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equal conditions as possible and at the same time to allow single plants to be 

 taken up by the roots for furthur study. After due examination in the field, 

 those cultures, especially in the case of wheat and oats, which reveal out- 

 standing defects such as weakness of straw or susceptibility to disease are at 

 once permanently rejected. The remaining cultures are carefully harvested 

 by hand all plants being pulled up by the roots, tied into bundles, taken to 

 the drying room and finally to the laboratory to undergo further examination. 

 In the case of barley the treatment is somewhat different as this plant is so 

 susceptible to external conditions that it is seldom considered safe when 



Photo by L. H. N. 



FIG. XVI. A large comparative trial plot of Grenadier II Autumn Wheat separated 

 from its neighbor by a narrow strip of Spring rye seen on left of illustration. 



dealing with such small plots, to reject any considerable number of them 

 the first year. The first serious attempt to eliminate barley strains is there- 

 fore made the second year when the plots are larger. 



A further measure which is coming to be used at Svalof as a form of Head-to-the- 

 pedigree taking is what is known as the head-to-the-row method. By this row metfwd - 

 method a large number of heads, representing as many different plants, are 

 plucked from the crop when mature. From each of these heads a definite 

 number of kernels (from 30 to 60 in the case of wheat) is taken to plant a 

 single row. The rows are consequently all of the same length. Careful field 

 notes are taken throughout the summer and in due time the absolute weight 

 of grain and weight per 1,000 kernels of each row is also determined. On 

 this basis a choice of rows and a reduction to perhaps half the number is 



