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

Made available in DSpace on 2014-08-20T13:32:58Z (GMT). No. of bitstreams: 1 dissertacao_pablo_machado_mendes.pdf: 827691 bytes, checksum: 944bff209792e2b057fea45540a30453 (MD5) Previous issue date: 2011-07-13 / The society is currently moving in the direction of finding solutions to environmental problems that threaten the continuity of life on the planet, and these problems not caused exclusively by man, according to differing opinions of several scientists around the world. The poultry industry is one of the most striking of these food producers taking responsibility for going to meet the worldwide research trying to solve the problems of environmental pollution, the idea is proposing a viable solution both technically and economically and provide back a critical need in the field of creation of broiler chickens: the bed where the chicken are created is able to be discarded in agricultural land safely and without damaging the soil, in these case, without causing environmental impact on the ground? To answer this question we sought to evaluate the poultry litter in relation to their chemical composition, number of lots created on the poultry litter and biosecurity of these beds. Currently producers perform physical and chemical analysis to determine whether the bed can be designed in agricultural land, among them the C/N (carbon/ nitrogen), which is the main parameter to decide whether the bed can be considered stable and it ready for disposal. This study proposes to develop a test that serves as a bioindicator phytotoxicity to determine if a litter is ready to be allocated to agricultural soil without causing environmental impact to soil, water resources and the environment in general. / A sociedade atualmente caminha no sentido de procurar soluções para os problemas ambientais que ameaçam a continuidade da vida no planeta, sendo estes problemas causados ou não, exclusivamente pelo homem, segundo opiniões divergentes de diversos cientistas pelo mundo. A avicultura é uma das atividades mais impactantes do ramo da produção de alimentos, tendo a responsabilidade de caminhar ao encontro das pesquisas mundiais que tentam solucionar os problemas de poluição ambiental, surgindo a idéia de propor uma solução viável tanto técnica quanto economicamente e que suprisse uma necessidade fundamental no ramo da criação de frangos de corte: a cama aonde o frango é criado tem condições de ser descartada em solo agrícola com segurança e sem prejudicar o desenvolvimento do solo, ou seja, sem causar impacto ambiental no solo? Para responder essa pergunta procurou-se avaliar a cama de frango em relação a sua composição química, quantidade de lotes criados em cima da cama e a biossegurança dessas camas. Atualmente os produtores realizam análises físico-químicas para determinar se a cama pode ser destinada em solo agrícola, dentre elas a relação C/N (carbono/nitrogênio), que é o principal parâmetro para se decidir se a cama pode ser considerada estabilizada e por isso pronta para o descarte. Este estudo propõe o desenvolvimento de um teste de fitotoxicidade que serve de bioindicador para determinar se uma cama de aviário está apta a ser destinada em solo agrícola sem causar impacto ambiental ao solo, recursos hídricos e ao ambiente em geral.