Master of Science / Department of Grain Science and Industry / Rebecca A. Regan / A laboratory-scale method for wheat germination was developed and used to compare hard red winter wheat varieties for sprout related attributes, activity, and whole wheat bread baking performance. WB 4458, WB Grainfield, LCS Mint, LCS Wizard, SY Monument, and T158 wheat varieties grown in three Kansas locations were germinated with the developed small-scale germination method and falling number values were compared. Byrd, Tam 204, and T158 were germinated with a scaled-up germination method aimed at generating samples in three falling number ranges of less than 120 seconds (low falling number and highly sprouted), 250±40 seconds (medium falling number), and 350±40 seconds (high falling number and low sprouting). Controls were un-germinated, sound (>400 seconds falling number), samples of each variety. The control whole grain and sprouted wheat was ground into flour. A mixograph was used to determine dough water absorption and mixing time. Whole wheat bread was made to determine bread volume, crumb characteristics, and bread texture. Overall there were few significant differences within each wheat variety for the different levels of germination. The only significant difference observed in all three varieties was that each highly sprouted grain (<120 seconds falling number) produced bread with significantly lower elasticity than the control within each variety, indicating that this level of germination produced a gummier bread. Elasticity was positively correlated with falling number (r=+0.71). A focused analysis on the Byrd variety compared the germinated samples to samples generated with added malted barley to the same falling number ranges. RVA analysis showed the gelatinization profiles for germinated and malted samples were similar within each falling number range. The highly and medium sprouted grain had significantly lower dough water absorption than the malted counterparts for those levels and the medium sprouted grain also had a lower mix time then the malted sample. There were no significant differences in bread volume, crumb characteristics, or bread texture except the highly sprouted grain had significantly lower elasticity than the control and the malted counterpart was not significantly different. In general, this experiment demonstrated that variety and germination conditions are important considerations in sprouting wheat and that whole wheat flour made from a wide range of germination levels produced quality bread that was not different from the control for most of the parameters investigated.

High pre-harvest rainfall in 2006 caused significant pre-harvest sprouting (PHS) and weathering throughout the mid-Atlantic soft red winter wheat (SRWW) (Triticum aestivum L.) growing region. Sprouting and weathering caused decreased flour quality due to lowered dough viscosity and decreased ability to withstand mixing and processing for baked goods. Due to its decreased quality, severely sprouted grain is sold for feed, at a lower price per bushel. Pre-harvest sprouting negatively affects the chain of production from the field to baking operations. The purpose of this research was to evaluate the inherent dormancy and PHS resistance, of current SRWW cultivars and to assess the relationship between falling number and flour quality after grain weathering. Employing a weighted germination index (WGI), a large range in dormancy was observed across SRWW cultivars and seed production. Artificial weathering tests confirmed the use of WGI as a tool for screening for dormancy of SRWW cultivars. The WGI consistently identified cultivars with significantly higher or lower inherent dormancy. "Coker 9553" was highly dormant and resistant to PHS. This cultivar maintained an average falling number of 300 seconds even after receiving an average of 215 mm of rainfall, while the mean falling number for all SRWW cultivars after this amount of weathering was 131 seconds. After only moderate weathering, nine of 15 SRWW cultivars in the study exhibited severe sprouting, demonstrating the need for increased PHS resistance in SRWW wheat. Pre-harvest sprouting resistance groupings, based on average 2008 cultivar falling number were accurately predicted by WGI at both 10 (R2=0.79) and 30°C (R2=0.72) No consistent relationship was observed between head angle, glume tenacity or awn length and PHS resistance. Water absorption, dough stability, farinograph arrival and departure times, peak, and 20-minute drop were measured from grain samples with varying degrees of weathering. All parameters were negatively affected by weathering in 2008. Flour quality parameters were more affected by genotype than falling number suggesting that falling number should not be used as the sole indicator of flour quality after grain weathering. It is clear that there are vast differences in dormancy levels and PHS resistance among SRWW cultivars and stronger dormancy and higher resistance to PHS does not automatically ensure higher quality flour. / Master of Science

[Truncated abstract] Wheat is the main crop in Australia and there are stringent quality requirements. Preharvest sprouting induced by rainfall between maturity and harvest lowers grain quality from premium to feed grades and reduces yield. Wheat production has expanded into the southern Western Australian region where preharvest sprouting occurs in ~1 in 4 seasons and development of more preharvest sprouting tolerant genotypes is required. The main mechanism for improving preharvest sprouting tolerance is grain dormancy. There is genetic variation for dormancy based in the embryo and seed coat but dormancy is complex and is influenced by environmental conditions during grain filling and maturation. Screening and selecting for preharvest sprouting tolerance is problematic and the level of tolerance needed for regions which differ in the level of dormancy they impose, requires clarification. The research presented here aims to answer the underlying question for breeders of how much dormancy is required for preharvest sprouting tolerance in contrasting target environments of the central and coastal wheat belt regions of Western Australia. In the central and coastal wheat belt regions, field trials with modified environments were used to determine the environmental influence on dormancy. Water supply (without directly wetting the grain) and air temperature were modified during grain development in a range of genotypes with different mechanisms of dormancy to determine the influence of environment on dormancy. ... Genotypes with embryo dormancy were consistently the most preharvest sprouting tolerant, even though this dormancy was influenced by the environmental conditions in the different seasons. Pyramiding the embryo component with the specific seed coat component and/or awnless head trait removed some of the environmental variation in preharvest sprouting tolerance, but this was generally considered excessive to the environmental requirements. The methods developed here, of field imposed stresses may provide a valuable tool to further understand the influence of environment on the regulation of dormancy, as different phenotypes can be made with the same genotype. Moisture stress, sudden changes in water supply or high temperatures during the late dough stages influenced dormancy phenotype and should be considered and avoided if possible when selecting locations and running trials for screening for genetic differences in preharvest sprouting tolerance. In the Western Australian context, the embryo component of dormancy appeared to be sufficient and should be adopted as the most important trait for breeding for preharvest sprouting tolerance.

