THE INTAKE AND UTILIZATION OF WATER 19 



The Handling and Transplanting of Nursery Stock. — The practical 

 bearing of the point just brought out upon the transplanting of fruit 

 trees or other plants is important. The transplanting of most deciduous 

 fruit trees and of many other plants is usually accompanied by the loss 

 of a considerable part of the large and of the fibrous roots and by the 

 destruction of practically all of the root hairs. New root hairs must be 

 produced before active absorption can begin; these new root hairs will 

 be formed only on new branch rootlets. This means that if the top of 

 the plant has any considerable water requirement at the time of trans- 

 planting it will suffer for lack of moisture and perhaps wilt and die if new 

 roots are not formed immediatel3^ The grower is likely to place a rather 

 high premium upon a large and extensive root system in nursery trees, 

 thinking that they will surely absorb enough water to maintain the 

 moisture supply of the tops until new roots are formed. A fairly ex- 

 tensive root system in the nursery tree may be an asset, but not because 

 these roots devoid of root hairs are of any material aid in the direct 

 absorption of water. This explains wh}'- tree roots pruned according to 

 the so-called Stringfellow method at the time of setting are usually as 

 sure to take root and grow as those pruned less severely, though the 

 subsequent growth may not be so satisfactory. More important still, 

 it explains also why it is desirable to prune back the tops of most plants 

 at the time of transplanting so as to reduce transpiration to a minimum 

 and prevent desiccation. It shows furthermore why in climates not too 

 cold, fall transplanted trees are more likely to give a good stand than 

 corresponding spring-set trees, for during the winter months new root 

 formation is initiated and water can be absorbed in the spring as fast as 

 the new shoots and leaves use it.^^^ The spring-set trees, on the other 

 hand, must wait until new roots are formed before they can take up 

 moisture and if soil conditions remain imfavorable for this root formation 

 and atmospheric conditions stimulate vegetative growth of the top, the 

 pushing shoots will wilt and die, and the tree will be lost. In the autumn 

 conditions are favorable for root growth for some time after good growing 

 conditions for the top have passed ; in the spring they frequently become 

 favorable for top growth before or simultaneously with suitable growing 

 conditions for the roots. 



In the light of the facts presented it is not difficult to understand why the 

 transplanting of trees after their buds have once started in the spring is 

 attended with very uncertain results. It is simplj^ a case of a demand 

 for water for supplying the top, great in comparison with the demand 

 while in the dormant stage, a demand that cannot be met by the roots 

 because, temporarily, they are practically without absorbing organs. If 

 it is necessary to plant trees late in the spring, after some vegetative 

 growth may be expected to take place, it is well to remember that the 

 transplanted tree will have practically no root hairs for several days or 



