Improved Seed is seed originating from hand-selected 

 seed, but which is not yet entitled to public recognition as 

 "Registered Seed." 



Elite Stock Seed is (1) the product of hand selected seed 

 plots after at least three years' selection; or (2) pure stock 

 originating from a single plant, the progeny provmg satis- 

 factory in plot or field tests. 



"Registered Seed" is the progeny of Elite Stock Seed, 

 handled in accordance with the rules of the Association. 

 Most of the Registered seed is now produced by Seed Centers , 

 usually groups of farmers who multiply Elite stock seed 

 according to the rules of the Association. 



The third line of plant improvement, viz., by Hybrid- 

 ization, has been in use for over 150 years, but no general 

 principle had been established until Mendel published a 

 report in 1865. Until 1900 no person seemed to be able to 

 predict with any degree of certainty the result of crossing 

 varieties of plants (See Mendelism, pages 81-87). 



Selection of Fluctuations 



Sugar Beets. 



The sugar content of sugar beets has been gradually 

 raised from 4-6 per cent, to 16-18 per cent, during the nine- 

 teenth century. The credit for the improvement is mainly 

 due to the methods of analysis and selection introduced by 

 Louis Vilmorin. For the last thirty-five years, however, 

 no perceptible inprovement has been made in spite of rigor- 

 ous selection of mother beets, and it would seem that the 

 strain is kept at the maximum range of fluctuation only 

 by the selection and isolation of the best plants. 



High Protein and High Oil Corn. 



The Illinois Agricultural Experiment Station during 

 the years 1896-1915 increased the protein content of corn 

 seed from 10.92% to 14.53% and the oil content from 4.70% 

 to 8.46% by selection. (See Babcock and Clausen for an 

 admirable discussion of the Illinois results). 



Methods of Breeding Timothy, Wheat, Potatoes, etc. 



It is impossible here to describe in detail the method 

 of breeding improved strains of grasses and cereals. 



Reference may be made to Cornell University bullet- 

 ins 251 and 313 by Dr. Webber, and to L. H. Newman's 

 ' ' Plant Breeding in Scandinavia. ' ' 



156 



