44 Diseases of Greenhouse Crops 



ment. With lettuce seed, for instance, there is a 

 higher per cent, of germination usually obtained in 

 the sterilized soil. With tomatoes, however, ger- 

 mination is retarded under similar soil treatment. 

 On the average, germination is favored by soil ster- 

 ilization. This is well shown in Table 2.* 



Table 2 



Kind 



of 

 Seed 



Total 

 Number 



of 

 Seed 

 Tested 



NU7 



Germin 



Steril- 

 ized 

 Soil 



nber 

 ated in 



Unsteril- 

 ited 



Soil 



Per 

 Cent. 

 Gain 



or 

 Loss 







6oo 



159 



81 



41 







6oo 



93 



no 



13 



Cucumber 





6oo 



281 



187 



33 







6oo 



26 



10 



61 







6oo 



37 



33 



10 







400 



48 



31 



35 



Mustard. . 





400 



84 



33 



61 







400 



105 



37 



64 







200 



57 



33 



43 







200 



87 



26 



70 



Effect of Soil Sterilization on Plants. That soil 

 sterilization is practicable cannot be doubted. With 

 some crops, the beneficial effect is especially marked. 

 The Massachusetts Experiment Station t found a 

 considerable increase in the production of violet 

 blossoms as a result of soil sterilization. This is 

 well shown in Table 3. 



♦From the Massachusetts Agr. Expt. Sta., 15th Rept.: 40-42, 1903. 

 t Massachusetts Agr, Expt. Sta., 12th Ann. Rept.: 165-167, 1900. 



