CORESTA Meeting, Agronomy/Phytopathology, Cape Town, 2001, APOST 12 (adjourned)

The influence of spacing the tobacco plants upon the weight and germination of the tobacco seed

Central Research Station for Tobacco Culture and Industrialization, Bucharest, Romania.

This experiment aimed to obtain tobacco seeds with higher weight and consequently a better germination, taking in account that Romania is confronted with problems with the germination of tobacco seed, especially for the late developing, broad-leaved cultivars. These cultivars belong to the type Baragan tobacco (broad-leaved local cultivars) which is used in the cigarettes of large consumption. The experiment was conducted in the period 1997-2000 at the Experimental Field Urziceni, near Bucharest, using the tobacco cultivar Baragan 185. Four experimental variants were studied, in four replications, using the design of randomized blocks: I. Transplanted at 60 x 40 cms, leading to a density of 41,600 plants/hectare (check), II. Transplanted at 60 x 35 cms, leading to a density of 47,000 plants/hectare, III. Transplanted at 60 x 55 cms, leading to a density of 30,000 plants/hectare, IV. Transplanted at 60 x 85 cms, leading to a density of 20,800 plants/hectare. During the vegetative period the following determinations were made:Biometrical measurements of the plants chosen for seed production; Number of branches of the inflorescence; Number of capsules in the inflorescence; The determinations made in laboratory consisted in: the establishment of the number of seeds per capsule; the establishment of the number of seeds in a gram; the determination of the germinative energy; the determination of the germinative faculty. The conclusions are as follows: The number of branches and the number of capsules in the inflorescence are bigger as the spacing is also larger; The number of seeds per gram is higher as the spacing is larger; The highest weight of the seeds was recorded for the variable III, for a density of 30,000 plants/hectare. The germinative energy and faculty for this variable also had values over 90%. These observations led to the final conclusion that the spacing for obtaining the seed of the plants of the cultivar Baragan 185 would lead to a density of 30,000 plants/hectare, in this case the seeds obtained have a rich content of endosperm and a good capacity for developing the future plant.