Productivity and quality of Brachiaria brizantha B4 seeds in function of nitrogen doses

• Main Authors: Gleiciane de Lima Benteo, Jaqueline Rosemeire Verzignassi, Celso Dornelas Fernandes, Cacilda Borges do Valle, Manuel Cláudio Motta Macedo, Cláudia Barrios de Libório, Lenise Castilho Monteiro
• Format: Article
• Language: English
• Published: Universidade Federal de Santa Maria 2016-01-01
• Series: Ciência Rural
• Subjects: adubação; forrageira tropical; qualidade de sementes.
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016005012105&lng=en&tlng=en

ABSTRACT: This study aimed to evaluate aspects of reproductive phenology, yield components and seed quality of the B4 genotype of Brachiaria brizantha in function of nitrogen doses applied at pre-flowering. The experiment was carried out at Embrapa Beef Cattle, in a randomized block design, with seeding density of 2.59kg SPV ha-1 in the first year, in free growth plants. Urea was applied at pre-flowering at doses of 0, 25, 50, 75, 100, 125 and 150kg ha-1. The reproductive cycle of the plant lasts 225 days, with late flowering. N doses influenced the following characteristics: number of fully expanded inflorescences, percentage of dry matter, dry biomass, number of spikelets per raceme, seed yield, weight of a thousand seeds, germination, germination speed index, viability and germination at 10 months after harvest. The maximum yield of pure seed was 144.8kg ha-1 for 50kg ha-1 N, with maximum biological potential, based on components of seed yield of 456.27kg ha-1. Seeds presented high dormancy and reduced physiological quality in higher N doses.