Sergio Guimarães

Tratamento químico de sementes de trigo

Treating wheat seeds with insecticides and fungicides is important for protecting them against insects and diseases. This study aimed to evaluate the effects of chemical treatments on the physiologic quality of wheat seeds. The experiment was installed in a completely randomized design, with four replications, in a 2x4 factorial scheme, being the A factor composed by wheat cultivars (Quartzo and Pampeano) and the B factor by insecticides and fungicides: control and, for each 100 kg of seeds, 21 g of the active ingredient (a.i.) of thiametoxan, 55 g a.i. of carboxin + thiram and 21 + 55 g a.i. of thiametoxan + carboxin + thiram. The thiametoxan (21 g a.i.) promoted a higher performance, concerning germination, germination speed index and fresh and dry matter weight, for the Quartzo cultivar. A higher dry matter accumulation was observed for the Pampeano cultivar, under the application of carboxin + thiram, at the 55 g a.i. dose. Both cultivars performed better, concerning the accelerated aging test, under the application of thiametoxan + carboxin + thiram (21 + 55 g a.i.). The seed treatments resulted in healthier seedlings, which will lead to more uniform plants stands, according to the higher germination percentage or protection against pests.

Potential of plant species for bioremediation of soils applied with imidazolinone herbicides

Imidazolinone herbicides present physicochemical characteristics that allow them to persist longer in environment, with increased chances of soil and water contamination, as well as carryover effects on subsequent crops. Phytoremediation is shown as a promising technique to decontaminate soils polluted by herbicides. The aim of this study was to assess the potential of some winter grown species in removing residuals from soils contaminated with imazethapyr + imazapic and imazapic + imazapyr, using pre-emergence to control weeds in summer grown rice fields. The experiment was conducted in a completely randomized design, with four replications. All species were subjected to herbicide application at different doses. Imazethapyr + imazapic and imazapyr + imazapic were applied at doses of 0.0, 1.0 and 2.0 L ha-1, and 0.0, 140 and 280 g ha-1, respectively, in pre-emergence of the species. Brassica napus and Festuca arundinaceae are not tolerant to herbicides, with 100% of phytotoxicity (plant death) for all doses assessed. The herbicide imazapyr + imazapic proved to be less selective, causing the highest phytotoxicity in the species tested. The most tolerant species to the herbicides was Vicia sativa, which may be the most suitable one for phytoremediation programs in areas contaminated with imazethapyr + imazapic and imazapyr + imazapic.

Simulated drift of herbicides applied alone and in tank mix in grapevine

1 Professor from the Federal University of Fronteira Sul, Chapecó, SC, Brazil. 2 Professor from the Federal University of Fronteira Sul, Erechim, RS, Brazil. 3 Undergraduate student in Agronomy from the Federal University of Pampa, Itaqui, RS, Brazil. 4 PhD student in Agronomy from the Federal University of Santa Maria, Santa Maria, RS, Brazil. *Author for correspondence: leandro.galon@uffs.edu.br.