Integrated weed management in long-term maize cultivation

The effects of different measures within maize cropping technology, aimed to suppress weeds as a part of integrated weed management (IWM) system, are analysed and evaluated in this manuscript, in line with the results of long-term experiments. For sustainable maize (Zea mays L.) production, implementation of IWM system aiming to reduce reliance on chemical weed control within Europe is a key priority. This IWM system includes all possible solutions, such as preventive, direct, biological, mechanical and alternative measures. A cropping system approach is essential to manage weeds, utilize genetic potential of maize genotypes and reduce yield losses due to weed competition. Long-term experiments are nowadays rare, but they are an excellent and reliable method for comparing cropping systems regarding yield and reduction of weed infestation level. In the research program implemented at the Maize Research Institute Zemun Polje in Central Serbia, the effects of different cropping measures and their interactions as a part of IWMs were studied during ten years. Maize rotations with winter wheat (Triticum aestivum L.) and soybean (Glycine max (L.) Men.), combined with herbicide application, showed the best effect on weed biomass reduction, 92.1% and 92.2%, respectively. Winter wheat was a better preceding crop for maize than soybean, especially in combination with herbicides applied in recommended as well as in half of recommended rate. Intensification of soil tillage significantly reduced maize weed infestation, especially abundance of perennial species: Johnson grass (Sorghum halepense (L.) Pers.), Canada thistle (Cirsium arvense (L.) Scop.) and field bindweed (Convolvulus arvensis L.). Other measures, such as type of fertilizer, maize row space and crop density, cover cropping and intercropping also affected weed biomass production in maize fields. Maize growing with reduced row spacing contributed to weed biomass reduction by 27.4%, while application of slow-release urea contributed to crop competitiveness. Weed biomass in sweet maize (Zea mays L. convar. saccharata) grown with common vetch as a cover crop was significantly reduced (48.5 g m(-2)) compared with the treatment without a cover crop (564.3 g m(-2)).