Evaluation of weed species, their frequencies, densities and current status in carrot fields in Hatay province.
Carrot [Daucus carota L.] is an important vegetable worldwide, which contains high levels of provitamin A, amino acids and other nutrients. Hatay province is the third province of the Turkey leading high amount and quality carrot production. Carrot crop production is hampered by diseases, pests and weeds which reduce production and quality of carrot in the fields and during storage. This study was conducted in major carrot growing districts of Hatay province for determination of densities, frequencies and current statues of major weeds species in randomly selected 80 carrot fields in surveyed districts between August 2018-October 2019. During weed surveys, a total of 78 plant species, belonging to 26 different families and 66 genera, including 2 parasitic plants, 41 winter, 32 summer, 3 summer-winter species and 16 grasses, 60 broad leaved were determined. According to life cycles the weeds were classified as, 9 species as perennial, 57 species as annual, 3 species as biennial, 3 species as annual-perennial and 4 species as annual-biennial. According to their density recorded, Cyperus rotundus (purple nutsedge) was >3.00 plant/m2; Portulaca oleracea, Amaranthus retroflexus, Sorghum halepense, Alopecurus myosuroides, Amaranthus graecizans, Amaranthus hybridus, Amaranthus spinosus, Avena sterilis, Chenopodium album, Convolvulus arvensis, Cynodon dactylon, Echinochloa colonum, Euphorbia chamaesyce, Medicago spp., Physalis angulata, Prosopis farcta, Silybum marianum, Triticum aestivum, Sinapis arvensis, Trifolium spp., Zea mays, Xanthium strumarium were at the density of 0.10-2.99 plant/m2. The density level of 55 different weeds, including important weed species such as parasitic Orobanche crenata (bean broomrape), Phelipanche ramosa (hemp broomrape) and invasive Ipomoea triloba (three-lobe morning glory) and Amaranthus palmeri (palmer amaranth), was found at the density of 0.10> plant/m2. Another important observation recorded in the study is the widespread and severe presence of rust disease agent Puccinia romagnoliana Maire & Sacc. which has potential to be used as biological control agent on C. rotundus. Overall the results suggested that there is a risk of spreading of O. crenata, P. ramosa, I. triloba and A. palmeri which have invasive potential in the region. Results also pointed out potential of rust disease, which was commonly observed in some regions, to be used in the biological control of purple nutsedge which is the most important and common weed species detected in the region.