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Wheat midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is a key pest of wheat, Triticum aestivum L. (Poaceae), in the Canadian Prairies. The larvae destroy wheat kernels, resulting in reduction of quality and quantity of wheat. Deployment of antixenotic wheat lines, which suppress oviposition of wheat midge, can reduce damage in wheat fields. The objectives of this thesis were to explore the interactions between wheat midge and spring wheat with emphasis on oviposition behavior and to explore the antixenosis of wheat to oviposition from the point of view of genetics and crop breeding. In this research, a doubled-haploid spring wheat population was studied, which was the progeny of a cross between a susceptible wheat cultivar ‘Roblin’ and a resistant (antixenotic and antibiotic) wheat line ‘Key 10’. Oviposition of wheat midge on wheat spikes in the laboratory was affected by visual and chemical cues. The visual contrast between wheat spikes and the background color in the laboratory was important in modifying oviposition of wheat midge on wheat spikes. Low contrast resulted in low egg density on wheat spikes in the laboratory. The egg density on wheat spikes in the laboratory decreased when the background color of the spikes was red or black; while yellow and blue backgrounds did not decrease egg density on the spikes. The laboratory study provided evidence that wheat midge oviposition was affected by volatiles emitted by wheat spikes. The volatiles of spikes of a post-anthesis susceptible wheat cultivar, ‘Roblin’, and a pre-anthesis resistant wheat line, ‘Key 10’, significantly suppressed the oviposition of wheat midge in the laboratory. It is hypothesized that these volatiles might be a factor in antixenosis of wheat against wheat midge in the doubled-haploid population studied. It is suggested that the differences of oviposition behavior in susceptible and antixenotic wheats, which was observed in the laboratory, might be due to volatiles emitted by wheat spikes. However, other factors such as tactile cues might also be involved. The observation of oviposition behavior in the laboratory on the susceptible wheat cultivar ‘Roblin’ showed that wheat midge started ovipositing sooner, stayed longer, laid more eggs and left the spike sooner after the last oviposition than on the antixenotic line ‘Key 10’. However, the time required for laying one egg was similar when wheat midge was on the susceptible or resistant wheat. The observed antennation behavior of wheat midge while probing the wheat spike might indicate that wheat midge probed for chemical cues emitted by the host plant. The observed ovipositor tapping and dragging on the wheat spike surface while probing the spike suggested that there might be receptors at the tip of the ovipositor which receive tactile cues from the plant surface, guiding oviposition. The correlations between morphological traits of bread wheat spikes and antixenosis in the laboratory were not high enough to conclude that those traits were associated with antixenosis. However, more research on fine scale morphological traits of the spike may reveal relationships with antixenosis. Based on data from a laboratory trial and trials in the field over two field seasons, it was concluded that the antixenosis to wheat midge in the doubled-haploid population was probably conferred by two genes with complementary interactions among genes, and a heritability of 67%. In the two field seasons, the least preferred line received 13% and 11% as many eggs as on ‘Roblin’; ‘Key 10’ received 57% and 20% as may eggs as on ‘Roblin’. Our study did not provide evidence for linkage between antixenosis genes and the antibiosis gene, Sm1, which is associated with death of larvae of wheat midge. The antixenosis of spring wheat against wheat midge can be considered as a promising mechanism for suppressing wheat midge oviposition in the field. More research is required to reveal additional genetic information which would help crop breeders in production of cultivars antixenotic to wheat midge.

