Origin and temperature on the germination of beggartick seeds/Procedencia das sementes e temperatura na germinacao de picao-preto

• Published in: Revista brasileira de engenharia agrícola e ambiental 2017-07, Vol.21 (7), p.448
• Main Authors: de Barros, Renato T, Ma, da Silva, Givanildo Z
• Format: Article
• Language: Spanish
• ISSN: 1415-4366
• DOI: 10.1590/1807-1929/agriambi.v21n7p448-453

The invasive behavior of beggarticks (Bidens pilosa L.) in cropped areas is due to its ecological adaptation and aggressive regeneration, which is dependent on seed germination. The objective of this research was to verify the effects of B. pilosa seed origin and temperature on seed germination. The seeds were collected in Entre Rios do Oeste, PR, Botucatu, SP, Capao Bonito, SP, Sao Joaquim da Barra, SP, Sertaozinho, SP, Selviria, MS, Barra do Garcas, MT, Areia, PB and Manaus, AM. The seeds were evaluated regarding moisture content, 1000-seed weight, germination speed index and germination at 60 days (normal seedlings, dormant seeds and dead seeds) at the temperatures of 10, 15, 20, 25, 30, 35, 40, and 45 [degrees]C. The replicates were distributed according to a completely randomized design in a 9 x 8 factorial arrangement (seed origin x temperature) with four replicates. The means were compared by the Scott-Knott test. B. pilosa seeds germination depends on seed origin. Temperatures higher than 35[degrees]C are lethal to the seeds. The temperature of 15[degrees]C allows maximum germination in the shortest time whichever the seed origin. Key words: Bidens pilosa weed production sites dormancy O comportamento invasivo do picao-preto (Bidens pilosa L.) em areas de cultivo se deve a sua adaptacao ecologica e regeneracao agressiva, alicercada na germinacao das sementes. Objetivou-se, com a presente pesquisa, conhecer o efeito de diferentes procedencias e temperaturas na germinacao de sementes de B. pilosa. As sementes foram coletadas em Entre Rios do Oeste, PR, Botucatu, SP, Capao Bonito, SP, Sao Joaquim da Barra, SP, Sertaozinho, SP, Selviria, MS, Barra do Garcas, MT, Areia, PB e Manaus, AM e avaliadas quanto ao teor de agua, massa de 1000 sementes, indice de velocidade de germinacao e germinacao conduzida a 10, 15, 20, 25, 30, 35, 40 e 45[degrees]C e avaliada aos 60 dias. O delineamento experimental adotado foi o inteiramente casualizado em esquema fatorial 9 x 8 (procedencias x temperaturas) com quatro repeticoes e as medias foram comparadas pelo teste de ScottKnott. A germinacao, o vigor e a massa de sementes de B. pilosa dependem do local de procedencia. Temperaturas superiores a 35[degrees]C sao letais as sementes. A temperatura de 15 [degrees]C permite a maxima germinacao das sementes em menor tempo da quase totalidade das procedencias. Palavras-chave: Bidens pilosa planta daninha local de producao dormencia