Sirvi Autor "Loit, Evelin" järgi

Nüüd näidatakse 1 - 20 48

Arabinoksülaani sisaldus nisu ja odra terades sõltuvalt väetamisest, ilmastikust ning sordist
(Eesti Maaülikool, 2023) Nigol, Andrea; Korge, Mailiis; Loit, Evelin
Maakera külvipinnast rohkem kui 50%-l kasvatatakse teravilja. Lisaks toitainetele sisaldavad need ka nii tervisele kui toidu omadustele kasulikke kiudaineid, arabinoksülaane. Käesoleva magistritöö eesmärk oli uurida arabinoksülaani sisaldust nisu ja odra terades, sõltuvalt lämmastikuga väetamise tasemest, viljelusviisist, katseaastast ja teravilja sordist. Töös analüüsiti arabinoksülaani sisaldust seitsmel eri väetusvariandil, sealhulgas mahe-ja tavaviljelusest aastatel 2019-2021 kasvatatud talinisu `Fredis` ja suvioder `Anni` jahvatatud teradest. Sordivõrdluskatse suviodra, tali- ja suvinisu proovid, mille arabinoksülaani sisaldust võrreldi, saadi Jõgevamaalt METKist. Talinisu ja suviodra terade arabinoksülaani sisaldus oli mõjutatud väetamisest. Vastupidiselt suvioder `Anni` teradele oli talinisu `Fredis` terade arabinoksülaani sisaldus kõrgem just väetist mitte saanud variantides, samas kui odra terade kõrgemad arabinoksülaani väärtused olid mineraalse lämmastikväetisega väetatud variantides. Tulemustest ei ilmnenud, et suurenev lämmastiku norm otseselt terade arabinoksülaani sisaldust tõstaks. Viljeusviisi mõju avaldus vaid suviodral, kus see oli madalam maheviljeluse tingimustes. Arabinoksülaani sisaldust mõjutas kõige rohkem õhutemperatuur, olles suurem kõrgema taimekasvuperioodi aegse õhutemperatuuri korral. Teravilja sordil oli usutav mõju nende arabinoksülaani sisaldusele. Nisud olid kõrgema arabinoksülaani sisaldusega võrreldes otradega. Suure erinevusega olid sõkal- ja paljasteralised nisud. Suviodra sortide arabinoksülaani sisalduse variatsioon oli usutav, kuid väiksem võrreldes nisudega.
Assessment of Verticillium dahliae Kleb. And Soil Fungal Communities Associated with Strawberry Fields
(Eesti Maaülikool, 2017) Mirmajlessi, Seyed Mahyar; Mänd, Marika; Loit, Evelin; Starzycki, Michael (reviewer); Kvarnheden, Anders (reviewer); Nigro, Franco (opponent)
Strawberry (Fragaria × ananassa) is a high value crop, and it is grown for its berries in many countries. Strawberry industry in Estonia has been fluctuating due to the limited selection of cultivars suitable for Nordic climate that are also susceptible to several diseases. Due to the complexity of soil systems and the inadequacy of conventional techniques for describing microbial community composition, it is difficult to diagnose and forecast all ongoing diseases. Strawberry fields are often subjected to disease complex involving different soil-borne pathogens. One of the most widespread and destructive diseases of strawberry is Verticillum wilt caused by Verticillium dahliae. So, knowing about the presence and amount of V. dahliae in the soil can be a key factor in determining appropriate management strategies. The general goal of the present dissertation was on assessment of V. dahliae inoculum density and soil fungal communities associated with Estonian strawberry fields in order to a better understanding of population dynamics. Additionally, finding new potential biocontrol agents was also important in terms of their implications for biological control. In this respect, PCR-based methods used for detection and/or quantification of the most widespread strawberry pathogens were systematically reviewed (I) and then general description of different real-time PCR (rtPCR) chemistries applied in plant pathology was illustrated (II). Also, a rtPCR assay combined with a conventional technique was developed for detection and quantification of V. dahliae directly from strawberry plants and soils of different major production areas (Vasula, Rohu, Unipiha, Utsu, Kaie-Mare and Marjamaa) in Estonia (III, IV). Moreover, soil fungal communities in same strawberry production areas (except Kaie-Mare) were investigated using Illumina-based sequencing as the first study, which may improve available management strategies against strawberry soil-borne diseases (V). Lastly, the antagonistic potential of a native Ttichoderma harzianum collected from Estonian fields as well as Gliocladium catenulatum isolated from a bifungicide toward V. dahliae was assessed with the aim of protecting biological resources (VI, VII). As the first study in Estonia, the newly developed rtPCR protocol efficiently enabled detecting and quantifying V. dahliae in strawberry plants and soils in which, 10.48 pg μl−1 of pathogen DNA represented at least one Microsclerotia (MS) per gram of soil, showing a high level of quantification in comparison with other studies. In fact, the presence of V. dahliae in strawberry production areas exhibited considerable variation, being high in samples from Vasula and Marjamaa, moderate in Rohu and Utsu, and low in Unipiha. No V. dahliae was detected from Kaie-Mare district. According to Illumina sequencing of strawberry soils from five commercially production sites, a high number of sequence matched V. dahliae in most samples particularly from soils with diseased plants (Vasula and Marjamaa) and so proved the interpretation of earlier estimates using rtPCR. Arbuscular mycorrhizal fungi were more abundant in areas with healthy plants (Rohu, Utsu and Unipiha), which may highlight their suppressive role against fungal pathogens. Moreover, biocontrol ability of T. harzianum isolates and G. catenulatum over V. dahlia was proven, representing as useful candidates for biocontrol of one of the most economically important pathogen of strawberry. The current dissertation provided important insights into the rtPCR as a valuable quantitative technique for diagnosis of important pathogens such as V. dahliae with high accuracy and rapidity as well as presented a comprehensive study to date on soil fungal communities in Estonian strawberry fields, which may help to achieve better understanding of the biological characteristics of soil in development of diseases. The data described within this dissertation may provide useful information for growers and agricultural organizations for applying suitable disease management strategies against plant pathogenic.