Objective of the research – the research was to determine the effect of different sulphur fertilisation rates on the mineral sulphur content in soil and the seed/grain yield and quality of spring rape and spring wheat crops grown on low in sulphur sandy light loam Epicalcari – Endohypogleyic Cambisols and very low in sulphur sandy loam on light loam Orthi-Haplic Luvisols. Tasks of the research: To determine the effect of different sulphur fertilisation rates applied to low in sulphur sandy light loam Epicalcari – Endohypogleyic Cambisols and very low in sulphur sandy loam on light loam Orthi-Haplic Luvisols on: • Spring rapeseed yield and crop structural elements; • Spring rapeseed quality; • Spring wheat yield and crop structural elements; • Spring wheat grain quality; • Changes in the mineral sulphur content in soil. / Tyrimų tikslas – nustatyti skirtingų sieros trąšų normų įtaką vasarinių rapsų ir vasarinių kviečių derliui, jo kokybei bei mineralinės sieros kiekiui mažai ir labai mažai sieringame smėlingame lengvo priemolio sekliai karbonatingajame giliau glėjiškajame rudžemyje (Epicalcari – Endohypogleyic Cambisol ) ir priesmėlio ant lengvo priemolio tipingajame paprastajame išplautžemyje (Orthi-Haplic Luvisol). Tyrimų uždaviniai: Nustatyti sieros trąšų normų įtaką mažai ir labai mažai sieringame smėlingame lengvo priemolio sekliai karbonatingajame giliau glėjiškajame rudžemyje (Epicalcari – Endohypogleyic Cambisol ) ir priesmėlio ant lengvo priemolio tipingajame paprastajame išplautžemyje (Orthi-Haplic Luvisol): • Vasarinių rapsų sėklų derliui ir struktūros elementams. • Vasarinių rapsų sėklų kokybei. • Vasarinių kviečių derliui ir struktūros elementams • Vasarinių kviečių grūdų kokybei. • Mineralinės sieros kiekio pokyčiams dirvožemyje.

Wheat midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is a key pest of wheat, Triticum aestivum L. (Poaceae), in the Canadian Prairies. The larvae destroy wheat kernels, resulting in reduction of quality and quantity of wheat. Deployment of antixenotic wheat lines, which suppress oviposition of wheat midge, can reduce damage in wheat fields. The objectives of this thesis were to explore the interactions between wheat midge and spring wheat with emphasis on oviposition behavior and to explore the antixenosis of wheat to oviposition from the point of view of genetics and crop breeding. In this research, a doubled-haploid spring wheat population was studied, which was the progeny of a cross between a susceptible wheat cultivar ‘Roblin’ and a resistant (antixenotic and antibiotic) wheat line ‘Key 10’. Oviposition of wheat midge on wheat spikes in the laboratory was affected by visual and chemical cues. The visual contrast between wheat spikes and the background color in the laboratory was important in modifying oviposition of wheat midge on wheat spikes. Low contrast resulted in low egg density on wheat spikes in the laboratory. The egg density on wheat spikes in the laboratory decreased when the background color of the spikes was red or black; while yellow and blue backgrounds did not decrease egg density on the spikes. The laboratory study provided evidence that wheat midge oviposition was affected by volatiles emitted by wheat spikes. The volatiles of spikes of a post-anthesis susceptible wheat cultivar, ‘Roblin’, and a pre-anthesis resistant wheat line, ‘Key 10’, significantly suppressed the oviposition of wheat midge in the laboratory. It is hypothesized that these volatiles might be a factor in antixenosis of wheat against wheat midge in the doubled-haploid population studied. It is suggested that the differences of oviposition behavior in susceptible and antixenotic wheats, which was observed in the laboratory, might be due to volatiles emitted by wheat spikes. However, other factors such as tactile cues might also be involved. The observation of oviposition behavior in the laboratory on the susceptible wheat cultivar ‘Roblin’ showed that wheat midge started ovipositing sooner, stayed longer, laid more eggs and left the spike sooner after the last oviposition than on the antixenotic line ‘Key 10’. However, the time required for laying one egg was similar when wheat midge was on the susceptible or resistant wheat. The observed antennation behavior of wheat midge while probing the wheat spike might indicate that wheat midge probed for chemical cues emitted by the host plant. The observed ovipositor tapping and dragging on the wheat spike surface while probing the spike suggested that there might be receptors at the tip of the ovipositor which receive tactile cues from the plant surface, guiding oviposition. The correlations between morphological traits of bread wheat spikes and antixenosis in the laboratory were not high enough to conclude that those traits were associated with antixenosis. However, more research on fine scale morphological traits of the spike may reveal relationships with antixenosis. Based on data from a laboratory trial and trials in the field over two field seasons, it was concluded that the antixenosis to wheat midge in the doubled-haploid population was probably conferred by two genes with complementary interactions among genes, and a heritability of 67%. In the two field seasons, the least preferred line received 13% and 11% as many eggs as on ‘Roblin’; ‘Key 10’ received 57% and 20% as may eggs as on ‘Roblin’. Our study did not provide evidence for linkage between antixenosis genes and the antibiosis gene, Sm1, which is associated with death of larvae of wheat midge. The antixenosis of spring wheat against wheat midge can be considered as a promising mechanism for suppressing wheat midge oviposition in the field. More research is required to reveal additional genetic information which would help crop breeders in production of cultivars antixenotic to wheat midge.

