The experiment was carried out during 1997/98, in Rio Verde (GO), to evaluate the efficacy ofpostemergence herbicides, applied at ditferent times, compared to atrazine+metolachor applied at preemergence.The etfect ofthese herbicides on some agronomic characteristics of com was also evaluated. The hybrid com used was AG-50 11, sown on 10/26/97, and the treatments were: postemergence application of atrazine+metolachlor (1400+2100 g/ha), early postemergence application of atrazine/metolachlor+nicosulfuron (1000/1500+ 12 g/ha), postermergence aplication of atrazine vegetal oil+nicosulfuron (1600+20 g/ha), late postemergence application of atrazine+nicosulfuron […]

The experiment was developed in 1998/99, in the illTESP Experimental Farm, in Selvíria (MS), on soil with a loamy texture. The objective ofthe present work was to evaluate the tolerance and efficiency ofpreemergence herbicides on rice and observe the effects ofthe treatrnents on the productivity ofthe crop. The rice strain used was Caiapó. The experimental design was a complete randomized block with ten treatments and four replications. The treatrnents were the following: trifluralin (1200 g/ha), oxyfluorfen (120 and 240 g/ha), […]

Edaphic characteristics, in interaction with the clímate and the specific cultivar, may cause crop toxicity in an area treated with a residual herbicide. Two experíments were carried out on two Cerrado soils, in Campo Grande (MS), to evaluate the selectivity of sulfentrazone on 21 soybean cultivars, as well as the residual effects on successive soybean crops.The first experiment was on a sandy soil, with 8% clay, 2% lime, 90% total sand and 2.3% organic matter. The second experiment was carried […]

The effects of alachor, metolachlor, dimethenamid and diuron herbicides on a predator ant guild were evaluated in Dourados, MS (22°13’16″S and 54°48’20″W). Two control areas, with and without weeds, were used in the study. The ants were sampled using two sardine baits per plot with four replications per treatment. Solenopsis sp. was the most abundant ant species among the five sampled species. There was a decrease in the number of ants in the treatment and control plots afier 40 days. […]

The objective of the experiment was analyse different no-tillage management systems and postemergence control under a soybean crop, in São João do Ivaí (PR), in the agricultural year 1998/99. The treatments used in the management system sequence to control Commelina benghalensis (from 2 leaves to ramified plants) and Brachiaria plantaginea (from 2 leaves to tillered plants) were: (M1) sulfosate and paraquatldiuron+diquat (864 and 300+240 g/ha); (M2) sulfosate+2,4-D and paraquatldiuron+diquat (864+670 e 300+240 g/ha); (M3) sulfosate and paraquat/diuron+diquat (672 e 300+240 […]

One obstacle to sunflower production is weed competition. A limited number of herbicides have been registered for this crop in Brazil and the lack ofwide spectrum broadleafweed control herbicides increases the need for other weed control methods. A field experiment was conducted at Embrapa Soja, Londrina county, Paraná State, Brazil, to evaluate sunflower tolerance to preemergence herbicides. The treatments were acetochlor+oxyfluorfen (1536+240 g/ha), oxyfluorfen (360 g/ha), oxyfluorfen (240 g/ha), Iinuron (1000 g/ha), aclonifen (1800 g/ha), oxadiargil (800 g/ha), diflufenican (25 […]

A trial was carried out on Bela Vista Farm, Serranópolis (GO), to evaluate the efficiency and selectiveness ofherbicide combinations applied in preemergence for soybean cv. Rainha. The treatments used were: metalochlor+diclosulam (2400+35 g/ha), sulfentrazone+diclosulam (250+25, 300+20, 350+ 15 and 200+35 g/ha), clomazone+diclosulam (504+25, 720+25, 828+25, 504+30, 720+30 and 828+30 g/ha), as well as an untreated control. It was concluded that the herbicide mixtures were selective for soybean cv. Rainha. Sulfentrazone+diclosulam and clomazone+diclosulam, independently ofthe dose used showed an efficient control […]

A trial was developed under greenhouse conditions to compare the summer development ofthree ALS resistant wild poinsettia (Euphorbia heterophylla) biotypes from Passo Fundo, Não-Me-Toque and Rio Pardo, and one susceptible, from Porto Alegre. The experimental design was completly randomised, with three replicates, in a 4 x 5 factorial design ,where the first factor corresponded to the four biotypes ofwild poinsettia and the second to five periods of development (13,23,33,43 and 53 days after emergence (DAE)). Except at 13 DAE, total […]

Since DNA tests are relatively expensive and time-consuming for the detection of the presence of the gene in plant materiais confering glyphosate tolerance to soybean, an experiment was carried out with the objective of developing a rapid and simple laboratory test for identifying glyphosate-tolerant soybean seeds, through standard seed germination tests. Seeds from six susceptible and twelve glyphosate-tolerant genotypes were used. The treatments consisted of cotiledonar/foliar spray of a glyphosate solution at the concentration of 8960 mg/l with 100 Ilha […]