Beetaglükaani sisaldus talinisu terades sõltuvalt lämmastiku normist, ilmastikust ning sordist
(Eesti Maaülikool, 2022) Kurg, Max; Loit, Evelin; Korge, Mailiis; Khaleghdoust, Banafsheh
Eesti põllumajanduse oluline eesmärk on suurendada tarneahelas loodavat lisandväärtust. Käesoleva bakalaureusetöö eesmärgiks oli uurida talinisu seemnete β-glükaani sisaldust sõltuvalt kasutatud lämmastiku normist, aasta ilmastikust ja kasvatatava nisu sordist ning analüüsida seoseid β-glükaani, tuhande tera massi ja saagikuse vahel. Töös analüüsiti talinisu terasid, mis olid koristatud aastatel 2020 ja 2021 seitsme väetusvariandiga (lämmastiku norm 0–150 kg ha-1 ) põldkatselt Tartus ning nelja sordiga (Fredis, Skagen, Toras, Creator) tootmispõllult Järvamaal. Lämmastiku norm ei mõjutanud β-glükaani kontsentratsiooni ning oli kahe aasta vältel stabiilne. Suurem kasvuaegne sademete hulk juunis ja juulis vähendas β-glükaani sisaldust tootmiskatses. Varajase sordi β-glükaani sisaldusele mõjus kuum ja kuiv ilm positiivselt, kuid hilisematel sortidel oli mõju vastupidine. Beetaglükaani sisaldus sõltus nisu sordist. Tootmispõllu katses leiti dispersioonanalüüsi põhjal, et β-glükaani sisalduse mõjust moodustab sort lausa 56%. Seosed β-glükaani, tuhande tera massi ja terasaagikuse vahel olid usutavad tootmispõllu katses, kus testiti nelja erinevat talinisu sorti. Tulemused on olulised teraviljade väärindamise kontekstis. Edaspidised uurimised näitavad, kas saadud tulemused kehtivad ka rohkemate aastate andmete põhjal.
Bioloogiliste silokindlustuslisandite mõju silo kvaliteedile tootmistingimustes
(Eesti Maaülikool, 2019) Nool, Deivi; Loit, Evelin; Selge, Are; Põllumajandussaaduste tootmine ja turustamine
Eesti turul müüakse erinevaid lisandeid, kuid vähe on informatsiooni, mis oleks kõige efektiivsem tootmistingimustes. Töö eesmärgiks oli uurida bioloogiliste silokindlustuslisandite mõju silo kvaliteedile reaalsetes tootmistingimustes. Tööks vajaminevad siloproovid koguti aastal 2018 ja kokku koguti 14. ettevõtte siloproovid ning nii esimese niite kui ka teise niite siloproovid. Siloproove analüüsiti Eesti Maaülikooli veterinaarmeditsiini- ja loomakasvatuse instituudi söötmise osakonna sööda ja ainevahetuse uurimise laboris. Tootmisettevõtetele saadeti ka kaks küsimustikku, mis hõlmasid küsimusi silokindlustuslisandite ja silo valmistamise tehnoloogiliste aspektide kohta. Nii siloproovid kui küsimustikud seoti hiljem omavahel edasiseks analüüsiks. Aastal 2018 paistsid siloproovid silma suure kuivaine sisalduse poolest (37,8%). Uurimistulemused näitasid, et aastal 2018 ei olnud silokindlustuslisanditel mõju silo kvaliteedinäitajatele. Ka niitekõrgusel, küljekile kasutamisel ja koristustehnikal ei olnud usutavat mõju silo kvaliteedinäitajatele. Kuigi aastal 2018 ei mõjutanud lisandid silo kvaliteeti, siis edasine uurimine oleks vajalik, et teada saada silokindlustuslisandi mõju eri aastatel ning lisaks tuleks ka metoodikat täiendada, et saada usaldusväärsemaid tulemusi.
Changes in the content of soil organic carbon and total nitrogen in the organic and conventional cropping systems
(Estonian University of Life Sciences, 2023) Kuht, Jaan; Eremeev, Viacheslav; Loit, Evelin; Alaru, Maarika; Mäeorg, Erkki; Talgre, Liina; Luik, Anne; Estonian University of Life Sciences. Institute of Agricultural and Environmental Sciences
Maintaining and increasing the stock of soil organic carbon is of vital importance in maintaining the soil fertility. In present research the changes in the content of organic carbon (SOC) and total nitrogen (Ntot) in the soil are investigated. The data is collected from the long-term field experiment, which compares organic and conventional farming systems in a crop rotation (barley undersown with red clover, red clover, winter wheat, pea, potato) during 2014–2018. Based on the 5-year experiment, it was concluded that the cropping systems have a significant effect on the SOC content and a smaller effect on the Ntot content of the soil. The diversification of organic cropping systems with cover crops and composted cattle manure significantly increases the content of organic carbon in the soil. The results of the experiment indicate that the content of organic carbon was significantly lower (by 7.6–12.6%) in conventional systems, where pesticides had been applied and cover crops and manure had not been used, compared to the organic cropping systems. The correlations between the SOC contents of main crops and precrops were statistically more significant in organic farming system, compared to the conventional system. Highest SOC and Ntot values were observed in organic systems with cover crops and composted manure fertilization. Hence, it can be stated that in order to improve the soil fertility and fix more carbon and nitrogen, high amounts of organic material should be applied into the soil and the activity of soil microbes should be a priority. The organic cropping systems have more advantages for sustainable crop production.
