284 PLANT PROPAGATION 



ficial by the American Association of Nurserymen, pre- 

 supposes that all grades of trees shall be of fair shape, 

 branched, and well rooted ; that caliper measurements 

 shall be taken two inches above the crown or the bud ; 

 that some exceptions may be made on such varieties as 

 are known to the trade to be light growers (for instance, 

 Yellow Transparent and Duchess apples, Seckel pears, 

 English Morello cherries, etc.), or due to weather condi- 

 tions which may affect tree growth, but that such excep- 

 tions shall be noted in the printed price list or the corre- 

 spondence of the grower's sales. 



STANDARDIZATION OF GRADES 



381. In packing plants for shipment, care must be taken 

 to prevent drying out, heating, freezing and breakage 

 during transit. For economy's sake, packages should be 

 light and strong and the packing material light, cheap and 

 respectively retentive of moisture or capable of resisting 

 wet for plants which demand one or the other. For mail 

 shipments, the most popular materials include sphagnum 

 or chaff, oiled or paraffined paper, express paper, stout 

 twine, pot and tree labels, shipping tags, cardboard, cor- 



