SUGAR CANE 41 



strains much superior to those in common use will be established. 

 The natural variations in timothy are shown in figures 30, 31 and 32. 



Potatoes. The hill-row method of improving the quality and 

 yields of potatoes is very successful. Record is kept of heavy- 

 yielding hills (Figs'. 23 and 24). Yields are also kept separate and 

 planted in individual rows or sections of rows, each being properly 

 labeled by stakes. Records are kept of the yields of each and the 

 best are again selected. Those which prove most inferior are 

 eliminated. Marked differences have been 

 found. 



New varieties of potatoes are established 

 through the use of seeds which are produced in 

 seed-balls (Fig. 33)', but this should not be com- 

 monly practiced. Improvement in quality and 

 yield by selection of tubers gives far better re- 

 sults. Variations in seedling potatoes are seen 

 by comparing figures 34 and 35. 



Sweet Potatoes.- -The 

 work of improving sweet 

 potatoes is similar to that 

 with white potatoes. They 

 are both chiefly propagated 

 by asexual methods. In both 

 attention may be given to 

 disease resistant qualities of 

 the vines and tubers. Size 

 of the tubers, neither too 

 large nor too small, should 

 be considered in both of 

 these crops. 



Sugar Cane. The Louisi- FlG 32. Variation in length of heads of timo- 



ana Sugar Station has con- 

 ducted a series of experiments in the improvement of sugar cane. 

 As the crop is.usuaily grown by planting the buds or joints, and not 

 by planting the seeds, the work is chiefly that of selection. Plants 

 grown from seed show a wider variation than those grown from 

 buds. New and improved varieties of sugar cane are started from 

 seed. After improved strains are established by planting seed 

 from the best canes the cutting method of propagation is followed 

 and little deterioration in quality will follow. Qualities to be 

 considered in improving sugar cane are the total yield of cane and 

 the percentage of sugar. 



