494 Forestry Quarterly. 



of the seedlings ; the cover is a necessary protection against 

 excessive transpiration. 



The author combats the idea that the use of heat in securing 

 the seed from the cones predisposes them to the disease. As re- 

 gards influence of the locaHty from which the seed is derived on 

 the susceptibility of the plants to the disease the author comes to 

 somewhat different conclusions from Prof. Mayr (see p. 301 of 

 this volume), especially, he denies that there are immune races; 

 simply more or less predisposition to the disease can be claimed. 



The practical results of the careful work are summarized as 

 follows : 



1. For choice of plant material, the best homegrown seed of 

 high germination per cent, should be relied upon. 



2. Infection takes place mainly from middle of July to end of 

 September. 



3. The spores develop on old as well as young needles, but the 

 heaviest infection is found in young plantations, the least -in 

 vigorous mixed growth. 



4. The infection may be either at a distance (by flying spores 

 uniformly over large areas) or in proximity (by contact in close 

 plantations). 



5. To avoid infection, seedbeds should be located away from 

 infected places. 



6. To avoid infection by contact, sowing and transplants 

 should not be placed side by side; only the healthiest most 

 vigorous material should be transplanted ; the poor material 

 should not be left lying, but be burned or buried. In the 

 forest dense sowings are to be avoided, or planting substituted 

 for sowing. 



7. It is desirable to make plantations so that they will rapidly 

 grow out of the danger period and close up, avoiding the necessity 

 of planting up fail places, such plantings being especially liable 

 to infection and propagating it. Hence good soil preparation, 

 the use of the best seed or plants from good soil help to secure 

 immunity. 



8. Spraying when the first apothecia open may be necessary 

 every year, especially when plantations are still quite young and 

 on the most endangered places, if thorough work cannot be done 

 on all. 



Drr Schiittepilz dcr Kiefer. Zeitschrift fiir Forst- u. Jagdwesen. April, 

 May, June, 1911, pp. 329-357, 402-423- 481-505. 



