Browsing by study line "Växtproduktionsvetenskap"

Long-term, one-sided cultivation of crops has become more common in farming systems in recent decades, but at the same time, it has had negative impacts on soil structure, soil carbon reserves and the biodiversity of farming systems. Pea (Pisum sativum L.) is a legume that can be used to diversify crop rotations and improve protein self-sufficiency. Pea can symbiotically fix nitrogen from the atmosphere with the help of nitrogen-fixing Rhizobium bacteria living in its root nodules, and convert it into usable forms for plants, thus reducing the need to use industrial fertilizers. The following crop may also benefit from the organic nitrogen derived from the pea crop residues and pea’s ability to reduce pest pressure on cereals. The aim of this study was to study the pre-crop effects of pea on the formation of dry matter and nitrogen yields of oat (Avena sativa L.) and rapeseed (Brassica napus L.). The study was conducted as a field experiment in Haltiala with a completely randomized block design in four replicates. The study included four oat treatments (fertilized with 90 kg (N) ha-1 and either oat, pea or pea-rapeseed mixture as a pre-crop, and unfertilized oat with a pea-rapeseed mixture as a pre-crop) and two rapeseed treatments (pea as a pre-crop, unfertilized or fertilized with 90 kg (N) ha-1). In the study, the pre-crop did not affect the amount or formation of dry matter or nitrogen yield of oats and rapeseed. The effect of fertilization on the formation of dry matter and nitrogen yield was also small, but the maximum rates of dry matter accumulation and nitrogen uptake occurred earlier in fertilized than in non-fertilized treatments. Although pea as a pre-crop did not significantly affect the amount of dry matter and nitrogen yield of the crops during the growing season, it did not either affect them negatively compared to the monoculture oat because their yields were similar. Drought in June and July limited the release of nitrogen for plant use, which explains the effect of both the pre-crop and the fertilization treatment being rather small in the dry matter and nitrogen yield of oats and rapeseed. Pea very likely has a positive effect on the growth of the following crop, but further research is needed in different soil types and in more favorable weather conditions.

Turnip mosaic virus (TuMV) is an economically important plant RNA virus causing huge damage to wide range of arable and vegetable crops. A study was conducted in Nicotiana benthamiana to know if a TuMV mutant carrying a mutation in a thoroughly conserved WD-domain interacting motif and WG motif in HCPro protein can be mechanically transmitted to a healthy plant or not. HCPRoWD is a mutation in “AELPR” motif where glutamic acid and arginine are replaced by alanine. This mutated virus is here referred as TuMVWD. Similarly, in TuMVAG the tryptophan residue in the WG pair is changed to alanine and this mutated HCPro is called as TuMVAG. Four treatments, TuMVWT (positive control), Mock (negative control), TuMVWD and TuMVAG were made. Three plants per treatment were agroinfiltrated and five plants per treatment were used for mechanical inoculation experiment. Green fluorescent protein (GFP), a quantitative reporter of gene expression, was measured followed by qPCR for quantification of vRNA (viral RNA) accumulation. In agroinfiltrated plants, newly emerged leaves showed strong fluorescence in TuMVWT and TuMVAG by 14 dpi (days post inoculation), but TuMVWD showed poor GFP as compared to TuMVWT. During mechanical inoculation experiment, none of the treatments developed GFP in systemic leaves by six dpi but by 14 dpi GFP accumulation in the upper leaves of TuMVWT and TuMVAG was increased. TuMVWD was not used for 2nd mechanical experiment as it did not cause systemic infection during 1st mechanical inoculation experiment even by 14 dpi. Results from vRNA accumulation showed that mechanical transmission of virus was reduced with TuMVAG and not possible with TuMVWD. However, mutations had negative effect on vRNA accumulation.