The content of weed seeds in the soil based on the management system
(2017) Kuht, Jaan; Eremeev, Viacheslav; Talgre, Liina; Madsen, Helena; Toom, Merili; Mäeorg, Erkki; Loit, Evelin; Luik, Anne; Estonian University of Life Sciences
In 2008 an experiment was set up on the field in Eerika experimental station (Estonian University of Life Sciences) as a 5-field crop rotation: barley (Hordeum vulgare L.) with undersown red clover, red clover (Trifolium pratense L.), winter wheat (Triticum aestivum L.), pea (Pisum sativum L.), potato (Solanum tuberosum L.). The objective of the study was to measure the content of weed seeds in the soil and to evaluate the diversity of the species at the beginning of the period of organic production in 2011. In conventional farming systems without fertilizer (Con I) and conventional farming with mineral fertilizer (Con II) herbicides were used for weed control. All the crops in Con II system received P 25 kg ha-1 and K 95 kg ha-1 , but the application rates of mineral nitrogen fertilizer differed. In organic systems (Org I – organic farming based on winter cover crop and Org II – organic farming based on winter cover crop and manure), the winter cover crops (ryegrass after winter wheat, winter oilseed rape after pea, winter rye after potato) were sown after the harvest and were ploughed into the soil as green manure in spring. Organic farming systems (Org II) had a negative effect on the content of weed seeds in the soil (2.0–22.7% less seeds than in other variants). The seeds of Chenopodium album were the most abundant among summer annual weeds and the seeds of Viola arvensis among winter weeds in the soil. Organic farming measures increased the domination of Chenopodium album – the dominance index D’ was increased by 0.09–0.14 compared to conventional variants. The content of seeds of winter weed Viola arvensis in Org II variant was decreased by 82%. The index of species evenness J’ and Shannon Wiener diversity index H’ were lower in organic plots by 0.10– 0.18 and 0.60–0.19, respectively. Org II variants showed the best results based on the decrease of soil weed seed bank and distribution of the weed species.
Eestis kasvatatavate odrasortide kohanemisvõime kliimamuutustest tulenevatele veerežiimi muutustele
(Eesti Maaülikool, 2021) Sepp, Siim Samuel; Tamm, Ülle; Loit, Evelin
Antud uurimustöö põhineb 2021. aastal Eesti Taimekasvatuse Instituudis läbi viidud kasvuhoonekatsel. Katses kasvatati viit Eestis levinud suviodra sorti optimaalse- , põua- ja üleujutuse veerežiimis kuus nädalat, mõõtes nende suhtelist kasvukiirust ja projekteeritud võrse pindala fenotüpiseerimise kaudu. Töö eesmärgiks oli uurida põua ja üleujutuse mõju odrataimede biomassile ja kasvukiirusele varastes kasvufaasides, võrreldes seejuures sortide kohanemisvõimet. Nii põud kui üleujutus on tugeva negatiivse mõjuga taimede biomassi moodustamisele varases vegetatiivses kasvus, vähendades projekteeritud võrse pindala katse lõpuks vastavalt 26% ja 49% ning keskmist suhtelist kasvukiirust katse kestel 6% ja 16%. Sellest ilmnes üleujutuse tugevam mõju taime kasvule võrreldes põuaga. Ekstreemsest veerežiimist tulenevale stressile kohastumisega seotud geneeetiline variatsioon sortide vahel on küllaltki madal, seda eriti üleujutuse puhul. Kui põua variandis oli sordi mõju taimede projekteeritud võrse pindalale 9%, siis üleujutuse variandis oli see 3%. Kuigi sortide projekteeritud võrse pindala ja kasvukiirus katsevariantide vahel erines enamusel sortidest, siis stressi variantides erinesid üksteisest vaid üksikud sordid. Eestis viljeletavad suviodra sordid on kliimamuutustest tulenevatele ekstreemsetest veerežiimidest tingitud stressile vastuvõtlikud. Muutustega kohanemisel kujuneb tähtsaks nii aretuses kasutatavate genotüüpide stressi tolereerimise hindamine kui ka kliimamuutustele vastupidava geneetilise materjali aretusprogrammi integreerimine. See võimaldab tõsta valmisolekut ebasoodsast keskkonnast tingitud riskide maandamiseks odrakasvatuses.
