104 THE PLUMS OF NEW YORK. 



nearly as hardy. So far as resistance to cold is concerned the Domestica 

 plums as a class are less hardy than the apple, ranking in this respect with 

 the pear. Of the Domesticas the Reine Claude plums are as tender to cold 

 as any though some consider Bradshaw as more tender. Between these 

 last sorts and the hardiest varieties there is a great range in capacity to 

 endure cold, as would be expected with so large a number of varieties originating 

 in widely separated climates. The Triflora plums vary more in hardiness 

 than any other of the cultivated species. Speaking very generally they 

 are less hardy than the Domesticas, the hardiest sorts, Burbank and 

 Abundance, being somewhat hardier than the peach, while the tenderest 

 varieties, of which Kelsey is probably most tender, are distinctly less 

 hardy than the peach. Of the remaining plums, the Hortulana, Munsoniana 

 and Watsoni groups, there are great diversities in opinion as to hardiness. 

 Probably all of the varieties in these last groups are as hardy as the 

 peach with a few sorts in each more hardy than the peach. It is to be 

 expected from the more northern range of the wild prototypes that the 

 Hortulana and Watsoni plums are somewhat hardier than Prunus 

 munsoniana. 



The rainfall is of comparatively small concern to plum-growers in 

 America, since, with now and then an exception, in eastern America it is 

 sufficient under proper cultivation, and on the Pacific Coast the crop is 

 largely grown under irrigation. Summarized statements of annual rainfall 

 are of little or no importance since almost all depends upon the distribution 

 of the amount throughout the year and upon the manner in which it falls. 

 Monthly and seasonal "means" of precipitation, as in the case of 

 temperature, may be of considerable importance in determining the 

 desirability of a locality for plums. 



Air currents are of local or regional occurrence and though not often 

 the determinant of profitable culture of plums have sometimes been im- 

 portant factors in choosing a location to grow this fruit. The occurrence, 

 direction, moisture condition and temperature are the attributes of air 

 currents usually considered. The failure of many plums to grow in the 

 prairie region of the Mississippi Valley and the Great Plains is no doubt 

 due in some measure to winter winds. The problem of varietal adapta- 

 tion is more or less complicated in any region by the nature of the air 

 currents. 



An extremity of any of the constituents of what we call " weather " 

 endangers the plum crop at blossoming time. In New York stresses of 



