The role ofTrichodermaspp. and silica gel in plant defence mechanisms and insect response in vineyard

Abstract

AbstractSeveral elicitors, stimulating induced resistance mechanisms, have potential in preventing or mitigating pathogen infections. Some of these compounds, triggering the production of jasmonic acid (JA), a precursor of herbivore-induced plant volatiles, could also play a central role in indirect resistance to pest species, by improving beneficial arthropod performance, and necrotrophic pathogens. In the current work,Trichoderma gamsii/T. asperellumand silica gel treatments – alone and in combination – were studied to evaluate the plant defence mechanism on grapevines (Vitis viniferaL.) by laboratory and field trials. JA production level was measured before and afterPlasmopara viticolainfection on potted vines. JA production induced by silica gel was higher than that caused byTrichodermabefore infection. InTrichoderma-treated plants, JA production increased afterP. viticolainoculation. In vineyard field trials, Mymaridae (Hymenoptera: Chalcidoidea) showed higher captures in transparent sticky traps on silica gel-treated plants, in comparison with control. On the other hand, no significant attraction was detected for Ichneumonoidea and other Chalcidoidea in silica gel andT. gamsii/T. asperellum-treated plants. The potential effects of elicitors are discussed, in the frame of attract and reward strategy.