Introduction

Elisa De Luca, Rauscedo Cooperative Nurseries

In recent years, the issue of sustainability has strongly entered the political and social discussion both in Italy and abroad, involving many productive sectors such as agriculture and, given its importance, the wine sector. The need to develop more sustainable production models, capable of successfully responding to the challenges posed by climate change and at the same time guaranteeing a high standard of health, as required by current regulations, is also very much felt in the vine nursery. The rootstock production process is complex and requires numerous steps, starting from the production and harvesting of propagation material, passing through grafting and forcing, breeding in the open field or in a protected environment, and finally the harvesting and selection of the plants. This complexity strongly impacts the use of inputs of various kinds, such as energy, labor, and consumables. Rauscedo Cooperative Nurseries is working to make the production process more sustainable in each of its parts: for example, experimental trials are underway to identify alternative practices for the preservation and restoration of propagation material through the use of treatments with selected antagonistic microorganisms and/or biological compounds. New formulations of paraffins, biostimulants, and antagonistic microorganisms capable of optimizing yields and limiting the impact on the environment are being evaluated for the delicate grafting and forcing stages, which are critical in determining rooting rates. From rootstock planting to harvest, inputs used for weed management, fertilization, irrigation and fungicide defense produce the greatest impact in terms of economic and environmental sustainability; the use of new varieties resistant to biotic and abiotic stresses is a real opportunity to make the use of pesticides, water and fertilizers less significant. Reducing the environmental impact of nursery practices is a major issue, and VCRs are making real efforts to develop an innovative model to offer their customers and associates a more sustainable future

The role of the microbiome, for sustainable viticulture

Giovanni Del Frari, University of Udine

The term microbiome is frequently used to refer to the collection of microorganisms that colonize the internal and external surfaces of plants, animals and other multicellular organisms. Bacteria and fungi, the main components of the plant microbiome, are closely associated with plant health and performance. For example, some microorganisms are essential for ensuring the bioavailability of nutrients, while others antagonize pathogenic microorganisms.

In recent years, thanks to new molecular biology techniques and bioinformatics tools, we have begun to explore the complexity of the grapevine microbiome, revealing previously unknown aspects of it. For example, the rhizosphere of different rootstock genotypes harbors distinct microbial communities; the phyllosphere microbiome varies between phenological stages and in different vines; endophytic communities in various plant organs contribute to the composition of the berry microbiome. Endophytes are of particular interest in the context of grapevine wood diseases, such as esca disease. It has recently been shown that the use of fungicides can result in altered microbial structures in wood, leading us to think that the rapid spread of grapevine wood diseases may depend on an imbalance at the microbiome level.

In the nursery, maintaining and/or restoring the balance of the microbiome would allow rootstocks to have access to microbiome resources that can contribute to their success in dealing with environmental challenges (e.g., drought) and in combating pathogenic phages including those believed to be responsible for grapevine wood diseases. From the perspective of sustainable viticulture, among the many potential applications of microbiome use are the assessment of compatibility between soil microbiome and rootstock, the use of the microbiome as a marker to establish plant health or the uniqueness of a vineyard/wine region, and the application of synthetic microbiomes in plant protection.

Plant biostimulants: what they are and why to use them

Giuseppe Colla, University of Tuscia

A plant biostimulant is an EU fertilizer product with the function of stimulating plant nutritional processes regardless of the nutrient content of the product, with the sole objective of improving one or more of the following characteristics of plants or their rhizosphere:
(1) nutrient use efficiency;
2) abiotic stress tolerance;
3) quality characteristics;
4) the availability of nutrients contained in the soil or rhizosphere.

There are numerous substances and microorganisms with biostimulant action that can be used in order to improve the agronomic response of crops. In particular, in viticulture nursery production, biostimulants can help shorten the production cycle, improve quality standards of rooted cuttings and plant resilience to climate change. For example, some biostimulant substances such as protein hydrolysates can improve adventitious rhizogenesis in rooted cuttings by increasing water and nutrient uptake capacity. In addition, foliar applications of biostimulant substances such as algae extracts and protein hydrolysates can increase resistance to abiotic stresses such as thermal and water stresses. Finally, root application of microbial biostimulants based on endophytic fungi such as arbuscular mycorrhizae can promote rapid overcoming of transplant crisis and increased plant resilience toward environmental stresses. Several examples of biostimulant application in the viticulture nursery sector will be shown during the presentation.