Improving the biochemical and physical quality of Sultani grapefruit by foliar spraying with different levels of potassium nano-chelate

This study aimed to investigate the effect of foliar application of potassium nano-chelate on the fruit quality of the Sultani grape cultivar in a vineyard located in Malekan, East Azerbaijan. The experiment was conducted as a multi-observation randomized complete block design (RCBD) with three replications. The experimental treatment was foliar application of nano-chelated potassium fertilizer at four levels (control, ۱, ۲, and ۴ kg thousand L-۱), which was sprayed in three stages: pre-flowering, two weeks after fruit set, and one month after the second spraying. To determine the morphological and physiological characteristics of the plant, leaf samples were collected as a multi-observation method from three positions: lower, middle, and upper. Results showed that the ۴ kg thousand L-۱ concentration of potassium nano-chelate had the most significant impact on fruit quality attributes. In the upper leaves, this concentration increased fruit firmness to ۴.۶۱ kg cm-۲, berry length to ۱۳.۸۷ mm, flavonoid content to ۵۸.۱۳ mg g-۱, and protein content to ۱.۹۲%. In the lower leaves, the same concentration enhanced total sugar to ۲۸.۲۶ mg g-۱, nitrogen to ۳.۶۸%, phosphorus to ۰.۹۷%, and potassium to ۲.۷۶%. Interestingly, the middle leaves treated with the ۴ kg thousand L-۱ concentration exhibited the highest levels of phenols (۶۸.۰۲ mg g-۱), chlorophyll (۴.۵۶ mg g-۱), and carotenoids (۰.۸۰ mg/g). Notably, the lowest fruit acidity (۱.۶۶) was observed in the lower leaves treated with the ۴ kg thousand L-۱ concentration. These findings demonstrate that using potassium nano-chelate at ۴ kg per thousand L-۱ concentration can serve as an effective strategy to improve the qualitative characteristics of Sultani grapes. However, the effects vary depending on the position of the sprayed leaves. These results provide valuable insights for producers to optimize nutritional management practices for grape production.

کلیدواژه ها:

Antioxidant ، Foliar nutrition ، Nanoparticles ، Photosynthesis pigments ، Yield ، آنتی اکسیدانی ، تغذیه برگی ، رنگیزه های فتوسنتزی ، نانو ذره