26o Missouri Agr. Exp. Sta. Research Bulletin No. 8 



tender in wood, although it is rather hardy in bud. The station 

 orchard contains no old trees of the Greensboro or Belle of Georgia 

 varieties but young trees of these varieties, and of Victor and Russell, 

 were among those that recovered best from the effects of the winter 

 of 1911-12. 



It is interesting to note that Elberta, Greensboro, Belle of Geor- 

 gia, Victor and Carman are among the more hardy varieties in wood, 

 and are seedlings of the Chinese Cling, which is one of the few most 

 tender varieties in wood. 



Killing Peach Buds. In the case of fully dormant peach buds 

 there is but little diliference in the killing temperature of the different 

 parts of the flower. In practically all cases where there is killing 

 at all, all of the flower parts are killed and, in addition to this, gen- 

 erally some of the vascular tissue extending down into the twigs 

 from the base of the buds. This was brought out by careful sec- 

 tioning of killed buds by Mr. R. G. Briggs.^ Just how much cold 

 a fully dormant peach fruit bud will withstand, it seems practically 

 impossible to approximate. According to Eustace,^ the minimum 

 temperature that prevailed in Western New York in the winter of 

 1903-04 ranged from -10 F. to -15 F. In most orchards of that 

 section there was a normal crop although the wood was badly injured, 

 indicating that under some conditions the bud will actually withstand 

 a lower temperature than will some of the woody tissues. 



In a letter from Professor F. A. Waugh, he says that in Massa- 

 chusetts practically a full crop of peaches has been harvested from 

 trees that had been through a temperature of -20 F. and a partial 

 crop of Greensboro had been secured following a minimum tempera- 

 ture of about -27 F. In a letter from Mr. Elmer B. Parker of Wilton 

 New Hampshire, he states that after a temperature of -14 F. in Jan- 

 uary, a sudden drop, the Elberta crop was a practical failure while 

 Carman had 50 to 75 per cent of a full crop, and Belle of Georgia 

 and Champion had practically a full crop; and in 1910-11 a tempera- 

 ture of -12 F. in December failed to kill enough buds to prevent 

 trees from yielding a full crop. In these cases the buds had not 

 been started into growth by warm periods. 



In the year of 1901-02 all of the buds were killed at the Missouri 

 Experiment Station orchard by a temperature of -23 F. on Decem- 

 ber 20th. In 1902-03 practically all buds were killed by a tempera- 

 ture of -15 F. on February 17. In 1903-04 buds were killed on all 

 varieties except General Lee, Chinese Cling, Thurber, Carman, Gold 



'Thesis, University of Missouri, 1912.- (Bibl. No. 13). 

 2New Yorlf (Geneva) Exp. Sta. Bui. 269, 190.5. (Ribl. No. 38). 



