The aim of this thesis is to evaluate basic yield formation and food quality of grain in selected winter wheat varieties, depending on the intensity of cultivation. There was 5 varieties chosen for the experiment of which 3 was linear (Patras, Turandot and Rumor) and 2 varieties was hybrid (Hyfi and Hybery). Each variety was repeated three times during the experiment. The vegetation was assessed in two variations - the checking one and the one fertilized by the nitrogen. This experiment was conducted in growing season 2017/2018 on the field of Faculty of Agriculture of University of South Bohemia. The withdrawal of the vegetal material for the purpose of the following sample analysis was done right before the harvesting. The yield formation and the health condition of the vegetation was assessed in the fieldwork. The determination of qualitative parameters was made with the help of the apparatus in the laboratory of the faculty. Then, the results was marked in tables and graphics. Finally, the statistical evaluation of the obtained data. An average yield of all assessed varieties of the winter wheat was 8,52 t.ha-1 at the checking variation. On the contrary, at the nitrogen fertilized one the average yield was 8,94 t.ha-1. The evaluated varieties in the growing season 2017/2018 had the baking quality A and B. Regarding the qualitative parameters, there was found lower values of volume quantity than those that are stated in the norm for the food wheat (at least 76,0 kg.hl-1). The highest values were found at the variety Turandot fertilized by nitrogen (77,8 kg.hl-1), which met the requirements of the ČSN 4611 00-2.

This thesis deals with yield formation with the 12 varieties of winter wheat during growing season 2013/2014. The experiment was established in four repetitions on the plot of Faculty of Agriculture, University of South Bohemia in České Budějovice. Examined yield components were the amount of spikes per 1 m2, amount of grains per spike and weight of thousand grains. Furthermore evaluated were the amount of plants per 1 m2, amount of spikelets in spike, real and theoretical yield, spike length and density. The next step was the processing of the results where the average value of all the varieties in the amount of ears per 1 m2 was 783 units/m2. The second element of the yield varieties reached the average number of grains per spike 36.2 pieces. And the mean weight of´thousand grains was 44.42 grams.

On the grounds of the South Bohemian University was founded in 2015 oneyear experiment. In this experiment we compared three classical and one naked variety of spring barley. Each variety were planted in four replications. For each repetition was assessed the number of emerged plants, number of tillers, number of ears, yield, thousand grain weight, the proportion of leading grain, density andcontent of nitrogenous substances. The average yield of the hulled varieties exceeded 6 t/ha, while in the nudevariety was 4,68 t/ha. The nude variety also showed the lowest HTZ, highest densityand the highest content of nitrogenous substances.

The theme of these Thesis - Yield formation of spring wheat - presents a comparison of selected varieties of spring wheat, which are grown in the Czech Republic. The field trials were set up in 2012 on the experimental area of the Faculty of Agriculture, University of South Bohemia in České Budějovice. In four replications was planted eight varieties of spring wheat - Corso, Brawura, Aranka, Tercie, Granny, Scirocco, Septima a Vánek. Results of spring varieties were compared with a control winter variety Baletka. During the vegetation was monitored weeds, diseases and pests and evaluated the number of plants. In the final section are evaluated yields main elements - number of spike per square meter, number of grains per spike, thousand grain weight. The yield, theoretical yield, spike lenght and density is presented there too. The average number of spikes in spring varieties reached of 520 pieces per square meter and control winter varietiy reached 491 pieces per sqare meter. Number of grains per spike was average 45 pieces and control winter variety was 37 pieces. The average thousand grain weight of spring varieties amounted to 31,7 grams and was comparable with the results of control winter variety.

The diploma thesis "Yield formation of winter wheat in ecological agriculture " is focused on classification of genotypes of bread wheat on the basis of the morphological characters and yield output of bread wheat in ecological farming system. The field trials were set up by using the method of random blocks in the years 2005 and 2006 on the experimental area of the Faculty of Agriculture, University of South Bohemia in České Budějovice. 10 Austrian genotypes of bread wheat were tested: Capo, Ludwig, Clever, Eurofit, Element, Eriwan, SE 408/04, SE 320/05, SE 304/05 a SE 322/04. The results are focused on the postharvest analysis the main yield components {--} number of spike per square meter, number of grains per spike, thousand grain weight (TGW). The yield and theoretical yield is presented there too. The number of grains per spike, the level of yield and TGW were relatively high. On the other hand the number of spikes per square meter doesn´t reach to expected value in ecological farming. The results were analysed by ANOVA of main effects in programme Statistica. The tested Austrian genotypes showed the possibility of using them in the conditions of ecological farming in the Czech Republic.

The Subject of diploma work: Yield formation of winter wheat depending on row width in ecological agriculture This work deals with the formation of winter wheat yield. Winter wheat was cultivated on the narrow and wide rows to field experiments. The attempt was focused mainly on creating yield components (number of plants per square meter, number of grains per spike, the weight of one thousand grains). There was also accomplished the verification during the vegetation and there was the comparison of the theoretic and real yield at the end.

