EMU DSpace – Eesti Maaülikooli digitaalarhiiv
Digitaalarhiiv EMU DSpace kogub, säilitab ja loob ligipääsu Eesti Maaülikooli liikmeskonna poolt loodud või Eesti Maaülikooli vastutusvaldkondadega seotud teadustöödele toetamaks maaülikooli konkurentsivõimet ja teadmistepõhist ühiskonna arengut. Digitaalarhiivi haldab Eesti Maaülikooli raamatukogu.
Valdkonnad DSpace's
Valige valdkond, et selle kogusid sirvida.
- Institute of Forestry and Engineering (MMI)
- Institute of Agricultural and Environmental Sciences (PKI)
- Institute of Veterinary Medicine and Animal Sciences (VLI)
- Publications
- Units
Hiljutised sisestused
Role of leaf anatomy in photosynthetic modifications during plant ontogeny and upon environmental acclimation
(Estonian University of Life Sciences, 2024) Kuusk, Vivian; Niinemets, Ülo (advisor); Institute of Agricultural and Environmental Sciences; Fernández-Marín, Beatriz (opponent)
To cultivate plant species and varieties best suited to our future environment, it is essential to gain a deep understanding of how plants acclimate to their surrounding conditions and which changes do they undergo during their life. The internal structure of plants, plant anatomy, plays a crucial role in this acclimation. This study focuses on investigating the anatomical and physiological changes that occur during plant aging and in response to high growth temperatures.
Plants are the most important component of Earth's ecosystem, as the existence of all other living organisms depends on them. Since plants cannot change their location, they have evolved the ability to adapt to environmental conditions and modify themselves as needed. For young plants, survival and sufficiently rapid growth, including the development of a strong root system and foliage, are of utmost importance. Using three Mediterranean pine species (Pinus halepensis, P. pinea, P. nigra) as examples, we demonstrate how their photosynthetic capacity changes over time depending on the anatomy of their needles and what causes these changes. What makes this study unique is the precise mapping of the changes occurring in the needles as they age and their correlation with photosynthetic capacity.
The second aim of this study is to investigate the effects of elevated growth temperatures on plant anatomy and isoprene emission. Almost all plant leaves emit isoprene, the most abundant volatile compound globally, whose emission is strongly influenced by the plant's growth environment. Isoprene is highly chemically reactive and significantly impacts atmospheric chemistry. Given its widespread importance, a detailed understanding of all aspects of its emission is essential to ensure more accurate models and future predictions related to isoprene.
This study demonstrates that elevated growth temperatures substantially alter leaf anatomy, which in turn affects photosynthesis and isoprene emission per leaf area. The research aims and succeeds to gain a better understanding of the anatomical changes in plants under challenging conditions: when a young plant establishes itself in its habitat and when it grows under temperatures higher than normal for the species.
Suitability of cruciferous oilseeds as cover crops, their disease resistance and optimized cultivation technologies for improved overwintering and yield
(Estonian University of Life Sciences, 2024) Lääniste, Peeter; Runno-Paurson, Eve (advisor); Niinemets, Ülo (advisor); Institute of Agricultural and Environmental Sciences; Kadžienė, Gražina (opponent)
Cruciferous field crops are important as oil crops and inhibitors of some soil pathogens. At the same time they can be susceptible to various other diseases, as they have been intensively cultivated in short rotations. There are lot of problems with the cultivation of the main oil crop - winter rapeseed in Estonia, mostly evident through instability of seed yields. Previous studies have indicated that the cultivation of winter rapeseed as a cover crop reduces the presence of pathogen, that is causing the potato late blight; different cruciferous species have large variation in resistance to crop diseases; and the successful overwintering of winter rapeseed is related to weather conditions, sowing time and seed rates. Therefore, following hypotheses were set at the start of present research: 1) The cultivation of winter rapeseed as a cover crop has positive effect on controlling the abundance of pathogen that is causing late blight in potato, resulting in higher tuber yield; 2) The alternative cruciferous oil crops are more resistant to powdery mildew than spring rapeseed; 3) The spring rapeseed is more susceptible to Alternaria black spot disease than alternative cruciferous species; 4) The growth and development as well as the yield of winter rapeseed is dependent on the sowing time, seed rate and the sum of active temperatures during autumn growth; 5) Successful overwintering and yield potential are directly related to certain crop parameters measured in autumn. Based on the results of present thesis it was found that when cultivating winter rapeseed as a cover crop, the late blight infection emerged slightly later and there was a decrease in damaged area, but the effects on disease suppression and tuber yield were not significant. The alternative cruciferous oil crops like white mustard, ruccola/arugula and oilseed radish were not infected with powdery mildew and black spot disease, even during favourable conditions for the pathogens. Hence, these species could be used as cruciferous crops in rotations without the use of pesticides. The most suitable period for sowing winter rapeseed was in the middle of August, allowing plants to optimize their parameters for winter survival. Good indicator was the time when 7-8 true leaves had been formed, resulting in 70% survival rate and also providing higher seed yield potential.
