n8 



GRAIN BREEDING 



This requires care and skill, as it is easy to injure the flower 

 sufficiently to destroy its fertilization. 



After the stamens are removed and the pollen from some 

 other plant is introduced, the flower is again closed and 

 covered with thin tissue paper to allow light to penetrate 

 but to prevent the pollen of any other plant from entering. 



Fig. 65. 



Usually all except a small number of the flowers on the 

 spike are removed, for more satisfactory results can be 

 obtained when only a few of the flowers are used. 



By this method of grain breeding, valuable new strains 

 may be produced, but up to the present time it has not 

 given as satisfactory results as the selection method. 

 Crossing causes mixture of characters, many of which may 

 be undesirable. Hence after crossing, it takes several 

 years of straight selection to establish a desirable combina- 

 tion of characters. 



