Fruits and Culture. * 381 



posed an hour, double the time usually allowed. A peach tree fumigated 

 April 26, '99, with 0.25 gramme for one hour, showed no injury. I 

 found, however, that when 0.45 gramme per cubic foot was used, nearly 

 double the ordinary amount and exposed one hour, first grade peach was 

 slightly injured on the terminal growth. The injury, however, was so 

 very slight that it was not considered harmful to the tree. When about 

 three times the normal charge was used, exposed one hour, I found the 

 trees were more or less seriously injurd. Under no circumstances have 

 I recommended this gas stronger than 0.25 gramme per cubic foot. It 

 is not necessary to use it stronger than this on any grade of stock, and 

 there need be no fear of injury, if the proper precaution is taken. 



Similar tests were made also upon apple and I found that even where 

 six times the normal was used, well-matured apple trees were not injured 

 at all. Plum was not injured until nearly three times the normal was 

 used, while pear stood from three to four times the usual dose. All ex- 

 posures were for one hour April 26, '99, and the trees were set out care- 

 fully the same day. They were watchd and cared for during the sum- 

 mer. 



June buds and low-grade peach, known usually as whips, were quite 

 seriously injured when exposed with the 0.25 gramme for one hour. I 

 reduced the cyanide to 0.18 gramme, with which amount I found no re- 

 sulting injury. It is now a well known fact that any wood not well ma- 

 tured will not withstand a heavy charge of this gas. I recommend 

 its use for June buds, peaph, plum and cherry stock of low grade 

 from 0.16 to 0.18 gramme per cubic foot, exposed one-half hour and 

 no longer. In previous experiments I found that the scale under 

 ordinary circumstances is destroyed when fumigated with 0.12 to 

 0.14 gramme, therefore the 0.16 to 0.18 formula given can be used 

 with perfect safety. 



Some nurserymen do not care to fumigate buds, grafts and scions 

 with the strong formulas. I suggest that the same amount recommended 

 for the June buds be used for stock of this kind. Any box can be made 

 perfectly tight by papering and painting it. An ordinary box can be con- 

 verted into a gas chamber very easily. I do not recommend the use of 

 very small boxes, as it is difficult to estimate and handle the exceedingly 

 small amounts of chemicals necessary to generate gas in an inclosure of 

 less than 15 cubic feet. A box amout 4 feet square and i^ to 2 feet 

 deep can be used to good advantage. The gas can be easily handled in a 

 box of this size by the average grower. 



It is not necessary to fumigate such plants as cedar, pine, etc. I do 



