A silica-based nanoformulation and method is used to treat citrus canker, inhibit the growth of mold and mildew, and add nutrients to soil used for agricultural purposes. The nanotechnology-enabled copper-loaded, silica nanoformulation (CuSiNP/NG) design is a &ldquorevolutionary re-invention&rdquo of Cu for safe application because it provides a formulation with maximum abundance of ionic Cu, provides sustained and optimal Cu ion release for long-term disease protection, better adherence to plant surfaces and structural surfaces due to gel-based nanostructure of CuSiNG, thus avoiding multiple spray applications and reducing the amount of Cu used in comparison to existing Cu compounds without compromising antibacterial activity. Thus, the silica-based nanoformulation releases copper in non-toxic quantities to the environment and the silica matrix provides an environmentally safe host material with a flexible design that is optimized to provide specific antifungal and antibacterial remediation using infrequent applications.