The effect of different farming systems on potato tuber yield and quality
(Eesti Maaülikool, 2015) Tein, Berit; Selge, Are; Eremeev, Viacheslav; Loit, Evelin; Struik, Paul C (Reviewer); Koppe, Mati (Reviewer)
The world’s population is estimated to exceed over 9 billion people by 2050 (FAO, 2013), thus the demand for high yielding, good quality crops as well as the “challenges for the sustainability of the ecosystems” increases (Somers and Savard, 2015). Proper crop management is a key element in achieving high yields of good quality. Crop rotation, animal manures, and winter cover crops as catch crops (CC) play important roles in sustainable plant production systems because they provide nutrients for the system (Stark and Porter, 2005). CC and animal manures are mainly used by organic producers, because these are the main nutrient-rich sources for organic crop production. Animal manures are used by conventional producers only if, in addition to crop production, they have also livestock. Conventional producers, who grow only crops, largely depend on mineral fertilizers and different synthetic agrochemicals. According to Luik et al. (2008) conventional systems might not be sustainable in the long term, because they tend to be oversimplifi ed and maximally intensifi ed. But Edwards-Jones and Howells (2001) claimed that neither conventional nor organic farming systems (FS) are sustainable because both of them require inputs from non-renewable resources and, one way or another, they both impact on the environment. For organic producers there are also two main challenges, such as managing diseases and nutrients since nutrient availability is limited and there are only a few effective pesticides available that are allowed for use (Finckh et al., 2006). Also, Nelson et al. (2009) confi rm that in organic systems nutrient transformations almost exclusively relyon soil. In conventional systems, if there are problems with diseases or pest and with plant malnutrition, synthetic agrochemicals and mineral fertilizers can be provided throughout almost the entire growing season. Despite some limitations in organic farming, organic agriculture is based on its own self-regulating production system, and the concept of a farm is as an agro-ecosystem (Lammerts van Bueren et al., 2002). But organic agriculture alone does not provide a suffi cient amount of food for the growing population (Oliver and Gregory, 2015). In contrast, conventional agriculture depends mainly on external inputs, which makes it somewhat more vulnerable. To consider farming systems to be sustainable they must be “productive and maintain their contribution to society in the long term” (Gadanakis et al., 2015). In general, the demand for agricultural practices and food security that are more environmentfriendly is increasing rapidly, which favours the development of new 10 integrated farming systems (Duc et al., 2015). Such farming systems that use integrated management practices, such as crop rotations and organic (green manure crops, leguminous crops, CC) and inorganic fertilizers, will maintain soil as well as human health (Marsh, 2000; Oliver and Gregory, 2015). Future agriculture must also evolve towards climate-smart agriculture technologies, which are more adaptive to climate change by improving resource use effi ciency and ensuring food security (Zhang et al., 2015). Achieving food security does not only mean an adequate food supply but it also means that the food must be nutritious, of good quality (Wei et al., 2015). The potato is one of the most important crops worldwide, ranking fourth in annual production (Fernie and Willmitzer, 2001). The potato can be grown in harsher climates, and it is able to give, relatively quickly, high nutritious yields compared to any of the other major food crops (Lutaladio and Castaldi, 2009). However, to be productive, the potato needs signifi cant nutrient inputs to maintain its productiveness and quality. Crop management is the main factor that infl uences crop production and disease resistance (Larkin and Halloran, 2014; Olanya et al., 2014). Previous research has shown that FS affect tuber quality characteristics such as tuber nutrients (Järvan and Edesi, 2009) as well as starch and dry matter (DM) contents (Roinila et al., 2003). Plant nutrition is an important factor that infl uences natural disease resistance. If there is a defi ciency of essential elements susceptibility to potato diseases increases (Czajkowski et al., 2011), because the plant’s natural ability to fi ght them is lowered (Mulder and Turkensteen, 2005). Nutrients affect the plant physiology and thus potential for infection with pathogens (Dordas, 2008). At the European Association for Potato Research (EAPR, 2014) conference last year it was concluded that the agronomy side of potato production has gained too little attention over the past years and needs to regain its importance, because the agronomic side of potato production determines the potato performance parameters. Potato is a crop that has been studied in Estonia extensively because of its importance in Estonians everyday diet. The fi rst true Estonian potato scientist was Julius Aamisepp who promoted the cultivation of potato and its research. The fi rst fertilization experiments were conducted by Arnold Piho in 1960–1980 which also included the potato crop. The latest potato fertilization research has been made by Kuldkepp et al. 11 (1999), by Astover and Roostalu (2003), by Järvan and Edesi (2009), by Toomsoo and Leedu (2002), by Toomsoo et al. (2009; 2012). However, such complex potato fertilization research (under different organic and conventional farming systems) presented in current thesis has not been made before in Estonia. Earlier potato research has had mainly domestic importance. In the past, besides potato fertilization, the effect of different potato pre-planting thermal treatments on the tuber yield formation has been studied by Viacheslav Eremeev. Also there has been some potato disease related research by Mati Koppel who studied the potato soft rot (Erwinia/Pectobacterium spp.) disease and by Eve Runno-Paurson who investigated the potato late blight (Phytophthora infestans). The potato meristem multiplication has been studied by Viive Rosenberg and Marje Särekanno. Potato research related to plant breeding has been conducted by Aide Tsahkna and Mati Koppel. There are many other great potato researchers in Estonia who are a true experts in their fi eld of study. Crop rotations are important tools that affect potato productivity (Carter et al., 2003) and diseases (Peters et al., 2004). Catch crops are essential to avoid nutrient losses (Stark and Porter, 2005). Brassica crops used as CC have, furthermore, been found to have a disease suppressing effect (Cohen et al., 2005). Since the potato is a high nutrient demanding crop, additional mineral or organic fertilizers must be provided. Despite nitrogen (N) being a basic potato nutrient, the selection of its appropriate application rate for the potato is quite diffi cult, due to signifi cant variation (Zebarth et al., 2009). The appropriate N demand can vary among many factors such as climatic conditions during the growth period, crop management practices the previous crops cultivated. Addressing all the aforementioned factors should ensure high potato yields of good quality. Currently, these are the following gaps in our knowledge: (i) how the yield increase through different agronomic practices affects the potato tuber mineral elements concentrations (which are considered tuber nutrients) (White et al., 2009) and overall crop quality (Wang et al., 2008), (ii) how crop rotations infl uence tuber quality parameters (Mohr et al., 2011), and (iii) how the plant nutrition and crop rotations together affect the occurrence of tuber diseases (VanderZaag, 2010). The focus of much research tends to be on organic or conventional management systems separately, it is important to investigate their infl uence together comparatively (Bernard et al., 2014). Thus, the overall aim of this thesis is to 12 investigate how different organic and conventional management practices under the same crop rotation infl uence tuber quality characteristics as well as yield.
