Evaluation of the effect of wild barley weed spike cut off in crop rotation on early and late sowing chickpea yield in Lorestan climatic conditions

IntroductionChickpea provides N benefit to cereals grown in crop rotation. In addition to the N benefit, chickpea provides a disease break for wheat grown in the crop rotation. Imazethapyr, applied preemergence at the rate of 0.053 kg ai/ha, reduced plant height, delayed plant maturity, and caused leaf chlorosis. Imazethapyr, applied at 0.053 kg/ha, significantly reduced plant height compared with the nontreated or hand-weeded checks. Visual injury symptoms observed with Imazethapyr treatment included chlorosis and delayed maturity of chickpea. There was an apparent rate effect with imazethapyr, when this herbicide was applied at 0.026 kg/ha with sulfentrazone, visual injury symptoms were significantly reduced. The risk of crop injury from the higher use rate of Imazethapyr is probably not commercially acceptable, whereas the injury from the lower use rate probably is acceptable. Pre-emergence application of low-rate of imazethapyr caused minor levels of injury to the plants, it had only minor effects on plant development and yield compared with sulfentrazone. Post-emergence applications of imazethapyr, imazamox and metribuzin, delayed flowering and maturity and reduced yield. Herbicide effects varied with chickpea cultivar. Most of the commonly used herbicides that are recommended for wheat fields weed control are not able to fully control the wild barley (Hordeum spontaneum C. Koch) weed. Hence, utilizing appropriate agronomic strategies for managing this weed is critical. The evaluation of the effect of Wild barley spike cut-off on the previous wheat field, and the effects of chickpea sowing date and weed control measurements in chickpea cultivation in the next year in crop rotation on chickpea yield are among the aims of this study. Materials and MethodsThe effect of wild barley weed spike cut off in wheat crop and sowing date and management strategies in chickpea cultivation on chickpea yield in the following year was evaluated in Khorramabad, Lorestan, during 2008-2009 and 2009-2010. The experiment was factorial split plot based on completely randomized block design with three replications. The factorial of the wild barley weed spike cut off in wheat (in two levels: 1- No spike cut off, and 2- Spike cut off) and chickpea sowing date in the following season (in two levels: 1- early sowing and 2- late sowing) was assigned to main plots, and the weed management factor levels in chickpea cultivation at five levels: 1- Pre emergence application of Metribu