G. L. KOTTUR 



271 



From these figures it will be seen that the fall in ginning percentage is 

 gradual to a defijiite limit, which is a little higher than that of the local kumjita 

 cotton. The biggest drop, however, takes place in the fifth or sixth gene- 

 ration. 



If this deterioration is due to crossing, then if the cotton can be self- 

 fertilized, it ought not to take place. A series of generations starting from 

 1913 were, therefore, self-fertilized, and the effect on the ginning percentage 

 of the following generations determined. 



The method adopted was as follows : A number of plants were taken at 

 random in each crop, and all the flowers of these plants were self -fertilized. 

 The selfijig was done by putting small iron rings on the flowei buds so as to 

 completely prevent the opening of the petals. The seed thus produced by 

 self-fertilization was taken for the next sowing, and was hand-dibbled on an 

 area of about one-twentieth of an acre. This supplies sufficient seed for trial 

 on a field scale. 



The result of applying this method to the broach cotton for a number of 

 generations, starting from seed imported in the several years since 1913, is 

 shown in the following table. The critical measurements were made in the 

 three successive years 1916, 1917, and 1918. 



The percentages vary, but no fall in ginning percentage is indicated in 

 the older generations. And it would seem to dispose completely of the idea 

 that the continued growing of broach cotton in a tract like the Dharwar District 

 to which it is unaccustomed is itself a caiLse of deterioration in the matter of 

 ginning percentage. It is perhaps not entirely due to cross -fertilization, 

 though the fact that cross-fertilization takes place in cotton is now established 

 beyond all doubt. All the Indian varieties cross easily and the aniomit of 

 natural crossing is considerable (up to six per cent.), when various varieties 

 are grown in adjoining plots. The deterioration in large scale cultivation 

 may not be entirely due, however, to this cause. There is also the question 



