Alleviating biotic stress of powdery mildew in mango cv. Keitt by Sulfur nanoparticles and assessing their effect on productivity and disease severity.

The control of powdery mildew disease is one of the main objectives in Mango production. Mango production with superior quality is becoming increasingly challenging due to climate change, which may negatively affect all stages of their development. Recently, Nanotechnology is a promising and rapidly evolving field that could be a very useful tool to raise the efficiency of fungicides. The aim of this study was to evaluate the role of sulfur nanoparticles (SNPs) and reducing the incidence of powdery mildew, improving growth performance and productivity of mango cv. Keitt (Mangifera indica L.). Four concentrations of SNPs (0, 100, 300, and 500 ppm) were compared to sulfur microform (bulk) at a concentration of 500 ppm. At a private farm on Cairo Alex Desert Road K78, Egypt, foliar spray treatments were administered to an eight-year-old mango cv. Keitt grafted on Sukari rootstock. The experiment was conducted using a randomized complete block design, with each tree receiving a five-liter spray of the solution. The results suggested that the use of 500 ppm concentration of SNPs led to reducing powdery mildew disease incidence by 8.8% but it negatively affected productivity, as it decreased by 27% compared to the control treatment. Whereas 100 ppm concentration of SNPs led to increasing the productivity by 342% compared to the control treatment, reducing powdery mildew disease incidence in mango was recorded at 14.6%. Furthermore, the TSS and vitamin C increased significantly by 16 Brix and 46.3 mg, respectively, in association with decreasing titratable acidity in fruits. In aggregate, our data demonstrated that 100 ppm and 300 ppm of sulfur nanoparticles was more efficient than 500 ppm of sulfur bulk in improving POD and PPO enzyme activity. It is recommended to add SNPs of 100 ppm as foliar spraying three times at 15-day intervals for alleviating the harmful impact of disease on mango trees by improving the enzyme activity, thereby yield, and fruit quality of mango trees exposed to powdery mildew disease.