P soil. In high P soil, uptake of P by the plants was 50 kg ha-1 and field P balance was negative in all treatments. In low P soil, uptake was 40-45 kg ha-1 and P balance was positive starting from treatment level 30 kg P ha-1. It is likely that P fertilization levels based on the maximum limits set by the national Agri-environmental Programme are unnecessarily high for white cabbage. A level of fertilization equaling the P uptake of the yield can be recommended.

The Rosaceae family accounts for more than 90% of the total fresh fruit production in Finland and for more than 25% worldwide in 2013. Thus, improving the yield potential of Rosaceae species works in favor of economic growth and food security. To achieve that, expanding the knowledge on Rosaceae species is required. Fragaria vesca (F. vesca), particularly the everbearing F. vesca semperflorens accession ‘Hawaii-4’ (H4), provides several features that makes it formidable as a model organism for the study of physiological processes in Rosaceae species, where the CENTRORADIALIS/TERMINALFLOWER 1/SELF-PRUNING (CETS) genes play a remarkable role. In this Thesis, I have studied the expression patterns and functions of the CETS genes by performing gene expression analysis, generation of H4 transgenic lines and observation on H4 plants (both transgenic and wild type) grown under different sets of conditions. My results confirmed the expression patterns and functions previously reported for F.vesca TERMINAL FLOWER1 and F.vesca FLOWERING LOCUS T1. I showed that F.vesca CENTRORADIALIS-LIKE2 is a floral repressor and demonstrated that F.vesca FLOWERING LOCUS T3 is a flowering promoter. Additionally, our data suggest that F.vesca MOTHER OF FT is directly related with stolon formation and that F.vesca CENTRORADIALIS-LIKE1 is most likely a floral repressor. This new information could be used in the future to improve the efficiency of Rosaceae crops farming by adapting flowering and vegetative responses and also for breeding more productive Rosaceae crops.

Gibberella zeae (Schwein.) Petch and its asexual form Fusarium graminearum Schwabe is a pathogen of oat, barley, wheat and maize that causes Fusarium head blight in cereals. F. graminearum produces mycotoxins that contaminate yields in humid and warm weather conditions. The pathogen spreads most effectively during its sexual stage. F. graminearum has become more common as a result of climate change and as reduced tillage has become more preferred in cultivation. This research was a part the Fustox Projet in Natural Resources Institute in Jokioinen research station. Develelopment of G.zeae in crop residues was studied. Crop residue samples were collected from no-till and tilled field plots in existing field trials in spring 2013. Occurrence of F. graminearum was studied in barley and oat from no-till and tilled field plots and in oat from a field trial of four tillage methods during the growing season 2013. Efficiency of two fungicides (DMI and DMI+QoI fungicides) were studied in two oat cultivars, barley and spring wheat in MTT Ylistaro research station. Yield samples were also analysed for deoxynivalenol (DON) contamination. Occurrence of the pathogen was determined by incubating straw pieces and kernels in laboratory conditions. Fusarium species were identified by their colony and spore morphology and colour. Contrary to expectations the pathogen was somewhat more prevalent in tilled plots than in reduced tillage. This may be due to greater microbe activity that is capable of decomposing or inhibiting the pathogen in fields with reduced tillage. In this study stem-bases were more infected by the pathogen in reduced tillage. Fungicide treatments were effective in reducing the occurrence of F. graminearum in the field and DON contamination in yield. There were no significant differences between fungicides. The most effective methods of controlling G. zeae and F. graminearum is selection resistant cultivars for cultivation. Careful selection of soil tillage method can also aid in controlling the pathogen.

