DAMPING-OFF. 



SOME GOOD OPINIONS AND PRACTICE CONCERNING THE MALADY. 



ing-off. 



AMPING-OFF is a common 

 and often serious injury to 

 young plants under glass, 

 either in houses or hot-beds. 

 It appears to be a variable 

 difficulty, and there are many 

 opinions concerning it. In 

 fact, all are not agreed as to 

 the proper definition for damp. 

 The following letters, from good observers, 

 give some of the various observations and practices 

 concerning it : 



From Thomas Meehan, Gciinanto-ii>n , Pa. — Damp- 

 ing-off is a term usually restricted to cuttings or seed- 

 lings just potted. In all cases it is applied to the sudden 

 rotting of the structure near the ground. I suppose no 

 intelligent gardener ever questioned the statement that 

 it is caused by a minute silk-like fungus, the scientific 

 name of which is not material here, which destroys as 

 it grows. The usual remedy with watchful propagators 

 is to take out the cuttings as soon as the fungus growth 

 is first detected, and change the soil or sand before re- 

 setting them. The fungus seldom appears in a new cut 

 ting bench — possibly from the spores or mycelium not 

 having found a home in it. We have been careful to 

 have fresh clean sand, and clean benches, and hence 

 have little trouble from fungus. Possibly sulphur — the 

 good gardener's panacea against mildew — scattered over 

 the surface, would be useful, or probably the new rem- 

 edy, copperas water, which proves an admirable fungi- 

 cide. No one plant is more liable to damp-off than 

 another, so far as my experience goes. 



From Professor W. F. Massey, Raleigh, N. C. — 

 Damping-off is the sudden collapse of the tissues of a 

 seedling or cutting in contact with the soil or sand. 

 The cause, so far as my present knowledge goes, is es- 

 sentially the same in both the cases of seedlings and 

 cuttings. My idea is that the watering of the soil or 

 sand encourages a growth of minute algse on the surface 

 which furnishes food for the rapid spread of the my- 

 celium of minute fungoid parasites, which are destruc- 

 tive to all organized tissues in their path. The minute 

 hyphae form a water-proof coating over the surface and 

 the seedlings perish not only from the fungus but from 

 drought and want of air. It troubles most in a close 

 atmosphere with high temperature and strong bottom 

 heat. 



The best preventions are abundant ventilation and 

 ^voidance of a high temperature overhead in the propa- 

 gating house. When seedlings or cuttings begin to 



damp-oft the best remedy is to clean up and transfer 

 the sound ones to fresh soil or sand. In a propagating 

 ho use for cuttings, no wood should enter into the con- 

 struction of the cutting bench. Make the bottom of 

 slate and the sides of brick and cement. Seed pans of 

 earthenware are better than wooden flats for sowing 

 seeds. The whole subject needs careful study, and I 

 hope ere long to be able to give more e.xact information. 



From Professor S. T. Maynard, Amlu-rst, Mass. 



Damping-off, as understood by the practical gardener, 

 is that rapid decay of cuttings and tender or soft-tissued 

 plants which takes place in a night or a few hours, and 

 is accompanied by a webby or downy fungus growth on 

 the outside of the parts of the plants. As understood 

 by the botanist, it is the rapid development of a para- 

 siticTfungus growth which, under favorable conditions, 

 quickly destroys the tissues of the host plant. The 

 cause may be traced largely to the conditions of moisture 

 and heat surrounding the plants, either under glass or 

 in the field. A very moist, close atmosphere, with a too 

 high temperature, is sure to bring on the damping. It 

 is most^troublesome in the cutting-bed, where a very moist 

 condition must be maintained, but under the same con- 

 ditions of moisture and heat, plants often damp-off 

 when growing in pots or even in the open field. Cut- 

 tings of all kinds, coleus especially, after they have be- 

 come chilled, and lettuce, are most often injured by 

 damping off with us. 



Preventive measures are by far the most important 

 and satisfactory. (<?.) Water the cuttings in the morning 

 only, (b,') Keep the temperature as low at night as is 

 permissible for the kind of plants grown, (r.) If the bed 

 or soil in pots become too wet, expose to the sun's rays 

 in the latter part of the afternoon. (</.) The use of evap- 

 orated sulphur will large prevent the fungus growth, 

 but not wholly if the temperature is allowed to run very 

 high. This is used by melting or boiling sulphur in shal- 

 low kettles heated by a kerosene lamp or small -stove, 

 and should be used in the early part of the evening, for 

 two or three hours, twice or three times per week. 



From John Gardner, Jol>sto7i<i!, Pa. — In my opinion, 

 damping-off is a decay in plants caused by a fungus, 

 superinduced by atmospheric conditions, as, for instance, 

 a warm and moist atmosphere. Such an atmosphere, 

 of 70°, will cause damping-off in forced beans. In 

 cuttings, damping-off is the decay of the lower end of 

 the leaf-stalk. This is particularly marked in the case 

 of cuttings of indoor grapes. If cuttings are made of 

 wood from which the leaf-fall has not been natural, a 

 portion of the leaf-stalk adheres to the cutting, and the 

 moisture of the bed causes it to decay. If the house is 



