YIELD AND QUALITY OF SELECTED HERB CULTIVARS IN FINLAND

Cultivars of six leaf herb species were grown during 1999-2000 at South Finland (Piikkiö, 60° N, 23 ´E) and North Finland (Ruukki, 64° N, 41 E). The plants were propagated by seedlings, grown in black plastic mulch, fertilized by 20 t/ha compost. Growth, fresh and dry leaf yield, essential oil content, and composition were studied.
The yields obtained from the southern growing site were generally higher by 10-40 % than those from the site 500 km further North. The shorter growing season affected the biomass production, but did not strongly influence the essential oil content and composition which were similar to other European results. The yield differences were very high in the case of Greek oregano and marjoram, but savory and dragonhead showed a better tolerance to the cooler climatic conditions and the yield differences were much smaller. Sage and thyme can be only grown in Finland as annuals and their yields were almost identical from both sites.
Using bred cultivars, sufficient quantities of high quality raw material can be produced under Nordic conditions.