Bull. Spec. CORESTA Congress, Jerez de la Frontera, 1992, p. 52, AP6, ISSN.0525-6240

The active physiological substances influence on the quality features of tobacco seed and seedling

Academy of Agricultural and Forestry Sciences, Bucharest, Rumania.
The use of active physiological substances for the stimulation of the tobacco seeds has become a widespread technique. The main biostimulators, tested in our experiments, with positive effect on germination percentage and uniformity were : gibberellic acid (0.05-0.1%), succinic acid (0.2-0.3%), nicotinic acid (0.1-0.2%), tartaric acid (0.2-0.3%), thiourea (0.1-0.2%), potassium nitrate (0.1-0.3%), potassium permanganate (0.1-0.3%), potassium bromide (0.1-0.3%), maltose (1-2%), polyethylene glycol (15-30%). As a result of the treatments, the area needed for seedbeds has been reduced by approx. 10 m2 per ha of tobacco, the seedbed preparation period has been reduced by 4-7 days for Burley 235, 4 days for Virginia 1173 and 4-6 days for Ghimpatzi 55. The dry weight of plants was increased by around 20-50 mg per plant. The cost of treatments was reduced, the needed quantity for afferent seed treatment per tobacco hectare being 2-5 ml growth regulators and 3-5 g inorganic salts. The biostimulating substances efficiency has been reflected even in the chemical components analyzed (chlorophyll and total reducing sugars), the photosynthesis possibilities of the seedling being higher. The treatments can be applied for all Rumanian tobacco types, especially in the colder regions of the country, with a reduced seedbed preparation period and a higher quality. It is considered that the most efficient biostimulating substances are : gibberellic acid (0.05-0.1%), tartaric acid (0.2-0.3%) and polyethylene glycol (15-30%).