Oct. 1,1921 Influence of Period of Transplanting 41 



A study of the proportion of the fresh weight of plant in the root 

 system shows that the relation between this proportion and the time of 

 transplanting, which was so evident two years before, had entirely dis- 

 appeared. All the plants were washed off, and the surfaces were allowed 

 to dry in the air; but as the evaporating power of the air varied, it was 

 not possible to compare directly the average fresh weights obtained at 

 tlie time of transplanting with those obtained on July i, 19 16. All 

 the weights obtained on the latter date are, however, comparable with 

 one another. Figures 3, 4, and 5 illustrate further the current height 

 growth of stem, the stem diameters, and the total fresh weight of the 

 plants. 



A striking similarity will be noted in the curves in figures 3 (weight), 

 4, and 5. All agree in shovnng two minima, the first for the May 20 lot, 

 and the second and still lower point for the July 14 transplanting. This 

 bears out the conclusion reached in the fall of 19 14 that the shock of 

 transplanting fell hardest upon the July 14 lot. But it now appears that 

 the transplanting on May 20 was almost equally lasting in its unfavorable 

 influence upon growth in the transplant bed. Between these two dates 

 there appears to have been a period of about a month in which trans- 

 planting worked less injury to the plant. 



As the roots of these plants were removed by washing, and with a 

 minimum of breakage, it seemed worth while to compare the average 

 numbers of laterals of the first and second orders. Figure 6 shows 

 graphically the data obtained. In order to bring the curves close 

 together, and thus facilitate comparison, the actual average number of 

 lateral rootlets of the second order, between 0.5 and 2 inches in length, 

 has in each case been divided by 2 in plotting the curves, and the average 

 total number of lateral rootlets in the four classes has similarly been 

 divided by 5. Because of the difficulty involved in recording them, and 

 the limited time available, no records were obtained of the number of 

 laterals of higher orders than the second, nor, in any case, of laterals less 

 than 0.5 inch in length. The figures obtained are, however, considered 

 indicative of the general nature of the root system. 



There is a close relation not only between the average number of 

 laterals in each of the two length classes of the second order but also 

 between these and the total number of rootlets of the recorded classes. 

 On the other hand, the curves for the two classes of the first order run 

 quite differently. Yet, so far as determining the total curve is concerned, 

 these two classes could obviously have been neglected. There is a con- 

 sistent decline in the fibrous development of the root system as the 

 transplanting season advances. Transplanting in early summer, and 

 even more so in late summer, holds back lateral root growth in the trans- 

 plant bed, the effect being strikingly noticeable two years afterwards. 



