Research and experimentation

The Arnaldo Caprai estate aiming at expressing all the potential of the local variety, Sagrantino, is carrying out a research study in collaboration with the Dipartimento di Produzioni Vegetali Sez. Coltivazioni Arboree of  the University of Milan and the Parco Tecnologico dell'Umbria - Sitech s. cons. a.r.l.
The research addresses different issues:

- Sagrantino Clonal selection
- Implementation of modern techniques in the management of new vineyards
 (study of the best combination of plant density, rootstock and training system)

Sagrantino Clonal Selection
Between 1990 and 1993 the research was aimed at identifying Sagrantino "mother plants" within its natural range of distribution,  that includes the area of Montefalco, Bevagna and Gualdo Cattaneo.
Mother plants are single individuals that belong to the variety Sagrantino, but show different genetic and morphological characteristics, such as shape and largeness of the grape; levels of fertility, vine vigour; level of grape constituents (sugars, acids, phenolics, aromas); and presence of virus diseases.
These mother plants were mainly found in old and abandoned vineyards or in small farms where a limited number of Sagrantino vines were grown only for family consumption and were reproduced for generations via vegetative propagation. Thus, the aim was to recover as much as possible the natural genetic variability that had been lost or significantly reduced as a result of past mass selection.
In nursery, cuttings of the mother plants were grafted onto two different rootstocks in order to obtain rootings. Thus, it was possible to obtain probable clones that were the basis for two experimental vineyards planted in 1994 in two different sites within the range of Sagrantino.
These putative clones were analysed to identify different characteristics such as: buds fertility, average cluster weight, largeness and shape of the grapes; sugar content, pH, total acidity, levels of malic and tartaric acid in the musts; levels of phenolics and anthocyanins in the skins; possible presence of virus diseases detected through ELISA test; DNA mapping to evaluate differences and similarities among the different clones.
The grapes produced by each type of clone undergo a microvinification process at the San Michele all'Adige Institute of Agriculture. It is thus possible to evaluate the characteristics of the wine both through analytic analysis and through panel tastings. These procedures of scientific research will be repeated in the next years in order to identify a group of clones that prove effective in the improvement of the quality of Sagrantino wine. These clones will be registered in compliance with the law.
This selected and certified genetic material will be used for the planting of new polyclonal vineyards. The final aim is the find the best combination of clones to be grown in different sites and for the various enological aims that are pursued.

Agronomic Techniques
In order to compare vegetative and productive characteristics of Sagrantino different agronomic techniques are implemented in two separate vineyards planted in 1994.
Comparative studies between different training systems are carried out. Plants trained with the traditional "Palmetta" system (at a density of 1,700 plants per hectare) are compared with those trained with more innovative systems, such as Guyot and Cordon de Royat planted at various densities (3.200, 3.800, 4.800, 5.700, 7000, 8000 plants/ha). Each combination of training system and density is repeated on five rootstocks (3309 C, 161-49 C, 1103 P, 110 R, 140 Ru, ) that show differences in terms of vigour and resistance to various factors including calcareous rocks, drought, etc. A total of forty different combinations are tested and compared in each experimental vineyard.
Production per plant is limited by manual cluster thinning, in order to obtain a production of 8t/ha in compliance with the DOCG regulations. For each combination the same tests carried out for the clonal selection (a part from DNA mapping and ELISA test) are performed in order to evaluate the vegetative and productive characteristics of the vines; finally microvinifications are also carried out. It is important to underline that in searching for the best combination possible between density, training system and rootstock, the possibility of  an effective mechanisation maintaining the highest level of quality it is also taken into account.
As with clonal selection, it is necessary to compare the results yielded in several years, in order to take into consideration how a vintage affects the characteristics of each tested combination. The final outcome of clonal selection will result in the identification and description of clones of Sagrantino that prove suitable to the various sites and to different winemaking purposes. Such clones will be registered and included in the National Register of clones in compliance with the Italian legislation.