Grapevine roots: interaction with natural factors and agronomic practices

Selection of a suitable rootstock lays the foundation for meeting vineyard, grape and wine objectives. Tolerance to biotic and abiotic conditions is a determining factor. Despite the significance of the grapevine root system in vegetative and reproductive growth as well as grape and wine composition and quality, root behaviour under an array of very complex and integrated environmental impacting factors is largely unknown and research in this regard is surprisingly limited. In this paper, a compilation of some of the research done over many years on root system behaviour is presented. Various aspects of the interaction between the root system and the complex natural environment in which it grows as well as commonly known viticulture practices are discussed. Results obtained under controlled and field conditions are shown. Physical and chemical properties and pre-establishment preparation of the soil have defining effects on metabolic behaviour and spatial distribution (horizontally and vertically) of roots. Alleviation of soil impediments to root penetration provides the best possible basis for above-ground growth. The health status of plant material, genetic characteristics and grafting and nursery processes have a steering impact on the ability of the root system to perform within biotic and abiotic constraints of the soil environment to such an extent that expectations in terms of growth, yield and grape quality of the scion are met. Agronomic practices exert a further tailoring impact on root system performance and support to above-ground growth. The study of only above-ground factors is clearly not sufficient to explain vineyard behaviour. Intensified inter-disciplinary research efforts are required in our quest to understand scion-root system inter-relationships and to control scion behaviour in order to facilitate greater sustainability in grape and wine production.