IMPROVEMENT OF BURNING QUALITY. 39 



time. This improvement not only reduces the cost of harvest, but 

 results in a more uniform crop of tobacco. 



The differences in rate of growth of the individual plants in to- 

 bacco fields, resulting in varying times of ripening of the plants, is 

 illustrated in Plate VI, figure 1. This degree of variability could be 

 found in all the tobacco fields visited by the writers. In Plate VI, 

 figure 2, are shown two rows of plants of the same variety treated 

 exactly alike from the time of sowing the seed to harvest, one grown 

 from the seed of the late and the other from the seed of the early 

 plant shown in Plate VI, figure 1. The difference in time of ripening 

 in this case was seven days; in other words, the early strain was 

 ready for harvest one week before the late strain. 



The experiments which have been conducted for the purpose of 

 improving the different varieties of cigar wrapper 1 and filler varieties 

 and of smoking varieties of tobacco have demonstrated that it is 

 possible for tobacco growers to improve the earliness of maturity of 

 their varieties wherever such improvements are desirable. This 

 improvement can be practically carried out by a careful study of the 

 habits of growth of the plants in the field and the selection of the 

 earliest and best plants for seed, saving the seed of these plants with 

 precautions to prevent cross- fertilization. The production of earlier 

 varieties requires several years of systematic selection and must be 

 accompanied by a careful study of the quality and character of the 

 product of the early strains. The practical limitation of earliness 

 or the process of shortening the period of maturity depends on the 

 effect of such change on the quality and yield of the early varieties. 



Other things being equal, early-maturing varieties of tobacco are 

 desirable, especially in northern sections, and can be produced by 

 the growers thru the systematic selection of early seed plants. Uni- 

 formly maturing plants in a field and uniformly maturing leaves on 

 the same plant are of great importance and can be produced by 

 similar practical methods of seed selection. 



THE IMPROVEMENT OP THE BURNING QUALITY. 



The nature of the " burn " presents to the grower of cigar, ciga- 

 rette, or pipe tobacco a most vital question, and, in the case of poor- 

 burning tobaccos, an obstacle which is very difficult to overcome. All 

 previous researches looking toward the solution of this problem have 

 been confined to studies of the conditions of soil, fertility, cultiva- 

 tion, and fermentation, and their relation to the character of the 

 burn of the tobacco, and thru the efforts of those who have care- 

 fully investigated these subjects improvements have been made in 

 the burn of most of the varieties of tobacco. A thoro understanding 

 of these phases of this question, however, does not wholly solve the 



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