266 Missouri Agr. Exp. Sta. Research Bulletin No. 8 



It should be said that there were more immature or partially 

 developed buds that were killed by a rather high temperature on the 

 twigs from Geneva than on the twigs from either Columbia or Brands- 

 ville, which probably explains the higher percentage of buds killed 

 on the Geneva twigs. 



It will be seen that except when the freezings were late in Feb- 

 ruary when buds in Missouri had been started into growth by warm 

 days, the buds from New York were not more hardy than those of 

 the same variety from Columbia. In the preceding chart will be 

 found curves showing maximum and minimum temperatures for Ge- 

 neva, New York; for Koshkonong, Missouri, six miles from Brands- 

 ville, Missouri; and for Columbia, Missouri. 



It will be seen that the buds from Geneva, New York, had been 

 exposed to lower temperature and to more continuously low tem- 

 perature preceding the freezing. Yet when they are thawed before 

 freezing and the temperature fall is equally rapid, there seems to 

 be no difference between their hardiness and the hardiness of buds 

 from central or southern Missouri. It is possible that the buds 

 from New York were started into some growth in transit shipment 

 having been made by express. However, the buds from Bransdville, 

 Missouri, came in the same way and, on account of poor railway 

 connections into Columbia from the South were about as long in 

 coming. If they were not as long in coming, they were kept in a 

 rather warm basement room until the New York twigs came. While 

 the data are not such that absolute conclusions could be drawn, at 

 the same time they certainly seem to suggest that the buds from New 

 York had not acquired appreciably greater hardiness due to their 

 having been previously exposed to low temperature. It seems possi- 

 ble that the buds are more resistant to a low temperature at the end 

 of a long cold period than are equally dormant buds to a low tempera- 

 ture that comes with a sudden drop, not so much because of a greater 

 resistance of the protoplasm brought about by prolonged exposure 

 to low temperature as because of the very slow temperature fall. 

 If this be true, a freeze following a thaw in winter should result in 

 greater injury than if there were no thaw, even if the temperature 

 during the thaw does not go high enough to cause growth. This 

 seems to be the experience of growers in the North. Letters from 

 men in Connecticut, New Hampshire, and the peach regions of Can- 

 ada state that with them killing of the buds generally occurs when 

 the cold period follows a thaw. It would hardly seem possible that 

 weather warm enough to start growth would be experienced in those 

 sections. It would seem more probable that the killing results from 



