BALANCE OF ROOT AND SHOOT 95 



crease the carbohydrate ratio and leads to the condition of 

 number two. With no pruning the plant may reach this 

 same condition, that is, a natural balance. 



If the entire top of a plant is removed as is done in cutting 

 weeds or brush, or in topping a tree we get different results 

 depending on the time of year and the amount of food stored. 

 Since most of these plants make rapid growth in the spring 

 they use much of the food stored the previous season, after 

 which storage takes place during the remainder of the sum- 

 mer. If plants are cut when the food supply is low in late 

 July or August, the remaining food may be used and little 

 will be stored for the next year. Under such a condition, the 

 spring growth would resemble that for condition number 

 four. But if the cutting is done in late fall or early winter 

 the storage of food and undisturbed root system will bring 

 about condition number three. Thus we can see the starved 

 condition explains the physiological reason for the old adage 

 "cut brush and weeds in August to kill them." 



Transplanting unbalances the root and shoot by the loss 

 of much of the plant's absorbing surface, so that transplants 

 make little growth for some time. The slight growth of 

 transplants, often called a time of "adjustment," may in 

 many cases be due to low nitrogen resulting in condition 

 number one. The removal of a part of the shoot is usually 

 suggested in order to balance the plant for its water problem. 

 It would be better to strive to save more of the root hair 

 region, water the soil, restrict transpiration by shading and 

 apply a little nitrogen to the soil. This will shorten the time 

 necessary for the "adjustment" of the transplant, often caus- 

 ing earlier fruiting if a quick acting nitrogen is used. 



In some plants such as lettuce or the lawn grass we may 

 want more vegetative growth, as results with condition num- 

 ber three. It should be remembered that unless a quick 

 acting, highly soluble nitrogen is used there is danger of 

 keeping the shoot growing at the expense of the root, causing 



