Effect of Treatment with Colloidal Silver Dispersions Stabilized with Polyhexamethylene Biguanide on the Yield and Biochemical Parameters of Potato Plants in a Field Trial

Abstract

A field trial to study the effect of preplant and foliar treatment of potatoes (lat. Solanum tuberosum) of Red Scarlett variety with dispersions of silver nanoparticles stabilized with polyhexamethylene biguanide hydrochloride was conducted. Silver nanoparticles were obtained by chemical reduction and characterized by UV–Vis spectrophotometry, transmission electron microscopy, and dynamic light scattering. The obtained nanoparticles were roughly spherical shape with the average diameter of 4.92 ± 2.66 nm. Preplant treatment of potato tubers and foliar treatment of potato plants were conducted with dispersions of silver nanoparticles with the concentrations of 5 and 0.2 mg/L, respectively. The treatment of potato with the dispersions resulted in an increase in values ​​of morphological indicators such as stem height, tops weight and leaf weight which in turn caused a significant increase in the yield (from 10.6 to 21.9% compared to the control variant) and commercial quality of the tubers. Notably, the maximum increase in the yield was obtained with the largest number of the treatments. In addition, silver dispersions showed a phytoprotective effect on potato plants which manifested in a decrease in damage to leaves by Phytophthora infestans from 30 to 7–8%. An explanation for the observed phytoprotective effect of silver nanoparticles based on the analysis of enzymatic activity in plant leaf tissues was proposed. The obtained results demonstrate high potential of application of drugs based on silver nanoparticles in horticulture as means of stimulating of growth and protection of plants.