seed dormancy and emergence pattern of ground cherry (physalis divaricata) in sugar beet and wheat farms of alashthar, iran

the most problematic weed in summer crops in alashthar town is ground cherry (physalis divaricata). in this research, the emergence pattern of this weed in sugar beet and wheat crop was investigated during 2006- 2007. seed dormancy was also studied from october to may in two depths 0 and 10 cm, based on a factorial experiment. the results indicated that the emergence of this weed starts late april and continues up to july and 70 percent of germination occurred in may and 45 percent in the first half of may. emergence growing of weed in wheat crop occurred early july (30 percent) and continued up to early september (45 percent) from october to may, the germination of seeds buried at two depths (0 and 10 cm) was more than 88 percent. this indicated the lack of seed dormancy for the majority of ground cherry population. therefore, irrigation and plowing after wheat harvest is very important in controlling this weed.