Crop yields are coming under pressure to continue to grow in the face of climate change, competition, disease and pressure to reduce inputs. Photosynthetic efficiency is being targeted for improvement to increase yields. This study examined the variation in parameters of photosynthetic efficiency including canopy structure (leaf length, canopy angle, and chlorophyll content and growth rate) and gas exchange (photosynthetic rate, stomatal density and chlorophyll fluorescence) in Spring Barley (Hordeum vulgare ssp vulgare). These were first established for modern cultivars representing the most widely grown lines in the last 60 years. As cultivars are developed from a small pool of parents they may have limited genetic variation available for breeding. Landraces have been suggested as sources of variation. Using field and growth cabinet based studies the photosynthetic efficiencies of canopy structure and gas exchange were established for a range of European landraces under high and low nutrient inputs. This study demonstrated that in modern cultivars the leaf length increased with year of release from 23.2 to 29.6 cm and the chlorophyll content decreased from 46.9 to 34.8 SPAD units. Once the ear had emerged no difference was seen in canopy structure or photosynthetic rate. There was variation in landrace canopy establishment rate, leaf angle and number of leaves present within the canopy. The landraces from Northern European latitudes pushed though booting and reached full canopy establishment up to 8 days sooner than those from Southern Europe. This may be a response to a shorter growth season at Northern latitudes requiring the canopy to be established quickly. The landraces held the leaves within their canopy in a more horizontal position than the Southern European lines with leaf angle ranging from 18-45 degrees at GS39 and 31-84 degrees at GS59. This regressed negatively with temperature so it may be that a vertical canopy structure is beneficial in areas with higher temperatures. The photosynthetic rate of the landraces showed no variation but when chlorophyll fluorescence examined the efficiency of photosystem II (PSII) there was a positive regression of Fv/Fm ratio with latitude. This suggested that lines from Southern Europe were experiencing a greater stress with a ratio of up to 0.822 compared to those lines from the North with ratios from 0.767. The stomatal density of the landraces showed a large difference in ranges from 22-41 stomata between the lines. When high and low nutrient inputs were compared reductions from a ratio of 0.48 to 0.47 in Harvest Index and from 55g to 52g in 1000 grain weight were seen. The chlorophyll content of the lines was also reduced from 41.7 to 39.2 SPAD units at GS39 and from 44.9 to 39.8 SPAD units at GS59 by the reduction in nutrient inputs which may be a result of less N available for the production of chlorophyll. In conclusion there is variation present in canopy structure in European landraces that may be useful for future breeding or in identifying landrace collections which could be targeted for traits of interest in photosynthetic efficiency. These landraces may provide traits which could be used to develop cultivars which are locally adapted to climate and environmental conditions.

The aim of this diploma thesis was an evaluation of the environmental aspects of growing of the chosen feeding varieties of a spring barley in various systems of farming. Further purpose of this diploma thesis was a quantification of an emission load bond with the unit of area, and the unit of yield of spring barley, in the scope of conventional and ecological system of farming. The part of this study was a formation of the literature survey about problems of the conventional and ecological growing of the spring barley, with the focus on the agrotechnical requirements and environmental aspects. The practical part was performed in the area of the Faculty of Agriculture in Czech Budejovice.

The dissertation is focused on the findings, whether it is combination of physical and biological seed treatment for selected field crops (oilseed rape, spring barley) comparable with chemical treatment. Evaluated the effectiveness of the physical seed treatment, low temperature plasma (Gliding Arc, microwave), a biological treatment culture mycoparasitic of the fungus Trichoderma virens and culture entomopathogenic fungus Metarhizium anisopliae. In the context of experiments in laboratory conditions, was evaluated the effect of treatment on the evolution grains (the seeds), the percentage of germination grains (the seeds) and the percentage of healthy grains (the seeds). Individual plasma treatment in combination with biological treatment had a significant positive effect on the germination rate of grains (the seeds).There was no negative effect of physical and biological treatments on the grains (seeds). Involved the evaluation of emergence of the treated seed in laboratory and field conditions. In the field conditions for the selected crops in different localities and in different years, was assessed the effect of treatment on the development of the crop health and yield parameters. Plasma and plasma with T. virens treatments positively affected by the model of the plant better integration of crops, the length of the cob, (shell) and yield. The combined adjustment should in oilseed rape positive effect on the faster development of the spring, the length and strength of the root, earlier flowering and ripening. In contrast, the combined adjustment for barley spring positively influenced the emergence and tillering. According to the obtained results it seems that the combined physical and biological seed treatment is an effective alternative to the chemical treatment of seeds.

