Grapevine Trunk Diseases: A Review of Fifteen Years of Trials for Their Control with Chemicals and Biocontrol Agents

Abstract

Grapevine trunk diseases (GTDs) represent one of the most important problems for viticulture worldwide. Beyond the original causes of this outbreak in some countries like France, the lack of efficient control protocols and the prohibition of using active ingredients such as sodium arsenite and benzimidazoles, until recently used to reduce the impact of some GTDs but deleterious for humans and the environment, have probably worsened the impact of the diseases, leading to increasing economic losses. Since 1990, searches have been made to find efficient tools to control GTDs, testing a wide range of active ingredients and biocontrol agents. This review provides readers with an overview of the results reported in the scientific literature over the last 15 years. In particular, the review focuses on the trials carried out applying chemicals or microorganisms to control Esca complex diseases, Botryosphaeria dieback, and Eutypa dieback, the most widespread GTDs.

Evaluation of long‐term protection from nursery to vineyard provided by Trichoderma atroviride SC1 against fungal grapevine trunk pathogens

“…Despite efforts since the early 1990s to investigate the etiology and epidemiology of fungal grapevine trunk diseases (GTDs), they still represent a threat to viticulture, being responsible for important economic losses worldwide . Petri and black‐foot diseases are considered as the main GTDs affecting young vineyards, and Eutypa, Botryosphaeria and Phomopsis diebacks, and Esca and Grapevine Leaf Stripe diseases are the prevalent GTDs in adult vineyards …”

“…Altogether, these factors can explain why the management of GTDs is so difficult, but other additional aspects to consider are the cultural practices that favor fungal infection, such as high‐density spur‐pruned trellised vineyards, often mechanically pruned, which present a high number of pruning wounds and multiple additional infection opportunities, and the banning in the early 2000s of effective fungicides against GTDs, such as sodium arsenite and benzimidazoles …”

“…Grapevine producers are aware of the high likelihood of infection and substantial yield losses from GTD but, in general, they do not adopt management practices until disease symptoms appear in the vineyard, frequently when the vines are around 10 years old . Viticulturists are currently assuming that they must face GTDs throughout the entire life of the vine, integrating different control measures that can contribute to mitigate the economic impact of the diseases, but taking into account that complete eradication of these diseases is not possible . In this sense, the most important objectives to be covered by a GTD‐integrated management program are the improvement of the phytosanitary quality of the vines produced in the nursery and the prevention of infections of pruning wounds in the vineyard from the moment of planting …”

“…The importance of this pathway is enhanced by the long susceptibility period of grapevine pruning wounds, which can last up to 4–6 months, even with decreasing susceptibility . Different fungicides have been reported to be effective for pruning wound protection, but they have a short‐term efficacy and, in Europe, the current range of authorized active ingredients for this purpose is very limited . New chemical and physical protection formulations are under development, aiming to give long‐lasting protection against GTD infection, but BCAs preventively colonizing the fresh wounds may also serve this purpose …”

“…Despite efforts since the early 1990s to investigate the etiology and epidemiology of fungal grapevine trunk diseases (GTDs), they still represent a threat to viticulture, being responsible for important economic losses worldwide. [1][2][3] Petri and black-foot diseases are considered as the main GTDs affecting young vineyards, and Eutypa, Botryosphaeria and Phomopsis diebacks, and Esca and Grapevine Leaf Stripe diseases are the prevalent GTDs in adult vineyards. 1,[3][4][5] GTDs are complex diseases due to several factors: (i) they are caused by up to 133 wood-infecting fungal species belonging to 34 genera, (ii) several GTDs can infect grapevines at the same time, and (iii) they have similar internal or external symptomatology, or different symptomatologies overlap when multiple infections occur.…”