n6 



been found that with the peach, the winter rest period of the fruit 

 buds is an important factor in influencing the amount of killing from 

 cold. By the rest period is meant the period during which the buds 

 will not respond in growth to favorable temperature conditions with- 

 out special treatment. This rest period is shorter with some varie- 

 ties than with others, and with all varieties tried at this station the 

 rest period is prolonged later into the winter if the tree makes a vig- 

 orous growth and continues growing rather late in the season. They 

 will not, therefore, respond so readily to warm periods that may 

 come in late December or January. 



Winter Protection of Buds. The buds of trees in winter are 

 covered with bud scales. Some hold that the insulation formed 

 by these scales will keep the buds from reaching a temperature as 

 low as that of the surrounding air. Wiegand 1 however, found that 

 when a thermometer bulb was carefully inserted in large buds there 

 was no great difference between the rapidity of the fall of tempera- 

 ture on such a thermometer and one with a naked bulb. He, there- 

 fore, holds that the bud scales offer little protection in the way of 

 holding heat in the buds, but that their protection is against evapora- 

 tion. To test this matter at this station the scales were removed 

 from buds of peaches in winter before freezing in the freezer pre- 

 viously described with the results shown in Table 38. 



•Bot. Gaz. Vol. 41, pp. 373-424. (Bibl. No. 117). 



