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