Sirvi Autor "Eremeev, Viacheslav" järgi
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Kirje Bataadi kasvatustehnoloogia Põhjamaade tingimustesse(Eesti Maaülikool; Maaelu Teadmuskeskus, 2026) Lääniste, Peeter; Rouhiainen, Markus; Eremeev, Viacheslav; Niinemets, Ülo; Runno-Paurson, Eve; Eesti Maaülikool. Põllumajandus- ja keskkonnainstituut. Taimebioloogia ja maaviljeluse õppetoolThe field experiment was conducted in 2022 at the Eerika Experimental Field of the Estonian University of Life Sciences. Three sweet potato (Ipomoea batatas L.) cultivars bred in the USA—’Beauregard’, ‘Covington’, and ‘Evangeline’—were included in the study. The cultivars were grown under two cultivation systems: black plastic mulch and conventional furrow cultivation. The results demonstrated that all evaluated cultivars are suitable for cultivation under Estonian agroclimatic conditions. Sweet potato grown under black plastic mulch produced significantly higher yield than that grown in furrows. The mean yield obtained with black plastic mulch was 55.7 t ha⁻¹, whereas the mean yield under furrow cultivation was 16.4 t ha⁻¹. No statistically significant differences in yield were detected among the cultivars. In conclusion, the findings indicate that sweet potato cultivation is highly promising in Estonia. However, further studies are required to validate these results, refine optimal cultivation techniques and evaluate additional cultivars potentially suitable for Nordic climate conditions.Kirje 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 SciencesMaintaining 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.Kirje 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 SciencesIn 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.Kirje Diversified cropping systems for promoting the beneficial insects - ground beetles (Coleoptera: Carabidae)(Estonian University of Life Sciences, 2023) Talgre, Liina; Eremeev, Viacheslav; Mäeorg, Erkki; Luik, Anne; Estonian University of Life Sciences. Institute of Agricultural and Environmental SciencesIn agro-ecosystems ground beetles - carabids (Coleoptera: Carabidae) are important as generalist predators of invertebrate pests and weed seeds and as prey for larger animals. This way they contribute to biodiversity and influence the most important ecological processes. Impacts of crop management practices on the carabids are not well described. Carabids were studied in winter wheat which is one crop in the rotation experiment (barley undersown with clover-clover-winter wheat-pea-potato). Carabids were collected with pitfall trap during one week at the end of June 2022. In laboratory, their species was identified. Trapping of carabids during the spiking phase of winter wheat has shown significant differences in carabids activitydensity and diversity depending on five different cropping systems. In two conventional systems where pesticides were used the number of carabids was two times smaller in comparison with three organic systems. Activity-density and diversity of carabids was significantly higher in all organic systems and especially in Org II system where winter cover crops and composted manure where used for rotation diversification. The Shannon–Wiener index values, which takes into account the number of species and their relative abundance were 1.24–1.53 in conventional systems, but higher in diversified organic systems (1.60–1.78). Only in organic systems Org I and Org II there were very rare species present, like Acupalpus meridianus (Linnaeus) and Microlestes minutulus (Goeze). In diversified organic systems the higher activity-density and abundance of carabids could be explained by the diverse plant community as possible source for better food and microclimatic conditions.Kirje Impact of weather conditions and farming systems on size distribution of starch granules and flour yield of winter wheat(MDPI, 