20 



FUMIGATION OF APPLES FOR SAN JOSE SCALE." 



ber 26, 1906, a few scales on one apple in No. 26 were regarded as 

 doubtfully dead, and hence were classed as alive; and upon the second 

 examination, December 14, six insects on one fruit and one on 

 another were also doubtful. 



In experiment No. 28 an iron screen "header" was used in the 

 lower end of the barrel, the top not being removed. This header, 

 devised by Mr. S. J. Dennis of Field Investigations in Pomology, as 

 shown in figure 3, consisted of a circular framework of strong iron 

 strips, somewhat smaller than the barrel head, to which was attached 

 a semicircular piece hinged along the middle, fitting over one-half of 

 the frame beneath, and firmly held by a locking device on the rim. 



Fig. 3.— Special barrel "header" for replacing lower barrel head in fumigating directly over discharge 



box. (Original.) 



The header, with screened surface turned inward, when pressed 

 in place fitted the head tightly and firmly held the apples in their 

 original positions, and permitted free access of the gas. This barrel 

 when fumigated had been one and one-half hours from cold storage 

 and the fruit was thoroughly wet from condensation of moisture, the 

 temperature of fruit being 1.5° C. On account of scarcity of scale 

 insects, only one examination was made, December 26, 1906, the 

 fruit examined being taken from the top, middle, and bottom of the 

 barrel. Of the 1,662 scales examined, one from an apple in the center 

 of the barrel was regarded as doubtfully dead. No injury to the fruit 

 was subsequently noted, despite the presence of the moisture. 



