224 



sulphur dust is effective. Perhaps a potassium sulfide spray (3 

 ounces to 10 gallons of water) is more effective. Application of 

 the fungicide should be started by mid-summer and repeated every 

 ten days or two weeks. 



Lilac Stem Rot. — Large old stems of lilacs are frequently covered 

 with the fruiting bodies of one of the higher fungi, Polyporus 

 versicolor. The fungus grows in the wood, producing decay, and 

 ultimately forming bracket-like fruiting bodies on the exterior. 

 Probably the lungus follows injuries due to borers or other cause's, 

 and is more of a saprophyte than a parasite. Thorough pruning 

 out ot the weakened stems is the effective procedure. 



Lilac Graft Blight. — This term has been applied to a disease of 

 lilacs, which frequently show a yellowing and rolling of the leaves; 

 in later stages the branches stop growing and ultimately die. The 

 exact cause is not definitely known; the evidence scons to be that 

 it is associated with the method of lilac propagation. Experiments 

 indicate that graiting or budding on understocks of species of 

 Ligustrum may result in the trouble. If this is true, the remedy 

 would appear to be the employment of methods of propagation in 

 which the lilac varieties are developed on their own roots. 



