PREVENTION OF INJURY IN TRANSPLANTING. 



57 



veins. This purpling of tlie old leaves is evidence of a severe stop- 

 page of growth and in these experiments has been observed to be 

 caused by low temperature, about 40° F. or lower, or by lack of 

 nutrition from any cause, or, apparently, by poisoning. 



If the soil into which j^oung blueberry seedlings are transplanted 

 is suited to their growth, purpling of the old leaves seldom occurs, 

 the evidence of the shock of transplanting being confined to the pos- 

 sible withering of a few of the stem tips and the temporary stagna- 

 tion of others. In some transplantings no withering of tips occurs. 



During the period of cessation of stem growth after transplanting, 

 the plant is by no means idle, for the roots, as shown in glass-pot 

 cultures, continue to make new growth, and when this has sufficiently 

 progressed stem growth is resumed. 



(22) When about ten weeks old and nearly two inches in height the 

 seedlings begin to send out basal branches. 



An important phase in the development of the seedlings of 1908 

 began on November 25, when one of the" plants commenced to send 

 out a branch from the axil of a cotyledon. 

 At the expiration of another month 75 per 

 cent of the ])lants in the flat had put out 

 similar basal branches, and the remaining 

 25 per cent ultimately did the same. 



These basal shoots are of the highest im- 

 portance in the economy of the blueberry 

 plant, for the}^ soon far outstrip the first 

 stem and become the principal seat of 

 growth, until they themselves are over- 

 shadowed by later and still more vigorous 

 basal shoots. The original stem of the seed- 

 ling never develops into an ultimate main 

 stem or trunk, but, as will be seen later 

 (p. 58), stops growing while the plant is 



still young, and afterward dies. It is this habit of sending up basal 

 shoots that makes the SAvamp blueberry a many-stemmed bush, not a 

 miniature tree with a single trunk. 



The development of basal shoots began when the seedlings had 

 about 12 leaves and were about 1.5 to 2 inches high. In this first 

 basal branching the number of branches varied from 1 to 3. Out of 

 73 plants on which the branching was recorded 30 had 1 branch, 30 

 had 2 branches, and 4 had 3 branches. The branches occurred in 

 the axils of the cotyledons or of one of the first four leaves. Of the 

 39 plants with 1 branch, 11 had the branch in the axil of a cotyledon, 

 17 in the axil of the first leaf, 8 the second, 2 the third, and 1 the 

 fourth. Of the 30 plants with 2 branches, 11 had both branches in 



193 





Fig. 22. — Normal tip of stem 

 in a blueberry seedling. 

 (Enlarged 4 diameters; 

 ttie smaller figure natural 

 size. ) 



