Implication of nutrition on root development

Grapevine depends on its root system for the uptake of both water and mineral nutrients. Uptake is related to root absorptive surface area, which is influenced by root length and density. In order to reduce inputs the root efficiency is a very important factor for developing sustainable agricultural practices and for assuring optimal quality of grapes. Our study evaluated different nutritional strategies with the aim to verify the effectiveness of new products (by PRP Technologies, France), based on calcium (Ca) and magnesium (Mg), on root development and vine performance. The trial was carried out in north-eastern Italy during the 2011-2014 period on the cultivar ‘Pinot gris’, in a vineyard in a sandy-loam soil. Three treatments, three times replicated according to a randomized experimental layout, were compared, where test (T) indicates fertilization suggested by advisory services, while S and SF, respectively the fertilization with PRP products via soil or soil plus foliar application. Each year quantitative and qualitative data were collected; nutritional, physiological (SPAD and NDVI measurements), ecophysiological (leaf water potential and quantum efficiency of photosystem II) parameters, and grape mechanical properties (by texture analysis) were recorded. In 2013 and 2014, from each thesis a small quantity of grapes were harvested and vinified in order to obtain wines that were subjected to sensory analysis in the spring of the following year. Density of the roots was evaluated every year in summer-fall by executing the excavation of soil profiles. Both S and SF treatment exhibited a larger number of roots (“medium” and “fine”) in the deeper layers in comparison to T. This behavior significantly reflected in higher yield and better physiological, ecophysiological and berry mechanical status, without modifying nutritional levels, indicating an earlier stage of ripeness of the grapes. PRP strategies seem interesting in stimulating root activity and performance responses of vines