The use of herbicides for weed control in direct wet-seeded rice (Oryza sativa L.) in rice production regions in the Republic of Macedonia

Field trials were conducted in the Agricultural Research Institute for Rice, at two localities during 2005 and 2006. The objective of the study was to establish an appropriate weed management strategy for the effective control of weed flora in direct wet-seeded rice. Herbicide selectivity and influence on grain yield were also evaluated. The weed population in the trials was composed of 8 and 5 weed species in Kočani and Probištip locality, respectively. The most prevailing weeds in both localities were:Cyperus rotundus, Echinochloa crus-galli and Heteranthea limosa. The average weediness for both years was 456.8 weed stems per m2 in Kočani locality and 589.0 weed stems per m2 in Probištip locality. In both localities all herbicides controlled Cyperus rotundus, Echinochloa crus-galli and Heteranthera limosa excellently except Mefenacet 53 WP. All applied herbicides showed high selectivity to rice, no visual injuries were determined at any rates in any year and locality. Herbicidal treatments in both localities significantly increased rice grain yield in comparison with untreated control.