Oxidative stress, described as an imbalance between the concentration of reactive oxygen species (ROS) and antioxidants, is one of the most important mechanisms of stressors’ action on plants. On the other hand, similar plants’ response to different stress factors and oxidative stress induced increase in the activity of antioxidative enzymes triggers plants’ adaptation to the particular stressor, as well as cross-adaptation to different stress factors. The aim of the dissertation research is to investigate the impact of different stress factors (ozone, UV-B radiation, drought and heavy metals) on growth and intensity of oxidative stress of spring barley, and to estimate the role of oxidative stress and antioxidative system on plants resistance and cross-adaptation to different stress factors. It was detected, that oxidative stress is the major cause of plant’s growth reduction induced by similar stress factors (heavy metals), whereas the specific impact of stressors is low. When plants are exposed to different stressors (drought, ozone, UV-B radiation, heavy metals Cd and Cu), the impact of their specific action increases, however, oxidative stress remains the major reason of plants’ growth reduction. The increase in antioxidative protection and the reduction in the intensity of oxidative stress is the reason of plant adaptation to the stressors with strong oxidative features (Cu and ozone); whereas cross-adaptation to the stressors with lower oxidative potential (Cd and UV-B... [to full text] / Vienas iš pagrindinių daugumos stresorių neigiamo poveikio augalams mechanizmų yra oksidacinis stresas – disbalansas tarp aktyvių deguonies junginių (ADJ) ir antioksidantų koncentracijos bei aktyvumo pokyčių ląstelėje. Kita vertus, panaši augalų reakcija į skirtingų veiksnių poveikį bei oksidacinio streso sužadintas antioksidacinių fermentų aktyvumo padidėjimas gali lemti augalų prisitaikymą ir padidėjusį jų atsparumą ne tik tam pačiam, bet ir kitiems nepalankiems veiksniams, t. y. kryžminę adaptaciją. Disertacijos tyrimų tikslas – ištirti skirtingų savo prigimtimi streso veiksnių (ozono, UV-B spinduliuotės, sausros ir sunkiųjų metalų) poveikį vasarinių miežių augimui ir oksidacinio streso stiprumui ir įvertinti oksidacinio streso bei antioksidacinės sistemos įtaką augalų atsparumui skirtingų stresorių poveikiui ir kryžminės adaptacijos formavimuisi. Nustatyta, kad skirtingų tos pačios grupės veiksnių (sunkiųjų metalų) sukeltas oksidacinis stresas labiausiai lemia miežių augimo depresiją, o savitasis atskirų veiksnių poveikis yra nežymus. Veikiant skirtingos prigimties aplinkos veiksniams (sausrai, ozonui, UV-B spinduliuotei, sunkiesiems metalams) savitojo jų poveikio įtaka miežių augimui sustiprėja, tačiau oksidacinio streso poveikis vis tiek lieka stipriausias. Antioksidacinės sistemos aktyvumo padidėjimas ir oksidacinio streso susilpnėjimas lemia miežių kryžminę adaptaciją stipriomis oksidacinėmis savybėmis pasižyminčių aplinkos veiksnių poveikiui (variui ir ozonui), o... [toliau žr. visą tekstą]

Vienas iš pagrindinių daugumos stresorių neigiamo poveikio augalams mechanizmų yra oksidacinis stresas – disbalansas tarp aktyvių deguonies junginių (ADJ) ir antioksidantų koncentracijos bei aktyvumo pokyčių ląstelėje. Kita vertus, panaši augalų reakcija į skirtingų veiksnių poveikį bei oksidacinio streso sužadintas antioksidacinių fermentų aktyvumo padidėjimas gali lemti augalų prisitaikymą ir padidėjusį jų atsparumą ne tik tam pačiam, bet ir kitiems nepalankiems veiksniams, t. y. kryžminę adaptaciją. Disertacijos tyrimų tikslas – ištirti skirtingų savo prigimtimi streso veiksnių (ozono, UV-B spinduliuotės, sausros ir sunkiųjų metalų) poveikį vasarinių miežių augimui ir oksidacinio streso stiprumui ir įvertinti oksidacinio streso bei antioksidacinės sistemos įtaką augalų atsparumui skirtingų stresorių poveikiui ir kryžminės adaptacijos formavimuisi. Nustatyta, kad skirtingų tos pačios grupės veiksnių (sunkiųjų metalų) sukeltas oksidacinis stresas labiausiai lemia miežių augimo depresiją, o savitasis atskirų veiksnių poveikis yra nežymus. Veikiant skirtingos prigimties aplinkos veiksniams (sausrai, ozonui, UV-B spinduliuotei, sunkiesiems metalams) savitojo jų poveikio įtaka miežių augimui sustiprėja, tačiau oksidacinio streso poveikis vis tiek lieka stipriausias. Antioksidacinės sistemos aktyvumo padidėjimas ir oksidacinio streso susilpnėjimas lemia miežių kryžminę adaptaciją stipriomis oksidacinėmis savybėmis pasižyminčių aplinkos veiksnių poveikiui (variui ir ozonui), o... [toliau žr. visą tekstą] / Oxidative stress, described as an imbalance between the concentration of reactive oxygen species (ROS) and antioxidants, is one of the most important mechanisms of stressors’ action on plants. On the other hand, similar plants’ response to different stress factors and oxidative stress induced increase in the activity of antioxidative enzymes triggers plants’ adaptation to the particular stressor, as well