Introduction
The increasing global population has made ensuring food security a critical challenge. Given the limited availability of water, energy, and arable land, improving the efficiency of agricultural production at various stages, including pest management, is essential to meet human food demands. Drones (UAVs) have been employed in agriculture since the 1980s, yet their application in pesticide spraying has notably expanded over the last two decades due to advancements in navigation systems, artificial intelligence, and high-capacity batteries. Drone-based spraying offers numerous benefits, including reduced fuel consumption, lower noise and chemical pollution, enhanced precision, and improved safety for operators. Despite these advantages, conventional methods such as manual mechanical sprayers remain widely used in many regions. These traditional approaches present several challenges, including excessive pesticide usage, labor shortages, low uniformity of application, environmental contamination, limited coverage efficiency, high operational costs, and lower effectiveness in pest control. Consequently, adopting drones in agriculture presents a promising solution to overcome these limitations. This study aims to evaluate and compare the technical and economic efficiency of two pesticide application methods,
modern (drone) and conventional (turboliner), for controlling wheat sun pest in Isfahan province. The novelty of this research lies in the simultaneous assessment of technical indicators, such as spray uniformity and field capacity, and economic factors, including operational costs and crop damage, which have received comparatively little attention in previous studies. By integrating both technical and economic perspectives, the study provides a comprehensive evaluation of drone applications in agricultural pest management.
Method
This study compared the efficiency of a spraying drone and a conventional Turboliner sprayer in controlling Sunn pest in wheat fields of Isfahan Province. Two one-hectare wheat fields were selected, with one treated using a tractor-mounted Turboliner and the other using a spraying drone, targeting both nymphs and adult Sunn pests. During and after spraying, multiple performance parameters were evaluated, including effective working width, solution consumption, spraying time, theoretical and effective field capacity, spray quality coefficient, spraying efficiency, wheat crop crushing percentage, and crop losses caused by Sunn pest. Additionally, an economic comparison of the two sprayers was conducted. The technical performance results were statistically analyzed using a t-test, and economic data were compiled into comparative tables. This integrated assessment of technical and economic indicators provides a comprehensive evaluation of modern versus conventional spraying methods for effective Sunn pest management in wheat cultivation.
Results
The results showed that the average effective working width for the Turboliner and drone sprayers was 40 meters and 10 meters, respectively. Although the pesticide dose was identical for both sprayers (100–125 cc/ha), the total spray solution volume applied per hectare differed significantly. The Turboliner applied the highest volume at 250 liters/ha, whereas the drone used only 10 liters/ha, representing a statistically significant difference at the 1% level. The spraying time per hectare was 10.9 minutes for the Turboliner and 7 minutes for the drone. Field capacity was higher for the drone at 8.57 ha/h, compared to 5.5 ha/h for the Turboliner. Field efficiency was 90% for the drone and 83% for the Turboliner. Using standard wheeled tractors in the Turboliner method, and based on measurements of tractor wheel width and the number of passes during spraying, crop lodging was estimated at 1.25%. The average Number Median Diameter (NMD) of droplets was 190 microns for the drone and 281 microns for the Turboliner.
In comparison, the Volume Median Diameter (VMD) was 300 microns for the drone and 690 microns for the Turboliner. Accordingly, the spray quality coefficient (VMD/NMD) was 1.57 for the drone and 2.45 for the Turboliner, indicating significantly better spray quality for the drone. Spraying efficiency, calculated using the Henderson-Tilton formula, was 100% for both methods, confirming equal effectiveness in controlling the Sunn pest. Assessment of pest damage in wheat kernels revealed that using a drone resulted in an average yield of 7.7 tons/ha, with only 0.05% of the kernels damaged.
In contrast, the Turboliner yielded an average of 9 tons/ha, with no observed pest damage. Economic analysis indicated that the average cost of drone spraying per hectare was 1,674,740 Rials for purchase and 5,913,000 Rials for rental. For the Turboliner, these costs were 19,418,150 Rials (purchase) and 21,728,000 Rials (rental). Thus, Turboliner spraying was 3.7 times more expensive when purchased and 11.6 times more expensive when rented, compared to drone spraying. Approximately 80–90% of the cost difference was attributed to crop damage caused by tractor and sprayer movement in the field, as well as the resulting yield loss.


Conclusions
A comparative study of drone and Turboliner sprayers for controlling sunn pest in wheat fields in Isfahan Province revealed that the drone's field capacity and efficiency were 56% and 8% higher, respectively, than those of the Turboliner. Moreover, the water volume required for the Turboliner spray solution was 25 times greater than that needed for the drone, highlighting the operational convenience of drones, especially under challenging conditions. For the drone, the number median diameter (NMD) and volume median diameter (VMD) of droplets were 37% and 59% lower, respectively, than those of the Turboliner. In comparison, the spray quality coefficient was 36% higher, indicating more uniform coverage. The study also showed that using the Turboliner caused at least 1.25% of the field to suffer crop lodging due to tractor and sprayer traffic, leading to irreversible yield loss. Cost analysis indicated that Turboliner spraying was 11.6 times more expensive under rental conditions and 3.7 times higher under purchase conditions, with 80–90% of the additional cost attributed to yield loss due to crop damage. Overall, considering improved spray uniformity, higher field capacity, and reduced crop damage, drone sprayers are superior to Turboliners and strongly recommended for crop protection.
Author Contributions
Heidarisoltanabadi Mohsen: Conceptualization, Formal analysis, Funding acquisition, Investigation, Methodology, Resources, Supervision, Validation, Visualization, Writing – review & editing.
Saeedi Rad Mohammad Hossein: Conceptualization, Formal analysis, Investigation, Methodology, Resources, Supervision, Validation, Visualization.
Imanmehr Abdollah: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Software, Validation, Visualization, Writing -original draft, Writing – review & editing.
Momeni Davood: Formal analysis, Investigation, Methodology, Software, Validation, Visualization, Writing – review & editing.
Beshart Nejad Mohammad Hasan: Formal analysis, Investigation, Methodology, Software, Validation, Visualization, Writing – review & editing.
Data Availability Statement
Data available on request from the authors.
Acknowledgments
The authors would like to express their sincere gratitude to the experts of the Organization of Agricultural Jihad in Isfahan Province, especially Ms. Engineer Eslami, for their valuable support and assistance in implementing this research.
Ethical Considerations
The authors confirm that research ethics were considered throughout the research methodology, including data definition, data collection, data analysis, data interpretation, and plagiarism prevention, to ensure the final report's accuracy.
Conflict of Interest
The authors declare no financial or personal conflicts of interest related to this paper.
Funding Statement
The authors received no specific funding for this research