Weeds infestation in corn intercropped with forages at different planting densities

Abstract

-Corn is planted in the Center West region of Brazil as a second crop, following soybeans or beans. Intercropping of Brachiaria species with corn as a second crop increases the mulching in the cropping system. This study aimed to evaluate the weeds infestation in soybeans following corn/forages intercrop, as a function of corn plant structure, forage species and density. Experiments were conducted in a completely randomized blocks design with four replications, in Ponta Porã and Dourados municipalities, Mato Grosso do Sul state, Brazil, in 2010/2011. Treatments consisted of three corn hybrids with distinct plant architectures intercropped with three forage species: Brachiaria ruziziensis, B. brizantha and B. decumbens, at five densities, and the resulting dry mass was maintained throughout the winter. During the following cropping season, forages were desiccated prior to planting soybeans, and the dry mass of weeds, dry mass of the mulching, soil coverage by weeds, and the broadleaf/grass weed species index (WPI) were determined 15 days after soybean emergence, submitted to an F-test, and analyzed either by regression or by multiple mean comparison, according to the nature of the data. When intercropping corn with species of Brachiaria, a reduction in the overall weeds infestation may always be expected; among the studied forage species, more problems with weeds may be anticipated in areas with a less competitive species, e.g. B. ruziziensis. Under the conditions of the trials, B. brizantha and B. decumbens were more capable of inhibiting the emergence of weed species in the winter. Palavras-chave: Brachiaria, índice de proporção de espécies, cultivo de inverno, palhada. Keywords

Weeds in Soybean Crop After Annual Crops and Pasture

“…Other authors also evidence the benefits of the corn-Brachiaria intercropping as a tool in integrated weed management (Jakelaitis et al, 2004;Concenço et al, 2012). These findings are corroborated by Seidel et al (2015), emphasizing higher dry matter production from the corn-Brachiaria intercropping than single corn.…”

“…The predecessor crop, such as intercropping and croplivestock integration associated with the no-till system, favors the subsequent crop competing with weeds (Concenço et al, 2012;Gontijo Neto, et al, 2014). Melo et al (2019) reported that the association between corn and Brachiaria cultivated with reduced spacing promoted a greater reduction in weeds occurrence in the subsequent soybean crop.…”

INTERFERÊNCIA DE CULTURAS ANUAIS NO CRESCIMENTO INICIAL DE Brachiaria ruziziensis

“…No Cerrado brasileiro, o consórcio mais utilizado tem sido milho-braquiária, objetivando a produção de grãos de soja em Sistema Plantio Direto (SPD), mantendo o solo, permanentemente coberto (Concenço et al, 2012). No entanto o objetivo final é determinante para a implantação do sistema, pois no consórcio de culturas anuais com forrageiras perenes, tem como objetivo a produção de palhada para a cobertura do solo e a produção de forragem para alimentação de animais (Ceccon et al, 2010).…”