The concept of ecological management can be seen tackling the relationship of agriculture and environment, not only from the perspective of limiting the negative effects of farming practices, but also promoting positive actions. This notion of managing and maintaining, rather than leaving alone, is currently in the core of biodiversity promotion in agricultural landscapes in Europe. The focus of this thesis are the perceptions Finnish agri-environmental actors have regarding ecological management innovation stemming from the grassroots. In this thesis I assess how i) Finnish agri-environmental actors perceive grassroots innovation, ii) weigh its barriers and enabling factors, as well as iii) envision further needs regarding these innovations. The study is based on a mixed-methods approach using both qualitative and quantitative data; a questionnaire and two focus group discussions conducted during a two-day seminar “Managing Nature - working together” 29.11.-30.11.2016 in Turku. The study was conducted in co-operation with the Finnish Environment Institute (SYKE), University of Helsinki Faculty of Agriculture and Forestry and a Horizon2020 project HNV-Link. I approached the research questions using an iterative approach, and my analysis is guided by Grounded Theory in constant comparative analysis and generating theory. The results indicate that Finnish agricultural actors acknowledge the heterogeneous nature of grassroots actors in agricultural areas. However, several common attributes are linked to innovation stemming from the grassroots such as practical, economic and local. Currently bureaucracy, lack of cooperation and the changes and challenges in the socio-cultural environment of grassroots hinder ecological management grassroots innovation. Finnish agri-environmental actors acknowledge that the challenges biodiversity in agricultural areas face, are of such magnitude that the need is rather to expand, not narrow down the actor-base for innovation.

Research has shown that the temperature sum or the average of daily mean temperature, together with the photoperiod and genotype, determines the progress of faba bean towards flowering. However, other environmental factors such as photosynthetically active radiation (PAR) and humidity conditions (Sielianinow´s hydrothermal index K) have been found to have a secondary effect on the progress towards flowering. The timing of the development stages of faba bean growth is of great importance for its regional adaptation and the profitability of its cultivation in new and changing environments. Progress towards flowering and the environmental conditions during flowering strongly affect the yield of different cultivars. Identifying the environmental factors affecting initiation and induction of flowering enables the breeding of new, more sustainable cultivars of faba bean. Negative effects of stress factors to yield can be avoided using earlier flowering cultivars in cultivation. Changing climatic conditions are leading to long periods of dry and warm weather in Finland, the effect of which is particularly pronounced during flowering. The stage of flowering has been found to be the most sensitive stage of the development of faba bean, during which the amount and quality of the crop yield is determined. The aim of this study was to validate the functionality and suitability of the improved model for predicting the progress towards flowering in field conditions. The significance of PAR, K-index, the temperature mean and photoperiod was tested in the model predicting flowering, were the observations of flowering were from two growing seasons, 2016 and 2017, using 20 cultivars of faba bean. The impacts of these environmental factors on the model were also tested with broader observation data from six growing seasons: 2009 to 2012 together with 2016 to 2017. The best model was obtained with the combination of all parameters with the highest value of R2 (R2v2=0.999, R6v2= 0.964). In the model containing only photoperiod and temperature mean, values for R2 were too low. The parameters of PAR and K-index significantly (R2>0.90) increased the value of R2. When tested alone, PAR explained over 90 % of the flowering. However, the photoperiod and the temperature mean played an important role in the development and flowering and they are known to be critical for the induction of flowering of certain cultivars. With six years of observations, the coefficients for temperature mean in the model were negligible (p >0.05). Significant parameters were photoperiod, K-index and PAR. The cultivar ‘Kontu’ started to flower earlier than other cultivars and it had greatest variation between predicted and observed value in the model. Therefore, adding it to the function as extra parameter was important to bring its values closer to regression line and to improve the overall value of R2. The conditions in greenhouse are usually adjusted to the optimum for the plant, when normally varying humidity conditions are ignored. Effects of photoperiod and PAR on the development of faba bean cannot be distinguished in controlled light conditions. Field experiments lasting several growing seasons are required to be able to distinguish their effects. The model for predicting the progress towards flowering could be used to identify different qualities of various cultivars. The parameters in this model worked well in prediction of flower induction of faba bean in Finland.

