Determination of the critical period of weed control in wheat (Triticum aestivum L.) and investigation of the control methods of wi̇ld mustard (Sinapis arvensis L.)

This study aimed to determine the critical period of wheat against weeds, investigate the subspecies of Sinapis arvensis in wheat fields, and the response of these subspecies to herbicides, and determine some biological characteristics of Sinapis arvensis. Studies of critical periods of wheat were carried out in the years 2020-2021 in Diyarbakir province. To determine the subspecies of Sinapis arvensis, the seeds were sampled from the wheat fields of 84 districts in 28 provinces, representing 7 regions of Turkey. The subspecies of Sinapis arvensis were investigated by classical and molecular (rDNA and cpDNA) methods and the response of these subspecies to herbicides under greenhouse conditions and investigated the germination biology of seeds. As a result of the studies, the critical period of wheat with 5%yield loss against weeds is 35-75 DAE in rainy climate conditions and 11-93 DAE in dry climate conditions. In addition, Zadoks-30 scale was determined to coincide on 3 March 2020 and 16th March 2021. Subspecies of Sinapis arvensis were confirmed as Sinapis arvensis subsp. arvensis, Sinapis arvensis subsp. allionii and Sinapis arvensis subsp. schkuhriana and phylogenetic relationships between these subspecies have been revealed. It was determined that the subspecies of Sinapis arvensis were affected by different levels of herbicides against the active substances consisting of Florasulam, Bromoxynil + MCPA, Dimethyl amine salt, and the subspecies were controllable against these actives. Although the germination temperature of S. arvensis varies according to the provinces and subspecies, determined generally germinated at a minimum temperature of 2-5 °C, optimum 10-25 °C, and maximum 35 °C.