SUMMARY

The content of nitrogen wos researched in a bark and in a tree of one year old brances, of selected types of wild apples and also autochthonous sorts of apple (in situ). All this sorts were from the area of Bijelo Polje, researched in period from 1996-1999. The average content of nitrogen in a bark wos from 0,85 % (type 1) till 1,20 % (senabija). The average content of nitrogen in the tree wos from 0,40 % (type 1) till 0,64 % (sort pa{inka). The content of nitrogen wasn t the same among the researched sorts and selected types of wild apple. We noticed that the diference between a content of nitrogen in a bark and a content of nitrogen in a tree of a year old branches were related with a mounth and a year in which they were researched. The results of this research showed that the content of the nitrogen wos genetic characteristics of the sort, namely the type which influences the resistance to low temperatures, and that is important from the aspect of generative rootstocks production. The highest content of nitrogen in the bark of autochthonous sorts was in January, in the second years of investigation 1,369 % (senabija). The lowest content of nitrogen was in January, in the first year of researching 0,502 % (arapka). The highest content of nitrogen in a bark, of selected types of wild apple, was in January, in the second year of researching, 1,362 % (type 3); (he lowest content of nitrogen was in a March, in the first year of researching, 0,389 % (type 9). The highest content of nitrogen in the tree among autochthonous sorts was in February, in the second year of researching, 1,117 % (senabija); the lowest content of nitrogen was in March, in the first year of the investigation, 0,181 % (painka). The highest content of nitrogen in the tree among the selected types of wild apple, was in February, in the second year of researching, 1,022% (type 9). The lowest content of nitrogen was in March, in the first year of researching, 0,187% (type 3). We reached the conclusion that the content of nitrogen in the bark is higher than the content of nitrogen in a tree of one year old branches of autochthonous sorts of apple and selected types of wild apples.