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.

This thesis focuses on assessing the effectiveness of selected herbicides for spring wheat protection against most occurring dicotyledonous weeds. To verify the effectiveness of selected herbicides was small plot trial on the Farm Kašík, Blanné . The most frequent weeds were (Atriplex patula L., Capsella bursa - pastoris L., Stellaria media L., Thlaspi arvense L. and Tripleurospermum inodorum L.). In an attempt were applied four herbicides (MUSTANG FORTE, Sekator OD, Basagran Super , tank mix glean 75 WG + Dicopur M 750) at two different doses (the minimum and maximum doses recommended by the manufacturers). Effectiveness were evaluated in four measurements with the percentage of subjective estimation methods .

This diploma thesis Comparison of yield capacity of spring wheat varieties deals with small-scale experiments of three varieties (Astrid, Epos, Tercie) in two vegetation periods. Repetition variations were established in 2015 and 2016 on the school grounds of the Agricultural Faculty of the University of South Bohemia in České Budějovice. During two growing seasons the production of yield elements (the number of plants and the number of fertile crops - ears) was monitored for all varieties and after harvest other yield elements were evaluated the number of grains in the ear and weight of a thousand grains. Actual revenue was determined. Grain analysis determined the bulk density as a quality indicator. In the results and discussion the individual yield elements are described and statistically evaluated. The number of plants was better in 2015 regarding soil density characteristics. The number of fertile offsprings was the highest in the case of Astrid variety in the first production year (642). The number of grains in the ear was very variable for all observed varieties, both production years 2015 and 2016 (from 15 grains in the ear to 68 grains in the ear). Total actual yield was higher in 2015 than in 2016 (by 1.1 t.ha-1). Each spring wheat is characterized by its shorter growing season, during which it must optimally produce the highest yield possible and therefore needs adequate responsible care.

Dough strengtheners are the most common and largest group of chemicals used in bread formulations. This study evaluated the capability of hard red spring (HRS) wheat flour to replace commercial dough strengtheners in bread production. Doughs were prepared by blending different percentages (10%, 20%, 30% and 40%) of four different HRS wheat flours with hard red winter (HRW) wheat flour. In addition, doughs were prepared by adding ten commercially available additives with HRW wheat flour to compare the dough strengthening ability of HRS wheat flour. All the HRS wheat flour blends had significantly (p<0.05) strong dough rheological characteristics than most of the additives. The 40% blends of HRS wheat cultivar Glenn and Linkert had better bread making quality than other blends and all the additives. The SE-HPLC unextractable protein fractions of these two cultivars also showed a better correlation with bread making properties than all the additives.

