Carnation Diseases 219 



Diseases of the Carnation 



White Tip 



Cause, gas injury. 



Symptoms. The trouble appears as a white or 

 creamy coloring of the unrolled tender tips of the 

 foliage (fig. 46, a). Occasionally, the white spots 

 appear across the leaves a short distance below the 

 tips. The cause of the injury is believed by Clin- 

 ton* to be due to gas rather than to spray injury. 

 The trouble may be brought about by the fumes of 

 sulphur or tobacco used as an insecticide or fungi- 

 cide. The injury affects the tip because of the ten- 

 derness of the tissue there. The Enchantress is par- 

 ticularly susceptible to it. The secret of its suc- 

 cessful control lies in the care exercised during fumi- 

 gation. 



Sleep 



Cause, gas injury. 



Growers in the vicinity of large manufacturing 

 plants are often troubled with what is called sleep 

 of carnation. This trouble is especially common in 

 cities where gas is used for illumination. The 

 symptom of sleep is a closing inward of the petals 

 (opened corolla). Once a blossom goes to sleep it 

 never opens again. The investigations by Crocker 

 and Knight t have shown that at least one cause of 

 sleep in carnation is due to traces of illuminating 



•Clinton, G. P., Conn. Agr. Expt. Sta., Thirty-ninth Ann. Rept.: 



428-439, 1915- 

 t Crocker, W., and Knight, L., Bot Gaz. 56:259-276, 1908. 



