Acessibilidade / Reportar erro

Production regions, physical and physiological quality of Brachiaria brizantha cv. BRS 'Piatã' seeds1 1 Parte da Tese de Doutorado do primeiro autor apresentada ao Programa de Pós-graduação em Agronomia, Universidade Estadual Paulista/UNESP; bolsa do CNPq de todos os autores

Regiões de produção, qualidades física e fisiológica de sementes de Brachiaria brizantha cv. BRS 'Piatã'

ABSTRACT

The quality of seeds is influenced by the climatic conditions of the production field. The identification of characteristics of the best forage seed fields allows the improvement of the sector. In this study, the aim was to identify climatic characteristics of producing regions that may affect the physical and physiological quality of Brachiaria brizantha cv. BRS 'Piatã' seeds. Seeds from 10 lots were evaluated for purity, other seeds, mass of a thousand seed, water content, germination, dormancy, emergence, seedling emergence in sand and seedling emergence in the field. Temperature and precipitation data of each production field from flowering to harvest were obtained. The means of treatments were compared by the Scott-Knott test at 5% probability. In order to discriminate which environmental factors influenced seed quality, multivariate statistical analysis was applied through Principal Component Analysis. It was concluded that production fields with temperatures above 30 °C in flowering, threshing and harvesting periods are related to the production of 'Piatã' grass seeds of lower physical and physiological quality. Fields with accumulated rainfall above 500 and 137 mm in the flowering and harvesting period, respectively, are unfavorable to seed vigor.

Key words:
Climatic factors; Commercialization of seeds; Tropical forage grasses

Universidade Federal do Ceará Av. Mister Hull, 2977 - Bloco 487, Campus do Pici, 60356-000 - Fortaleza - CE - Brasil, Tel.: (55 85) 3366-9702 / 3366-9732, Fax: (55 85) 3366-9417 - Fortaleza - CE - Brazil
E-mail: ccarev@ufc.br