FRUIT-BUD FORMATION 69 



only influenced the succeeding crop but also the crops for 

 several seasons afterward. 



63. Individuality. — Aside from the many and varied 

 factors that influence fruit-bud formation, the trees them- 

 selves are to be considered. Some trees in an orchard may 

 be consistently high yielders, and others veiy low. But 

 whether this is due to an hereditaiy difference which can be 

 perpetuated is an open question, with the burden of proof 

 on those who claim such to be the case. Whether it is due 

 to a difference in the original bud or cion or in the rootstock 

 is not clear at present. Probably it is most frequently 

 traceable to environmental factors which may not be ap- 

 parent. 



64. Climate is the sum of all the weather conditions 

 and has a definite effect on the growth behavior of the trees. 

 If northern fruits such as the apple are grown in the tropics, 

 the growth is one of vegetative extension only. In the 

 temperate zone a balance between vegetative and reproduc- 

 tive growth is manifest, while still further north there is a 

 tendency to somewhat dwarfer trees and increased fruitful- 

 ness. If it is accepted that there are different optima of 

 temperature for the maximum development of the several 

 plant parts, then it may be assumed that some varieties of 

 fruit will develop flowering parts more readily under one 

 climatic condition than another, other things being equal. 

 Therefore, climate, as is discussed later, plays its part in the 

 flowering and fruiting of trees. 



65. Plants threatened by death. — The statement is 

 commonly made that if a tree is seriously injured or threat- 

 ened by death, it will make a last effort to reproduce itself 

 before it dies. The reason assigned for the phenomenon 

 seems sentimental and offers no real interpretation. That 

 such a tree does flower freely is sometimes true but more 

 frequently it is not. When it occurs, frequently a condition 



