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Phytotoxicity of herbicides to different popcorn cultivars

Aiming to evaluate the selectivity of different herbicides to 10 genotypes of popcorn in Campos dos Goytacazes-RJ, herbicides were applied at the recommended maximum dosage (atrazine + S-metolachlor + extravon 1.665 + 1.035 kg ha-1 i.a. + 0.1%; foramsulfuron + iodosulfuron + hoefix 45.0 + 3.0 g ha-1 i.a. + 0.5%; mesotrione + mineral oil 192 g ha-1 + 0.5%; tembotrione + mineral oil 240 mL ha-1 + 0.5%) and a treatment without herbicide in a factorial scheme 5 x 10 x 5. The experiment was conducted in a randomized block design with four replications. Visual phytotoxicity symptoms were evaluated at 2, 4, 8, 12 and 20 days after application (DAA). Plant height and stem diameter were evaluated at 36 DAA, and leaf area and dry mass of the aerial part at 39 DAA. The treatments found to be the most selective to the tested varieties were atrazine + S-metolachlor, applied in pre-emergence; however, atrazine + S-metolachlor, mesotrione and foramsulfuron + iodosulfuron, applied in post-emergence, caused high levels of phytotoxicity to the popcorn plants, with the varieties Beija-Flor, Pr-023, SE-013, Angela, PA-038 and UFV being extremely sensitive to these products.

selectivity; herbicide management; Zea mays


Sociedade Brasileira da Ciência das Plantas Daninhas Departamento de Fitotecnia - DFT, Universidade Federal de Viçosa - UFV, 36570-000 - Viçosa-MG - Brasil, Tel./Fax::(+55 31) 3899-2611 - Viçosa - MG - Brazil
E-mail: rpdaninha@gmail.com