Determination of weed species, their frequencies and densities in onion fields in Hatay province

Aims: Surveys were carried out in order to determine the species, density and frequency of the weeds in onion (Allium cepa L.) fields of the Hatay province in 2015. Methods and Results: Surveyed fields were chosen randomly by stopping at every 5 km and weed species and their densities (plant/m2) were determined. Total of 93 weed species in 82 genus belonging to 29 different families, including 2 monocotyledoneus, 26 dicotyledoneus and 1 parasitic, 66 winter and 27 summer species, 17 narrow leaved, 76 broad leaved were determined. According to their life cycles the weeds were classified as, 24 perennial, 64 annual, 5 biennial, 6 annual-perennial and 8 annual-biennial. Conclusions: In onion fields, Avena sterilis L., Sinapis arvensis L., Convolvulus arvensis L had the highest incidence rates. Significance and Impact of the Study: Among all the weeds, level “A” Avena sterilis L., level “B” Sinapis arvensis L., level “C” Convolvulus arvensis L had the highest population density