Levantamento fitossociológico de plantas daninhas em pastagens degradadas do Médio Vale do Rio Doce, Minas Gerais

Abstract

O levantamento fitossociológico é uma ferramenta importante, na análise do impacto que os sistemas de manejo e as práticas agrícolas exercem sobre a dinâmica de crescimento e ocupação das plantas daninhas no agroecossistema. Por essa razão, esta pesquisa teve como objetivo realizar a caracterização fitossociológica de plantas daninhas, em oito áreas de pastagens degradadas, de cinco municípios do Médio Vale do Rio Doce, em Minas Gerais. No total foram identificadas 68 espécies, pertencentes a 18 famílias, sendo que o gênero Sida ocorreu em todas as áreas avaliadas. De maneira geral, a Uroclhoa decumbens, a Sida glaziovii e a Sida carpinifolia foram as espécies encontradas com maior frequência. Todavia, constatou-se grande diversidade de plantas daninhas nas áreas avaliadas, sendo a maior riqueza observada no município de Galiléia e, a menor, em Governador Valadares. As áreas estudadas apresentaram baixa similaridade entre si, sendo, portanto, indicado que o manejo de plantas daninhas seja específico para cada situação.

Bank of Weed Seeds in Agrosystems in the Brazilian Cerrado

“…On grazing areas, the diversity was low, since this is a very peculiar, poorly managed and compacted environment, determining that only the species with higher adaptation capacity to these conditions will germinate and proliferate. Ferreira et al (2014), when studying the diversity of weeds on degraded grazing areas on different locations of the Médio Vale do Rio Doce, observed a large diversity across the studied areas; however, within each location, there was a higher diversity on some places and, on others, the diversity was very low. Jakelaitis et al (2014) found low values for Shanonn's index (between 1.33 and 1.70) on cultured areas with pastures.…”

Does the Use of Adjuvants Alter Surface Tension and Contact Angle of Herbicide Spray Droplets on Leaves of Sida spp.?

“…In Brazil, these species have been basically controlled through herbicide application (Ferreira et al, 2014). The herbicide aminopyralid + fluroxypyr, whose mechanism of action is to mimic auxin, interferes in the apical meristem of plants, thus affecting the division of tissues; it has been used in Brazil to control these weeds in pasture areas.…”

Weed community composition in different agro-systems

“…Similarly, changes in the composition of weed communities were also observed in different agricultural crops, such as sugarcane (Kuva et al, 2007;Soares et al, 2011), pastures (Ferreira et al, 2014), bean (Tavares et al, 2013), cover crops (Lima et al, 2014;Lamego et al, 2015), manioc (Cardoso et al, 2013;Soares et al, 2015), corn (Correa et al, 2011), corn intercropped with legumes (Oliveira et al, 2014) and corn intercropped with forage (Batista et al, 2014;Concenço et al, 2015), millet (Teodoro et al, 2015), lettuce (Ferreira et al, 2013), Jatropha curcas (Concenço et al, 2014) and coffee under organic management (Maciel et al, 2010a;Partelli et al, 2010).…”