Determination of effective minimum doses of herbicides commonly applied in maize fields in Çukurova

This study was carried out in pot and field experiments in 2007 and 2008 to determine effective minimum doses (ED90) of herbicides with active ingredients of foramsulfuron, nicosulfuron and 2,4-D amin and commonly used against weeds which cause problems in maize fields in Çukurova. In pot experiments, the herbicide with the active ingredient of foramsulfuron was applied against Amaranthus retroflexus L. (Kızıl Bacak), Xanthium strumarium L. (Domuz Pıtrağı), Sorghum halepense (L.) Pers. (Kanyaş) and Echinochloa colonum (L.) Link (Benekli Darıcan); the herbicide with the active ingredient of nicosulfuron was applied to A. retroflexus, S. halepense and E. colonum, and the herbicide with the active ingredient 2,4-D amin was applied against A. retroflexus. Dose-response curves were drawn using plant dry weight in pot experiments and effective minimum doses yielding a success rate of 90 percent were determined using these curves. In field experiments, of the effective minimum doses, the 4,05 g a.i./da dose of foramsulfuron, except for X. strumarium, the 4,4 g a.i./da dose of nicosulfuron and the 90,0 g a.i./da dose of 2,4-D amin were found to be successful (90 % ?) in controlling the weeds against which they were applied. However, among effective minimum doses calculated for weeds in the experiments, 4,05 g a.i./da dose of foramsulfuron and 4,4 g a.i./da dose of nicosulfuron were found to be successful in terms of maize grain yield (kg/da) and thousand grain weight(g).