A forthcoming threat for winter wheat: feral rye (Secale cereale L.).
Feral rye (Secale cereale L.) is an annual grassy weed species which is a native weed to Anatolia and is commonly found in wheat fields. It has a growth ability faster than wheat because it is more tolerant to adverse climatic and environmental conditions. Therefore, feral rye competes for nutrient, water, and space with wheat from the beginning of growth to the harvest. In addition to its direct impact, feral rye seed is generally harvested during wheat harvest, reduces value of wheat seed, and may carry the ergot which is a fungus cause an important human disease, ergotism, by its ergotoxine and alkaloids. A roadside survey was conducted along Ankara-Bilecik state road to determine the presence and abundance of feral rye in wheat fields adjoining to the road in 2020 and 2021. As a result of the survey, feral rye was found nearly in one-third of Eskişehir and Ankara's wheat field, and quarter of Bilecik's. It was also found that feral rye infestations in wheat were two common kinds; scattered and patch. The abundance of feral rye in Ankara, Eskişehir, and Bilecik were changed in 0.23-8.79, 0.32-10.35 and, 0,12-14.63 plant m-2, respectively. A preliminary study was also conducted in Gölbaşı, Ankara and Bozüyük, Bilecik to determine yield losses in wheat due to natural feral rye infestation. Grain yield loss in scattered field was 18.47% in Gölbaşı whereas it was changed 4.23 to 13.72% in Bozüyük. The grain loss in patches reached to 62.81%, depending on the feral rye number in the patch. These results indicated that feral rye is a significant weed species in Ankara, Eskişehir and Bilecik Provinces, and its impact on the wheat yield will increase in the near future.