پي جويي مقاومت علف هاي هرز به علف كش ها در برخي استان هاي كشور

A Survey for Determining Weeds Resistance to Herbicides in Some Provinces of Iran

In order to determining herbicide resistance in weeds, a stud}ʹ was carried out during 1997-1998 at four provinces of Iran including Golesian, iʹirs, Esfxhan and Khu/esLan. In 1997, the fields that some ACCase and ALS inhibitors, dinitroanalins and synthetic auxin herbicides were used for many years and weed control was unsatisfied, were identified and the seeds of uncontrolled weeds were collected as suspicious resistant biotypes. At the same time, the seeds of susceptible biotypes of each species were also collected. In 1998, after breaking seed dormancy of resistant and susceptible biotypes, each weed was grown in a set of greenhouse experiments in a completely randomized design with 4 to 6 replications. Both resistant and susceptible biotypes of each species were treated with and without recommended dosage of herbicide. EWRC method was used for visual assessment of the weeds response. The results showed no weed species had evolved resistance to mentioned herbicide groups by 1997 except Abuthilon theophrasti resistance to trifluralin in Golcstan and a suspicious resistant biotype of A vena ludoviciana to ACCase in Fars province. With respect to these points that frequent use and similar mode of action for each herbicide are most important factors in the development of herbicide resistance, and some herbicides are used for many years in Iran, lack of weed resistance to some ALS inhibitors and dinitroanilins herbicides is doubtful and we have to pay more attention to this subject in the future.