Investigation of the possibility of using some wild sunflower species as ornamental plants

Sunflower which is the most important oil plant in our country, have been contributing to both garden ornament and cut floriculture since before the 18th century. In order to create wild sunflowers with high market value for the widespread use of this field of use, it is necessary to have information about the inheritance of wild sunflower species and to examine the interaction of inheritance with the environment. In this thesis, the characteristics affecting the ornamental plant trade were observed. This study was conducted in the research land of Trakya University in the Central district of Edirne province in 2024. Within the scope of the study, it was aimed to observe the stem diameter, root diameter, plant height, projection (spreading) area, first flowering days, 50% flowering days, full flowering days, flowering time, total flowering days, tray diameter, tray number and seed number of 18 different wild sunflower species. In this framework, H. agrestis, H. annuus, H. anomalus, H. agrophyllus, H. atrorubens, H. cusickii, H. debilis, H. deserticola, H. exilis, H. longifolius, H. maximiliani, H. mollis, H. niveus, H. nuttallii, H. pauciflorus, H. petiolaris, H. porteri and H. praecox wild sunflower species were observed. Among the wild sunflower species within the scope of the thesis study, the species with the shortest first flowering time (91 days) were determined as H. debilis and H. pauciflorus, while the species with the longest (202 days) were determined as H. atrorubens. Among the wild sunflower species within the scope of the thesis study, the species with the shortest 50% flowering time (97 days) was determined as H. debilis and H. pauciflorus, while the species with the longest (221 days) was determined as H. atrorubens. Among the wild sunflower species within the scope of the thesis study, the species with the shortest full bloom time (173.33 days) was determined as H. agrestis, while the species with the longest (266.67 days) was determined as H. maximiliani. Among the wild sunflower species within the scope of the thesis study, the species with the shortest flowering time (50 days) was determined as H. atrorubens, while the species with the longest (162.67 days) was determined as H. maximiliani. Among the wild sunflower species covered by this thesis, the species with the smallest head diameter (1,13 cm) was determined as H. deserticola, while the species with the tallest (18,33 cm) was determined as H. agrestis. Among the wild sunflower species covered by this thesis, the species with the smallest head diameter (5) was determined as H. agrestis, and the species with the tallest head diameter (45.67) was determined as H. atrorubens. Based on the evaluation of stem diameter, those between 0.5 and 1,5 cm are suitable for cut flower production; those with a stem diameter of 1.5 cm or more are suitable for outdoor ornamental use. According to this evaluation, H. annuus, H. cusickii, H. debilis, H. deserticola, H. exilis, H. longifolius, H. maximiliani, H. mollis, H. pauciflorus, H. petiolaris, and H. porteri suggested to use for cut flower production, while the remaining (7) species could be used as outdoor ornamental plants.