2020) Keres, Indrek; Alaru, Maarika; Talgre, Liina; Luik, Anne; Eremeev, Viacheslav; Sats, Andres; Jõudu, Ivi; Riisalu, Anu; Loit, Evelin; Institute of Agricultural and Environmental Sciences. Estonian University of Life Sciences; Institute of Veterinary Medicine and Animal Sciences. Estonian University of Life Sciences; ERA Chair for Food (By-) Products Valorisation Technologies of Estonian University of Life Sciences. Estonian University of Life SciencesThe size distribution of wheat-grain starch granules has an impact on the yield of fine flour. The aim of the study was to compare the impact of conventional (mineral fertilizers, pesticides) and organic farming treatments (cover crops, composted cattle manure) on (i) the size distribution of starch granules, (ii) the level of the first break whole and fine flour yield. The grain samples of winter wheat cv Fredis were taken from a long-term field crop rotation experiment established in 2008 at the Estonian University of Life Sciences in Tartu County (58 220 N, 26 400 E) on Stagnic Luvisol soil. The weather conditions during the grain filling period of winter wheat had a strong impact (p < 0.001) on the grain starch granule size distribution. The proportion of starch granules with a smaller diameter (C-type granules) was higher in years with a longer grain filling period. The size distribution of starch granules was not influenced by farming system. The increased proportion of C-type granules increased the fine flour yield significantly. Fertilisation with organic manure and twice with mineral nitrogen increased significantly the mean diameter value of different starch granules.Kirje Impacts of nitrogen fertilization and planting date on the physiology and yield of purple sweet potato at the extreme Northern edge of cultivation(Estonian University of Life Sciences, 2019) Zekker, Ivar; Kännaste, Astrid; Eremeev, Viacheslav; Kask, Kaia; Meinson, Pille; Nassar, Helina; Mäeorg, Erkki; Runno-Paurson, Eve; Niinemets, ÜloGlobal warming causes plant stress and reduces crop productivity. Cultivation of the warmer region crop sweet potato (Ipomoea batatas (L.) Lam) in Northern regions can be an opportunity to benefit from climate warming, but there is little information of how growing season length interacts with agricultural practices such as nitrogen (N) fertilization. We studied the photosynthetic characteristics, biomass accumulation, carbon (C) and N contents of plant organs of the cultivar ´Purple Bud´ in relation to the planting date (the 2nd of May, 10th of May, 20th of May, 30th of May and 10th of June) and N fertilization (kg ha-1; N0, N50, N100 and N150). Nitrogen content of leaves (NL) and tubers (NT) increased with N application dose and was moderately affected by planting time. Despite the fertilization-dependent increase of leaf N content, photosynthesis rate (A) was unaffected or somewhat reduced by N fertilization. This reflected reductions in stomatal conductance (gs) and ratio of intercellular CO2 to ambient CO2 (Ci/Ca), suggesting that enhanced N availability and concomitant increase in whole plant area resulted in reduced plant water availability. The highest values of leaf C/N ratio, tuber to root mass ratio and dry weight content of roots (DWR) were found in N0 plants and the ones planted on the 10th of May and 20th of May. Our results collectively demonstrate that the growth and productivity of sweet potato is strongly dependent on the length of the growing season, and can be further constrained by utilization efficiency of N. We conclude that future research should focus on optimum sweet potato cultivation technologies at Northern latitudes.Kirje The influence of thermal shock and pre-sprouting on formation of yield structure elements in seed potatoes(Eesti Maaülikool, 2007) Eremeev, Viacheslav; Jõudu, Juhan (advisor); Noormets, Merrit (advisor)Stabiilse, majanduslikult tasuva kartulisaagi saamiseks on üheks põhikomponendiks