Tiivistelmä - Referat – Abstract Acid sulfate soils are formed from sediment deposits containing sulfides, in which sulfur is present in the form of iron sulfides. In contact with air, the sulfur layer initiates a long-chain of biochemical and chemical reactions that increase the acidity of the soil and the amount of sulfate. Excessive acidity restricts plant development and growth. In acid soil, the aluminum solubility reaches a high level of toxicity for roots and slows down the microbiological degradation of organic matters, resulting in a reduction of nitrogen mineralization. Previous research results have shown that important liming has the potential to raise the pH of sulphate soils, and thereby reduce its acidity. With a high pH, the concentrations of ammonium and nitrate in the soil increase, facilitating nitrogen uptake and thereby also improving the efficiency of nitrogen uptake by plants. It has been speculated that, by increasing the nitrogen uptake efficiency and nitrogen utilization in plants, it will improve nitrogen use efficiency and so will reduce denitrification in sulphate soils and the resulting N2O emissions. However, to date, the studies on the effect of liming on plant nitrogen uptake (UPE) and utilization efficiency (UTE) and, consequently, on plant nitrogen utilization efficiency (NUE) have been minimal. The purpose of this study is to investigate how liming affects the yield formation and nitrogen uptake efficiency for barley (Hordeum vulgare L.) in unfertilized and fertilized acid sulfate soils. The field trial was established in Viikki, Helsinki, in the spring 2018. It followed split-plot design, in which the main plots were combinations of plant and nitrogen fertilization treatments (0 or 100 kg of nitrogen per hectare of fertilized barley (Kaarle) or unfertilized fallow) and lime treatments (0; 7,7; 15,3 t/ha) in four replicates. Liming raised the soil pH as expected and also increased nitrogen mineralization during the growing season, which is reflected in the nitrogen uptake. The effect of liming and fertilization on crop formation was small for barley biomass, yield component and grain yield. On the other hand, the liming effect reduced the nitrogen absorption efficiency and the nitrogen utilization efficiency and thereby the efficiency of nitrogen use. Fertilization also increased nitrogen uptake, but also decreased nitrogen utilization efficiency and nitrogen harvest index. The combined effect of liming and fertilization increased nitrogen mineralization. Liming treatment clearly increased nitrogen mineralization more in unfertilized soils than fertilized (there was no difference between liming levels). The drought in June and the low moisture limited the mobilization of nitrogen released from fertilizer in the soil, which would explain the effect of the nitrogen fertilizer treatment remaining relatively small. The drought also limited the development of the roots and thus the uptake of nitrogen and other nutrients. Lime treatment did not change NUE, UPE and UTE, but increased nitrogen mineralization and nitrogen uptake during the growing season, suggesting that under more favorable conditions the liming treatment could improve the efficiency and therefore improve the profitability and ecology of the barley crop. Further studies are needed as the results of studies performed elsewhere may not be valid under boreal conditions.

Maissi (Zea mays L.) on yksi maailman yleisimmistä viljelykasveista. Maissia hyödynnetään maailmanlaajuisesti esimerkiksi ihmisravinnoksi, bioenergian tuotannossa sekä nautakarjan karkearehussa. Rehuna käytetään tuleentunut jyväsato tai koko kasvusto tuleentumattoman korjattuna. Tuleentumattomasta maissisadosta saadaan yhdellä korjuukerralla suurempi kuiva-ainesato kuin muista yksivuotisista rehukasveista tai säilörehunurmista. Runsas yhdellä korjuukerralla korjattava sato on lisännyt viljelijöiden kiinnostusta rehumaissinviljelyä kohtaan. Maissi voidaan kylvää muovista tai muusta katekalvomateriaalista valmistetun katteen alle. Katekalvo luo kasvulle kasvihuonemaiset olosuhteet ja nopeuttaa itämistä ja kasvuunlähtöä. Maissinviljelyä on tutkittu Suomen olosuhteissa vain vähän, joten lisää tutkimusta maissin viljelymenetelmistä tarvitaan. Tämän maisteritutkielman tavoitteena oli selvittää, miten katekalvon käyttö vaikuttaa rehumaissisadon määrään ja laatuun. Kenttäkoe tehtiin Helsingissä kasvukaudella 2018. Koe oli osaruutukoe, jossa pääruututekijä oli kolme korjuuajankohtaa ja osaruututekijänä oli katekalvo (katekalvo, ei katekalvoa). Katekalvon käyttö lisäsi tuore- ja kuiva-ainesadon määrää verrattuna katekalvottomaan käsittelyyn. Katekalvon käyttö lisäsi rehumaissista saatua tuoresatoa keskimäärin 5 tn/ha ja kuiva-ainesatoa (KA-sato) 2,2 tn/ha. Laatuominaisuuksista katekalvon käyttö vaikutti ainoastaan tärkkelyspitoisuuteen. Katekalvon käyttö lisäsi tärkkelyspitoisuutta 40 g/kg KA verrattuna katekalvottomaan. Katekalvon käyttö vaikutti odotetusti sadon määrään mutta ei laatuun. Johtopäätöksenä voidaan todeta, että katekalvon käyttö mahdollistaa runsaamman tuore- ja KA-sadon kuin ilman katekalvoa. Tämän tutkimuksen perusteella katekalvoa voidaan käyttää Suomen olosuhteissa kasvattamaan sadon määrää.