The aim of the thesis was to assess the formation and reduction in the yield of naked and hulled oat varieties. The research was conducted two years and it was mainly focused on the main elements of income as a number of plants, cuttings, and lat per m2, further was assessed the number of grains per panicle 1, weight of thousand grains and total grain yield. As an additional assessment of quality indicators have been established; volume weight and the proportion of grains of the front. The values of determined individual elements have been compared to each other and evaluated by statistical analysis. The results based on the naked oat varieties attain average yields of grain; diameter compared varieties of naked oats totalled 3.03 tons per hectare, diameter of hulled varieties amounted to 5.03 tons per hectare and other indicators also moved around the average values. It was confirmed that the newer varieties are breeding to a higher threshold of revenue, while old varieties exhibit better values of the quality parameters.

Comment concilier productivité et réduction de l'usage des pesticides ? Le développement de l'oïdium, maladie majeure en viticulture, peut être limité (service de régulation de l'oïdium) par un faible niveau de développement végétatif de la vigne associé à une forte porosité du couvert. Or, de telles caractéristiques limitent également la quantité de rayonnement intercepté par la vigne, et donc la production de biomasse par photosynthèse, et finalement le rendement (service d'approvisionnement). Peut-on augmenter la régulation de l'oïdium sans diminuer le rendement de la vigne ? Autrement dit, existe-t-il une relation de compromis entre ces deux services ? Pour répondre à cette question, deux expérimentations ont été mobilisées : une expérimentation au champ réalisée près de Montpellier de 2010 à 2012 (Syrah), et un réseau de témoins non traités suivis par l'IFV dans la région de Bordeaux de 2007 à 2013. L'analyse des données issues de ces expérimentations a permis de montrer (i) que l'effet des stress hydrique et azoté sur la formation des inflorescences dans les bourgeons latents à la floraison de l'année n-1 détermine 65 à 70 \% du rendement de la vigne lors de l'année n ; (ii) que l'effet du développement végétatif de la vigne sur le développement de l'oïdium n'est significatif que dans le cas d'épidémies de précocité moyenne, dont les premiers symptômes ont été détectés sur feuilles entre la floraison et la fermeture de la grappe. Le développement végétatif de la vigne à la floraison est donc un indicateur pertinent du service de régulation de l'oïdium. Ces résultats ont ensuite permis de confirmer expérimentalement l'hypothèse de l'existence d'un compromis entre rendement de la vigne et régulation de l'oïdium et d'identifier le stress hydrique à la floraison comme un déterminant partagé de ces deux services. Ce dernier point a alors été transcrit dans un modèle simple dans lequel le rendement de la vigne de l'année n dépend principalement de l'année n-1, et le développement végétatif dépend seulement de l'année n. L'analyse des propriétés mathématiques de ce modèle a permis de montrer que la réalisation de compromis favorables entre ces deux services (i.e. un fort niveau des deux services) est possible mais déterminée par l'occurrence de séquences climatiques particulières (une année humide suivie d'une année sèche). Ainsi, les compromis favorables ne peuvent être atteints deux années consécutives et ne sont donc pas stables dans le temps. Les règles de décisions d'application des traitements phytosanitaires pourraient ainsi être adaptées en fonction de la variabilité climatique inter-annuelle et de ses conséquences sur les compromis entre le rendement de la vigne et la régulation des maladies cryptogamiques. / How to combine crop productivity and reduction in pesticide use ? A reduction in plant growth and an increase in crop canopy porosity has been shown to limit the development of the grapevine powdery mildew (powdery mildew regulation service), which is a major disease in viticulture. However, this could also limit grapevine yield through a reduction in light interception and biomass production through photosynthesis. Can regulation of powdery mildew be increased without grapevine yield impairment ? In other words, do these two services trade off ? To address this question, two experiments were used. A field experiment was conducted in Montpellier from 2010 to 2012 on Shiraz, and a network of non-sprayed vineyard plots was monitored by the French Institute of Vine and wine in the Bordeaux region from 2007 to 2013. Data analyses showed that: (i) 65 to 70 \% of grapevine yield in year n were determined by the effect of water and nitrogen stresses on inflorescence formation in the latent buds at flowering in year n-1; (ii) the effect of grapevine vegetative development on powdery mildew depended on epidemic earliness and was significant only when first symptoms were detected on leaves between flowering and bunch closure. Grapevine vegetative development at flowering was therefore a relevant indicator of the powdery mildew regulation service. Based on these results, the hypothesis of a trade-off between grapevine yield and powdery mildew regulation was experimentally confirmed and water stress at flowering was identified as a shared driver of these two services. Then, a simple model was built that accounted for the effect of water stress at flowering on the two services, where grapevine yield depended mostly on year n-1 and grapevine vegetative development depended only on year n conditions. Analysis of the model's mathematical properties showed that "win-win" scenarios (high level of both services) did exist and were reached when specific climatic sequences occured (a wet year followed by a dry year). The "win-win" scenarios could not be reached two consecutive years and were therefore temporally unstable. Decision rules for pesticides application may be adapted in function of the inter-annual climatic variability and its effect on the trade-off between grapevine yield and regulation powdery mildew.