terve, bioloogiliselt aktiivne ja suure saagipotentsiaaliga seeme, mis vastavalt kasutusotstarbele ka mahapanekuks ette valmistatakse. Seemne kvaliteedist sõltub kartuli tärkamine, pealsete moodustumine ning põllupinna kattumise kiirus. Kartuli kõrge saagipotentsiaali säilitamiseks tuleb kartuliseemne mahapanekuks valmistumise käigus jälgida, et kõik olulisemad saagikust suurendavad meetmed oleksid rakendatud. Seemnemugulate mahapanekueelne eelidandamine on laialdaselt kasutusel Hollandis, seda mitte üksnes varajase, vaid ka hilise kartuli puhul. Füsioloogiliselt noorel seemnemugulal on eeldused välja arendada täiuslikumad ja tugevamad juured ning kõik taime maapealsed osad, mis tagavad võimalikult suure assimilatsioonipinna. Nimetatud eeldused on aluseks suure mugulasaagi kujunemisele. Puuduseks on see, et mõningane tärkamise ja lehestikuga vaovahede kattuvuse hilinemine vähendab kartulitaimede konkurentsivõimet umbrohtudega. Hilisem assimilatsioonipinna ‘tööaeg’ langeb ajale, kui väheneb fotosünteetiliselt aktiivse kiirguse hulk. Kõige selle tagajärjel hilineb ka mugulasaagi koristusküpseks muutumine. Suhteliselt varajasema kartulisaagi saamine on oluline mitte ainult varajastel, vaid ka hilistel kartulisortidel. Hiliste sortide kasvatamine on vajalik nende suure saagipotentsiaali tõttu ja nad säilivad paremini. Varajasema kartulisaagi saamiseks on kasutusel mitmeid meetodeid, sealhulgas ka seemnemugulate termiline töötlemine, millega saab kartulimugulatele lisada füsioloogilist vanust ja muuta lühemaks see kronoloogiline aeg, mis on vajalik mugulasaagi koristusküpseks kujunemisel. Sellise meetodi kasutamine soodustab ensüümide aktiivsust mugulates, stimuleerib idude kiiremat arenemist silmadest, lühendab tärkamisperioodi pikkust, kiirendab taime arengut ja saagi moodustumist. Kui seemnemugulaid kevadel hoida mõnda aega kõrgemal temperatuuril, saame füsioloogiliselt vanemad mugulad. See on asjakohane nii varajase kui ka hilise kartuli kasvatamisel, sest pealsete massi ja lehepinna maksimum saavutatakse kiiremini ning majanduslikult optimaalset mugulasaaki on võimalik koristada varem. Samas aga füsioloogiliselt nooremad taimed võivad olla elujõulisemad ja moodustada isegi suurema mugulasaagi, kuid seda mõnevõrra hiljem. Käesoleva uurimuse hüpoteesiks oli, et kartuli erineva kasvuajaga sortide seemnemugulate lühiajaline mõjutamine kõrgema temperatuuriga mõjutab kartuli lehepinda, pealsete massi, mugulate arvukust ja mugulate massi arengut ning suurust. Käesoleva väitekirja eesmärgiks oli uurida: (1) kuidas termošokk ja eelidandamine mõjutavad kartulitaime erinevate osade (lehepinna, pealsete massi, ühe taime mugulate arvu, ühe mugula massi ja mugulasaagi) kujunemist vegetatsiooniperioodil, tagamaks kvaliteetse ja võimalikult varajase saagi moodustumise. (2) kas termošokiga on võimalik asendada pikaajalist ja energia-mahukat eelidandamist. Tulemused ja järeldused Katsete tulemused sõltusid olulisel määral konkreetse aasta ilmastikutingimustest. Ilmastikuliselt osutus kartulikasvuks kõige soodsamaks 2001. a, mis oli suhteliselt soe ning mugulate moodustumise ja intensiivse kasvu perioodil oli rahuldatud taimede veevajadus. Ja efektiivne lehemädanikutõrje tagas aktiivselt töötava lehepinna koristamiseni. Kolmeaastase uurimuse tulemustest saadud peamiseks järelduseks on, et väga varajase kartulisaagi saamiseks tuleb kasutada eelidandamist, sama ajal kui termošokk on eriti kasulik keskmise kuni varajase saagi moodustumiseks. Eelidandamise mõjul moodustub fotosünteetiliselt aktiivse lehepind, mis tagab suuremad mugulad ja sellest tulenevalt ka suurema saagi kui teiste töötlusvõtete puhul. Kuigi eelidandamisele kulub märkimisväärselt aega ja energiat, saadakse väga varajase saagiga kartulisordi täielik saagipotentsiaal. Termošokk seevastu on kasulik seemnemugulate tootmiseks, aga kuna see annab taime kohta rohkem mugulaid, siis nende keskmine mass on väiksem kui eelidandatud