Reaction of cycloxydim-tolerant corn depending on hebricide dose and application date

Abstract

Field trials have been organized in order to assess the tolerance of the corn hybrid NS 444 Ultra to cycloxydim doses of 200, 400, 800 and 1200 g/ha applied in the stages 14, 17 and 20 of the BBCH scale. The trials showed high tolerance of the hybrid to single applications of 200 and 400 g/ha doses in stages 14, 17 and 20 and two applications of 400 g/ha in stages 14 and 20. The application of 800 and 1200 g/ha of cycloxydim in stages 14 and 17 caused a transitory bleaching of the newly-formed leaves and retarded plant growth, but no effect on grain yield. The doses of 800 and 1200 g/ha of cycloxydim applied in stage 20 were not phytotoxic to corn. The results indicate an exceptional flexibility of use of cycloxydim-based preparations in the production of tolerant corn hybrids whose selectivity tends to increase in later phenological stages.

U poljskim ogledima ispitivana je tolerantnost hibrida NS 444 Ultra prema cikloksidimu primenjenom u količinama 200, 400, 800 i 1200 g/ha u fazama 14, 17 i 20 BBCH skale. U ogledima je utvrđena visoka tolerantnost ovog hibrida prema cikloksidimu primenjenom jednokratno u količinama 200 i 400 g/ha u fazama 14, 17 i 20 BBCH skale i 2 x 400 g/ha u fazama 14 i 20 BBCH skale. Primenom 800 i 1200 g/ha cikloksidima u fazama 14 i 17 BBCH skale, prouzrokovano je prolazno etioliranje novoformiranih listova i zaustavljanje rasta biljaka, ali bez uticaja na smanjenje prinosa zrna. Količine 800 i 1200 g/ha cikloksidima primenjene u fazi 20 BBCH skale nisu prouzrokovale fitotoksičnost prema kukuruzu. Dobijeni rezultati ukazuju na izuzetnu fleksibilnost primene preparata na bazi cikloksidima u proizvodnji hibrida kukuruza tolerantnih prema ovom herbicidu, čija se selektivnost povećava sa primenom u kasnijim fenofazama kukuruza.