Introduction of flora, diversity and distribution of weeds in the micro climatic areas of Eshtehard county during 2013-2018.
Field weed identifications is considered as the most important step in weed management in crops. Weed numbers for each genus and species were counted. Based on the cultivated area and the area of the farms in Eshtehard county, weed population indices were calculated using weed numbers in each area at the sampling points. In each area, latitude and longitude, and altitude from the sea level, and the place of measurements were recorded by the GPS device. Results showed that there are 47 weed species in Eshtehard. The most abundant species of weeds in this county were: Syrian beancaper (Zygophyllum eurypterum), wild barley (Hordeum murinum), camel thorn (Alhagi camelorum), Black bindweed (Convolvulus leiocalycinus Boiss.), Russian thistle (Salsola dendrioides), common lambsquarter (Chenopodium album), woodsorrel (Rumex vesicarius L), bermudagrass (Cynodon dactylon), barley grass (Hordeum spontaneum), respectively. In addition, the most important weeds of the Eshtehard county are wimmer ryegrass (Lolium rigidum), prickly lettuce (Scariola orientalis), russian knapweed (Acroptilon repens), corn cockle (Vaccaria grandiflora), common yarrow (Achillea wilhelmsii), sophora (Sophora alopecuroides), burdock (Xanthium strumarium) and other weeds with a lower frequency. The most noticeable point in this experiment was the increase in the prevalence of weed and goatmeat (11 and 9%) over the past five years, which gives rise to the concern that, due to the climatic conditions and soil and soil conditions, these two weeds are prone to become the dominant weed of the region. New species of creeping thistle (Circium arvense), swallow wort (Cynanchum acutum) and prickly lettuce (Lactuca scariola), could be a serious threat to the county farms, which could further expand to adjacent areas, although found at low densities.