mugulatel. Teiseks leiti, et füsioloogiliselt vanematest seemnemugulatest moodustunud taimede pealsete mass moodustus kiiremini ning jäi väiksemaks. Seemnemugulate mahapanekueelne töötlemine (s.o füsioloogilise vanuse suurendamine) tagas põllul kiirema tärkamise. Mida aeglasemalt kartulitaimed oma pealsete maksimaalse kaalu saavutasid, seda suuremaks see kujunes. Füsioloogiliselt vanematel mugulatel ilmnesid selged vananemise märgid (alumiste lehtede osaline närbumine ja kolletumine) varem. Maksimaalse LAI väärtus ja selle moodustumise aeg olid sordispetsiifilised, varajasel sordil ‘Agrie Dzeltenie’ 4,0 ühikut 72. päevaks, keskvalmival sordil ‘Piret’ 3,7 ühikut 74. päevaks ja hilisel sordil ‘Ants’ 3,9 ühikut 75. päevaks. Kartul ei jõudnud realiseerida oma potentsiaali maksimaalselt, ta ei jõudnud saavutada oma saagi maksimumi. Eelidandamine ja termošokk avaldasid positiivset mõju terve vegetatsiooni perioodi jooksul, algul tugevamalt ning seejärel sujuvalt kahanedes. Seemnemugulate termiline töötlemine enne mahapanekut avaldab erineva kasvuajaga sortidele ka erinevat mõju. Kui võrrelda sorte omavahel, võib järeldata, et ‘Piret’ ja ‘Agrie Dzeltenie’ hakkavad varakult mugulaid moodustama ning ületasid sorti ‘Ants’ kuni 60. kasvupäevani pärast kartulipanekut. Sort ‘Ants’ saavutas oma maksimumsaagi juba 114. päevaks 47,0 t ha–1, millele järgnesid ‘Agrie Dzeltenie’ ja ‘Piret’. Termiline töötlemine ei andnud lõppsaagi moodustumises eelist, võrreldes töötlemata seemnega, välja arvatud sort ‘Agrie Dzeltenie’ eelidandatud variant, mis andis lõppsaagis 7,08 t ha–1 enamsaaki võrrelduna töötlemata variandiga. Termošokk ei olnud lehepinna ja mugulasaagi moodustumisel nii efektiivne kui eelidandamine. Sellele vaatamata olid töödeldud seemnemugulad füsioloogiliselt vanemad kui mitte-töödeldud proovid, võimaldades kiiremat lehepinna ja mugula kasvu ning arengut. Seemnemugulate mahapanekueelsel eelidandamisel oli taimede areng kogu kasvuperioodi jooksul kiirem, kuid termošokiga mõjutati vaid kasvutsükli esimesi etappe. Eelidandatud variant andis kogu vegetatsiooniperioodi jooksul märkimisväärselt suurema mugulasaagi.Kirje Kartulimardika (Leptinotarsa decemlineata Say) populatsiooni arvukuse prognoosi võimalikkus Eestis(Estonian Academic Agricultural Society, 2017) Hiiesaar, Külli; Eremeev, Viacheslav; Williams, Ingrid H.; Estonian University of Life Sciences. Institute of Agricultural and Environmental SciencesOn the basis of phenological observations and overwintering mortality data in 2015/2016 we tried to predict the population density of Colorado potato beetle (Leptinotarsa decemlineata Say) (CPB) for the following season. Because of the late and cool spring in 2015, the beetles started to emerge from the soil at the end of May and, because of the low temperatures, did not start to reproduce immediately. The first egg clutches did not appear until the end of June. The low density of larvae and beetles in mid-summer lead us to expect low damage for the whole season. However, very warm weather in August and September induced the beetles to lay eggs and the population density increased sharply. A lot of the summer beetles managed to terminate their development in time and to dig into the soil for overwintering. Consequently, we expected the beetles to be abundant the following spring. However, a short, snowless, very cold period in January when air temperature fell to –30 °C and soil temperature to –6.6 °C nullified this prediction as over 90% of overwintering beetles perished. In spring 2016, very few beetles were found on the field and the potato plants remained undamaged until the end of June. Then, due to south-east storms at the end of June, very large migrations occurred and, some weeks later, various development stages of CPB were very abundant in potato fields. Thus, none of our predictions came true. The main reason for this was our extremely unstable weather conditions