-The timing of seed treatment application is important to keep soybean seeds quality. Therefore, the aim of this study was verify the effect of fungicides and insecticides treatment in soybean seeds quality before and after storage. Seeds of NS 7494, NS 8693 and NS 7338 IPRO were utilized and analyses separately, through a factorial scheme 3x6, with three application moments: treated and assessed; treated, stored and assessed; stored, treated and assessed; and six combination of fungicides and insecticides:

Resumo: A crescente demanda por forrageiras tem impulsionado o desenvolvimento da indústria sementeira no Brasil que busca oferecer sementes de qualidade com valor agregado por meio de tecnologias. O cultivar Mulato II é a primeira espécie híbrida de braquiária comercializada no Brasil. Foi desenvolvido a partir do cruzamento de três espécies de Urochloa (U. brizantha x U. decumbens x U. ruziziensis). O revestimento de sementes é uma técnica de tratamento na pré-semeadura capaz de melhorar o desempenho das plantas no campo. Porém, o revestimento pode acarretar problemas com relação à qualidade das sementes. Diante do exposto, objetivou-se com esta pesquisa avaliar o efeito do revestimento de sementes sob a qualidade fisiológica de sementes de braquiária híbrida cv. Mulato II. A pesquisa foi conduzida no Laboratório de Análise de Sementes, da Universidade Federal de Lavras -MG, com delineamento inteiramente casualizado, em esquema fatorial 6x2, sendo seis lotes de sementes, sem e com incrustação. Os testes fisiológicos utilizados foram: germinação, emergência, índice de velocidade de emergência, tempo médio de emergência, tetrazólio e análise da enzima α-amilase. O revestimento das sementes de Braquiária híbrida cv. Mulato II reduz a viabilidade, a velocidade de germinação, a germinação, a velocidade de emergência de plântulas e a porcentagem de plântulas emergidas da espécie, comprovada pela redução da expressão da enzima α-amilase. Palavras-chave: Brachiaria. Incrustamento. Tratamento pré-semeadura. Abstract:The increasing demand for fodder has driven development of the seed industry in Brazil, which seeks to provide value-added quality seeds by means of technology. The Mulato II cultivar is the first hybrid species of brachiaria to be marketed in Brazil. It was developed from the crossing of three species of Urochloa (U. brizantha x U. decumbens x U. ruziziensis). Coating seeds is a pre-sowing technique, which is able to improve plant performance in the field. However, the coating can lead to problems of seed quality. Given the above, the aim of this research was to evaluate the effect of seed coating on physiological quality in seeds of the hybrid brachiaria cv. Mulato II. The research was carried out at the Laboratory for Seed Analysis of the Federal University of Lavras, in the state of Minas Gerais, (MG), using a completely randomised design, in a 6 x 2 factorial, six seed batches, with and without incrustation. The physiological tests carried out were: germination, emergence, speed of emergence index, average time of emergence, tetrazolium, and α-amylase (enzyme) analysis. Seed coating in the hybrid brachiaria cv. Mulato II reduces viability, speed of germination, germination, speed of seedling emergence and the percentage of emerged seedlings, demonstrated by a reduced expression of the α-amylase enzyme.

Germination does not guarantee plant establishment if there is no efficient and enough reserve mobilization from seeds to the initial seedling growth, mainly in adverse situations. Therefore, this study aimed to evaluate the mobilization of reserves in soybean seeds under water restriction. Four soybean seed lots previously stored for one year were used in the study. To simulate water stress, we used polyethylene glycol (PEG) solutions at concentrations of 0.0, -0.1, and -0.2 MPa. The number of normal, infected and abnormal seedlings were evaluated, along with the number of dead and hard seeds. The radicle, hypocotyl, and cotyledons were separated to determine the dry weight based on the total seed reserve available for mobilization. From this value, the seed reserve reduction, relative dry matter yield, seed reserve reduction rate, and reserve conversion efficiency into dry seedling weight were determined. The increase in water restriction elevates the reserve consumption during the germination process. Vigorous seeds are more efficient in mobilizing and converting grains reserve in dry seedling mass. In less vigorous seeds, mainly those on water restriction, the increase in reserve consumption does not result in conversion into dry seedling mass.