Submitted by Eunice Novais (enovais@uepg.br) on 2017-08-22T23:40:55Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Marina Senger.pdf: 1761600 bytes, checksum: 7e23e8f0e9c9b891e3c733edf20e817f (MD5) / Made available in DSpace on 2017-08-22T23:40:55Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Marina Senger.pdf: 1761600 bytes, checksum: 7e23e8f0e9c9b891e3c733edf20e817f (MD5) Previous issue date: 2017-04-28 / O trigo é um dos cereais mais importantes a nível mundial e é um alimento básico para cerca de um terço da população do mundo, fornecendo mais proteína do que qualquer outro cereal. O desafio global para a cadeia de produção do trigo é aumentar a produtividade de grãos e a qualidade industrial. A produtividade e a qualidade do trigo podem ser comprometidas por diversos fatores que ocorrem no campo, como modo de cultivo, manejo, acamamento e condições de clima e solo. Com o objetivo de avaliar o efeito de épocas de aplicação de nitrogênio em cobertura, densidades de semeadura e épocas de aplicação do regulador de crescimento e sua influência na produtividade e na qualidade industrial dos grãos, foram instalados doze experimentos, diferindo pelo manejo, cultivar e ano de cultivo, na Fazenda Escola da Universidade Estadual de Ponta Grossa, no município de Ponta Grossa, PR, região Campos Gerais, no ano de 2013 com repetição em 2014. O delineamento experimental utilizado nas diferentes épocas de aplicação de nitrogênio em cobertura, para cada cultivar (Gralha Azul e BRS-Pardela), foi de blocos ao acaso, com 6 tratamentos e 4 repetições. Os tratamentos constaram de seis épocas de aplicação de nitrogênio em cobertura, aos 0, 10, 20, 30, 40 e 50 dias após a semeadura. A dose utilizada foi de 100 kg ha-1 de N na forma de uréia (222 kg ha-1). O delineamento experimental utilizado nas diferentes densidades de semeadura, para cada cultivar (Gralha Azul e BRS-Pardela), foi de blocos ao acaso, com 6 tratamentos e 4 repetições. Os tratamentos constaram de seis densidades de semeadura, com 150, 300, 450, 600, 750 e 900 plantas por metro quadrado. O delineamento experimental utilizado nas diferentes épocas de aplicação do regulador de crescimento Trinexapac-ethyl, para cada cultivar (Gralha Azul e BRS-Pardela), foi de blocos ao acaso, com 4 tratamentos e 4 repetições. Os tratamentos constaram de três épocas de aplicação, no perfilhamento, entre o 1º e o 2º nó perceptível, entre o 2º e o 3º nó e testemunha. O sistema de cultivo utilizado foi o plantio direto na palha, sendo a soja a cultura antecessora nos dois anos de pesquisa. Na fase de antese foram avaliados o número de perfilhos; comprimento e largura das folhas e estatura da planta mãe. Na maturidade fisiológica foi avaliado o número de espigas por metro e de espiguetas por espigas; o número de grãos por espiga; massa de mil grãos e índice de colheita aparente. Quando os grãos atingiram o ponto de colheita foi estimado a produtividade e o índice de acamamento. Dos grãos colhidos foi determinado o peso hectolítrico (PH) e o Número de queda (NQ). Fundamentado nos resultados encontrados pode-se concluir que a aplicação de nitrogênio em cobertura na fase de perfilhamento proporcionou maior produtividade na cultura do trigo. A época de aplicação de N não afetou o PH e o NQ, visto que essa resposta também está relacionada com a interação da cultivar e as condições ambientais. As diferentes densidades de semeadura afetam a produtividade na cultura do trigo, sendo as melhores densidades aquelas que também são recomendadas pela pesquisa oficial. As diferentes densidades de semeadura não afetaram o PH e o NQ, e essa resposta também pode estar relacionada com a interação da cultivar e as condições ambientais. As épocas de aplicação de Trinexapac-ethyl não proporcionaram maior produtividade na cultura do trigo. A época de aplicação do regulador afetou os valores de PH apenas em um ano e não afetou os valores de NQ, essa resposta pode estar relacionada com a interação da cultivar e as condições ambientais. / Wheat is one of the world's most important cereals and is a staple food for about a third of the world's population, providing more protein than any other cereal. The overall challenge for the wheat production chain is to increase grain yield and industrial quality. Wheat yield and quality can be compromised by several factors that occur in the field, such as cultivation, management, lodging, and soil and climate conditions. In order to evaluate the effect of nitrogen