as cross-adaptation to different stress factors. The aim of the dissertation research is to investigate the impact of different stress factors (ozone, UV-B radiation, drought and heavy metals) on growth and intensity of oxidative stress of spring barley, and to estimate the role of oxidative stress and antioxidative system on plants resistance and cross-adaptation to different stress factors. It was detected, that oxidative stress is the major cause of plant’s growth reduction induced by similar stress factors (heavy metals), whereas the specific impact of stressors is low. When plants are exposed to different stressors (drought, ozone, UV-B radiation, heavy metals Cd and Cu), the impact of their specific action increases, however, oxidative stress remains the major reason of plants’ growth reduction. The increase in antioxidative protection and the reduction in the intensity of oxidative stress is the reason of plant adaptation to the stressors with strong oxidative features (Cu and ozone); whereas cross-adaptation to the stressors with lower oxidative potential (Cd and UV-B... [to full text]

Integrated Pest Management (IPM) has long been promoted as a means of reducing reliance on pesticide inputs as compared to conventional farming systems. Reduced pesticide application could be beneficial due to the links between intensive pesticide use and negative impacts upon biodiversity and human health as well as the development of pesticide resistance. Work assessing the potential of IPM in cereal production is currently limited, however, and previous findings have generally covered the subject from the perspective of either field trial data or social science studies of farmer behaviour. This thesis attempts to help to address this knowledge gap by providing a more holistic assessment of IPM in Scottish spring barley production (selected because of its dominance in Scotland’s arable production systems), in relation to three of its most damaging fungal pathogens: Rhynchosporium commune, Blumeria graminis f.sp. hordei, and Ramularia collo-cygni. Several IPM techniques of potential relevance to the sector were identified, and the prospects of three in particular – crop rotation, varietal disease resistance, and forecasting disease pressure – were assessed in several ways. Preliminary analysis of experimental field trial data collected from 2011 – 2014 across Scotland found that the majority of spring barley trials in this period (65%) did not show a statistically significant impact of fungicide treatment on yield, with the average yield increase due to fungicide application being 0.62 t/ha. This initial analysis was expanded upon using stepwise regressions of long-term (1996 – 2014) field trial data from the same dataset. Here, the difference between treated and untreated yields could be explained by disease resistance, average seasonal rainfall (whereby wetter seasons saw an increased impact of fungicide use on yield), and high combined disease severity. Stakeholder surveying provided information about current practice and attitudes towards the selected IPM techniques amongst a group of 43 Scottish spring barley farmers and 36 agronomists. Stakeholders were broadly open to taking up IPM measures on farm; sowing of disease resistant varieties was most frequently selected as the best technique in terms of both practicality and cost, though individual preference varied. However, a disparity was seen between farmer perception of their uptake of IPM and actual, self-reported uptake for both varietal disease resistance and rotation. Farmers and agronomists also overestimated the impact of fungicide use as compared with the field trials results – the majority of stakeholders believed fungicide treatment to increase yields by 1 - 2 t/ha, while the majority of 2011 – 2014 field trials had a yield difference of under 1 t/ha. The reasons behind these differences between perception and practice are not currently known. Finally, an annual survey of commercial crops, gathered from 552 farms across Scotland (from 2009 – 2015), highlighted two gaps where IPM practice could be improved upon. Firstly, relatively few of the varieties listed in the commercial crops database were highly resistant to the three diseases – 26.1% were highly resistant to Ramularia, 14.2% to Rhynchosporium, and 58.1% to mildew. Secondly, 71% of the farms included in the database had planted barley in at least two consecutive seasons, indicating that crop rotation practices could be improved. The overarching finding of this project is that there is scope for IPM uptake to be improved upon and fungicide use to be reduced while maintaining high levels of yield in Scottish spring barley production. Incorporating experimental field data, stakeholder surveying, and commercial practice data offered a unique view into the potential for IPM in this sector, and provided insights which could not have been gained through the lens of a single discipline.

