*1 Department of Floriculture and Dendrology, Urban Planning and Garden Art, Institute of Landscape Architecture, Hungarian University of Agriculture and Life Sciences, Budapest, Magyarország
The aim of this trial was to find the optimal substrate (sand, peat and 1:1 mixture of them) for germination and growing of Tagetes patula ’Robuszta Kénsárga’, ’Vénusz’ and ’Tigris’, with the use of 40 seeds according to substrates and cultivars in nine groups. Germination and survival ratio, plant height, root length, flower number and –diameter were examined. Almost all seeds germinated successfully, and the highest surviving was around 80% in case of peat + sand, and the lowest (50%) when plants grown in pure sand. The latter substrate resulted the longest roots (especially in the groups of ‘Tigris’) and all cultivars (particularly ’Vénusz’) reached the lowest height with the use of this soil. On the other hand, peat effected the shortest roots, tallest specimens, most flowers of every cultivars. In case of flower number, there were significant differences between ‘Tigris’ (with averagely 58-70 flowers) and the other two types (23-39 flowers), irrespectively of the substrates. ‘Vénusz’ developed the smallest flower heads (maximum 3.5 cm) in all cases; the other cultivars produced at least 4 cm inflorescences. The lowest plant values experienced with the use of sand and the best results on peat.