Effect of organic management methods on yield and quality of carrot and on weeds
(Eesti Maaülikool, 2021) Bender, Ingrid; Luik, Anne; Loit, Evelin; Tamm, Ilmar; Suojala-Ahlfors, Terhi (opponent)
The thesis covers two organic studies. The first one aimed to estimate organic carrot yield and quality in comparison of conventional production. Comparison of vegetable production systems has often provided inconsistent results as fertilization rates have been higher in conventional production. This thesis deals with two different fertilization regimes: (1) optimal level of nitrogen (N) fertilization in both systems (TP1); (2) below optimal N fertilization only in organic production (TP2). Quality studies consisted of the determination of the content of total sugars (TS), vitamin C, dry matter (DM), N, nitrate (NO3) and pesticide residues in carrots. The second research aimed to study the effect of rolling-crimping technology (RC) on weed density, weed species richness and weed community in organic vegetable no-till cultivation. For the first time in Estonia, RC technology was used and compared with green manure technology (GM). RC technology crushed or crimped the stems of agroecological service crops (ASC) and retained the residues as mulch on the soil surface thereby suppressing weeds during the cultivation period of the cash crop (cabbage). The results showed that significantly higher marketable yield and lower discarded yield in organic management in TP1 was produced. Despite below optimal N fertilization level in TP2, the marketable yield was on the same level and discarded yield was lower in organic treatment compared to these in conventional treatment. These advantages of organic production over conventional can be explained by the influence of compost on the soil properties compared to the synthetic fertilizer. The content of vitamin C was higher in organically produced carrots in TP1. No significant differences in content of TS, vitamin C and DM were found between organic and conventional treatment in TP2. Conventionally produced carrots had a higher N content only in TP2 and a higher content of NO3 than organic carrots in both trials. Pesticide residues were found in conventional carrots of both trials. RC technology reduced weed density and weed species richness but increased the share of perennial weeds compared to GM.
Effects of cropping systems on soil fertility and winter wheat dough quality
(Estonian University of Life Sciences, 2022) Keres, Indrek; Tosens, Tiina; Niinemets, Ülo; Loit, Evelin; Institute of Agricultural and Environmental Sciences; Grausgruber, Heinrich (opponent)
The long - term effect of organic and mineral nitrogen fertilizers on soil fertility in five - field crop rotation and on the quality of winter wheat grain yield and dough was studied in the doctoral thesis. The aim was to find out the long-term effect of organic and conventional cropping on total yield, soil fertility (phosphorus and potassium content, pH) and the combined effect of different cropping systems and year on the size distribution of starch granules, the yield of whole grain and fine flour, the interaction of gluten-starch on the rheological properties of wheat dough. The total yield of the five-field crop rotation was on average 25% higher than in organic farming due to mineral fertilizers. During the 10-year experimental period, the soil P content of the conventional treatments did not change, while the K content decreased to 40 mg K per kg dry soil and the soil became more acidic. The use of winter crops and well-composted cattle manure did not maintain the basic levels of P and K in the soil, which is why it is important to monitor the nutrient balance, especially in organic farming, so that soil fertility does not decrease. The effect of the cropping system on the size of the starch grains was not significant, but it was affected by the weather conditions during the experimental years. Flour yield was affected by the size distribution of starch granules, while the increased proportion of smaller diameter granules significantly increased the yield of fine flour. The quality of the dough was affected by several factors, with the nitrogen fertilization regime having a significant effect. If the protein content is more than 13% and the glutenin-gliadin ratio is optimal, the dough has a longer stability time, a lower softening degree and a higher dough quality. The quality of the dough varied more in the organic treatments. The amount of 150 kg/ha of mineral N applied in two parts before flowering ensured stable plant growth and protein and gluten content in different years. Treatments fertilized with lower amounts of nitrogen and organic treatments were more vulnerable to changing weather conditions.
Geenitehnoloogia kasutamine tomati näitel
(2013) Urbalu, Lauri; Loit, Evelin
Diplomitöö tegemisel lähtuti geenitehnoloogia võimalustest ja kasutusest tänapäeval. Eraldi spetsialiseeruti tomati järelküpsemise pikendamisele läbi geneetilise muundamise. Töö eesmärgiks oli uurida erinevaid vahendeid ja kasutusi geenitehnoloogiast nende arengust, tänapäevast ning geenitehnoloogia tulevikust. Töö koostamisel kasutati peamiselt teadusartiklite (ISI Web Of Science; Scopus) andmebaase, aga ka entsüklopeediaid ja erialakirjanduslikke allikaid. Töö käigus töötati läbi 43 inglise keelset teadusartiklit. Kogutud teadustööde põhjal leiti, et tomatit Solanum lycopersicum L. on hea kasutada geenitehnoloogia mudeltaimena, samuti leiti, et tomat on üks taimeliikidest, mille kogu genoom on hiljuti täielikult sekveneeritud. Veel leiti, et GM-tomat on olnud ka inimtoiduks tarbimiseks, kuid halbade kvaliteediomaduste tõttu turul olnud GM-tomat (FlavrSavr) enam tootmises pole. Uurimustöös leiti, et ACC deaminaasi ekspresseeriva geeniga GM tomat osutus oma eesmärgilt edukaks ning säilis muundamata tomatist kuni 6 korda kauem. Leiti ka, et ühe areneva teaduse, kasvava inimpopulatsiooni ja halvenevate keskkonnatingimuste tõttu on GMO’del täita tulevikus väga tähtsaid rolle alustades toidust, lõpetades biomeditsiiniga. Samuti saadi teada, et palju statistilisi näitajaid GM-põllukultuuride kasvatuse ja kasu kohta maailmas. Märksõnad:
