HEART-ROT IN CONIFERS. 37 



4. Heart-Rot in Conifers. 



By Mark L. Anderson. 



In a previous article, which was published in a recent issue 

 of the Transactions} I drew attention to the widespread 

 occurrence of heart-rot among plantations of coniferous trees 

 throughout the country. There can be no doubt that root 

 diseases, caused by fungi, rank amongst the most serious of 

 all the enemies of the forest. It is surprising, therefore, that 

 so little attention is given to such diseases, while others of 

 much less significance are recognised as worthy of special 

 inquiry and treatment. 



There may be two main reasons for negligence in respect 

 of heart-rot. In the first place, the damage caused begins 

 below the ground surface and occurs within the stems. It 

 is, therefore, not apparent until the stems either die or happen 

 to be cut over. Fellings in young plantations are not frequent, 

 while, in the past, thinnings have generally been light or 

 moderate. The greater number of stems removed have 

 usually been either dead, dying, or suppressed. In consequence, 

 any appearance of heart-rot, especially where the fellings were 

 carried out with axes, may have been overlooked, or, where 

 observed, the disease would be liable to be considered as the 

 direct result of the weakening of the stems and not as a 

 contributing factor — possibly the main factor — toward the 

 deterioration of these stems. 



Secondly, while the serious state of affairs may have been 

 noted, the impossibility of applying curative or preventive 

 measures in stands, once established, may have been recognised. 

 A "do-nothing" policy has, therefore, been adopted. There can 

 be no doubt, so far as our experience goes, that heart-rot is one 

 of those ills against which preventive measures are the best, 

 if not the only ones to be taken. These measures must be 

 considered before the plantation is actually established. 



The problem, therefore, with regard to these root diseases 

 is two-fold ; first, to rouse interest in the serious nature and 

 wide occurrence of these diseases, and, secondly, to investigate 

 and discover the best measures to be adopted to combat and 

 eradicate them. 



^ See vol. XXXV. p. 112, 



