Ratarstvo 48. hrvatski i 8. međunarodni simpozij agronoma | Dubrovnik | Hrvatska 457 ORIGINAL SCIENTIFIC PAPER The response of maize lines to different herbicides Brankov Milan 1 , Simić Milena 2 , Vrbničanin Sava 3 , Dragičević Vesna 2 , Spasojević Igor 2 1 Scholar of the Ministry of Education, Science and Technological Development, Republic of Serbia, Nemanjina 22-26, 11000 Belgrade, Serbia 2 Maize Research Institute, Slobodana Bajića 1,11185 Zemun Polje, Belgrade-Zemun, Serbia 3 Faculty of Agriculture, University of Belgrade, Nemanjina 6,11000, Belgrade, Serbia (mbrankov@mrizp.rs) Abstract Maize production technology involves the application of herbicides, especially if it is a seed crop. The application of herbicides can negatively affect the seed maize plant growth and development, reduction or failure yield. The first signs of phytotoxicity may occur for several days after the application of herbicide, while still visible symptoms are not pronounced. Sulfonylurea herbicides reduced content of soluble protein and phenolics of most inbred lines. All applied herbicides reduced yield compared to the control. Key words: maize lines, herbicides Introduction Maize production technology involves the use of herbicides, as a part of IWM, especially in seed crop. Maize seed crop is characterized by slow growth and smaller habit and generally higher susceptibility to many stresses. As a result, in maize seed crop weeds are present during all vegetation cycle (Stefanović, et al. 2007). Herbicide application should eleminate weeds and allow maize developing. Howewer, herbicide application in some genotyps that are susceptible could lead slowdown in growth and yield reduction. The maize inbred susceptibility towards herbicides was recorded immedeatelly after herbicide use. With introduction of sulfonilurea herbicides in the eighties there was a higher occurrence of phytotoxicity to the inbred lines in relation to previously applied herbicides (Green and Urlich, 1993). The introduction of sulfonylurea herbicides has led to the solution of the problem with narrow-leaved weeds in maize crop, but also created many problems after the application. Tolerance to herbicides, among others, is possible with rapid activation of detoxification mechanisms which influence decreasing or shortening of present stress. Those mechanisms imply the presence of antioxidants compounds that protect the cell and its compounds from various stresses. Van Eerd et al., (2003) stated that glutathione and other tioredoxins play a significant role in reducing herbicide stress. Changes in the content of phytate and inorganic phosphorus can be an indicator of plant tolerance to a specific stress (Graf and Eaton 1990). Also, the presence of phenolics compounds is associated with the process of inactivation of herbicides. Soluble proteins content, which represent small proteins chains – enzyms can be an indicator of plants susceptibillity towards herbicides (Dragičević et al. 2010). The aim of this study was to examine the effecs of four postemergence herbicides on soluble proteins and phenolics content, as wel as, the grain yield of five maize inbred lines. Material and Metods The trial was set up on slightly calcareous chernozem in the experimental field of the Maize Research Institute, “Zemun Polje”, during 2010 and 2011. Wheat was a preceding crop in both years. The effect of four herbicides (mesotrione, topramezone, foramsulfuron and rimsulfuron) on five maize inbred lines (L1-L5) was observed in experiment.