Selectivity is the capacity ofherbicides to control weeds in a crop without reducing the productivity and quality ofthe final product. It cannot be determined only by the verification of presence or not oftoxicity symptoms, because there are already well-known herbicides that can reduce the productivity of crops without producing visual effects and also herbicides that provoke quite accentuated toxicity, but that allow the crop to manifest its productive potentials fully. This work has the objective to evaluate the selectivity of […]

Weed control in sunflower is required to avoid poor growth, yield loss, and weed problems in crops grown after sunflower. Limited availability of sunflower herbicides requires a rigid weed control program consisting of cultural, mechanical, and chemical measures for the most profitable crop production. Two experiments were carried out at Embrapa Soja, Londrina, Parana State, Brazil, in 1998, to evaluate the selectivity ofpre-emergence broadleafweed herbicides in sunflower crop.ln one of the experiment, acetochlor was used at rates of O, 1152,2304,3456 […]

An experiment was conducted at the Bom Futuro Farm, Rondonópolis, MT during 1999/2000 in a sandy soil, to determine the effects of metsulfuron-methyl on postemergence control of weeds in a field of Brachiaria brizantha seed production. Treatments were: metsulfuron-methyl at 3.0 glha and at 3.6 glha in one application or in two applications, 2,4-D at 288 glha (as a reference) and a check. Tridax procumbens, Spemacoce latifolia, Chamaesyce hirta were controlled by metsulfuron-methyl at 3.0 and 3.6 glha in a […]

A experiment was carried out at the Bela Vista Farm, in Serranópolis, State ofGoiás, with the objective to evaluate the effects of postemergence herbicides on agronomic characteristcs of soybean cv. Emgopa 316, with premature maturation cycle. Treatments consisted oflactofen (168 glha), chlorimuron-ethyl (15 glha) + mineral oil (0.2 v/v), fomesafen (250 g/ha) + mineral oil (0.2 v/v), imazethapyr (100 g/ha), chlorimuron-ethyl+lactofen (12.5+96 g/ha), chlorimuronethyl+ fomesafen (12.5+ 150 g/ha), chlorirnuron-ethyl+imazethapyr (12.5+50 g/ha), imazethapyr+lactofen (50+96 g/ha), imazethapyr+fomesafen (50+ 150 g/ha), and a […]

The experiment was carried out in 99100, at the experimental field ofthe State University ofSão Paulo, in Selvíria,MS, on a medium texture soil. The objective of the study was to evaluate the tolerance and agronomic efficacy of postemergence herbicides in the control of adult plants of Euphorbia heterophylla for no-till planting of soybean cv. Tucano. Planting was done in area with adult plants of E. heterophylla, in the system of”direct planting on the weeds”. The herbicides were applied in postemergence […]

An experiment was conducted on a Cerrado sandy soil during 1999/2000. The objective ofthe experiment was to evaluate the residual effect of chlorimuron-ethyl tank mixed with glyphosate applied as burndown treatment for pre-site preparation, to control Bidens pilosa in preemergence. The experimental design was a randomized complete block with four replications. Treatments were as follows: glyphosate at 720 and 1440 glha, glyphosate+chlorimuron-ethyl at 720+ IO and 720+20 glha, glyphosate+chlorimuron-ethy”I+flumioxazin at 720+20+40 glha and glyphosate+ 2,4-0 at 720+460 glha. An untreated […]

Euphorbia dentata is an annual weed which grows during spring and summer. Its has acquired importance mainly associated with soybean crops in the central area in Buenos Aires Province, Argentina. This weed is highly competitive in soybean fields and its control is very difficult. The objective of this work was to evaluate the effectiveness of Euphorbia dentata control with postemergence herbicides in soybean crops. Field studies were conducted in Azul Co., in a highly naturally infested soybean crop (110 plants […]

The objective ofthis trial was to study the reactions ofthe residual herbicide mixtures metolachlor plus atrazine and atrazine plus isoxaflutole applied in pre-ernergence for com under no-till system. The experiment was settled in Londrina, using black oat (Avena strigosa) mulch. A randomized complete block design was used. The treatments comprised the following rates ofherbicides: zero, 0.5N, 1.ON, I.5N and 2.0N (N=normal rate ofherbicide). In the present study, N=21 00 g/ha metolachlor + 1400 g/ha atrazine and 1660 g/ha atrazine + […]

This research was done to evaluate the tolerance and efficacy ofpostemergence herbicides to contrai established weeds in no-ti 11soybean. Experiment was conducted at Rondonópolis, Mato Grosso, from 1999 to 2000, in the Sementes Maggi 2 Farm, on a loamy texture soil, using Emgopa 313 variety. Planting was done in an are a with adult weeds, in the system of “direct planting on the weeds”. Herbicides were applied in postemergence ofthe weeds and the culture. Experimental design was a randomized complete […]

Two experiments were carried out to test the efficacy offlumioxazin to desiccate Ageratum conyzoides and Commelina benghalensis previous to soybean planting. One of them tested doses of the herbicide alone and the other tested doses of flumioxazin in mixture with sulphosate. Flumioxazin (30, 40 and 50 g/ha) mixed with mineral oil (0,5 and 1,0%) showed an excellent control (more than 90%) of Ageratum conyzoides and Commelina benghalensis. The mixture flumioxazin (20 or 25 g/ha) + sulphosate (960 or 1,440 g/ha) […]