Weed control in wheat cultivation with site-specific herbicide application

In the context of this thesis; the aim was to contribute to the development of strategies for the management of weeds in wheat cultivation areas, specifically in Antalya province, by implementing site-specific herbicide applications based on the density of weeds in order to reduce chemical usage, as well as to examine their effects on yield and quality. For this purpose, field trials were established in two different locations within Antalya province, with partially different climate characteristics, one in the southern coastal region and the other at an elevation of 306 meters in the north. The experiment consisted of four treatments: conventional herbicide application, site-specific herbicide application, reduced-rate site-specific herbicide application, and weedy control. The experiment was set up according to a randomized complete block design with four replications. In the study, a herbicide containing 4.5% Mesosulfuron-methyl + 2.25% Thiencarbazone-methyl + 0.9% Iodosulfuron-methyl-sodium + 13.5% Mefenpyrdiethyl (safener) active ingredients was applied at the registered dose for controlling narrow and broadleaf weeds in wheat. Weed density and coverage areas were determined by counting and observations conducted at three-week intervals from pre-application to harvest. In mature wheat plants, plant height, tiller number, spike number, spike length, biomass, stem and spike weights, moisture content in grains, thousand kernel weight, test weight, and yield were determined. A total of 14 weed species were observed within the experimental areas in both locations. Overall evaluation of the results obtained from conventional and site-specific herbicide applications in both locations indicated that the applications reduced weed density and coverage area compared to the weedy control. However, there was no significant difference between conventional herbicide application and site-specific herbicide applications in terms of density and coverage area, and they were statistically grouped together in almost all observations. When looking at the yield values in both locations, herbicide application increased the yield compared to the weedy control. However, there was no statistically significant difference between conventional herbicide application and site-specific and reduced-rate site-specific herbicide applications, indicating that the reduced amount of herbicide applied through site-specific application did not decrease the yield. Furthermore, compared to conventional spraying, site-specific herbicide application resulted in an average reduction of 15.8% in herbicide usage, while the reduced-rate site-specific herbicide application resulted in an average reduction of 61.2% in herbicide usage. In conclusion, it was found that by implementing site-specific herbicide applications based on the distribution and density of weeds in wheat fields, the amount of herbicide used can be reduced without compromising the yield. Future studies are needed to further explore the use of precision farming technologies, such as mapping fields using drones or similar tools, to autonomously apply site-specific herbicide treatments. This study will provide insights for future research in this area.