Use of prohydrojasmon to suppress Frankliniella occidentalis and tomato spotted wilt virus in chrysanthemums

Abstract

We evaluated the suppressive effect of prohydrojasmon (PDJ) on Frankliniella occidentalis and tomato spotted wilt virus (TSWV) in chrysanthemums under semi-commercial conditions. The overhead sprinkling of plants with PDJ did not suppress the initial colonization of plants by released adult thrips. However, it significantly reduced subsequent feeding damage on leaves and the reproduction of larval offspring. Rates of 1 and 2 L/m2 of 0.8 mM PDJ equally suppressed F. occidentalis and feeding damage without phytotoxic effects, although 3 L/m2 reduced plant growth. Frequencies of 2 and 3 applications of PDJ at different intervals had similar inhibitory effects on F. occidentalis, suggesting the possibility of low-frequency, labor-saving applications in chrysanthemums. Weekly applications suppressed the occurrence of TSWV transmitted by viruliferous adult thrips dispersed from inoculum sources to a degree consistent with that of feeding damage, so PDJ might inhibit primary infection via disruption of feeding behavior. All our findings suggest that PDJ offers a valuable option for controlling F. occidentalis and orthotospovirus diseases transmitted by it in chrysanthemum production greenhouses.