Metal nanoparticles against fungicide resistance: alternatives or partners?

Abstract

Chemical control suffers from the loss of available conventional active ingredients due to strict environmental safety regulations which, combined with the loss of fungicide efficacy due to resistance development, constitute major problems of contemporary crop protection. Metal-containing nanoparticles (MNPs) appear to have all the credentials to be next-generation, eco-compatible fungicide alternatives and a valuable anti-resistance management tool. Could the introduction of MNPs as nano-fungicides be the answer to both reducing the environmental footprint of xenobiotics and dealing with fungicide resistance? The potential of MNPs to be utilized as nano-fungicides, both as alternatives to conventional fungicides or/and as partners in combating fungicide resistance, is discussed in terms of effectiveness, potential antimicrobial mechanisms as well as synergy profiles with conventional fungicides. However, their "golden" potential to be used both as alternatives and partners of conventional fungicides to combat resistance and reduce environmental pollution is challenged by undesirable effects towards non-target organisms such as phytotoxicity, toxicity to humans and environmental ecotoxicity, constituting risks that should be considered before their commercial introduction as nano-pesticides at a large scale.

Copper nanoparticles interfere with insecticide sensitivity, fecundity and endosymbiont abundance in olive fruit fly Bactrocera oleae (Diptera: Tephritidae)

“…Metal nanoparticlesespecially smaller oneshave been shown to possess cell membrane-penetration properties which could extend to plant or even human cells. 22 Furthermore, since their impact on biological systems is not yet fully understood, ecotoxicity tests commonly used for their bulk counterparts may not be sufficient to evaluate their toxicity. This also applies for their combinations with pesticides which may cause an additional toxicity effect to non-target organisms.…”

Potential Antifungal Effect of Copper Oxide Nanoparticles Combined with Fungicides against Botrytis cinerea and Fusarium oxysporum

“…Combining metal nanoparticles (MNPs) with other antimicrobial agents (e.g., antibiotics, essential oils, or other metals) has been proposed as one of the most interesting strategies to avoid or reduce their harmful effects once released into the environment [ 19 , 20 ]. In this sense, some studies have evidenced that the combination of MNPs, such as silver or zinc oxide, with fungicides has provoked additive and synergistic interactions, implying that the antifungal effect has been higher than that of either agent alone [ 21 , 22 ]. In particular, the interaction of NCuO with fungicides remains poorly explored in this context.…”

Transport of Thiophanate Methyl in Porous Media in the Presence of Titanium Dioxide Nanoparticles

“…Consequently, the existing agricultural system is pressured to increase food production in order to meet the demand. Therefore, the use of pesticides worldwide has increased in order to control or exterminate the development of plant pests and diseases, including mites, insects, and nematodes [2][3][4]. In countries where pesticides are widely used, such as Brazil, the world's largest consumer of these substances, the average pesticide use is greater than 10 L per hectare, which corresponds to a mean exposure of 4.5 L of pesticides per capita per year [5].…”