As a new low volume application technology, unmanned aerial vehicle (UAV) application is developing quickly in China. The aim of this study was to compare the droplet deposition, control efficacy and working efficiency of a six-rotor UAV with a self-propelled boom sprayer and two conventional knapsack sprayers on the wheat crop. The total deposition of UAV and other sprayers were not statistically significant, but significantly lower for run-off. The deposition uniformity and droplets penetrability of the UAV were poor. The deposition variation coefficient of the UAV was 87.2%, which was higher than the boom sprayer of 31.2%. The deposition on the third top leaf was only 50.0% compared to the boom sprayer. The area of coverage of the UAV was 2.2% under the spray volume of 10 L/ha. The control efficacy on wheat aphids of UAV was 70.9%, which was comparable to other sprayers. The working efficiency of UAV was 4.11 ha/h, which was roughly 1.7–20.0 times higher than the three other sprayers. Comparable control efficacy results suggest that UAV application could be a viable strategy to control pests with higher efficiency. Further improvement on deposition uniformity and penetrability are needed.

Uncrewed aerial vehicles (UAVs) for plant protection play a vital role in modern agricultural operations. In recent years, advancements in UAVs and pest control technologies have significantly enhanced operational efficiency. These innovations have addressed historical challenges in agricultural practices by improving automation and precision in managing insect pests, diseases, and weeds. UAVs offer high operational efficiency, wide adaptability to different terrain, and safe applications. The development and demand for these technologies have increased to boost agricultural production. In agricultural settings where conventional machinery struggles to carry out farming operations, UAVs have transformed farming practices by providing high operational efficiency and significant profitability. The integration of UAVs and other smart technologies has driven advancements. The UAV sector has received substantial attention as a convergence of production, service, and delivery, introducing synergy through the presence of several developing areas. The market for this technology is expected to grow in the future. In this comprehensive review, we analyzed an overview of historical research, diverse techniques, the transition from conventional to advanced application, development trends, and operational milestones across diverse cropping systems. We also discussed adoption and subsidy policies. In order to properly understand UAV operational efficiency, we also analyzed and discussed smart atomization systems, spray drift, droplet deposition detection technologies, and the capabilities of related technologies. Additionally, we reviewed the role of software programs, data-driven tools, biodegradable materials, payloads, batteries, sensing technologies, weather, and operational and spraying factors. Regulatory limitations, operating and farmer’s training, economic effects, and guidelines were also acknowledged in this review. This review highlights deficiencies and provides essential knowledge of the use of UAVs for agriculture tasks in different regions. Finally, we examine the urgency of UAV technology implementations in the agricultural sector. In conclusion, we summarize the integration of UAVs and their related technologies with applications and future research prospects, offering directions for follow-up research on the key technologies of UAVs and encouraging the enhancement of agricultural production management in terms of efficiency, accuracy, and sustainability.

Anthracnose disease, caused by Colletotrichum truncatum, affects marketable yield during preharvest production and postharvest storage of fruits and vegetables worldwide. Demethylation inhibitor (DMI) fungicides are among the very few chemical classes of single-site mode of action fungicides that are effective in controlling anthracnose disease. However, some species are inherently resistant to DMIs and more information is needed to understand this phenomenon. Isolates of C. truncatum were collected from the United States and China from peach, soybean, citrus, and begonia and sensitivity to six DMIs (difenoconazole, propiconazole, metconazole, tebuconazole, flutriafol, and fenbuconazole) was determined. Compared with DMI sensitive isolates of C. fructicola, C. siamense, and C. fioriniae (EC₅₀ value ranging from 0.03 to 16.2 µg/ml to six DMIs), C. truncatum and C. nymphaeae were resistant to flutriafol and fenbuconazole (with EC₅₀ values of more 50 µg/ml). Moreover, C. truncatum was resistant to tebuconazole and metconazole (with resistance factors of 27.4 and 96.0) and displayed reduced sensitivity to difenoconazole and propiconazole (with resistance factors of 5.1 and 5.2). Analysis of the Colletotrichum spp. genome revealed two potential DMI targets, CYP51A and CYP51B, that putatively encode P450 sterol 14α-demethylases. Both genes were identified and sequenced from C. truncatum and other species and no correlation between CYP51 gene expression levels and fungicide sensitivity was found. Four amino acid variations L208Y, H238R, S302A, and I366L in CYP51A, and three variations H373 N, M376L, and S511T in CYP51B correlated with the DMI resistance phenotype. CYP51A structure model analysis suggested the four alterations may reduce azole affinity. Likewise, CYP51B structure analysis suggested the H373 N and M376L variants may change the conformation of the DMI binding pocket, thereby causing differential sensitivity to DMI fungicides in C. truncatum.