1910.] PUBLIC DOCUMENT — No. 31. 53 



is necessary to get it all out of the soil before planting, and the 

 honse must remain idle some days. One gallon of the solution 

 of the strength given above to each square foot has been recom- 

 mended. 



The dry rot, caused by Fusarium, is more difficult to handle, 

 and the methods employed for the control of the wet rot appear 

 to be of little use for this disease. Fusarium rots in general 

 have increased during the last decade. In the case of carnations 

 this is due possibly to the more extensive forcing common in 

 recent years. Too extensive forcing, too close planting and 

 shading have a tendency to weaken the stem, and undoubtedly 

 render it more susceptible to attacks from fungi. On the other 

 hand, low temperatures and exposure to the light harden the 

 plant tissue, rendering it less susceptible to disease. There are 

 authentic cases known where certain plants subject to stem rots, 

 when transplanted and raised out of the ground slightly, become 

 hardened and perfectly immune. 



Damping-off Fuxgi. 



There are two serious damping-off fungi which cause trouble 

 to the greenhouse grower by affecting seedlings and cuttings. 

 The damping fungus Boirytls is the most common, and affects 

 plants in a low state of vitality. The Botryiis propagates freely 

 by spores, and therefore does not yield to treatment by sterili- 

 zation. The most healthy plants will become affected with the 

 damping-off fungus if they remain in an abnormal condition for 

 brief periods, and if cuttings are kept too moist or too warm, 

 or lack sufficient light, they are likely to damp off. By paying- 

 close attention to cultural and sanitary conditions, damping-off 

 can almost always be prevented. 



Another damping-off fungus, known as Pythium deBaryamim, 

 often gives considerable trouble to cucumber, tobacco and other 

 seedlings when the conditions are not normal for their best 

 development. Even sudden changes in the condition of the 

 plant will cause the trouble. For example, when plants are 

 taken from hotbeds where they have been forced too freely, and 

 placed out of doors in damp, cold weather, they will damp off, 



