-7- 



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IJBW LIGHT ON YflKTER INJURY ^X^^*^ 





Some very interesting studies of tree trunk temperatures during 

 winter are being made in Mse*W5, by means of thermocouples. On a particular 

 day when the air temperature was 32° F., thermocouples inserted in the cam- 

 bium of the south side of an apple tree, which was exposed to the direct 

 rays of the sun, revealed a temperature of from 60 to 64°. A similar 

 measurement in the cambium of the south side of a peach tree indicated a 

 temperature up to 83°, The cambium on the north side of the tree in no 

 case showed a temperature more than 10° higher than that of the air. These 

 measurements emphasize the tremendous absorption of heat by a dark colored 

 surface. And when we consider the wide range in temperature of the tis- 

 sues on the south side of a tree betv/een late afternoon and evening, after 

 the sun has set, it is easy to understand why sunscald, splitting of the 

 bark and other forms of winter injury sometimes occur. 



One of the larger dealers in farm supplies dis- 

 tributed 40 tons of epsom salts among Massachusetts 

 fanners last season, practically all of v/hich Viras used 

 in orchards as a means of correcting magnesium de- 

 ficiency. A report from Maine indicates the use of 

 33 tons of this material by fruit growers, for the 

 same purpose. 



FRUIT NOTES INDEX FOR 1944 



Apple Advertising. Jan. (6) 



Apple Buying Frogram. Dec. (6) 



Apple Maggot. June (2), July (1) (5) (8) 



Apple Scab. Jan (6), Mar. (9), Apr. (1), June (5) (7) 



Apple Varieties, Jan (1) (5), Apr. (8), Dec. (2) 



Bees, July (2) 



Bee Repellents. Apr. (5), May (8) 



Bitter Pit. Oct. (4) 



Blossom Thinning. Mar, .(2), Apr. (8), May (10), Jvine (7) 



Blueberries, Feb, (6) (7), Mar. (8), Apr, (9), July (1) 



Borax. May (3) 



Brush Fushers, Oct, (5) 



Bud Sports, Oct, (2) 



Codling Moth, July (8) 



Containers, May (9), Nov. (4) 



Controlled Atmosphere Storage. Apr. (6), May (4) 



Costs of Production. Apr. (6) (7) 



DN. June (7), Sept. (6) 



I^T. Dec. (6) 



Do You Know? Feb, (3), Mar. (3), Sept. (7), Nov. (5) 



Dusting. July (2) (7), Oct. (4), Dec. (5) 



