The G 1 rootstock, also known as Grézot 1, is a hybrid variety resulting from the cross between Vitis Riparia and Vitis Rupestris. Its breeding took place against the backdrop of the phylloxera crisis, which devastated European vineyards in the late 19th century, necessitating the development of resistant rootstocks to ensure the survival of viticulture.

Rootstock Profile

Adaptation to different soil types

The adaptation of a rootstock to soil characteristics is an essential criterion for the success of a vineyard plot. Although specific data regarding G 1's tolerance to active lime, drought, or waterlogging is not detailed, rootstocks derived from Riparia x Rupestris crosses are generally recognised for their adaptability to diverse soils. Choosing an appropriate rootstock allows the scion to thrive, even under challenging soil conditions.

The influence of G 1 on the scion

Owing to its genetic composition, the G 1 rootstock influences the vigour and development of the scion. The primary objective is to provide the cultivated variety with resistance to phylloxera while ensuring a balanced uptake of water and nutrients. The impact on ripening and yields is a major consideration for winegrowers, who select the rootstock according to the qualitative and quantitative goals sought for the grape variety.

Graft compatibility and vineyard management

Graft affinity between the G 1 rootstock and Bordeaux grape varieties is a determining factor for vineyard longevity. Good compatibility ensures better sap flow and sound vine growth. Cultural practices such as pruning or planting density are tailored to the characteristics of the rootstock to optimise its performance and that of the scion.

Sensitivities and limitations of use

Like any rootstock, G 1 may present certain vulnerabilities. It is crucial to identify potential risks such as iron chlorosis, susceptibility to nematodes (vectors of fanleaf virus), or other grapevine diseases. This information guides winegrowers in their choice of plots and vineyard protection strategies.

An asset in the face of climate challenges in Bordeaux

In the context of climate change, the search for well-adapted rootstocks has become a priority. Drought tolerance and the ability to influence scion ripening are key traits studied to help Bordeaux vineyards adapt. G 1 could play a role in this adaptation, contributing to vine resilience in the face of extreme weather events. This rootstock has not been trialled at the estate.

Studying and understanding rootstocks like G 1 is fundamental for the viticulture of tomorrow. At Château Cazebonne, we are dedicated to preserving and enhancing the biodiversity of the Bordeaux vineyard, in particular by replanting heirloom grape varieties. This work is made possible thanks to the support of wine lovers who accompany us in this endeavour. To learn more about the fascinating history of grape varieties and our region, feel free to download our book "Bordeaux, a history of grape varieties" or test your knowledge with our wine quizzes. You can also explore the rich variety of our wines by browsing our online shop. For a deeper look into rootstocks, we invite you to read our article on The RSB 1 rootstock (Rességuier Sélection Birolleau 1). For further useful viticultural insights, our article on The 101-14 MGt rootstock (Millardet et de Grasset) may also be of interest.