Aasta muld 2025. Klibumuld : [teavik ja postkaart]
(Eesti Maaülikool, 2024) Leedu, Enn; Astover, Alar; Penu, Priit; Kikas, Tambet; Eesti Maaülikool. Põllumajandus- ja keskkonnainstituut
Klibumullad on rähkmuldade alamliik, mis on välja kujunenud rannavallidel oleval karbonaatsel veerisel ja klibul või koreselistel liustikujõgede setetel. Nende lähtekivimiks on klibu, mida iseloomustab väga vähene peeneselise materjali sisaldus ja kohati
isegi selle puudumine. Klibu on korese alajaotus, mille hulka kuuluvad ümardunud servadega lapikud 1–10 cm läbimõõduga kivid. Klibu kivid on kujult sobivad lutsuviskamiseks.
Comparative welfare evaluation of sheep production systems
(Estonian University of Life Sciences, 2024) Marcone, Giovanni; Arney, David (advisor); Piirsalu, Peep (advisor); Institute of Veterinary Medicine and Animal Sciences; Norring, Marianna (opponent)
The welfare of animals in livestock production is of importance for the animals, the general public and the sustainability of animal agriculture. Ways of assessing welfare for sheep have been developed, but those available are complex, time-consuming and may not be appropriate for the different ways of keeping sheep, different sheep breeds and different climatic conditions. This doctoral thesis examines some welfare problems of sheep farming, including issues related to weather conditions, and devises and tests a simplified welfare evaluation system for sheep that is reliable, easy-to use and is focussed on actual problems. Findings include: Sheep prefer to be outside even in the winter, and even in the cool winters of Estonia, so we should allow sheep to have access to the outdoors, even in winter. In the summer, even in the relatively cool summers of northern Europe, sheep can suffer from heat stress. If sheep are at pasture during warm days they will use shade if it is available, and if they do not have access to shade they are more likely to suffer from the heat. So we should ensure that sheep have access to shade while at pasture. Sheep panting score was used to assess heat stress. This is a simple measure to observe and could be included in sheep welfare assessment protocols. The importance of different welfare indicators for sheep of different interest groups was investigated. In brief, farmers thought that body condition (too thin sheep) was the most important welfare indicator, whereas the general public thought that lameness was the most important. Female respondents thought that welfare issues were more significant than male respondents. A simplified protocol to assess the welfare of sheep was developed, using inputs from welfare scientists and from farmers themselves. This was demonstrated to be practical and easy to use. This could be used by welfare assessors but also by farmers to easily check the welfare of their own sheep themselves.
Response on light interception and radiation use efficiency of selected winter cereals at optimum N fertilizers : [Retracted]
(Estonian University of Life Sciences, 2018) Biabani, A.; Etesam, M.; Rahemi Karizaki, A.; Gholizadeh, A.; Sabouri, H.