Macroptilium lathyroides control with pre and post-emergence herbicide applications

Macroptilium lathyroides (wild bushbean) specie was found infesting relatively large areas of soybeans in the southern region of Mato Grosso do Sul State, Brazil, where farmers complained about lack of herbicides efficiency in controlling this species. There is no herbicide registered for controlling this species in Brazil, and the amount of researches involving its susceptibility to several actives principles is so limited. This study aimed to verify the efficiency of glyphosate herbicide, isolated or in association with other actives principles, in controlling M. lathyroides at three crop growth stages, as well as to find alternative herbicides for chemical control of this species in pre- and post-emergence. The experiment was conducted under greenhouse conditions, where plants were established in plastic vases containing 4 dm3 of soil, where herbicides were applied, according to the treatments, in three moments: pre-emergence (4 days after seeded), early post-emergence (4 to 6 definitive leaves) and late post-emergence (initial flowering). Under pre-emergence applications M. lathyroides was particularly susceptible to sulfentrazone and diuron herbicides; in early post-emergence, glyphosate and trifloxysulfuronsodium were efficient, and in late post-emergence glyphosate and ammonium-gluphosinate were also efficient in controlling this species. Carfentrazone-ethyl efficiency was dependent on growth stage and pyrithiobac-sodium did not show satisfactory control. Further studies must be conducted under field conditions to confirm the results obtained in this study under controlled environment.