PHYSIOLOGICAL DISEASES 183 



a physiological disease. It is induced by 

 the excessive use of fertilizers. The fol- 

 lowing facts from the letter of a grower 

 who wrestled with this trouble will help to 

 confirm the belief in the physiological 

 nature of this disease: "The seeds were 

 sown November 1 in pots and planted De- 

 cember 15 in the beds in the greenhouse. 

 Previous to the planting, the beds were 

 well manured with horse manure, which 

 was applied six months before planting. 

 Besides this, wood ashes were also applied 

 at the rate of 1,500 lb. to 4,500 square feet 

 of bed space. This would be equivalent 

 to nearly seven and one-half tons per acre. 

 About one month after planting, some of 

 the plants turned yellow and died ; others 

 remained dwarfed and offered a languid 

 appearance." Upon examining some of 

 the plants, they were found to be dwarfed 

 and to have a sickly yellowish look. The 



