CHAPTER X 



DAYLIGHT FUMIGATION AND COST OF 

 APPLICATION 



N California experience has shown that the 

 citrus orchards can not be successfully fumi- 

 gated during the day. On the other hand, 

 in the East, in deciduous orchards, daylight 

 fumigation has been found most practicable. As a 

 rule, Eastern orchards are fumigated during the fall, 

 after growth is stopped and after the function of the 

 foliage has been performed. In such instances it mat- 

 ters little whether or not the foliage is injured by the 

 gas. In Fig. 44 will be seen a Japanese plum tree, one 

 of a block of 5,000, fumigated in October with the 0.20 

 gramme formula. While these trees were fumigated 

 in daylight, the foliage in this particular instance was 

 practically uninjured. In some cases where the fumi- 

 gators were left over the trees longer than thirty min- 

 utes, the foliage was somewhat seered, but no injury 

 resulted to the trees. By referring to Chapter III. it 

 will be seen that the physiological effect of this gas 

 varies with certain kinds of trees, and is influenced by 

 weather conditions and time of day. 



In the Eastern orchards the gas is best applied 

 during the daytime late in the fall or early spring, as 

 will best suit conditions and circumstances. In Fig. 

 84 



