Publicação on-line; 28 ref.; 5 tables; 1 illus.; Summaries (En, Pt)

ABSTRACT - This research aimed to assess the selectivity of treatments involving
the commercial formulations tank mixtures of iodosulfuron-methyl with herbicides
ACCase inhibitors (fenoxaprop-p-ethyl and clethodim) and synthetic auxins (2.4-D),
applied in post-emergence of wheat (Triticum aestivum) and barley (Hordeum vulgare)
crops. Three experiments were conducted in the field, during the 2014 crop year.
A randomized complete block design was used with 11 treatments and five
replications. Treatments consisted of (g ha-1): 1) iodosulfuron-methyl (6.5),
2) fenoxaprop-p-ethyl (82.5), 3) fenoxaprop-p-ethyl + clethodim (55 + 54); 4) 2.4-D
(335), 5, 6 e 7) iodosulfuron-methyl + fenoxaprop-p-ethyl (6.5 + 82.5; 6.5 + 110 and 6.5
+ 165), 8) iodosulfuron-methyl + fenoxaprop + clethodim (6.5 + 55 + 54), 9) iodosulfuron
+ fenoxaprop-p-ethyl + 2.4-D (6.5 + 110 + 335), 10) iodosulfuron-methyl + fenoxapropp-ethyl +
clethodim + 2.4-D (6.5 + 82.5 + 72 + 335) and 11) check without weeds.
Associations of iodosulfuron-methyl + fenoxaprop-p-ethyl (6.5 + 82.5; 6.5 + 110 and
6.5 + 165 g ha-1) associations, as well as of iodosulfuron-methyl + fenoxaprop-pethyl +
2.4-D (6.5 + 110 + 335 g ha-1) were selective for BRS Campeiro and BRS Gralha
azul wheat cultivars and did not feature symptoms of intoxication and significant
losses in grain yield and hectoliter weight, when compared to the treatment with no
application. For BRS Brau barley cultivar, only iodosulfuron-methyl + fenoxaprop-pethyl
associations, in doses of 6.5 + 82.5 and 6.5 + 110 g ha-1 were feasible for selectivity.
Clethodim addition in iodosulfuron-methyl + fenoxaprop-p-ethyl or iodosulfuronmethyl +
fenoxaprop-p-ethyl + 2.4-D associations caused negative effects for wheat
and barley crops. Commercial formulation of iodosulfuron-methyl (Hussar™) resulted
in protection for damage effects of fenoxaprop-p-ethyl (Podium EW™) for studied
crops.

Keywords: Triticum aestivum, Hordeum vulgare, intoxication, tank mixtures

RESUMO - A pesquisa teve como objetivo avaliar a seletividade de tratamentos
envolvendo a mistura em tanque de formulações comerciais de iodosulfuron-methyl
com herbicidas inibidores da ACCase (fenoxaprop-p-ethyl e clethodim) e auxinas
sintética (2,4-D), aplicados em pós-emergência das culturas do trigo (Triticum
aestivum) e cevada (Hordeum vulgare). Três experimentos foram conduzidos em
campo, durante a safra agrícola de 2014. O delineamento experimental utilizado
foi o de blocos casualizados, com 11 tratamentos e 5 repetições. Os tratamentos
foram constituídos por (g ha-1): 1) iodosulfuron-methyl (6,5), 2) fenoxaprop-pethyl (82,5), 3)
fenoxaprop-p-ethyl + clethodim (55,0 + 54,0); 4) 2,4-D (335,0); 5,
6 e 7) iodosulfuron-methyl + fenoxaprop-p-ethyl (6,5 + 82,5, 6,5 + 110,0 e 6,5 +
165,0); 8) iodosulfuron-methyl + fenoxaprop-p-ethyl + clethodim (6,5 + 55,0 +
54,0); 9) iodosulfuron-methyl + fenoxaprop-p-ethyl + 2,4-D (6,5 + 110,0 + 335,0); 10) iodosulfuronmethyl +
fenoxaprop-p-ethyl + clethodim + 2,4-D (6,5 + 82,5 + 72,0 + 335,0); e 11) testemunha
capinada. As associações de iodosulfuron-methyl + fenoxaprop-p-ethyl (6,5 + 82,5, 6,5 + 110,0 e 6,5 +
165,0 g ha-1), assim como de iodosulfuron-methyl + fenoxaprop-p-ethyl + 2,4-D (6,5 + 110,0 +
335,0 g ha-1), foram seletivas para os cultivares de trigo BRS Campeiro e BRS Gralha Azul, não
apresentando sintomas de intoxicação e perdas significativas na produtividade e no peso hectolitro
dos grãos. Para a cevada BRS Brau, apenas as associações de iodosulfuron-methyl + fenoxaprop-pethyl,
nas doses de 6,5 + 82,5 e 6,5 + 110,0 g ha-1, foram viáveis em relação à seletividade. A adição de
clethodim nas associações de iodosulfuron-methyl + fenoxaprop-p-ethyl ou iodosulfuron-methyl +
fenoxaprop-p-ethyl + 2,4-D teve efeitos negativos para as culturas de trigo e cevada. A formulação
comercial de iodosulfuron (Hussar™) proporcionou proteção aos efeitos deletérios do fenoxaprop-pethyl
(Podium EW™) para as culturas estudadas.

Palavras-chave: Triticum aestivum, Hordeum vulgare, intoxicação, mistura em tanque.