Engineered core-shell Cu particles demonstrate strong potential for plant disease control

摘要

Copper (Cu) bactericides/fungicides are used extensively for crop protection in agriculture, leading to accumulation and antimicrobial resistance. Increasing Cu bioavailability can reduce the amount required for crop protection. We have developed Core-Shell-Cu particles (CS-CuPs) containing an inert silica core coated with a Cu silica shell. Electron microscopy results confirmed the formation of spherical sub-micron size particles. Field efficacy of CS-CuPs was evaluated by assessing its ability to protect citrus trees from canker infection. Analysis of 2014 citrus canker infection on 'Ray-Ruby' grapefruit showed a 62.8% incidence of fruit lesions on untreated trees while commercial copper hydroxide reduced incidence to 16.4% at a rate of 1.0 kg metallic Cu/hectare. The CS-CuPs reduced canker incidence to 15.6 % at 0.22 kg metallic Cu/hectare. Maintenance of efficacy at a significantly lower metallic Cu rate (about 4.5 times) clearly demonstrates the potential of CS-CuPs for successful use as an agricultural bactericide/fungicide.