Langzeitdüngungsversuche (LTFE) sind für die Agrarforschung von entscheidender Bedeutung, da sie dokumentieren, überwachen, lernen und zeigen können, was in der Vergangenheit geschehen ist, und mit Hilfe von Vorhersagemodellen vorhersagen und simulieren können, was in Zukunft geschehen wird. Diese Modelle dienen dazu, zukünftiges Pflanzenwachstum unter verschiedenen Klima- und Bewirtschaftungsszenarien abzuschätzen und so Entscheidungsprozesse zu unterstützen. In diese Studie wurden die Reaktionen der Getreideerträge auf das Düngermanagement in Sandböden in einem LTFE (1971 bis 2016) in Nordostdeutschland analysiert. Die Ziele dieser Studie waren a) die Analyse der Ertragsreaktionen von Sommergerste, Winterroggen und Winterweizen auf das Düngemanagement, b) die Analyse der Sensitivität der Ertragsreaktionen auf den Zeitpunkt von Wetterereignissen und c) der Vergleich verschiedener Analysemodelle. Die Studie ergab, dass die Reaktion der Getreideerträge auf das Düngermanagement von komplexen Beziehungen zwischen Klimaabhängigkeit, Vorfrucht und Bodeneigenschaften beeinflusst wurde. Die Witterungsbedingungen bei der Aussaat und in den frühen Wachstumsstadien des Getreides beeinflusste den Kornertrag. Bei Wintergetreide waren die Intensität und Dauer der extremen Temperaturen im Sommer, insbesondere die Anzahl der Tage mit einer Höchsttemperatur von über 30°C im Juli, eine wichtige Variable für den Ertrag. Unter den untersuchten Modellen zeigte das LMM-Modell eine bessere Vorhersageleistung als das M5P-Modell, und beide hatten umfangreichere Regressoren als die ANOVA und die BMA. Das M5P-Modell bot eine intuitive Visualisierung wichtiger Variablen und ihrer kritischen Schwellenwerte und offenbarte andere Variablen, die vom LMM-Modell nicht erfasst wurden. Die Ergebnisse dieser Analyse tragen zu umfassenden Strategien für eine nachhaltige Pflanzenproduktion im Hinblick auf den zukünftigen Klimawandel bei. / Long-term fertilizer experiments (LTFEs) are essential for agricultural research as they provide necessary information and data to build predictive models. These models can be used to estimate future plant growth under different climate and management scenarios to support decision-making processes. The current study analyzed cereal grain yield responses to fertilizer management in sandy soil in a LTFE (1971 to 2016) in Northeast Germany. The objectives of this study were to a) analyze yield responses of spring barley), winter rye, and winter wheat to fertilizer management, b) analyze the sensitivity of yield responses to timing of weather events, and c) compare different analysis models. The study revealed that cereal yield response to fertilizer management was influenced by complex relationships among climatic dependence, preceding crop, and soil characteristics. Weather conditions at seeding and early growth stages of cereal were found to be sensitive to grain yield. For winter cereals, the intensity and duration of extreme temperatures in the summertime (harvest year), especially the number of days recorded with a maximum temperature above 30°C in July was an important variable for the yield. Among the investigated models, LMM-model had a better predictive performance compared to M5P-model and both had richer regressors than the ANOVA and BMA-model. The M5P-model presented an intuitive visualization of important variables and their critical thresholds, and revealed other variables that were not captured by the LMM-model. The findings of this analysis contribute to comprehensive strategies for sustainable crop production with regard to future climate change.