30 Forestry Quarterly 



remedy will meet all of them. Since the fungi demand optimum 

 conditions of heat and moisture to develop, it would seem that 

 a control of the moisture -conditions would be most eflfective in 

 regulating the trouble, and this is the usual procedure. It is 

 commonly secured through the manipulation of the screens. 

 Besides using the charcoal, two other means of regulating the 

 moisture conditions have been tried. One is the use of sand as 

 a seed cover. A mixture of sand and compost, half and half, 

 proved most effective in preventing a caking of the surface soil, 

 but a larger percentage of sand seemed to help more in damage 

 prevention. However, it cannot be said that pure sand was an 

 absolute preventative, even though it was sterile. In most cases 

 the sand was an aid, but there were conspicuous exceptions, 

 especially on some beds in heavy clay. Another means tried was 

 a change in the method of watering the beds. It was observed 

 that in dry, hot weather, watering, even with the utmost care 

 as to time and amount, increased the liability of attack. A por- 

 tion of the nursery was so planned that it was made possible to 

 irrigate the paths. The water seeped in very rapidly from the 

 side and supplied the roots of the seedlings without wetting the 

 surface of the bed farther than by the water drawn up by capil- 

 larity. This was a very great aid in maintaining favorable con- 

 ditions at the surface of the bed. Incidentally, it forced out large 

 numbers of the white grubs which are so destructive. 



It is too early to give definite answers to the questions raised 

 in the use of commercial fertilizers. By the end of another 

 summer it is expected there will be a large amount of data at 

 hand by which the seedlings of charcoal and fertilized beds can 

 be compared. In the same soils, "damping-ofif" has been much 

 worse in the fertilizer beds. This is true whether in clay or char- 

 coal beds. Probably the fertilized seedling will have a little 

 advantage in weight, but even that is not certain. The greatest 

 advantage of the charcoal is that the effect is permanent. The 

 fertilizer must be constantly renewed. 



