Galls of Andricus hungaricus Htg, forming on Quercus robur L, together with Andricus quercuscalicis Burg galls, were used for many years in Romania in tannery. Austrian-Hungarian Empire, at the end of XIXth century, exported these galls and the forestry industry substantially profited financially. Because of the high level of tannin, compared with other natural plant or product components, galls were used to tan the thickest oxen hide parts utilized for shoe making. It was discovered that gall tanneries used galls up the the year 2000 in the Pancota area of Arad County, Romania. The galls used to be collected by locals, and sold to tanners in places like Pancota, Arad County. After that, the galls used to be dried out in the attics of their own houses and a local stone mill was used to grind the galls and obtain flour used in tannery. The goal of the paper is to determine, by scientific methods, the period of time that is needed for the galls to dry out, to constant mass, and also to establish the dry mass of the Andricus hungaricus Htg galls. In order to do that, 303 galls were randomly collected from Lunca Muresului Natural Park, Arad County, Romania. All the galls were brought to the lab and were cleaned up using a plastic brush. The mass of each gall was measured every two days, using a precision balance. The measurements were stopped when the mass of the galls was constant from one determination to another, on constant lab temperature conditions (19ºC). The galls were split into 10 classes and the decline curve of the humidity was established for each class. Five galls from each class were put into lab drying oven and the dry mass was obtained, by measuring the mass of each gall every 6 hours, to constant mass. The equation that establishes the dry mass from the “green mass” was determined. The research could have a practical use in case of collecting the galls for different economical use or research (besides tannery, the galls were/are used for ink production, pharmaceutical industry and others ).

galls, Andricus hungaricus, dry mass, Quercus robur, tannery

Presentation: oral