during summer and the overwintering period and the unpredictable large migrations from southern regions.Kirje Kartulipealsete N, P ja K sisaldus 85. kasvupäeval ning nende seos mugulate kuivainesaagiga 100. kasvupäeval mahe- ja tavaviljeluses(Eesti Maaülikool; Maaelu Teadmuskeskus, 2026) Eremeev, Viacheslav; Margus, Kalle; Kuht, Jaan; Loit-Harro, Evelin; Luik, Anne; Talgre, Liina; Eesti Maaülikool. Põllumajandus- ja keskkonnainstituut. Taimekasvatuse õppetool; Eesti Maaülikool. Põllumajandus- ja keskkonnainstituut. Taimetervise õppetoolThis study examined whether potato haulm nutrient uptake near the end of the growing period is associated with tuber dry-matter yield and whether these relationships differ between organic and conventional management. Data were obtained from the long-term farming systems experiment at Eerika, Estonia for the periood of 2013–2016. Haulm was sampled on day 85, and total N, P and K uptake (kg ha–1) was calculated from nutrient concentrations and haulm dry mass. Tuber dry matter yield (t ha–1) was determined on day 100. Associations were evaluated using linear regression and Pearson correlation separately for organic (n = 48) and conventional (n = 64) systems. For N, the association with tuber dry-matter yield was statistically significant but weak in the conventional system (R = 0.27; p < 0.001) and not significant in the organic system (R = 0.19; p = 0.20). The strongest association was observed for phosphorus (conventional R = 0.78, p < 0.001; organic R = 0.31, p < 0.05). For potassium, the association was strong in the conventional system (R = 0.68; p < 0.001), but not significant in the organic system (R = 0.23; p = 0.114). Overall, late-season haulm nutrient uptake – particularly phosphorus – was associated with tuber dry matter yield, with stronger and more consistent associations in the conventional system.Kirje Umbrohtude biomassi, arvukuse ja mitmekesisuse muutused pikaajalise külvikorra katse teises rotatsioonis(Estonian Academic Agricultural Society, 2023) Madsen, Helena; Luik, Anne; Eremeev, Viacheslav; Mäeorg, Erkki; Talgre, Liina; Eesti Maaülikool. Põllumajandus- ja keskkonnainstituutThe effects of long term (established in 2008) five-field crop rotation (barley (Hordeum vulgare L.) with undersown red clover (Trifoium pratense L.), red clover, winter wheat (Triticum aestivum L.), pea (Pisum sativum L.), potato (Solanum tuberosum L.)) on the biomass, abundance and diversity (Shannon-Wiener index) of weeds in three organic (Org) and two conventional (Conv) systems after the second rotation were investigated. The results include data from the second rotation in 2013 – 2017. The control system (Org 0) followed only the crop rotation. In the organic systems Org I and Org II winter cover crops were used. In Org II system composted cattle manure was also applied. The conventional cropping systems were treated with herbicides and fungicides and system Conv 0 acted as control (no fertilizer use). Mineral fertilizer was used in Conv II. In general, the significant differences were evident between conventional and organic cropping systems. There were also some differences depending on the crop. The weed biomass was the lowest in barley and potato plots, with significantly higher values in organic than in conventional systems. In clover plots the highest biomass of weeds occurred in Conv II whilst the lowest in Org I. In winter wheat plots the biomass of weeds was significantly lower in conventional systems than in any of the organic systems. Pea plots had the highest biomass, abundance and diversity of weeds in all systems within all rotational crops. Slight tendencies showed the decrease of weed abundance and diversity at the end of the rotation in systems with cover crops (Org I and Org II). This could be explained by better growing conditions due to higher microbial activity and organic carbon content in the soil of organic systems.