This experiment was intended to evaluate the selectivity to maize hybrid AG 30 I O and efficiency of acetochlor herbicide alone and tank mixture with atrazine applied in preemergence to control Cenchrus echinatus, Brachiaria plantaginea, Digitaria horizontalis, lndigofera hirsuta, Bidens pilosa and lpomea grandifolia . The experiment was conducted in laboticabal, SP, on red oxissol. Treatrnents inc1ued acetochlor 2.52,3.36 and 4.20 kg!ha, acetochlor/atrazine 3.76, 4.38 and 5.0 I kglha, and the commercial pattem atrazine/metolachlor at the rate of 3.50 kg!ha, […]

The best time to harvest the bean crop is after the occurrence ofphysiological maturation, when the seeds vigour, the gemination and the weight of dry matter are high. To carry out mechanical harvesting at this moment is difficult because a high number of leaves is still green. Besides, the mechanical injuries may be inflicted on the seeds. The use of defoliation can minimize this occurrence, promoting uniformity of plants maturity at harvest with grains maintaining low moisture. ln order to […]

A field experiment was carried out in Itapira, SP, to evaluate the selectivity and efficiency ofthe herbicide flumioxazin alone or in a tank mix with diuron or diclosulam applied in post-ernergence to weed control in cotton cv. Coodetec 40 I,with two different mineral oils. The experimental design was a randomized block with four replications and the foIlowing treatments: flumioxazin (30 g/ha), flumioxazin+diuron (25+800 and 25+ 1,000 g/ha), flumioxazin+diclosulam (25+30 and 25+35 g/ha), MSMA+diuron (1,800+1,000 g/ha) with standard treatrnent and controls […]

Euphorbia dentata is a highly competitive and difficult to control weed in soybean crops in the central are a of Buenos Aires Province, Argentina. Development of transgenic soybean resistant to glyphosate (GR) allows exploration of new techniques of chemical weed control, mainly where the herbicides traditionalJy used are inefficient. The objetive of this . research was to evaluate the effectiveness of Euphorbia dentata control with different formulations of glyphosate in soybean GR. The trial was carried out in Azul district, […]

Different strategies to reduce C. benghalens is and C. diffusa tolerance to glyphosate were studied in two field experiments in coffee. The effect of glyphosate sequential application at increasing doses and comparing the glyphosate formulations, glyphosate SA (isopropilamine salt) and glyphosate WG (ammonium salt) in the control ofthese species and the respective phytotoxicity was evaluated. No significant difference were foundamong formulations of glyphosate SA (2160 g/ha a.e.) and glyphosate WG (2160 g/ha a.e.), in C. diffusa and C. benghalensis controI. […]

The main management problem in the cassava crop in due to interference by weeds, where they bring about root yield reductions. Inexistence of selective postemergence herbicides, makes weed control only possible with preemergence herbicides or through hand hoeing. The objective of this research was to evaluate broadleaf herbicide selectivity when applied postemerg.ence on cassava plants. An experiment was carried out at University of Rio Grande do Sul, Brazil, using 10-liter volume pots, where four cassava cuttings were planted. The experimental […]

The effects of chlorimuron-ethyl at the rate of 10.0 g/ha applied alone and as tank mixture or in sequence with glyphosate, and diclosulam at the rate of35.2 g/ha plus glyphosate, as tank mixture, were studied for burn-down and residual control of Brachiaria p/antaginea (Link) Hitchc. and Bidens pilosa L. and for their safety to soybean in no-til. The study was conducted during the 2001/2002 growing season at the National Wheat Research Center of Embrapa in Passo Fundo, RS, Brazil, on […]

An experiment was carried out on a “Cerrado” oxisol with a loamy texture during 1996/97. The objective of present work was to evaluate the selectivity and efficacy of cloransulam-methyl, alone or tank mixed with lactofen, applied postemergence on soybean (cv. Doko) in controlling broadleafweeds. The experimental design was a complete randomized block with seven treatrnents and four replications. The treatrnents were: cloransulam-methyl (20, 30 and 40 g/ha), chloransulammethyl+ lactofen (30+96 glha), chlorimuron-ethyl+lactofen (12.5+96.0 g/ha) and control with and without weeds. […]

With the purpose of evaluating the selectivity of the imazethapyr herbicide at different dosages to common bean genotypes, an experiment was conducted in greenhouse at the Department of Agriculture of the Universidade Federal de Lavras, from April, 20 to August 4, 2001. The experimental design was a completely randomized with four replications in a 3×4 factorial arrangement, i.e., three common bean genotypes (Pérola, CII-I02 and Ouro Negro) and four dosages of the imazethapyr herbicide (O, 50, 100 and 150 g/ha). […]

Balloonvine (Cardiospermum halicacabum) is distributed throughout South Brazil. Because of size and shape similarities, balloonvine seeds are difficult to separate mechanically from soybean seed and this weed is spreading quickly by contaminated soybean seed. It is tolerant to most herbicides, mainly to contact products and highly infested soybean areas are difficult to harvest. Three experiments were carried out at Embrapa Soybean, Londrina, Paraná State, in order to evaluate balloonvine chemical control with pre and postemergence herbicide applications. Oxyfluorfen (480 g/ha), […]

The present research involved two field experiments. The first one, carried out at Iguaraçu, PR, inc1uded rates of diclosularn (30,35 and 40 g1ha), imazaquin (140 g/ha), flumetsulam (108 g1ha) and a weed-free control were evaluated in a completely randomized block design with four replications. Diclosulam provided efficient control ofthe grass Pennisetum typhoideum up to 42 days after application (DAA), requiring a suplementary postemergence grass herbicide to alow suitable control at harvest. In relation to Commelina bengalensis, diclosulam at 30 g1ha […]

The region of Ribeirão Preto, SP, Brazil, is located on the Guarani aquifer, the most important source of ground water in the South Central region of the country. The recharge area of this aquifer is located in the Espraiado watershed. The presence of sandy soi! and a sugar cane crop treated with pesticides makes the aquifer vulnerable to groundwater contamination. The herbicide picloram was among the pesticides used. To study its behavior, a gas chromatography analytical method for residue analysis […]