Geenitehnoloogia kasutamise võimalused kartuli näitel
(2012) Matus, Helena; Loit, Evelin
Töö koostamisel lähtuti sellest,et millised on geenitehnoloogia võimalused valitud kultuuri (kartuli) aretamisel. Töö eesmärgiks oli uurida kartuli sobivust geneetiliselt muundatud kultuurina ja välja tuua geneetiliselt muundatud kultuuridega seotud riskid ning GMO-de tulevikuperspektiivid. Töö koostamisel kasutati põhiliselt andmebaase, aga ka interneti-allikaid, kust valiti välja sobivad artiklid vastavalt otsingu märksõnadele. Enamus artikleid on inglise keelsed. Tehtud töö käigus sai läbi töötatud suurel hulgal erinevaid artikleid, mis enamuses põhinesid katsetel ja teooriatel. Töö tulemustest võib järeldada seda, et kartul on väga perspektiivikas põllukultuur, mida on võimalik geenitehnoloogia abil muuta vastavalt eesmärkidele. 2010. aastal kasvatusõiguse saanud Amflora tärklisekartuli kasvatus on Euroopas kogumas järjest rohkem hoogu. Kindlasti on veel raske teha konkreetseid järeldusi, kui tasuv on geneetiliselt muundatud Amflora võrreldes tava tärklisekartuliga, sest Amflora on turul olnud kõiges 2 aastat. Siiski usun, et tegemist on tööstuslikus mõttes väga otstarbeka GM taimega, mis võimaldab lihtsustada tärklisekartuli töötlemisega seotud protsesse. Töödeldud kartulitärklis on taastuv ressurss, mis vähendab taastumatute ressursside kasutamist (loodetavasti). Seega on ühelt poolt tegemist väga ökonoomse biotehnoloogilise produktiga, kuid samas tõstatavad geneetiliselt muundatud organismid omakorda riskitaset, mis väljendub geenisiirdes, antibiootikumide resistentsuses ja võimalikust ohust eeskätt inimorganismidele ning keskkonnale üldiselt. Arvestades maailma rahvastiku kiiret tõusu, mis tähendab seda, et inimkonnal tuleb leida alternatiive, mis suudaksid konkureerida järjest kiiremini kasvava inimeste arvuga, peab tunnistama, et tavaaretatud sordid ei suuda konkureerida geneetiliselt muundatud sortidega, mis on võimelised saama sama kasvupinna pealt märgatavalt suuremaid saake. Üheks olulisemaks kartuli tulevikuperspektiiviks on geneetiliselt muundatud kartul, millel oleks lehemädanikukindlus. Kas ja kui tasuv on selline GM kartul selgub ilmselt lähiaastate jooksul, sest hetkel on leitud juba vastavaid geene, mis suudavad põllutingimustes muuta kartulit lehemädaniku kindlaks.
Geneetiliselt muundatud maisi keskkonnamõju Eestis
(2015) Siiman, Siim; Loit, Evelin
Antud uurimustöö eesmärgiks oli anda ülevaade maisi kasvatamisest Eestis, GM maisist ja selle kasvatamisest ning samuti GM maisi mõjudest keskkonnale: mõju mitteeesmärk putukatele ja leviku potentsiaal transpordiga. Samuti oli üheks eesmärgiks ka välja selgitada GM maisi võimalik mõjud keskkonnale Eesti tingimustes ning arutleda GM maisi kasvatamise vajaduse üle. Euroopas on küll ühe GM maisi (MON810) kasvatamine lubatud, kuid Eesti ei ole seda heaks kiitnud. MON810 põhieesmärgiks on tõrje varreleediku vastu, kuid õnneks ei ole varreleedik veel Eestisse jõudnud, seega ei oleks antud hetkel ka MON810 maisi kasvatamine põhjendatud. Seevastu oleks Eestis kasu glüfosaadiresistentse sordi kasvatamisest, kuna tänu GM maisile vähenevad kulutused nii taimekaitsele kui ka põllutöödele. Analüüsitud katsetest uuriti GM maisi mõju lutikalistele, lepatriinulastele, jooksiklastele, ämblikele ja vesikirpudele. Tulemustest selgus, et GM maisil on negatiivne mõju ainult vesikirpudele ja kõrges kontsentratsioonis ka lepatriinudele Globaalsetes ekspordi ja impordi tingimustes võivad GM maisi seemned levida riikidesse, kus need ei tohiks kasvada. Uuringutest selgus, et Lõuna – Koreasse oli transpordi käigus sattunud GM taimed. Positiivseid GM proove leiti nii sadama ümbrusest, karjalautade juurest kui ka sööda tootmisettevõtte ligidalt.
Harimisviisi mõju herne saagile ja lämmastiku kasutusele
(Eesti Maaülikool, 2020) Kunnus, Priit; Voor Ivo; Loit, Evelin
Uurimustöö põhineb Lakeniidu talu tootmispõldudele 2019. aastal rajatud põldkatse andmetele. Katsepõldudel teostati 2018. aastal künniga (põld 1) ja tüükultivaatoriga (põld 2) harimine. Töö eesmärgiks oli võrrelda harimisviiside mõju herne saagikusele ja lämmastiku (N) kasutusele. Andmed analüüsiti ja töödeldi statistiliselt. Tüükultivaatoriga haritul katsepõllul jäi mulla N sisaldus peaaegu samaks, aga küntud katsepõllul vähenes 612 kg/ha võrreldes alg varuga. Künni puhul oli keskmine kuivaine saak 3751 kg/ha ja tüükultivaatoriga haritud põllul 3119 kg/ha, mis on 632 kg/ha, ehk 17% väiksem. N-sisalduses kogu biomassis usutavat erinevust harimisviiside vahel ei olnud. Tüükultivaatoriga haritud katsepõllul oli N-sisaldus põhus suurem kui künniga haritud põllul. Juurtes oleva N-sisaldus oli aga küntud katsepõllul suurem kui tüükultivaatoriga haritud põllul. Herne agronoomiline N-kasutusefektiisus, ehk mitu ühikut terasaaki toodeti ühe mullas ja õhus saadaoleva N ühikuga, oli künni korral 18 kg ja tüükultivaatoriga 15 kg saaki ühe kg N kohta. N-jääk, ehk kadu leostumise või lendumise kaudu oli künni korral väiksem. Et paremini mõista harimisviiside mõju põldherne saagikusele ja lämmastikukasutusele on väga oluline veel korrata katset mitmel järjestikusel aastal, seejuures hinnates eelvilja mõju.
