Search

SEM RESUMO

The work aimed to evaluate, in sugar cane crop, the selectivity and effectiveness of S-metolachlor herbicide associated to ametryn and [hexazinone+diuron], applied terrestrial and aerial forms, in pre and post emergent weeds control. The experimental design used in experiment 1 (terrestrial application) was randomized complete blocks with 16 treatments and four repetitions, applied in pre and post emergence: S-metolachlor + ametryn (1920 + 1500; 2400 + 1500 and 2880 + 1500 g a.i. ha -1 ; S-metolachlor + [ hexazinone+diuron ] (1440 + [ 702+198 ] and 1920 + [ 702+198 ] g a.i. ha -1 ; [ hexazinone+diuron ] + ametryn ([ 936+264 ] + 1500 g a.i. ha -1 ; tebuthiuron + ametryn (1000 + 1500 g a.i. ha -1 and checks with and without weeding. In experiment 2 (aerial application), the treatments were constituted by S-metolachlor (2880 g a.i. ha -1 ), S-metolachlor + ametryn (2400 + 1500 g a.i. ha -1 ) and checks without application, being herbicides applied in two bands of one hectare for each treatment. All herbicides treatments caused initial phytotoxicity to sugar cane crop (RB 835486), with total recovery at 45 DAA (days after application). Terrestrial application in S-metolachlor + ametryn, S-metolachlor + [hexazinone+diuron], [hexazinone+diuron] + ametryn and tebuthiuron + ametryn pre-emergence was efficient in controlling Digitaria horizontalis , Ipomoea nil and Amaranthus deflexus. In post emergency, treatments were less efficient in controlling D. horizontalis; more efficient in controlling I. nil and equivalents in A . deflexus control. Aerial application of S-metolachlor and S-metolachlor + ametryn was efficient in D. horizontalis e B. plantaginea control, providing higher sugar cane yield than the check without herbicides application.

The objective of this work was to evaluate herbicides efficacy and selectivity applied in post-emergence for controlling weeds in two corn cultivars. The experiment was conducted between December/2007 and April/2008, at FEP – UNESP, Selviria County/MS. The experiment was conducted in conventional tillage, by using seven treatments and four replications, in split plot scheme for cultivar factor: Pioneer 30 S31 and Dow Agroscience 2B710. Applications were effected in crops and weeds post-emergence, 7 and 14 days after crop emergence, by using a pressurized sprayer (CO2), with spray volume of 200 L.ha-1. It was concluded that the treatments: HerbitrinTM + AccentTM + Joint OilTM (2500 mL + 25 g. ha-1 + 0,5% v/v); HerbitrinTM + Sanson 40 SCTM + Joint OilTM (2500 mL + 470 mL ha-1 + 0,5% v/v); HerbitrinTM + CallistoTM + Joint OilTM (2500 mL + 250 mL ha-1 + 0,5% v/v); and sequential applications of HerbitrinTM + AccentTM + Joint OilTM (1250 mL + 21 g ha-1 + 0,5% v/v))/ HerbitrinTM + CallistoTM + Joint OilTM (1250 mL + 125 mL ha-1 + 0,5% v/v); HerbitrinTM + CallistoTM + Joint OilTM (1250 mL + 125 mL ha-1 + 0,5% v/v)/ HerbitrinTM + AccentTM + Joint OilTM (1250 mL + 21 g ha-1 + 0,5%v/v) and HerbitrinTM + AccentTM + CallistoTM + Joint OilTM (1250 mL + 13 g + 100 mL ha-1 + 0,5% v/v)/(1250 mL + 13 g + 100 mL ha-1 + 0,5% v/v) were highly selective to Pioneer 30 S31 and Dow Agroceres 2B710 cultivars, with expressive efficacy in controlling Amaranthus deflexus, Ipomoea nil, Commelina benghalensis e Panicum maximum weeds. It was also observed that these treatments may be recommended for controlling weed in corn crop.

The work was developed with the objective of evaluating the carry over effect in soil of nicosulfuron herbicide isolated and nicosulfuron + atrazine over soybean, bean, cotton, cucumber, sunflower and rice crops, sown in different periods after herbicides application. The experiment was carried out from November/2008 to April/2009, at FEP-UNESP, in Selviria, County/MS, with clayey soil. The experiment was conducted under conventional tillage with crops sown in 0.5 cm spacing. The experimental design was randomized complete block with 13 treatments and 4 replications per crop. Plots were scaled with 15 m2 (3m x 5m), with 10 m2 of applied central area. Treatments consisted of nicosulfuron + atrazine (30 g + 1500 g .ha-1) and nicosulfuron (60 g .ha-1) herbicides applied to the soil at 75, 60, 45, 30, 15 and 7 days before crop sowing and a check without herbicide. Considering the obtained results, it was concluded that bean (Carioca cultivar), cucumber (Caipira-Esmeralda cultivar) and sunflower (Doe M734-G3 genotype) crops may be sown 30 days after atrazine + nicosulfuron application, as soon as isolated nicosulfuron. Soybean crop (Carrera cultivar) may be sown between 15 and 30 days after nicosulfuron + atrazine application and isolated nicosulfuron, respectively. Cotton crop (DeltaOpal cultivar), may be sown after 60 and 45 days of nicosulfuron + atrazine and isolated nicosulfuron application, respectively. However, rice crop (Primavera cultivar) may be sown 60 days after nicosulfuron + atrazine and isolated nicosulfuron application.