Narrow row spacing of corn crop and its influence on herbicide dose

Abstract

Management practices integration as an auxiliary tool in weeds chemical control in post emergence in corn crop (Zea mys L.) may reduce herbicide dose to be applied. Thus, this study aimed to evaluated by  spacing changes, the reduction possibility of tembotrione and mesotrione herbicides  recommended doses of and without damaging weeds control and corn yield. The experimental design was randomized complete blocks, arranged in split-plot scheme with four replications. Treatments used were two row spacing (0.40 and 0.80 m); two herbicides (tembotrione - 100 g a.i. ha^-1 and mesotrione - 192 g a.i. ha^-1); and four herbicides doses (100, 80, 60 and 0% of recommended dose). It was evaluated effect phytotoxicity visual to the crop, wild radish (Raphanus raphanistrum L.) control and alexandergrass [Urochloa plantaginea (Link) Hitchc.] at 7, 14, 21 and 28 days after treatment application), as well as the number of plants per plots, ears per plant, thousand grain mass and yield. Results evidenced that spacing did not interfer in wild radish and alexandergrass control and in corn yield. Mesotrione herbicide was more efficient in wild radish control, and tembotrione for alexandergrass control, allowing the use 80% of recommended dose for both herbicides without affecting weeds control and corn yield.