Heina ja kuivsilo tootmise ja tasuvuse analüüs Hacienda OÜ põhjal
(Eesti Maaülikool, 2019) Šois, Sten; Loit, Evelin; Lillak, Rein; Põllumajandussaaduste tootmine ja turustamine
Põllumajandustootmise tulukus oleneb väga paljudest välistest faktoritest nagu mullastikust, ilmastikust, aga ka turul valitsevatest tingimustest. Sellest tulenevalt on ettevõtte edukaks majandamiseks vaja täpselt teada, millistes tingimustes ja piirides on tootmine efektiivne. Magistritöö eesmärk on välja selgitada hobustele söödaks toodetava kvaliteetheina ja kuivsilo peamised kvaliteedinäitajad ning 2018. aastaga samas mahus heina ja kuivsilo tootmise majanduslik otstarbekus kuni 30% müügihinna languse puhul Hacienda OÜ andmete näitel. Samuti on eesmärk uurida püsirohumaadelt lühiajalistele rohumaadele ülemineku mõju tasuvusele. Hobusekasvatajate seisukohast on peamisteks heina ja kuivsilo kvaliteedinäitajateks kuivaine, energia, proteiini, mineraalide ja vitamiinide sisaldus. 400-500 kg kaaluva hobuse igapäevane toitainete vajadus sõltuvalt töö raskusest ja tööaja kestusest on järgmine: 1) 5-8 kg kuivainet; 2) 64-85 g metaboliseeruvat energiat 3) 80-150 g/kg toorproteiini; 4) 36,7-39,1 g kaltsiumit ja 5) 20,4-21,7 g fosforit. Omahinna ja tasuvuse seisukohast oli müügihinna 30% languse korral tootmine kasumlik vaid lühiajaliste rohumaade puhul, püsirohumaade puhul mitte. Lühiajalistel rohumaadel on võimalik kasumit teenida veel ka 40% müügihindade languse korral. Käesolev analüüs võib kõige rohkem huvi pakkuda hobusekasvatajatele ja põllumajandusettevõtjatele, kes tegelevad heina ja kuivsilo tootmisega.
Heina ja kuivsilo võrdlushobusekasvatuses
(Eesti Maaülikool, 2021) Razumov, Renee; Lillak, Rein; Loit, Evelin
Käesoleva töö eesmärgiks oli saada ülevaade Eesti hobusekasvatuse hetkeseisust ning söötmistavadest. Teiseks eesmärgiks oli võrrelda hobuste maitse eelistusi (hein contra kuivsilo) konkreetsetes talutootmise tingimustes, mille alusel oleks võimalik edaspidi kaasa aidata silo osakaalu tõstmisele hobuste söödaratsioonis. Ankeetküsitluse osas uuritakse Eesti hobusekasvatajate söödatootmist kasutades küsimustikupõhist lähenemist. Lisaks analüüsitakse Põhjako talus hobuste sööda tootmist ning hobuste sööda eelistust katsepõhisel meetodil. Katse tulemusena leiti, et hobused eelistvad kuivsilo heina asemel ning ankeetküsitlusest selgus, et enamus eestlasi toodab ma hobustele sööda ise ning põhisöödaks on hein. Käesolev töö võib kõige enam pakkuda huvi hobusekasvatajatele.
Herbitsiidide mõju kinoa kasvule ja umbrohtumusele
(Eesti Maaülikool, 2020) Tuusis, Deivi; Loit, Evelin; Lauringson, Enn
Põllumajandus on aastatega intensiivistunud ning see häirib erinevaid ökosüsteeme. Selle probleemi üheks leevenduseks on põllukultuuride mitmekesistamine. Kinoa ehk Tšiili hanemalts on gluteenivaba ja toitainerikas seemnekultuur, lisaks on kinoa hea kohanemisvõime ja vastupidavusega. Seda tõestab tema võimekus kasvada erinevat tüüpi muldadel. Käesolev töö on katsepõhine, kus selgitatakse kinoa kasvupotentsiaal Eesti kliimatingimustes ning erinevate toimeainetega herbitsiidide mõju kinoa saagile ja kasvule ning herbitsiidide mõju umbrohtude pärssimisele. Katse viidi läbi 2019. aasta suvel Tartumaal. Katses kasutati kolme erineva toimeinega herbitsiidi: Butisan 400, Stomp CS ja Lontrel 72 SG ning lisaks jäeti üks katselapp kontrollalaks, kus ühtegi herbitsiidi ei kasutatud. Kõige suurema umbrohufooniga oli kontrollvariant. Kõige efektiivsem herbitsiid oli Butisan 400 ning kõige väiksema efektiivsusega Stomp CS. Kontrollala saagikus oli 745,1 kg/ha. Kinoa taimede saagikust pärssis kõige rohkem Lontrel 72 SG ning neljast katsevariandist oli saagikaim, herbitsiid Butisan 400, vastavalt 462,6 kg/ha ja 847,4 kg/ha. Töö tulemusena näidati, et kinoa kasvab ja annab saaki ka Eesti tingimustes. Kinoa ei ole väga hea umbrohtude allasuruja, seega on oluline herbitsiidide kasutamine. Katse tulemustel oli kõige efektiivsem herbitsiid Butisan 400 (toimeaine metasakloor), mis tõrjus kõige efektiivsemalt umbrohtu ning võimaldas saada kõige kõrgema kinoa saagi. Edaspidi peaks kasvatama erinevaid kinoa sorte, katsetama erinevate külviaegadega ning erinevate herbitsiidi normidega ning tegema tasuvusanalüüsi.
