Activity of Trichoderma asperellum Strain ICC 012 and Trichoderma gamsii Strain ICC 080 Toward Diseases of Esca Complex and Associated Pathogens

Abstract

Grapevine trunk diseases are widespread in all grape-growing countries. The diseases included in the Esca complex of diseases are particularly common in European vineyards. Their distinctive foliar symptoms are well known to be associated not only with losses in quantity, as with all grapevine wood diseases, but also with losses in the quality of the crop. Protection of pruning wounds is known to reduce infections in artificial inoculations and, to some extent, reduce the external leaf symptoms. The application of biological control agents in the field is typically started at the first appearance of symptoms. In this article, the two strains belonging to two different species, Trichoderma asperellum ICC 012 and T. gamsii ICC 080, which are present in a commercial formulation, were tested in vitro, in vivo in artificial inoculation, and in the field in long-term experiments where the wounds on four young asymptomatic vineyards were protected since 1 or 2 years after planting. The in vitro trials highlighted the different temperature requirements of the two strains, the direct mycoparasitizing activity of T. asperellum, and the indirect activity shown by both Trichoderma strains. The in vivo trials confirmed the ability of the two strains to reduce the colonization following artificial inoculations with the high, unnatural concentration of spores used in artificial infections, even if with variable efficacy, and with long persistence as they could be reisolated 7 months post-application. The preventive applications carried out over 9 years showed a very high reduction in symptom development in the treated vines, on annual and cumulated incidence and on the death of vines, with disease reduction varying from 66 to almost 90%. Early and annual application of protection to the pruning wounds appears to be the best method for reducing damages caused by grapevine leaf stripe disease (a disease of the Esca complex of diseases). Trichoderma appears to offer an efficient, environmentally friendly, and long-lasting protection in the presence of a natural inoculum concentration.

Control of Grapevine Downy Mildew by an Italian Copper Chabasite-Rich Zeolitite

“…Therefore, studies on beneficial microorganisms and natural substances are being carried out. Specific studies are focused on the reduction in the use of cupric fungicides to limit the environmental impact of copper in the soil, following the EC regulations 1981/2018 [24,[26][27][28][29]. In particular, some studies assessed alternatives to copper or new formulations with lower copper content [30].…”

Tannins-lignin mixed nanoformulations for improving the potential of neem oil as fungicide agent

“…In particular, Esca disease shows several symptoms (Surico et al, 2009;Gramaje et al, 2015) in the wood of the trunk and branches as well as in leaves and berries. Infections start from wounds in the wood, and therefore recently investigations concerned several trials for wounds protection in the search of products with a slow release of the active substance and long persistence (Mondello et al, 2018; del Pilar Martínez-Diz et al, 2021; Di Marco et al, 2022). Both pathogens can induce in young vines discoloration of the wood, besides chlorosis, stunted leaves, short internodes, and lack of vigour in young grapevines (Díaz et al, 2014).…”

The Biocontrol Potential of Endophytic Trichoderma Fungi Isolated from Hungarian Grapevines, Part II, Grapevine Stimulation

“…Trichoderma spp. could effectively colonize wounds [ 23 ], and they were re-isolated from the proximity of the pruning wound 21 days after treatment of detached canes [ 24 ]. In the case of injury inoculation of grafted plants, Trichoderma sp.…”

“…was detected only near the injury [ 25 ]. In field studies, grapevine pruning wound colonization was described with commercial T. asperellum ICC 012 and T. gamsii ICC 080 strains in grapevine canes up to seven months after the spraying of fresh prunes [ 23 ]. In the case of trunk wound inoculation of old grapevine, re-isolation was successful up to 20 months after inoculation with T. atroviride (previously T. harzianum ) strain AG1, and whole-trunk colonization was also described [ 26 ].…”

“…Trichoderma -based products have been demonstrated to be effective biocontrol agents (BCAs) against grapevine trunk diseases (GTDs) both in planta and in field experiments [ 23 , 28 , 29 , 30 ]. T. afroharzianum T22 (formerly: T. harzianum Rifai) and T. atroviride SC1 strains—currently the most important biocontrol fungi in grapevine nurseries and the vineyards—promoted the rooting of grafts, and suppressed GTDs [ 29 , 31 ].…”