316 



Plums and Plum Culture 



of maturity is always understood to be of great practi- 

 cal consequence. All these things have a definite re- 

 lationship to climatic conditions; and it seems probable 

 that any one phenomenon, like the blossoming of 

 Abundance, or the maturity of Green Gage, might be 

 so carefully studied as to discover just what the con- 

 ditions are on which it is dependent. The trouble is 

 that no such case has ever been sufficiently studied. 

 It seems probable that the sum total of heat received 

 from the air, more than anything else, determines when 

 a given tree shall open its blossoms or mature its fruit. 

 But this is too complicated a question for discus- 

 sion here.* 



Before leaving this subject finally, however, it 

 will be interesting to note that the same plant will be- 

 have differently in different climates. With plum 

 trees this is most noticeable in the relative seasons of 

 flowering and leafage. In southern latitudes the flow- 

 ers appear before the leaves, often when the leaf buds 

 are scarce bursting. The leaves come on one, two or 

 even three weeks later. In northern latitudes, on the 

 other hand, flowers and leaves come out together. In 

 some cases the first leaves may be seen nearly full 

 grown on the same twigs with the freshly-expanded 

 flowers. This difference may be observed in any va- 

 riety. It sometimes proves puzzling to the pomolo- 

 gist who tries to identify a tree in one locality from 

 his experience with the same variety in a different 

 latitude. 



*The author has given a general view of this subject, with certain 

 computations, in Vermont Experiment station Report, 11:263. 1898. 



