*Article* **Electrospun Polymer-Fungicide Nanocomposites for Grapevine Protection**

**Nasko Nachev <sup>1</sup> , Mariya Spasova 1,\* , Petya Tsekova <sup>1</sup> , Nevena Manolova <sup>1</sup> , Iliya Rashkov <sup>1</sup> and Mladen Naydenov <sup>2</sup>**


**Abstract:** Nowadays, diseases in plants are a worldwide problem. Fungi represent the largest number of plant pathogens and are responsible for a range of serious plant diseases. Esca is a grapevine disease caused mainly by fungal pathogens *Phaeomoniella chlamydospora* (*P. chlamydospora*) and *Phaeoacremonium aleophilum* (*P. aleophilum*). The currently proposed methods to fight esca are not curative. In this study, polymer composites based on biodegradable polymer containing chemical fungicides with antifungal activity were successfully prepared by electrospinning. The obtained materials were hydrophobic with good mechanical properties. In vitro studies demonstrated that the fungicide release was higher from PLLA/K5N8Q fibrous mats (ca. 72% for 50 h) compared to the released drug amount from PLLA/5-Cl8Q materials (ca. 52% for 50 h), which is due to the better water-solubility of the salt. The antifungal activity of the fibrous materials against *P. chlamydospora* and *P. aleophilum* was studied as well. The incorporation of the fungicide in the biodegradable fibers resulted in the inhibition of fungal growth. The obtained materials are perspective candidates for the protection of vines from the penetration and growth of fungal pathogens.

**Keywords:** biodegradable polymer; electrospinning; fungicide; *Phaeomoniella chlamydospora*; *Phaeoacremonium aleophilum*; esca
