Effect of fungi addition, root preparation, and other factors on the success of vine replacement in an established vineyard

Dead or dying vines must be replaced regularly in order to ensure the sustainability of a vineyard. Successful plant replacement is crucial to maintain yield and quality by encouraging balanced root and leaf development in vines. However, young vines planted within an established vineyard encounter several problems, ranging from poor soil conditions to competition with older vines with well-established root systems.  

Aim: The aim of this project is to study the impact of plant material and plant replacement practices, including the addition of microorganisms.

Methods and Results: Three trials were set up in the Médoc region, north of Bordeaux. The first trial had four modalities in which two rootstocks, previously inoculated with arbuscular mycorrhizal fungi (AMF) or not, were planted in April 2019. The second trial was designed to study the influence of root preparation (bare roots versus balled roots) and the period of replacement of the plants, while the third trial, set up in 2018, crossed the modalities of the root preparation and mycorrhization. Measurements of plant recovery rate, nitrogen status of the leaves and development of shoots were carried out.

In the first trial, the mycorrhization of the plants did not reveal differences in terms of recovery. It did not induce a better development of the shoots or differences in nitrogen status in leaves. In contrast, the other mycorrhizal trial found shoots from mycorrhized plants had better growth, although this result was not confirmed in the second year. The two trials addressing root preparation found that plants with balled roots had better shoot growth and nitrogen status compared to bare rooted plants. However, these results are moderated by other parameters of the trials such as planting period, soil maintenance practices or choice of the rootstock.

Conclusions: 

These results are a first step to understand the effect of fungi addition and root preparation on success of vine replacement. To conclude on the interest of balled plants or mycorrhization, these measures on development and production should be continued until the first years of grape production.