Study of Flora and structure of weed communities of saffron fields in Kashmar and KhalilAbad counties

In order to identify weedspeciesand their community structure in saffron fields of Kashmar and Khalil-Abad counties, 45 farms were selected randomly based on cultivation area during 2014- 2015. In each farm weed species were counted separately and also the geographical information of each farm was recorded by GPS. These data were used for mapping of weed species and geographic distribution in ArcGIS software. The results showed that 82 weed species belong to the families of Astraceae, Brassicaceae, Poaceae and Caryophyllaceae had the highest frequency, respectively. The most important weeds in the surveyed area based on the abundance index were: downy brome (Bromus tectorum L.), Hordeum spontaneum C. Koch, from grasses and hoary cress (Cardaria draba (L.) Desv.), Holosteum glutinosum F.et M, Russian knapweed (Acroptilon repens (L.) DC), Sisymbrium subulatum E.Fourn , creeping thistle (Cirsium arvense (L.) scop) from Broad leaves. Annual weeds had the greatest species diversity (53 species), biennial weeds had the lowest species diversity (4 species), and perennial weeds were intermediate (25 species). 82 percent of weeds were broadleaf, and 18 percent were narrow leaf weeds. The weeds such as Bromus tectorum L., Holosteum glutinosum F.et M, Acroptilon repens (L.) DC, Descurainia sophia (L.) Schar, and Cardaria draba (L.) Desv., were dominant species in Kashmar, while Cardaria draba (L.) Desv., Hordeum spontaneum C. Koch, Sisymbrium subulatum E.Fourn, Hordeum murinum L., Cirsium arvense (L.) scop, and Malcolmia africana (L.) R.Br., were dominant species in Khalil-Abad . Cardaria draba was problematic and dominant species at both locations.