Investigation of weed flora of alfalfa fields and floristic diversity according of alfalfa age in Agri provience

Alfalfa (Medicago sativa L.) is the oldest and most important forage crop species fed as hay to livestock in Ağrı. Weeds play the most important role in reducing quality and quantity of alfalfa crops among many other plant protection factors. In order to determine weed species distribution and floral changes of alfalfa fields in relation to the age of the fields. Weed surveys were conducted during June and July of 2017 in alfalfa production areas of Ağrı province. For this aim field surveys were done according to the farmer support application files for forage crops datas of Ağrı Directorate of Provincial Agriculture and Forestry. Fields were visited with the help of GPS(Global Positioning System) intentionally according to the present datas in the files. A total of 160 fields were surveyed and including 40 fields for each year. The seeding year (2017) was evaluated as first year and second (2016), third (2015) and fourth (2014) year of established alfalfa for other years respectfully. Of all these surveyed fields were chosen from Ağrı Centre (10), Eleşkirt (10) and Patnos (20) for each year according to alfalfa production areas of Ağrı province and its districts. The surveys resulted with 87 weed species belonging to 26 families in alfalfa fields in totally. According to the weed species included, top four largest families were found to be Asteraceae (16), Poaceae (15), Apiaceae (6) and Brassicaceae (6) in alfalfa fields. Several perennial weeds such as Taraxacum officinale F.H. Wigg., Convolvulus arvensis L., Cirsium arvense L. Scop., Rumex crispus L., and Plantago spp. dominated weed flora in third and fourt years while annual weeds such as Avena fatua L., Amaranthus retroflexus L., Sinapis arvensis L. and Chenopodium album L. were dominaed in the first year according to their frequencies.