Red Morningglory (Ipomoea coccinea) Control with 2,4-D and Alternative Herbicides¹

Abstract

Field studies were conducted to evaluate red morningglory control with 2,4-D alone and in combination with dicamba, along with other postemergence herbicides applied both over the top and as directed treatments. For red morningglory 30 and 60 cm in height, complete control 14 or 21 d after treatment (DAT) was obtained during 2 yr with 2,4-D at 0.53 kg ai/ha, 2,4-D at 0.4 kg/ ha or more plus dicamba, atrazine at 2.23 kg ai/ha, flumioxazin at 0.10 kg ai/ha, and sulfentrazone at 0.35 kg ai/ha. When red morningglory were 1.8 m, weed control with most herbicides was less consistent than when applied to smaller plants. Red morningglory (1.8 m) was controlled 100% 28 DAT the first year with 2,4-D at 1.06 kg/ha and 78% the second year. In the first year, the 2,4-D plus dicamba prepackaged mixture at 0.8 + 0.28 kg ai/ha or 2,4-D plus the 2,4-D/dicamba prepackaged mixture (0.53 + 0.2/0.07, 0.53 + 0.4/0.14, or 0.79 + 0.1/0.04 kg/ha) provided control equal to that by 2,4-D alone at 1.06 kg/ha. In the second year, when herbicides were applied 3 wk earlier than the previous year and when weed growth was more vigorous, the 2,4-D plus the 2,4-D/dicamba prepackaged mixture at 0.79 + 0.1/0.04 kg/ha provided control equal to that by 2,4-D alone at 1.06 kg/ha but was the only 2,4-D plus dicamba treatment to control red morningglory equal to that by 2,4-D at 1.59 kg/ha (87%). Directed applications to the lower 45 cm of 1.8-m red morningglory plants with atrazine at 4.47 kg/ha and sulfentrazone at 0.35 kg/ha controlled weeds at least 96% 28 DAT in 2001, but control was 23 and 30 percentage points less, respectively, the second year.

Manejo químico de convolvulaceae e euphorbiaceae em cana-de-açúcar em período de estiagem

“…Essas plantas daninhas são agressivas e, segundo Milholon et al (citado por Siebert et al, 2004), podem proporcionar até 24% de prejuízo na produtividade da cana, em condições de clima temperado. Outro fator que desperta preocupação entre os produtores é o fato de que a presença das espécies dos gêne-ros Ipomoea e Merremia (Correia & Durigan, 2004) e Euphorbia (Martins et al, 1999) se intensifica em cultivos que têm o solo coberto por palha.…”

Efficacy of Selected Herbicide Programs in 2,4-D Tolerant Cotton (<i>Gossypium hirsutum</i> L.)

“…The 2,4-D choline + glyphosate + glufosinate and 2,4-D choline + glyphosate treatments (TRT 3 and 5) resulted in the lowest control of 83% at 3 WAP1 in 2013 (Table 4). Other studies have reported that auxin herbicides mixed with glufosinate provided excellent control of morningglory species [8] [22]. Culpepper [23] also observed that 2,4-DB plus glyphosate provided control of annual morningglory.…”

Action of rain on the efficiency of herbicides applied post-emergence in the control of Senna obtusifolia

“…Visual assessments of weed control were conducted at 7, 14, 21 and 28 days after application (DAA), by means of a percentage grading scale, where 0 (zero) corresponds to no demonstrable damage and 100 (hundred) to the death of the plants, as proposed by SBCPD (1995). The parameters used to establish the grades for visual control were: biomass accumulation; growth inhibition; amount and uniformity of damage; and plant capacity for regrowth.…”

“…Reports of the possible effects of rain on the efficacy of the herbicide 2,4-D are scarce in the literature, but there are several works that demonstrate its efficiency in the control of numerous species of weeds (BIJANZADEH; GHADIRI, 2006, CASON;ROOST, 2011;CORREIA;ZEITOUM, 2010;EVERITT;KEELING, 2007;SIEBERT;GRIFFIN;JONES, 2004).The aim of this work therefore, was to evaluate the influence of rainfall at different intervals after the post-emergence application of the herbicides 2,4-D, glyphosate and glufosinateammonium in different formulations (Roundup Original, Roundup Transorb, Roundup Transorb R, Roundup Ultra and Roundup WG) in the control of S. obtusifolia.…”