Fertilization is one of the most significant factors that affects the yield formation of cereals. Decline of organic matter and soil degradation are consequences of excessive use of chemical fertilizers and other unsustainable ways of producing food. Industrial and urban by-products contain nutrient-rich biomass that can be utilized as fertilization for cereal crops. Organic recycled fertilizers also enhance the physical, chemical, and biological properties of soil and reduce agriculture’s dependence on external inputs. However, impacts of recycled fertilizers on yield components of barley is understudied topic in Finland. Research of the topic would provide important information of yield formation of cereals with recycled nutrients. The aim of this thesis was to study the effects of meat and bone meal, ammonium sulphate, biogas sludge and vinasse on yield components and yield of barley in comparison with unfertilized control and chemical fertilizer. Data for this study was collected from HYKERRYS2-project’s (2019-2020) field in Helsinki. Yield components were separated and calculated from barley plant samples. One of this thesis’ aim was to study how the different nutrient contents of fertilizers and properties of loamy soil affect to yield formation between the fertilization treatments. Yield components or yield from recycled fertilizers didn’t differ statistically significantly from chemical fertilizer either year. In 2019, ammonium sulphate significantly increased yield by 55 % in comparison to the unfertilized control, and the difference was due to increased weight of heads (g/m2) and number of heads (m2). In 2020, biogas sludge significantly increased yield by 71 % in comparison to the unfertilized control and the difference was due to increased number of grains (m2) and weight of heads (g/m2). Grain yield correlated positively with the amount of soluble and total nitrogen, manganese, magnesium, and potassium in fertilization. In conclusion, recycled fertilizers are as effective on yield formation of barley as chemical fertilizers in a clay soil. In the future the use of recycled nutrients will likely increase, hence further research of the topic is needed. Climate change is predicted to increase drought and heat stress during the growing season, which will alter the yield formation. Farmer can’t fight the weather, but sustainable cultivation methods ease the adaptation to the new growing conditions. Recycling of nutrients also promotes the shift from current linear economy to circular economy.

