Bull. Spec. CORESTA Congress, Brighton, 1998, p. 103, APOST2

Researches concerning the production of tobacco seedling in Float system using trays with cells

Central Research Station for Tobacco Culture and Industrialization, Bucharest, Romania.
During 1996-1997 a programme for obtaining tobacco seedlings by unconventional methods was conducted in Romania. The tests were made in three experimental fields of the Central Research Station for Tobacco Growing and Industrialization in Bucharest, in areas with different soil and climatic conditions. For the experiments, pools covered with polyethylene sheet were used, the hydroponic solution being made up of the following: - growth stimulating substances (Revital etc.)- protection substances - Enide, Previcur, Ridomil- micronutrients and complex chemical fertilisers (N, P, K) - water (about 20 cm deep) The pH of the solution was slightly acid (~ 5,8), good for the growing of the small tobacco plants. For filling the trays, different compositions of nutritive mixture were used: 1. peat + sand in the ratio 2:12. soil + manure + sand in the ratio 2:2:13. soil + manure + peat + sand in the ratio 2:1:1:1 4. soil + peat + sand in the ratio 2:2:1 5. peat 100%Because of the adverse climatic conditions during the spring of the both years, the sowing was delayed, to until April 20th. The results recorded were not significantly different between the variants, regarding the time necessary for the different stages of growing of the seedling. The number of days from sowing to emergence was between 4-6, that for reaching the stage of "little cross" was of 10-12 days and for the stage of "little ears" of 17-20 days from the emergence. The seedling was ready to be transplanted after 30-35 days from sowing, being totally healthy, vigourous and uniformly developed thus being usable for mechanical transplantation. After the transplantation in the field there was recorded a high percent of striking root, around 96 %. The most important advantage of this system compared to the traditional one was that of using very little labour for looking after the seedling. The results obtained proved that this system is viable also for the conditions in Romania, and in 1998 it will be used on a larger scale in seedling production.