THE DAMPING-OFF FUNGI. 85 



is shown in Fig. 29, page 87), which is one of the most 

 serious of all greenhouse pests, he will remove the soil, 

 paint the benches with lye or kerosene, and thereafter use 

 only soil which has been very thoroughly frozen since a 

 crop was grown in it (a proceeding which is practically 

 impossible in solid beds). 



damping-off is here reprinted because the disorder is a very common 

 and serious one, although it is not particularly germane to the subject 

 of the forcing of vegetables : 



" In the treatment of this trouble, especial attention must be given 

 to the environment of the plants and those conditions which favor the 

 rapid development of the parasites. These conditions are known in 

 most cases to be high temperature accompanied by a large moisture 

 content of the soil, humid atmosphere, insufficient light, and close 

 apartments, and soil which has become thoroughly infested with the 

 fungi by the development of the disease in plants growing in the same. 

 Some excellent notes on the treatment of the disease by gardeners and 

 horticulturists are given in the American Garden for 1890, by Meehan, 

 Massey, Maynard, Watson, Lonsdale, Gardiner, and Bailey, and a 

 short description of the potting-bed fungus (Artotrogus Debaryanus) 

 by Seymour. The principal lines of treatment suggested there from the 

 practical experience of the writers are as follows : 



" When cuttings are badly diseased, they should be taken out, the 

 soil removed, benches cleaned and fresh sand introduced, when only 

 the sound cuttings should be reset. For cuttings is recommended a 

 fairly cool house, and confined air should be avoided in all cases. As 

 much sunlight as possible should be given as the plants will stand 

 without wilting. When close atmosphere is necessary, guard against too 

 much moisture, and keep an even temperature. The soil should be 

 kept as free as possible from decaying vegetable matter. This is a 

 very important matter, for several of the most troublesome of the para- 

 sites grow readily on such decaying vegetable matter, and in many 

 cases obtain such vigorous growth that they can readily attack a per- 

 fectly healthy plant which could resist the fungus if the vegetable 

 matter had not been there to give it such a start. Soil which is dry 

 beneath and wet on top, as results from insufficient watering by a 

 sprinkler, favors the disease more than uniformity of moisture through- 

 out the soil. 



" In seed beds, use fresh sandy soil free from decaying matter. 

 Avoid over-watering, especially in dull weather, shade in the middle 

 part of the day only, and keep temperature as low as the plants will 

 stand. 



" If the seedlings are badly diseased it will be wise to discard 

 em and start the bed anew. In the ear! 

 frequently be saved by loosening the soi 



them and start the bed anew. In the early stages, however, they can 

 Dil to dry it, and placing the 

 pots in "sunny places "at such times as they will not wilt. Some 



advocate sprinkling sulphur on the soil, and in some cases sulphur 

 at the rate of i to 30 is mixed in the soil before sowing, with 

 good effect. When the beds are badly infested, Humphrey (Kept. 

 Mass. State Agr. Exp. Sta. 1890) advocates the entire removal of the 

 soil, whitewashing the beds, and the introduction of fresh soil. 



" In houses heated by steam if it were possible to have, without 

 too great expense, a steam chest, where the pots and seed pans 

 which are used could be placed and the soil thoroughly steamed for 