Idavere Mõis OÜ agromajanduslik analüüs aastatel 2016–2018
(Eesti Maaülikool, 2019) Karro, Sander; Loit, Evelin; Lauringson, Enn; Põllumajandussaaduste tootmine- ja turustamine
Lõputöö eesmärk on analüüsida minimeeritud tehnoloogia kasutuselevõtu tasuvust Idavere Mõis OÜs. Antakse ülevaade kultuuride saagikusest, analüüsitakse omahinda mõlema tehnoloogia puhul, võrreldakse tava- ja minimeeritud tehnoloogia kasutuskulusid ning analüüsitakse tehnoloogilisi võimalusi minimeeritud tehnoloogia kasutuselevõtuks. Töö koostamisel on kasutatud Idavere Mõis OÜ andmeid, mis on kogutud 2016–2018 aastate raamatupidamise andmetest, mullaproovide analüüsi tulemustest ja põlluraamatutest, millele lisandusid agronoomi kommentaarid ja täpsustused. Analüüsi aluseks on koostatud tehnoloogilised kaardid talinisu ja suviodra näitel nii minimeeritud kui ka tavatehnoloogia puhul 1 hektari kohta. Seni on talus kasutatud vaid tavatehnoloogiat.
Impact of changing weather on the crops yield stability in different cropping systems
(Estonian University of Life Sciences, 2023) Viikoja, Ragnar; Alaru, Maarika; Keres, Indrek; Lillak, Rein; Voor, Ivo; Loit, Evelin; Estonian University of Life Sciences. Institute of Agricultural and Environmental Sciences. Chair of Crop Science and Plant Biology
Changes in weather conditions make it possible to change the schedule of agricultural works and introduce new crops and crop rotations in Northern Europe. It is important that the yield of the crops in the rotation are stable under highly variable weather conditions, which would ensure a high total yield for the rotation. One of the goals of this long-term field experiment (2008–2022) was to study the effect of weather conditions on the total yield and stability in the crop rotation; crops of the given crop rotation were grown in organic and conventional cropping systems. Compared to the pre-experimental period 1964‒2007, the annual average air temperature of the test period 2008‒2022 was higher by 1.1 degrees, whereas the increase in the annual average temperature was primarily due to the increase in winter and June–July temperatures. In the 3rd cropping cycle (2018–2022) the total yield of crop rotation as an average of fertilizer variants and experimental years was 21% and 24% lower than in the 1st (2008–2012) and 2nd (2013–2017) cropping cycles, respectively, which was mainly caused by the decrease in field pea yield. The effect of weather on yield stability was greatest for field pea. Fertilization with mineral fertilizers improved the stability of the total yield in the conventional cropping system. Correlation, factorial analyses of variance (ANOVA) and two-factor ANOVA were used to test the effect of cropping systems and climatic conditions on total and average DM yield of crop rotation, also each crop’s DM yield. Despite the negative impact of the weather, most of the yield loss can be prevented or the damage can be eased by careful planning and detailed knowledge about the influence of different weather factors. Further investigation is required to determine the change in growing season length, sowing dates and harvesting to provide farmers more detailed tools to predict and plan their actions.
Impact of cropping systems on soil microbiome and barley transcriptome
(Estonian University of Life Sciences, 2023) Esmaeilzadeh Salestani, Keyvan; Loit, Evelin; Institute of Agricultural and Environmental Sciences; Singh, Jaswinder (opponent)
Crop production needs to be more sustainable. Farmers are confronted with the challenge to use less nutrients while maintaining food security and other ecosystem services. Therefore, it is essential to examine the agricultural strategies that address sustainability. This dissertation compared the effects of conventional and organic cropping systems on soil biodiversity and gene expression patterns of barley in a five-field crop rotation. Soil DNA analysis showed that all treatments in organic cropping system as well as conventional treatments with low to medium rates of mineral fertilizers increased the diversity and changed the relative abundance of the soil microbiome. Conventional treatment with no added nutrients decreased bacterial and fungal diversity. Yield is important for food security, and thus it is important to understand the processes in the barley plant. The number of differentially expressed genes was higher in conventional treatments, particularly in N2 that received 80 kg of mineral nitrogen per hectare and provided the highest yield, compared to organic treatments. Amide and peptide metabolism and response to acid chemical and inorganic substances were enriched biological processes in studied conventional treatments whereas polysaccharide and glucan metabolic processes were among the dominant biological processes under organic treatments. Expression of ammonium transporters was analysed more precicely over the early stages of crop growth. Up-regulation of HvAMT1;1 started at the anthesis growth stage in the conventional system and its activity had a strong correlation with the nitrogen content of leaves and 1000-kernel weight. Knowledge about the mechanisms being impacted by different nitrogen rates and cropping systems are valuable for agronomists and crop breeders in increasing the sustainability in crop production.

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