276 TOBACCO 



Since 1906 the Deli Testing Station has been occupied 

 with the isolation of pure strains -of tobacco, the study 

 of their behaviour, and the following up of this method 

 in practice. Several strains have been successfully 

 isolated, which has convinced planters of the advantage 

 of this method of working, and at the present time many 

 companies are >in the habit -of collecting self-fertilized 

 seed from the best plants and sowing this separately 

 later on. 



The study of this subject is still in its infancy, and 

 this year at a number of places comparative speci- 

 mens have been planted between tobaccos derived from 

 the seed of various estates. 



In addition to an altogether excellent and pure strain 

 which has naturally to be sought for separately for each 

 soil and for each climate selection is also carried on with 

 a view to obtaining immune varieties, especially in con- 

 nection with the slime disease. 



For crossing trials a very large number of foreign 

 kinds of tobacco have been collected during the last few 

 years from all parts of the world and planted out in the 

 trial grounds. Presumably some of these will prove to 

 be of valu-e; a Japanese kind has already been planted 

 out on one estate on a small scale, whilst the same kind 

 is much appreciated at Djember in Java. 



A study of the germinating power of tobacco seed has 

 led to the following conclusions : 



(1) The germinating energy of tobacco seeds from 

 large brown pods is higher than that from small dark 

 brown seeds pods, but the difference is a small one. 



(2) The germinating energy of large seeds is generally, 

 but not always, greater than that of small seeds, and the 

 difference is even smaller than the preceding. 



(3) The germinating energy of heavy seeds is greater 

 than that of light seeds, and this difference is much in 

 excess of the two preceding ones. 



The practical conclusion is that by the blowing 

 out and removal of the lightest seed the germinating 

 power (i.., germinating percentage after seven days) is 

 increased to a greater extent than by selecting the seed 

 pods or sifting the seed. 