Hiilineutraalin yhteiskuntamme tavoite on sitoa hiiltä yhtä paljon kuin tuotamme hiilidioksidia. Samaan aikaan maatalouden tulisi tuottaa ruokaa kasvavalle ihmisväestölle maapallon kantokyvyn rajoissa ja siinä on avainasemassa viljavuudeltaan heikentyneiden maiden parantaminen. Nurmet toimivat tärkeänä ekosysteemipalveluna sitoen hiiltä ja typpeä maaperään sekä parantaen maan kasvukuntoa. Biohiiltä tutkitaan potentiaalisena maanparannusaineena peltoviljelyssä sekä ilmastonmuutosta ehkäisevänä maaperän hiilensitojana. Se on kuivatislauksessa eli pyrolyysissä syntyvä orgaaninen, kiinteä lopputuote, joka peltomaahan levitettynä pysyy maassa satoja tai tuhansia vuosia. Ei kuitenkaan vielä tiedetä tarkkaan kuinka biohiili vaikuttaa peltomaassa, sillä pitkäaikaiskokeita biohiilen pitkän ajan jälkivaikutuksista ei ole toistaiseksi julkaistu. Tutkimuksen tavoitteena oli selvittää neljä ja viisi vuotta sitten levitetyn biohiilen sekä biohiilen ja lannoitekäsittelyiden yhdysvaikutusta maaperän kosteus-, hiili- ja ravinnepitoisuuksiin Etelä-Suomen olosuhteissa. Lisäksi tutkittiin niiden vaikutusta puna-apila-timoteinurmen kasvilajisuhteisiin ja sadontuottokykyyn. Biohiilikoepelto sijaitsi Helsingin yliopiston opetus- ja tutkimustilalla Helsingissä, Viikissä. Osaruutukoe oli perustettu keväällä 2010, jolloin kuusi-mäntyhakkeesta kuivatislattu biohiili oli levitetty maahan. Pääruudut olivat biohiilitaso 0 t/ha, 5 t/ha ja 10 t/ha. Osaruudut olivat lannoitustaso osuutena suositusten mukaisesta lannoitusmäärästä. Lannoitteena käytettiin puutarhan PK 3-5-20. Kasvukaudella 2014 kalium oli porrastettu tasolle 100 %, 75 % ja 50 %. Keväällä 2015 kaikki ravinteet annettiin kolmena eri tasona 100 %, 65 % ja 30 %. Neljä ja viisi vuotta sitten levitetty biohiili nosti maaperän hiilipitoisuutta ja laski johtolukua. Joinakin mittauskertoina biohiili pidätti kosteutta pintamaassa kuivana aikana ja tasasi maaperän kosteusolosuhteita. Biohiilellä ei ollut vaikutuksia nurmen satoon. Myöskään biohiilellä ja lannoitekäsittelyillä ei ollut yhdysvaikutusta satoon. Suurin lannoitekäsittely nosti nurmen satoa kasvukaudella 2015. Suositeltavaa on edelleen tutkia biohiilen pitkäaikaisvaikutuksia peltomaahan ja sadontuottoon, sillä vanhasta, monia vuosia sitten levitetystä biohiilestä ei ole julkaistuja tutkimuksia. Biohiiltä on oletettavasti turvallista käyttää pohjoisissa olosuhteissa hiilensidontaan torjumaan ilmastonmuutosta.

