Vine Root System

The optimal development of the root system of the vine is essential for the achievement of the production potential, both in yield and quality. From the formation of the vine, after being planted in the ground, the root activity determines, to a large extent, the capacity for its formation.

Once the vineyard enters production, the root influences the quality and yield for three reasons (Ruiz, 2005):

1. The roots are the main factor in the carbohydrate balance in the vine.
2. They provide water and nutrients for aerial growth and fruit production.
3. Collects positive or negative signals from the soil that are transmitted biochemically to the aerial part, with repercussions on the fruit.

The root system of the vine varies in terms of its distribution, this due to several factors, but mainly due to the conditions of the soil where it develops. When these are optimal, the roots can develop up to three meters deep. However, normally the root concentration is in the first 60 cm of the soil with the highest root emission in each root flow in the first 30 cm (Mullins 1992).

During the root fluxes, the roots responsible for the absorption of water and nutrients are emitted, which are distinguishable by their characteristic white coloration and small size, this in terms of diameter. These roots have an average period of maximum metabolic activity of three weeks after which the suberization period begins, notable for the change from white to dark brown color and decreased assimilation of nutrients, reaching the minimum metabolic activity in 6 weeks (Comas 2000).

Given the morphological characteristics of the roots responsible for the greater assimilation of nutrients, they are the most susceptible to damage due to conditions adverse to their development. This leads to taking into account factors inherent to the soil where the roots develop, which promote these adverse conditions. Such as compaction, lack of aeration, excess agrochemicals, excessive salinity or acidity, excess or lack of humidity, pests and root diseases.

When the soil has greater resistance to root penetration, there is less exploration and development of the root system, which translates into a lower rate of absorption of nutrients, negatively reflecting the vegetative development of the plant. If the demand produced by the fruits for carbohydrates and nitrogenous compounds is added to this, it causes the generation of weak roots in the future.

The aforementioned leaves us with the need to work with an integrated management for development and achieve the best root activity. Considering both the varietal characteristics of the type of vine that is being produced, as well as those of the soil where the vineyard is established, as well as the environmental conditions of the producing region.

Soil conditioning

It has been observed in vines that root penetration into the soil decreases when the apparent density exceeds 1.4 g / cc (Richards 1978) (Van Huyssteenn 1984). In addition, it was possible to observe vines with premature decay when at ground level there were apparent density values below 10cm of the order of 1.4 to 1.44 gr / cc, associated with penetration resistance values between 1.082 and 1.238 KPa, and macroporosity of the order of 5% (Selles 2000).

The time indicated for initial soil conditioning is prior to sprouting, when hydration irrigations are carried out that seek to initiate the metabolic activity of the root, ending the dormancy period. The objective of conditioning is to balance the pore space in the soil, reducing resistance to new root development and even the movement of accumulated salts to prevent them from generating root stress.

Root flow

During the year the vine normally presents two major root flows. The first and largest is prior to flowering and coincides with the average growth of the guides, approximately when they have exceeded 40cm in length. This flow occurs when the plant has consumed the reserves accumulated in the roots a year before and will promote the growth of those that will support the demands of the clusters to develop after the fruit set. The second is after the clusters are cut, about a month, and its objective is to promote roots that will be responsible for the accumulation of reserves before entering dormancy and that will serve for the initial development of the shoots of the following year.

Inoculation of beneficial microorganisms.

The microbial activity of the rhizosphere is, to a large extent, responsible for the functioning of the ecosystem and the fertility of agricultural soils. Among beneficial soil microorganisms, both arbuscular mycorrhizal fungi (AM) and growth-promoting rhizospheric bacteria (BRPC), key constituents of the rhizospheric zone, contribute to improving plant development and nutrition, as well as to increase the tolerance of crops against certain biotic or abiotic stress situations. The integration of these microorganisms in the systems guarantees sustainability, helping to optimize the quality and health of the soil, limit the supply of nutrients and increase yields.

The common practice in vine production systems is to apply or inoculate microorganisms, directed at the roots, prior to the start of root flows to achieve the establishment of new colonies on new roots from their initial growth.

Bibliografía

• Ruiz Sch., Rafael. 2005. Raíces y Condiciones de la Fruta. Seminario organizado por Subsole: Alternativas Técnicas en Uva de Mesa II – 2005.
• Comas, Louise H. and Eissenstat, David. 2000. Assesing Root Death and Root System Dynamics in a Study of Grape Canopy Pruning. New Phytologist (2000) 147: 171-178.
• Azcon-Bieto, J. y M. Talon. 1996. Fisiología y Bioquímica Vegetal. Madrid. 1ra edición.