application times on cover, seeding densities and application times of the growth regulator and the influence on grain yield and industrial quality, twelve experiments were carried out, differing in the management, cultivar and Year of cultivation, in the School Farm of the State University of Ponta Grossa, in the Ponta Grossa, PR, Campos Gerais, in the year 2013 with repetition in 2014. The experimental design used in the different times of nitrogen application in coverage, for each cultivar (Gralha Azul and BRS-Pardela) was randomized blocks with 6 treatments and 4 replicates. The treatments consisted of six times of nitrogen application in cover, at 0, 10, 20, 30, 40 and 50 days after sowing. The dose used was 100 kg ha-1 of N as urea (222 kg ha-1). The experimental design used in the different sowing densities, for each cultivar (Gralha Azul and BRS-Pardela), was randomized blocks with 6 treatments and 4 replicates. The treatments consisted of six sowing densities, with 150, 300, 450, 600, 750 and 900 plants per square meter. The experimental design used in the different application times of the Trinexapac-ethyl growth regulator for each cultivar (Gralha Azul and BRS-Pardela) was a randomized complete block with 4 treatments and 4 replicates. The treatments consisted of three application times, in the tillering, between the 1st and 2nd node perceptible, between the 2nd and 3rd node and control. The cultivation system used was no-till in the straw, and soybeans were the predecessor crop in the two years of research. In the anthesis phase, the number of tillers was evaluated; Length and width of the leaves and height of the mother plant. At physiological maturity, the number of ears per meter and spikelets per ear were evaluated; The number of grains per spike; Mass of one thousand grains and apparent harvest index. When the grains reached the harvest point, yield and lodging index were estimated. From the harvested grains, the hectolitric weight (PH) and Falling Number (NQ) were determined. Based on the results found, it can be concluded that the application of nitrogen under cover in the tillering phase provided higher productivity in the wheat crop. The time of N application did not affect the pH and NQ, since this response is also related to the interaction of the cultivar and the environmental conditions. The different sowing densities affect yield in the wheat crop, with the best densities being those recommended by official research. The different sowing densities did not affect the PH and the NQ, and this response could also be related to the interaction of the cultivar and the environmental conditions. The times of application of Trinexapac-ethyl did not provide greater yield in the wheat crop. The time of application of the regulator affected the values of PH only in one year and did not affect the values of NQ, this response could be related to the interaction of the cultivar and the environmental conditions.

The quality of food wheat is annually evaluated with all deliveries of agricultural primary production in the chosen farming enterprise. During the years 2008 - 2012 particular characteristics with files of 42 - 222 samples were determined, except for the year of 2009 when only one supply was technologically incorporated to food wheat. Countrywide observation of the quality of food wheat is executed in Agricultural research institute Kroměříž, Ltd and in Agrotest fyto, Ltd. It is co-financed by Ministry of Agriculture within a functional task which follows the project of Ministry of Agriculture number QG50041 Factors of quality and safety with food grains (2005-2010). Harvest samples, obtained from producers in time span 2008-2012, were represented by files of 500-1035 samples. Characteristics which influence the quality of the grains as well as criteria and methods of the evaluation of food wheat were described. Their applications in Agrotest fyto, Ltd and under operating conditions in ZZN Pelhřimov a.s. were given. Average values of observed parameters were calculated from the results of each testing in the laboratory of the detached post Záhoří and consequently compared with countrywide norm and the norm of South Bohemia. The quality of food wheat grains in years 2008-2012 showed a large-scale variability in particular parameters both at countrywide level and in South Bohemia as well as in chosen farming enterprise. Final quality was considerably influenced by course of weather annually.