The advantages of foliar fertilizers are to provide the necessary plant nutrients to the crop at the optimal time of growth and the miscibility of foliar fertilizers with plant protection products in the same tank mix, thus avoiding additional costs. The aim of this experiment was to determine whether the foliar fertilizers which are most commonly used by sugar beet farmers can be safely mixed with standard Conviso® One herbicide tank mixture without mixing problems or without phytotoxic symptoms on Smart KWS sugar beet (Beta vulgaris subsp. vulgaris Altissima-Group). There was no previous study about the compatibility of foliar fertilizers in the standard Conviso® One tank mix and the result of this experiment were believed to provide significant information for the cultivation of Smart sugar beet. Two subtests were performed; a field trial for phytotoxic symptoms and a miscibility and 24 -hour standing test to determine the effect of hard and soft water on miscibility. The field test was organized at the one trial site of Sugar Beet Research Center in Meltola, Paimio and the mixing and standing trial was performed indoors in the same location. In both experiments, 11 different foliar fertilizers were tested. During the experiment visual mixing and application evaluations of sugar beet were performed. Sugar beet leaf and root samples were collected from the experiment area and one row of sugar beet was harvested for yield and quality analysis. There were two hypotheses; the miscibility of the standard Conviso® One tank mix together with foliar fertilizers doesn`t show any miscibility problems during the mixing or spraying, and the tank mixture doesn`t decrease the yield or quality of Smart sugar beet. The conclusion of this experiment was that the tested foliar fertilizers can be safely mixed into the basic Conviso® One tank mix without any miscibility problems during the mixing, spaying or after 24-hour standstill period. Miscibility problems were not observed with either water type (hard or soft) during mixing or after 24-hour standing time. The tank mixture didn`t have negative effect to Smart sugar beet yield but the treatments showed a difference in the potassium content of the root, which is one of the factors determining the quality of the sugar beet.

Grain legumes are grown on less than 2% of the arable area of Europe, while large quantities of soybean and soymeal are imported for feed for pigs and poultry. Crop rotations need diversifying by adding grain legumes for soil health and for the break-crop effect, lowering pest, disease and weed pressures in the subsequent crop. The economic effects are of interest from adding legumes to crop rotations and can be evaluated by modelling crop rotations and comparing the means of the gross margins (GM) from the rotations. In Finland, cereal-based crop rotations dominate the important crop growing areas of Southwestern Finland. The most common rotation during a five-year-period can consist of a cereal monoculture with two or more cereal species. The largest potential for diversification in crop rotations can be found on pig, poultry, and cereal farms. Modelling of grain legumes in crop rotations has previously been done for Västra Götaland in Sweden, Brandenburg in Germany, Calabria Italy, eastern Scotland in the United Kingdom, and Sud-Muntenia i Romania. The aim of this work was to create modelled crop rotations for Southwestern Finland to evaluate the gross margin, NO3-N-leaching, and N2O-emissions of the crop rotations. Yields were modelled for a ten-year period following actual yield fluctuations. They were analysed and there were no significant differences in gross margin detected in the crop rotations, whether they were a legume or an all-cereal rotation. Significant differences were found in N2O-emissions between the crop rotations

Perunalla on viime vuosien aikana havaittu tummia nekroottisia oireita mukulan kuoressa ja oireiden ulkonäön perusteella oireita on alettu kutsua kuoppataudiksi. Kuoppatauti voi näyttäytyä hyvinkin eri asteisena ja sitä voivat aiheuttaa monet erilaiset mikrobit. Tässä työssä tutkin Boeremia ja Fusarium -sienten tunnistamista perunanäytteistä PCR-menetelmällä sienilaji- tai sukuspesifisten PCR-alukkeiden ja geelielektroforeesin avulla. Tutkimusmateriaalina oli kuoppaoireisista perunaeristä keväällä 2021 saatuja mukulanäytteitä. PCR-tuotteet lähetettiin sekvensoitavaksi. Saatuja DNA-sekvenssejä verrattiin geenipankissa oleviin sekvensseihin BLASTn-menetelmällä ja tuloksista pääteltiin, mitä lajia kukin näyte-DNA edusti. Sen toteamiseksi, ovatko mukuloista eristetyt sienet todella kuoppataudin (ainoita) aiheuttajia, tehtiin taudinymppäyskokeita viljelymaljoilla kasvatetuilla sienillä. Terveiden mukuloiden pintaan tehtiin kolhuja, joihin ympättiin sienikasvustoa ja mahdollisten oireiden kehitystä seurattiin usean viikon ajan. Saatuja oireita verrattiin alkuperäisissä näytteissä havaittuihin oireisiin. Tutkimuksen tavoitteena oli selvittää mitkä patogeenit voivat aiheuttaa siemenperunoille nekroottisia ja väriltään tummia kuoppia. Inokulointikokeen tuloksia analysoitaessa todettiin tilastollista merkitsevyyttä (p< 0.01) ensimmäisen aikapisteen mittauksissa kontrollin ja Boeremian S- ja K-isolaattien välillä sekä kontrollin ja Juxtiphoman välillä. Toisen aikapisteen mittauksissa tilastollista merkitsevyyttä (p< 0.01) todettiin myös kontrollin ja Fusariumin välillä. Tulokset viittaavat siihen, että nämä kuoppaoireisista perunoista eristetyt sienet voivat aiheuttaa tautioireita perunan mukuloissa