Ilmastonmuutos uhkaa maataloussysteemejämme muuttuvan sään, ja veden kierron muodossa aiheuttaen kuivuuden ja tulvien yleistymistä. Samalla globaalin väkiluvun ennustetaan kasvavan huomattavasti, vaatien maataloudelta yhä suurempaa tuottavuutta kasvattamatta kuitenkaan hiilidioksidipäästöjä. Biohiili on pyrolysoitua eloperäistä ainesta, joka on erittäin vastustuskykyistä kemiallista- ja mikrobiaalista hajotusta vastaan ja se voi säilyä maassa sadasta vuodesta tuhansiin vuosiin. Biohiilen fysiokemiallisilla ominaisuuksilla on potentiaalia parantaa maan ominaisuuksia ja kasvattaa satotasoja samalla hidastaen ilmastonmuutoksen etenemistä. Biohiilten tuotannosta, ominaisuuksista ja niiden vaikutuksesta maan ominaisuuksiin ei kuitenkaan ole vielä tarpeeksi ja harvat tutkimukset ovat pitkäkestoisia. Tämä kenttäkoe suoritettiin Etelä-Suomessa, Helsingissä. Tutkimuskenttä oli viljavaa hiuesavea, jonka pH oli 6,6. Tässä kenttäkokeessa tarkasteltiin 6 vuotta sitten levitetyn kolmeen biohiilitason, 0 tha-1, 5 tha-1 ja 10 tha-1, vaikutusta maan ja herneen ominaisuuksiin. Maan hiilipitoisuus ja C/N-suhde olivat merkitsevästi kontrolliruutujen tasoa korkeammalla (p<0.05) biohiilikäsittelyn vaikutuksesta. Maan B- ja Mn-tasot olivat myös kohonneet, mutta vain suuntaa-antavalla merkitsevyydellä (p<0,1). Biohiili kohotti maan kosteutta merkitsevästi (SM) 18－30 cm syvyydessä käytettäessä 10 tha-1 biohiilitasoa. Tämä käsittely kohotti kosteutta myös 30－58 cm syvyydessä ja vedenkyllästämän maan vedenjohtavuutta (KSat), mutta vain suuntaa-antavalla merkitsevyydellä. Biohiili ei kuitenkaan vaikuttanut merkitsevästi maan fysikaalisiin parametreihin. Vuoden 2016 keväällä ruuduille levitettiin kolme lannoitustasoa: 30, 65 ja 100 % suositustasosta. Lannoite vaikutti merkitsevästi maan johtolukuun (EC), pH:hon, P-, K-, ja Ca-pitoisuuksiin sekä nosti lehtialaindeksiä (LAI) ja maanpäällisen biomassan (AGB) määrää, palko per kasvi (SPK) ja kasvien C/N-suhdetta suuntaa- antavalla merkitsevyydellä. Biohiilen ja lannoitteen yhteisvaikutus vaikutti merkitsevästi LAI ja suuntaa-antavalla merkitsevyydellä EC, AGB, palkoa per kasvi (PPK), satoindeksiin (HI) kasvien C/N-suhteeseen ja satotasoon.

Caraway (Carum carvi L.) is a spice, which belongs to Apiaceae-family. In 2019 25% of the worlds caraway crop was produced in Finland. 99% of it was exported. Caraway is an important cultivated plant in Finland, and broader knowledge of its crop formation is important. As a flowering plant, the sufficient gain of boron is especially vital for caraway. The aim of this study was to study the effect of foliar micronutrient fertilizers, and especially the effect of boron, to crop formation of caraway. The study was conducted as a field experiment in Lantmännen Agro experimental farm in Hauho. The experiment was carried out as a completely randomized block design, with four replicates. The experiment included seven different foliar fertilization treatments. The amount of embels, series and lateral shoots and crop potential were counted, seed and oil crop was determined from the samples, gathered from the plots, Seed samples were sent to oil analysis. In the study above normal crop were achieved with each foliar fertilization treatment, also the control. The soil of the plot was so nutrint-rich that lack of nutrients never existed. Only on statistically significant difference was obtained. It was between two foliar fertilizer treatments when counting the amount of series in an embel. The difference was propably an effect of another factor than the treatments, though. Foliar micronutrient fertilizatin might not be cost-effective farming procedure if soil is already nutrient-rich. Foliar fertilizers may be a good solution in certain situations to back up the nutrient deficit, but they are not a replacement for granular fertilizers.

The polyketide synthases (PKSs) are a large group of enzymes that catalyze the decarboxylative condensation of malonyl-CoA with various CoA thioesters, in order to biosynthesize different plant secondary metabolites. Anther specific chalcone synthase like (ASCL) enzymes are a novel group of plant type III polyketide synthase involved in the biosynthesis of sporopollenin, which is the stable biopolymer present in the exine layer of pollen walls. A gene encoding polyketide synthase, GhPKS8, was isolated from Gerbera hybrida from RNA sequencing data using gene specific primers. The structure, expression pattern and enzymatic activity of the corresponding enzyme were analyzed. The expression studies revealed that the GhPKS8 transcript is expressed at an early phase of anther development. Sequence analysis showed that the gerbera GhPKS8 gene displayed a high level (79%) of similarity to AtPKSB, the ASCL gene of Arabidopsis thaliana and all the important residues were seen to be conserved in the deduced amino acid sequence of GhPKS8. Additionally, the catalytic properties showed that the enzyme accepts medium chain starter as a substrate. The sequence homology, expression studies together with enzymatic assays revealed that the gerbera GhPKS8 may be an ASCL, involved in the development of anther. The putative role of GhPKS8 in anther exine development is discussed.