The objective of this work was to evaluate the efficacy of different herbicides, applied both at pre and post-emergence, to control Alternanthera tenella. Two assays were accomplished: the first one for pre-emergence herbicides, and the second one for post-emergence herbicides, applied at two pair of leaves stage. Pre-emergence herbicide treatments and respective rates (g i.a. ha-1) were: alachlor (2880); chlorimuron-ethyl (15); metribuzin (576); clomazone (1000); flumetsulam (120); sulfentrazone (600); trifluralin (540); amicarbazone (1050); pendimethalin (1500); oxyfluorfen (360); ametryn (1500); diuron […]

The weed Chloris distichophylla (Lag) has been selected in areas of orchards and RR soybean in the Rio Grande do Sul- RS (Brazil), resulting of its possible tolerance to the herbicide glyphosate. This selection occurs due to intense use of this herbicide in the last years resulting in a disturb caused by the high pressure selection imposed by the herbicide occurs, resulting in selection of tolerant plants. The objective of this study was to evaluate the effectiveness of herbicides pertaining […]

Resistant populations of Bidens pilosa and Bidens subalternans to the ALS inhibitors herbicides become more frequent at the soybeans fields from middle-west, that is due the intensive use of ALS herbicides, aimed to obtain data that can contribute on the choose of the best alternative of control for those populations. A trial in a green-house, in Piracicaba, SP, to test many herbicides as an possible alternatives of management of those resistant weeds. Initially we used two populations of Bidens pilosa and […]

The control efficient of the weeds is one of the essential factors to obtain high rice yields, primarily in areas moistened fields, that generally represent higher number of species, probably due to heterogeneous of physical characteristics and chemicals of the soil and moisture contents in the different areas. For the development of these control systems of the unwanted species, it is necessary to anticipate the stage of emergence of weed plants in relation of emergence of the crop. These models […]

In order to study the influence of the herbicides diclosulam and flumetsulam on soybean IAC-19 growth and nodulation, an experiment was carried out in pots, in greenhouse, using sandy-loam and clay soils. The seeds were inoculated with Bradyrhizobium japonicum. The treatments were: no herbicide and no innoculation, no herbicide with innoculation, diclosulam at 16,8, 33,6 and 50,4 g/ha; flumetsulam at 60, 120 and 180 g/ha, applied in pre-emergence, all innoculated. Nodulation was evaluated at 41 days after treatment (DAT). Plants […]

It was evaluate the efficacy of the herbicide flumioxazin, applied isolated and in mixture with glyphosate, in orange orchard, for control of Panicum maximum, Cenchrus echinatus, Digitaria horizontalis, Alternanthera tenella, Bidens pilosa, Malvastrum coromandelianum, Commelina benghalensis, Amaranthus spinosus and Ageratum conyzoides. The treatments were: 0.025 and 0.05 kg ha-1 of flumioxazin (plus mineral oil 0.5%); 0.025 kg ha-1 of flumioxazin plus 1,08 kg e.a. ha-1 of glyphosate (plus mineral oil 0.5%); 0.025 kg ha-1 of flumioxazin plus 1.44 kg e.a. […]

Weed herbicide resistance is a phenomenon defined as ability of a biotype survives to herbicide sprayed, at a recommended rate that control a susceptible population. This research had the objective of determine, the level of resistance the herbicides of the Bidens subalternans. The herbicides treatments they were with bentazon, fomesafen, imazethapyr e chloransulam-methyl. Sprayed in post-emergency, when B. subalternans reached stage four-leaf pairs. The herbicide rates sprayed was crescents in a logarithm scale of 0,0; 0,001; 0,01; 0,1; 1,0; 10 […]

The phytotoxicity level caused by hormonal herbicides that work as growth regulators in wheat plants is associated with the growth stage of the apical meristem. Applications of such herbicides when wheat plants are at double ridge and at terminal spikelet stages are very unlikely to cause damage to the ear and to the grain production. So, it is necessary to determine precisely the stages of plant development for having a secure use of these herbicides. However, small alterations may occur […]

In 2004, abnormalities in the formation of potato tubers were observed in the region of Casa Branca and Aguaí, São Paulo State, Brazil, due to the contamination of sprayer tanks with sulfonylurea. Most of the tubers from all plants presented many cracks and other deffects that disqualified them commercially. Potato response to simulated tank contamination of three sulfonylurea herbicides was evaluated in pot studies in Águas da Prata, São Paulo State, Brazil. Metsulfuronmethyl, nicosulfuron and sulfometuron-methyl were applied in post-emergence […]

Glyphosate is a broad spectrum herbicide, used for more than 15 years in apple orchards in the Vacaria-RS region for vegetation management on the crops row. In general, 3-4 glyphosate applications are done in each crop cycle with the normal herbicide rate of 720-1,080 g e.a. ha-¹ . Lolium multiflorum is a frequently found weed specie in orchards and regularly sensible to glyphosate. Biotypes of Lolium multiflorum resistant to the glyphosate did not show any significant glyphosate symptoms. Clethodim is […]