1911.] PUBLIC DOCUMENT — No. 31. 221 



following concerning its behavior in the southern Appahichian 

 Mountains : — 



At 1,500 feet altitude in Albemarle County, Va,, on Porters clay, this 

 variety is not considered of special value, but at the same elevation in 

 Georgia on a soil containing rather more sand than Porters clay does, 

 with good culture it comes to a high degree of perfection, and when 

 held until midwinter it generally brings very satisfactory prices in local 

 markets. In the southwestern part of North Carolina, at 1,700 feet 

 elevation, on a friable, porous loam, with good culture it bears annual 

 crops of highly colored fruits, which develop to a larger size than under 

 most conditions. In North Carolina at 3,500 to 3,800 feet, while the 

 Shockley bears heavily and colors well, it is usually too small to be of 

 much value, especially as other more desirable sorts succeed at these 

 elevations. The clay and clay loam soils of the Piedmont region, with 

 the usual elevations of those soils, may be expected, as a rule, to produce 

 this variety in a fair degree of perfection.' 



The Relation of Temperature to Development. 



The Mean Summer Temperature. — There is a close relation 

 between the mean summer temperature and the development of 

 the fruit. For every variety there can be determined a mean 

 summer temperature at which it reaches its highest and most 

 satisfactory development. Any departure from this mean re- 

 sults in greater or less inferiority of the fruit, the degree of in- 

 feriority depending on the amount of the departure, and the 

 variety. For the successful growth of the tree the mean sum- 

 mer temperature is of little significance, but the major control- 

 ling factors are the minimum winter temperature and the mean 

 of the hottest part of the summer. Other factors enter in, but 

 Ave believe that these are the principal ones and nnist first be 

 complied with if a variety is to succeed. 



The Winter Mitiimum. — The temperature which a tree of a 

 given variety can withstand cannot be stated with definiteuess. 

 If depends not only on the degree of cold, but also on the con- 

 dition of the tree and the rapidity and amount of the fall anf] 

 subsequent rise of the temperature. In the northwestern belt 

 ibis is the great problem of apple culture, and much study has 

 been given to it. The Minnesota ITorticnltnral Society men- 



> Bureau of Plant Industry. Bulletin 135, p. 43. 



