Killing of Plant Tissue by Low Temperature 259 



Eustace reports that trees pruned in January, shortly after 

 a severe freeze, gave much better results than trees pruned in March, 

 probably because a large amount of drying out had been avoided by 

 reducing the top. At this station better results have been secured 

 by the early pruning. Fertilizing the soil with a nitrogenous fer- 

 tilizer, as nitrate of soda or ammonium sulphate, has, at Brandsville, 

 Missouri, resulted in much more satisfactory recovery from winter 

 injury. Where the fertilizer was applied both the year before and 

 the year following the freeze, very slight permanent injury was to 

 be found when surrounding unfertilized trees suffered great injury. 



Hardiest Varieties in Wood. The effect of the condition of 

 growth on the hardiness of peach wood is so great that it is difficult 

 to reach an accurate conclusion as to which are the hardiest varieties. 

 Observations must be on a large number of trees, and through a 

 large enough number of years to include many different seasonal 

 conditions. Hedrick,^ basing his opinion on replies secured from 

 New York growers, places Crosby, Hills Chili, Stevens Rareripe, 

 Gold Drop and Elberta as most hardy in wood; and from replies 

 from Michigan growers. Hills Chili, Crosby, Gold Drop, Kalamazoo, 

 and Bernard. Elberta, Smock and Salway, considered hardy in 

 New York, were considered tender in Michigan. Wager, Jaques 

 Rareripe, Carman, Belle of Georgia, and Hale 's Early were considered 

 above the average in hardiness. Eustace^ found in New York, fol- 

 lowing the winter of 1903-04, that Stevens Rareripe, Elberta, Thur- 

 ber and Salway showed little or no wood injury, while Chinese C ling 

 was the most seriously injured. R. F. Howard, formerly of the 

 Nebraska Experiment Station, states in a letter that RusselP is one 

 of the most hardy in wood. 



At the Missouri Experiment Station there is a peach orchard 

 that has been exposed to the severe winters of 1898-99, 1904-05 and 

 1911-12. These trees have had such different treatment that they 

 necessarily went into winter in conditions not equally favorable 

 to withstanding the low temperature. We arc, therefore, not able 

 to place the varieties as to hardiness with any degree of accuracy. 

 However, it can be said with certainty that, although Elberta is very 

 tender in hud, its wood is exceeded in its ability to recover from such 

 winters by very few varieties. At least this is true of any but one- 

 or two-year-old trees. Hills Chili, Salway, Bernard and Gold Drop 

 have also proved hardy. Chinese Cling has been prol)al)ly most 



Procs. Westorn N. Y. Hort. Soc. 1908. p. 180. (Blbl. No. an). 

 N. y. (Gonova) Kxp. .Sta. Hul. 2tl<J. 1005. (Bibl. No. 38). 

 Yearbook. U. S. Dopt. Aur. 1011. p. 129. (HIbl. No. 109). 



