Surfactants in plant disease management: A brief review and case studies

Abstract

In plant disease management, surfactants are generally used in combination with pesticides to facilitate delivery of the pesticide chemicals to the target sites in plants, vectors, or pathogens. Their intended use is rarely for direct effect on plant pathogens. However, trends in recent studies have revealed an appreciable increase in their use for direct management of plant diseases. In this paper, we briefly review the progress made in the use of surfactants for disease management, as adjuvants and when applied for direct effect. We carried out experiments to evaluate the effect of selected synthetic surfactants (Cohere, Kinetic, Silwet‐77, and Induce) on powdery mildew in squash and bacterial spot in tomato. Results from this study showed that the effect of surfactants on these pathogens is dependent on the type of plant pathogen or disease. All tested surfactants exhibited in vitro bactericidal activity against Xanthomonas perforans, a causal pathogen of bacterial spot of tomato. In the greenhouse, Cohere significantly reduced disease severity of powdery mildew in squash compared to the untreated control. Cohere also showed promise in field trials against bacterial spot of tomato, but the other surfactants tested promoted this disease. Our studies demonstrate the importance of evaluating surfactants for their use in management of plant diseases both for direct effect and as adjuvants in tank mix.

Microbial Biosurfactant: A New Frontier for Sustainable Agriculture and Pharmaceutical Industries

“…Currently, a range of chemically synthesized surfactants, such as Triton X-100, Cohere, Agral 90, Silwet L-77, and Tween 20, are some of the most common synthetic surfactants used for plant disease management, and they have displayed improved insecticidal potential during in vitro and in vivo applications [ 138 , 139 ]. However, due to its chemical and toxic nature, direct application on the plant surface was avoided.…”

“…Pseudomonas and Bacillus are the most common bacterial genera used for biosurfactant production. There are numerous reports available that showed their potency in biosurfactant production and their implication in successful phytopathogen management [ 138 ]. Varnier et al [ 144 ] reported on Rhamnolipid, produced by the Pseudomonas aeruginosa , which enhanced the immune response of grapevine against the Botrytis cinerea after application.…”

“…( a ) Pesticide applied without surfactant; ( b ) pesticide applied with a surfactant, increasing the surface area of the pesticide in contact with the leaf. Figure adapted from Jibrin et al [ 138 ].…”

Microbial Biosurfactant: A New Frontier for Sustainable Agriculture and Pharmaceutical Industries

“…Currently, a range of chemically synthesized surfactants such as Triton X-100, Cohere, Agral 90, Silwet L-77, Tween 20 are the some most common synthetic surfactant, has been available in the market used for plant disease management and displayed improve insecticidal potential during in vitro and in vivo applications [138,139]. However, due to its chemical and toxic nature, it avoided direct application on the plant surface.…”

Hexaconazole-Micelle Nanodelivery System Prepared Using Different Surfactants for Ganoderma Antifungal Application

“…The surfactants have been shown to play a promising role in formulating agronanochemical products as they can reduce surface tension, maintain the turgidity of droplets on the target site and lower the pH solution to ensuring the ingredients to be preserved. The effect of different surfactants towards fungal disease in plants such as Fusarium head blight, Beauveria bassiana [ 8 ] and powdery mildew [ 9 ] have been reported recently. Currently, the study on the use of surfactants for the treatment of the Ganoderma boninense pathogen, a causal pathogen for BSR disease, is still lacking.…”