1.4.5 Selection of plant traits

Should the plants be enriched with trichodermia ?

Trichoderma is a genus of fungi. They occur naturally in all soils and plant debris. Some strains have properties which offer protection against other fungi, especially those responsible for Esca.

Management of wood diseases and viruses

It is an effective protection method because the fungi take up space and produce molecules which inhibit the development of other harmful fungi.
Enriched plants are therefore useful tools to prevent wood disease.

Should the vines be treated with hot water?

Le traitement à l’eau chaude est un moyen de lutte contre les phytoplasmes responsables de la flavescence dorée (Gestion des maladies du bois et des viroses). Les bois sont immergés dans de l’eau chaude sur un temps donné afin de détruire les phytoplasmes. C’est une opération délicate puisque la sensibilité thermique de la vigne est proche de celle des phytoplasmes. A noter que cette opération peut fragiliser le plant si elle est mal pratiquée. Certaines appellations ont rendu cette pratique obligatoire.

Hot water treatment is a means of controlling the phytoplasmas responsible for flavescence dorée Management of wood diseases and viruses The vines' wood is immersed in hot water for a given time to destroy the phytoplasmas. This is a delicate operation because the vine’s thermal sensitivity is very similar to that of the phytoplasmas. This operation can weaken the plant if it is not performed correctly. In certain appellations this treatment has become mandatory.

Should the plants be mycorrhized?

Mycorrhizae are a type of fungi that live in symbiosis with the vine. They are connected to the roots of the vine and this enables nutrient exchange between the plant and the mycorrhizae. The vine provides sugar which it produces via photosynthesis and the fungus provides mineral elements, mainly phosphorus but also nitrogen. We can assume that other interactions also take place, but they have not yet been clearly established. The main advantage is the creation of a highly-developed root network at a very early stage, which gives production a headstart and increases the chances of plant recovery. The benefits are multiplied for selectively-replaced vines, as they suffer from intense competition with pre-existing vines. The presence of mycorrhizae alters six factors:

• Water absorption
• Hormonal activity
• Pathogen protection
• Resistance to environmental stress
• Soil aggregation
• Adsorption of mineral and trace elements

How tall should the vine be?

A classic vine height is 28 cm. The first 20 cm are underground when planted, which only leaves 8 cm above the surface, meaning that the vines do not fully benefit from treatments and they are more likely to be damaged when tractors pass in between the rows when working the soil. It is possible to order vines that have already reached 45 cm in height.
At this point it's important to consider the plot’s management. If the vineyard is maintained at a very low vine height, tall plants should be avoided when formative pruning is underway, because it may make it difficult to train the vine trunk along the first wire.

Potted or traditional plants?

Traditional plants have exposed roots. They are often the easiest to use.

Potted plants are a more recent invention. Their advantage being that the vine has a more developed root system and therefore recovers better when first planted. They are most pertinent to consider when planting in an extreme clay based soil or when the rootstocks have weak root development. On the other hand, when the soils are too dry and draining, they are less useful (the pot dries out too quickly which risks slowing root development). They are also more limiting when planting since a specific hole needs to be dug. Finally, transport is more complicated. On the other hand, the planting period is more flexible than for traditional vines.