SELECTION OF HERBICIDES TARGETING THE USE IN CROP SYSTEMS CULTIVATED WITH SHOWY CROTALARIA

• Published in: Planta daninha 2015-09, Vol.33 (3), p.521-534
• Main Authors: BRAZ, G. B. P, OLIVEIRA JR, R. S, CONSTANTIN, J., TAKANO, H. K., CHASE, C. A., FORNAZZA, F. G. F., RAIMONDI, R. T.
• Format: Article
• Language: English
• Subjects: control of volunteer plants; crop rotation; Crotalaria spectabilis; PLANT SCIENCES; selectivity
• ISSN: 0100-8358; 1806-9681; 0100-8358
• DOI: 10.1590/S0100-83582015000300014

ABSTRACT The increase in the area planted with Crotalaria spectabilishas occurred by several factors, highlighting the potential to reduce the nematodes, nitrogen fixation and the high production of biomass. By becoming a species sown as a crop, it is necessary to control the weeds that coexist with showy crotalaria. This change in the use of this crop creates the possibility of this specie becoming a weed. The aim of this study was to assess the potential use of herbicides applied in preemergence and postemergence of C.spectabilisfor different purposes (control of volunteer and selectivity plants). Three experiments were installed in a greenhouse (two with herbicides applied in preemergence - in soils with distinct textural categories; and one experiment with herbicides applied in postemergence). The results of the experiments with herbicides applied in preemergence showed that: amicarbazone, atrazine, diuron, metribuzin, prometryn, fomesafen and sulfentrazone showed effectiveness for control of C.spectabilis in clayey soil. Besides these, flumioxazin and isoxaflutole also showed potential to be used in the control of showy crotalaria in soils with loam texture. In relation to the postemergence herbicides, atrazine, diuron, prometryn, flumioxazin, fomesafen, lactofen, saflufenacil, amonio-glufosinate and glyphosate can be used aiming the chemical control of C.spectabilis. Herbicides chlorimuron-ethyl, diclosulan, imazethapyr, pyrithiobac-sodium, trifloxysulfuron-sodium, clomazone, pendimethalin, S-metolachlor and trifluralin applied in preemergence, and imazethapyr, pyrithiobac-sodium, flumiclorac, bentazon and clethodim applied in postemergence caused low levels of injury to C.spectabilis plants, making necessary the development of new searches to ensure the selectivity of these products. RESUMOO acréscimo da área plantada com Crotalaria spectabilis tem ocorrido por diversos fatores, destacando-se o potencial de redução de nematoides, fixação de nitrogênio e elevada produção de biomassa. Ao se tornar espécie semeada como cultura, faz-se necessário o controle de plantas daninhas que convivem com a crotalária. Essa mudança na utilização dessa cultura cria a possibilidade de a espécie se tornar planta daninha. O objetivo deste trabalho foi de avaliar o potencial de utilização de herbicidas aplicados em pré e pós-emergência de C. spectabilis para diferentes finalidades (controle de plantas voluntárias e seletividade). Foram instalados três experimentos em ca