Since the natural sources of medicinal plants are rapidly diminished in the country and the needs for medicinal plants have increased, the need for their plantation cultivation is obvious.

Cultivation of medicinal plants in FR Yugoslavia is carried out in the areas characterised with different climatic-edaphic factors being crucial for achieving high yields and good quality of medicinal plants. These reasons required from us to study and pay due attention to the possible effect of the environmental factors in achieving high yields and good quality leaves in the grown broad-leaf great plantain.

Field trials were conducted over 1998 and 1999 on the localities, as follows: Pancevo, marsh meadow soil at the altitude of 70 m a.s.l. in the environmental conditions existing in South Banat, followed by Gorobilje, brown soil at the altitude of 420 m a.s.l. West Serbia.

Preliminary results of the simultaneously conducted investigation indicated that the highest yield of dry leaf averaging 2560.5 kg/ha was achieved on the locality of Pancevo, comparing with 2145.5 kg/ha great plantain dry leaf achieved on Gorobilje locality.

On both localities higher yields were achieved in 1999. Laboratory investigation also implied determination of aukubin content. Higher content (1.3%) being achieved in the leaf of great plantain produced on the locality of Gorobilje.

Key words: great plantain, dry leaf, yields, environmental conditions, aucubin.