Capacidade de restabelecimento da grama-estrela-africana após aplicação de glifosato em pré-semeadura de milho

Abstract

Resumo -O objetivo deste trabalho foi avaliar a capacidade de restabelecimento de pastagem de grama-estrela-africana (Cynodon nlemfuensis) após aplicação do herbicida glifosato, na pré-semeadura da cultura do milho. Utilizou-se o delineamento experimental de blocos ao acaso, com quatro repetições. Os tratamentos foram: doses do equivalente ácido (e.a.) do herbicida glifosato (0, 720, 1.440, 2.160, 2.880 e 3.600 g ha -1 ) e a testemunha capinada. A grama-estrela-africana é tolerante às doses normalmente recomendadas do herbicida (720 a 1.080 g ha -1 de e.a). Doses de glifosato de 1.232 a 1.439 g ha -1 de e.a. suprimem a grama-estrela-africana, evitam sua competição com a cultura do milho, e permitem a recuperação da pastagem após a colheita do milho.Termos para indexação: Cynodon nlemfuensis, consórcio, formação de palhada, integração lavoura-pecuária, plantio direto, tolerância ao glifosato. Recovery capacity of African star grass after application of glyphosate in pre-sowing of cornAbstract -The objective of this work was to evaluate the recovery capacity of African star grass (Cynodon nlemfuensis) after glyphosate application in pre-sowing of corn. A randomized block design was used, with four replicates. The treatments were doses of acid equivalent (a.e.) of the herbicide glyphosate (0, 720, 1,440, 2,160, 2,880, and 3,600 g ha) and a hoed control. African star grass is tolerant to the usually recommended doses of the herbicide (720 to 1,080 g ha -1 a.e.). Doses of glyphosate, ranging from 1,232 to 1,439 g ha -1 a.e. suppress the grass, avoid its competition with corn, and allow the recovery of the pasture after the corn harvest.

Behavior of Five Sulfonylurea Herbicides and a Low-Dose Glyphosate on Cynodon nlemfuensis Pasture

“…This observation was also verified in Tifton 85 which showed tolerance to glyphosate at 720 g ha -1 (Santos et al, 2007(Santos et al, , 2008. This same behavior was also previously observed in African star grass pasture (Brighenti et al, 2012(Brighenti et al, , 2013. Lower doses of glyphosate were tolerated by African star grass that had been established over 8 years; thus, such application is a viable tool for chemical weed control in African star grass pastures.…”

Crescimento e teor de pigmentos de Paspalum notatum em resposta a aplicação de herbicidas

“…However, these authors verified size reduction without, nonetheless, observing alterations in the chlorophyll content. Similarly, Brighenti et al (2012) observed size reduction and phytointoxication increase on African star grass (Cynodon nlemfuensis) with the increase in glyphosate doses, starting from 720 g a.e. ha -1 .…”

Differential tolerance and selectivity of herbicides in forages of the genus Cynodon

“…Abdullahi (2002) found that plowing with the application of 2,160 g ae/ha of glyphosate after sprouting was necessary to provide satisfactory control of Bermuda grass (C. dactylon). Brighenti et al (2012) observed that African star grass pastures tolerate lower doses of glyphosate. Doses ranging from 720 to 1,080 g ae/ha provided suppressed-African star grass plants, avoiding weed competition and resulting in pasture recovery later (Brighenti et al, 2012;Brighenti & Vieira, 2013).…”

“…Brighenti et al (2012) observed that African star grass pastures tolerate lower doses of glyphosate. Doses ranging from 720 to 1,080 g ae/ha provided suppressed-African star grass plants, avoiding weed competition and resulting in pasture recovery later (Brighenti et al, 2012;Brighenti & Vieira, 2013). Younger plants of sour grass (D. insularis), originating from seeds, were efficiently controlled by glyphosate (Gazola, Belapart, Castro, Cipola Filho, & Dias, 2016).…”