86 PRINCIPLES OF PLANT CULTURE 



needed check to growth. In wet seasons, the drying of 

 the soil may be promoted by stopping cultivation before 

 midsummer and sowing a crop that will increase evap- 

 oration from the soil, as oats, clover or buckwheat (200). 



136. Pinching to promote flowering. — In certain 

 cases, as with seedling trees of which we would early 

 know the quality of the fruit, we may give an abnormal 

 check to growth by pinching the tips of the young shoots 

 or by root pruning (416). These operations should be 

 performed early in summer, before the period of flower- 

 bud formation, and if the tree is not too young, flowers 

 and fruit may be expected the following season. Frequent 

 transplanting of young trees acts like root pruning, espe- 

 cially if the tap-root is severed. Such harsh measures, 

 however, while they promote early fruiting, doubtless tend 

 to shorten the life of trees. 



137. Ringing (415) often causes the formation of 

 flower-buds in otherwise barren trees, by obstructing 

 the rootward current of prepared food. Twisting a 

 small wire about the branch, violently twisting the 

 branch itself, or simple bending and fastening it in an 

 unnatural position, answers the same purpose. But 

 these devices probably weaken the tree and shorten its 

 life by robbing the roots of' their normal food supply 

 and are excusable only in special cases, as with seedling 

 trees. It is generally a reproach to the care or knowl- 

 edge of the cultivator, if his trees of bearing age cannot 

 form flower-buds without such choking. 



Fruit-trees grafted on slightly uncongenial stocks 

 sometimes flower and fruit more freely for a time than 

 when growing on their own roots, because the imperfect 

 union of cion and stock (383) forms an obstruction to 

 the rootward food-current. 



