Revista Brasileira De Herbicidas 2000; 1(1): 45-52
Efficacy of mixtures of imidazolinone herbicides on tolerant mayze
DOI: 10.7824/rbh.v1i1.314
Mixtures of imidazolinone herbicides were applied in pre and postemergence on a hibrid of maize tolerant to this group, to control Richardia brasiliensis, Acanthospermum australe, Brachiaria decumbens and Spermacoce latifolia. Two experiments were conducted, one in each time of application. ln pre-emergence the following mixtures were tested: imazethapyrl imazapyr (79+26, 90+30, 70+35 and 80+40 g/ha), imazethapyr/imazapic (60+30, 70+35 and 80+40 g/ha), imazapicl imazapyr (68+22, 70+35 and 79+26 g/ha), compared with atrazine/metolachlor (3250 g/ha). The following mixtures were tested in postemergence: imazethapyr/imazapyr (57++ 18, 68+22, 79+26, 50+25, 60+30 and 70+35 g/ha), imazapic/imazapyr (40+20,50+25,60+30,45+ 15,57+ 18 and 68+22 g/ha), compared with nicosulfuron (60 g/ha). Two other controls were also included on both experiments: presence or absence ofhand weeding. No toxicity was observed on maize by any mixture, dose or time of application. The used doses of imazethapyr/imazapyr, imazapic/imazapyr and imazethapyr/imazapic, applied in pre-emergence, showed an excellent control of A. australe, R. brasiliensis and S. latifolia. lmazethapyr/imazapic also controlled B. decumbens. ln postemergence application an excellent control of both R. brasiliensis and A. australe was only achieved with imazapic/imazapyr, Imazethapyr/imazapyr also controlled very well A. australe. The control of B. decumbens was acceptable in postemergence applications.
123