Grain protein content is an essential component to producing a profitable Hard Red Spring Wheat (HRSW) (Triticum aestivum L.) crop in the northern Great Plains. Growers can increase grain protein content through in-season N fertilization; however, the cost of these applications may outweigh the benefits. Predicting the grain protein content of early-season HRSW would give growers crucial information as they decide whether to apply in-season fertilizer to boost grain protein content. This research encompasses three studies; two of which aim to predict grain protein content with hand-held and aerial sensors respectively, and a third, which investigates the optimal rate, timing, and source of N fertilizer to boost grain protein content. Results of these experiments seemed to be greatly influenced by environmental factors. Findings of this research suggest that an in-season N application should be used for ameliorative purposes and not as a regular practice. / Minnesota Research and Promotion Council / Minnesota Association of Wheat Growers

Magistrantūros studijų baigiamajame darbe pateikiami skystųjų amidinio azoto trąšų su magniu Lyderis Mg poveikio, vasariniams kviečiamas, tyrimai. Darbo objektas - Vasariniai kviečiai ‘Tybalt C2‘. Darbo metodai – Eksperimentas buvo atliktas ASU Bandymų stotyje, karbonatingame giliau glėjiškame išplautžemyje. Dirvožemis buvo artimas neutraliam (pHKCl 6,8), didelio fosforingumo (230 mg kg-1 P2O5), vidutinio kalingumo (152 mg kg-1 K2O), mažo azotingumo (2,0 proc.). Tyrimas buvo atliktas siekiant nustatyti optimaliausią LYDERIS Mg trąšų koncentraciją (0,25, 0,5, 0,75, 1,0 ir 2,5 %) vasariniams kviečiams. Tiriamomis priemonėmis augalai buvo nupurkšti krūmijimosi tarpsnio pabaigoje ir susiformavus antrajam bambliui. Darbo rezultatai - skystosios amidinio azoto trąšos (LYDERIS Mg) teigiamai įtakojo vasarinių kviečių produktyvumą. Didžiausi grūdų derliaus teigiami pokyčiai gauti vasarinius kviečius krūmijimosi tarpsnio pabaigoje tręšiant 0,75 – 2,5 % koncentracijos tirpalais, o bamblėjimo tarpsniu – 0,5 – 0,75 % koncentracijų tirpalais. Tiriamos priemonės teigiamai įtakojo grūdų technologines savybes. Grūdų baltymingumas tendencingai didėjo, didinant trąšų tirpalo koncentracijas, tačiau esminis poveikis nustatytas tik naudojant 0,75 % koncentracijos tirpalą. Sedimentacijos vertėms didesnį poveikį turėjo augalų tręšimas bamblėjimo tarpsnio pradžioje 0,5 - 0,75 % koncentracijų tirpalais. / Master's thesis presentsthe research that was carried out to investigate the effect of nitrogen liquid fertilizer with magnesium ‘Lyderis Mg’on spring wheat. Object of the research: spring wheat ‘Tybalt C2’. Research methods: the experiment was conducted at the Experimental Station of Aleksandras Stulginskis Universityon the Calc(ar)i-Endohypogleyic Luviso). The soil was neutral (6,8pH_KCl), high in phosphorus (230 mg kg^(-1)1P_2 O_5), medium in potassium (152 mg kg^(-1) K_2O), low in nitrogen (2,0 %). The research was conducted to determine the optimal concentration of fertilizer ‘Lyderis Mg’ (0,25, 0,5, 0,75 , 1,0 and 2,5 %) in spring wheat. Applying the measures under investigation the plants were sprayed at the end of tillering stage and at the second formation of a toddler. Research results: the liquid amide nitrogen fertilizer ‘Lyderis Mg’ has positively influenced the productivity of spring wheat. The application of fertilizer solution on spring wheat both at the end ofetillering stage with the concentrationvarying from 0,75 to 2,5 % and at the booting stagewith the concentration varying from 0,5 to 0,75 % resulted in the highest grain yield.The researched measures have positively influenced the technological properties of grains. By increasing the concentration of fertilizers grain protein content tended to rise, however, thesubstantial effect was determined only applying 0,75 % concentration of fertilizers. Values of sedimentation were higher when spring wheat were... [to full text]