RECENT ADVANCEMENT IN IlUliTlCLT/rUUE. 145 



Mr. ^^Mlliams : In the iiuitter of spraying to prevent in- 

 jury from very lute frosts, 1 don't understand wlietlier tliat 

 benefit was occasioned Ijy tlie spraying tliat spring or season, 

 or does the tree become hardier, or does the spraying of it 

 that season cause it to resist the freezing weather? 



Prof. ^N'hitten : ]>oth are true. 1 think more directly, 

 the first spring spraying you give it just before the blossoms 

 open is more beneficial than when they are in bloom because 

 it keeps the fungus from growing in the flowers at that time; 

 on the other hand, spraying on through the season makes 

 the foliage better and it stays on the trees later in the autumn 

 and makes them hardier. You will find that a tree has more 

 nourishment held in solution when it holds its leaves well on 

 into the winter. T think you can see that if a tree sheds its 

 leaves earlier it can not store up plant food. You get, so to 

 speak, a thicker cell sap. Clear water freezes quickly, but 

 a little salt will check it. The more a tree takes on of the 

 cell sap the greater cold it can withstand. That freezing 

 (effect injures these cells in the early spring and the earlier 

 the tree sheds its leaves the less will be its capacity to with- 

 stand the cold. If you go to making laboratory experiments 

 to show the difference between spraying and not spraying 

 trees you will find it is related to the time just preceding the 

 opening of the blossoms. And by holding the leaves on the 

 trees late in the season, stronger buds are developed. Last 

 winter the Alberta peaches had been pruned back enough 

 to make them grow more luxuriously and in giving them better 

 care through the season to keep them in growth up to autumn 

 they stood 13 degrees more cold than those that shed their 

 leaves earlier. In some degree that is true of the apples. 

 They will also stand more cold if they are in a vigorous grow- 

 ing condition late and still ripen for winter. Professor 

 Anderson has made some experiments to enable him to state 

 how late he could keep the leaves on the trees, and he found 

 that by- keeping the leaves healthy during the summer that 

 they would stand a long rough bad winter better. 