Potato (Solanum tuberosum L.) is the world's third most important food crop, and its biggest threat is late blight caused by the fungus Phytophthora infestans (Mont.) de Bary. Although plant breeding has been aimed at developing resistant varieties, the use of fungicides is still the main control method. Breeding has the potential to produce functional and sustainable varieties, but its slowness and the adaptive nature of the pathogen make development challenging. Along with breeding and fungicides, different management practices, and prediction and monitoring models based on understanding the epidemiology of the pathogen and the combined effects of weather conditions, are means to develop more sustainable potato cultivation. In Finland, the Potato Research Institute conducts variety testing of potatoes. In the variety trials carried out in 2019 and 2020, the susceptibility of different potato varieties to late blight and the progression of foliar blight during the growing season were monitored. In addition to late blight resistance, an important criterion for the usefulness of the varieties tested is the yield level, which is examined in the trials. Differences were observed between the varieties in terms of foliar blight and the speed of its progression between the years. In both years, the foliar blight epidemic appeared later than expected in the trial area. The main reason for the delayed appearance of foliar blight was the weather conditions during the growing season. Late starch potato varieties proved to be the most resistant to foliar blight in the trials, and the weakest foliar blight resistance was observed in food potato varieties. Differences were also observed between the varieties in terms of 1000 tuber weights and tuber blight. Variety selection and weather conditions during the growing season have a significant impact on late blight pressure and the amount of damage caused. The most important characteristic of a variety is the yield, which was not measured in the experiments. Variety research conducted in Finland is important because the late blight resistance and agronomic characteristics of varieties coming from mainland Europe may not necessarily correspond to the information provided by the breeder in Finnish conditions. In the future, the development of integrated plant protection will play an increasingly important role in controlling P. infestans epidemics, as single actions will not provide sustainable solutions.

The biological control of carrot psyllid (Trioza apicalis Förster (Hemiptera: Triozidae)) was the focus of this study. The carrot psyllid is an important pest that causes significant yield loss. There is a lack of knowledge of the biological control of carrot psyllid with predators. In a recent study, larvae of Chrysoperla carnea Stephens (Neuroptera: Chrysopidae) and adult Anthocoris nemoralis Fabricius (Heteroptera: Anthocoridae) were used as biological agents. The field research was carried out in Western Finland in the year 2021. The flight peak was monitored with yellow sticky traps, and predators were applied at the beginning of the flight peak. The number of carrot psyllids’ nymphs and eggs was calculated in the biocontrol treatments as well as untreated controls and chemical control treatments and results were compared. Due to severe drought during the field experiment, biocontrol treatments were studied also in semi-field conditions in the pallet collar cultivation experiment. The number of predators per square meter in the semi-field experiment was the same as in the field experiment and the effect on the controlled amount of carrot psyllids was observed. Both results were analysed with SPSS-program. According to the results, the combined treatment with C. carnea and A. nemoralis (Anthocoridae), where C. carnea were released one week later than A. nemoralis, decreased statistically significantly the number of carrot psyllids’ eggs. The C. carnea treatment or A. nemoralis (Anthocoridae) treatment alone did not reduce the number of eggs or larvae. There is no previous research on the biological control of carrot psyllid, so there is no background literature on the subject. The research aimed to get information on the biological control of carrot psyllid and that goal was achieved. It is essential to do further research on this subject. The following aims might be to find out more information on predator density, the timing of the predator release, and the effects of different predators’ combinations in the biological control of carrot psyllids.