TOMATO LEAF-MOLD 



21 



Table 12. Control of Tomato Leaf-Mold witli Vaporized Sulfur. Waltham. 



Fall Crop 1926. 



Date 



September 20 

 October 1 . . . 

 October 10. . 

 December 20. 

 January 11.. 

 January 29 . . 



Total... 



SuLFUKED House No. 3 



Leaflets 

 Counted 



529 

 585 

 553 

 428 

 1130 

 1027 



4252 



Leaflets 

 Diseased 



per cent 

 5.2 

 1.6 

 0.7 

 17 .5 

 U.6 



Check House No. 7 



Leaflets 

 Counted 



396 

 1368 

 2259 

 1096 

 1433 

 1081 



7G33 



Leaflets 

 Diseased 



per cent 

 9.5 

 2.4 

 23.1 

 75.1 

 66.3 

 27.1 



33.0 



Spring Crop at Melrose WS7. Three houses were employed in the experi- 

 ment, two of which were treated with vaporized sulfur (Table 13). The 

 houses were set in the middle of February. Six stoves were used in No. 2 

 house and eight in No. 3 house. The stoves were operated sixteen times in 

 No. 2 house beginning March 2 and ending June 24; and fifteen times in No. 

 3 house beginning March 7 and ending June 30. At these intervals electricity 

 was used for periods of one to two and one-half hours, a total of 24V2 

 hours for No. 2 house and 26% hours for No. 3 house for the season. All 

 three houses were grown under the same conditions. The houses were cleaned 

 out the last week of July. 



Table 13. Control of Tomato Leaf-Mold with Vaporized Sulfur. 

 Spring Crop 1927. 



Melrose. 



Fall Crop at Melrose J927. Four houses were treated with vaporized sulfur 

 and one house was left untreated. No leaf counts were made, but frequent 

 observations during the growth of the vines showed that vaporized sulfur 

 furnished almost perfect control of infection. Leaf-mold was hard to find. 

 In the untreated greenhouse the disease was epidemic and as a result the 

 yield was poor and of second grade. 



