453 



DISINFECTION OF RUBBER SEEDS. 



The question of the possibiHty of introduction of the spores or 

 mycelium of the various fungi attacking Para rubber on the seeds of 

 the rubber tree has been the subject of much discussion at the 

 Chambre d'Agriculture de La Cochin Chine at Saigon, and the sub- 

 ject of disinfection by chemicals discussed. 



The smooth seed of the Para rubber, I do not think, could retain 

 spores, but should there be any fragment of soil attached to them 

 spores could be carried, the subsequent washing or soaking in water 

 that seeds should receive on arrival from some distance to faciHtate 

 their germination should however remove any possible risk. 



M. Morange thinks that there is always a risk in seeds picked up 

 and not disinfected, and as to mycelium he urges that if seeds of Para 

 rubber are piled in a heap and left they go mouldy and this mould is 

 a mycelium growing on the seeds. 



Para rubber seends, if left in a pile, become heated very quickly, 

 in fact commence a chemical decomposition, the polished surface of 

 the seed is rapidly destroyed and the thin outer layers broken up so 

 that the mould can then attack the seed. But it is not assumed that 

 rotten seed is imported and carefully planted by a rational planter. 

 Would a planter sow a Hevea seed covered with the very conspicuous 

 mycelium of Fomes} and should a fragment of mycelium of Fames be 

 buried with the seed what are the chances of its being planted in 

 actual contact with dying shrub or tree on which it could continue to 

 develop.'* Besides, even supposing the seed had not been exposed to 

 the light and heat of the sun which in a few minutes would certainly 

 kill the mycelium, the chances of survival of the mycelium threads 

 are very small indeed. 



A fungus to establish itself requires a good deal more than im- 

 portation of one or two spores, or a scrap of mycelium. It requires 

 to be brought and put in such a position that it can actually then and 

 there continue its growth luxuriantly, the actual chance of this in 

 most cases is extremely small, otherwise we should utterly fail to 

 keep out any fungus that happened to be suited for growth on any 

 particular crop. 



Fungus spores can be borne by the wind to any distance and 

 doubtless are, but wide as the distribution of these air-borne cellular 

 plants is, many quite fail to effect a settlement in many places. 

 Nothing that man can do can prevent this method of invasion. What 

 we can do is to prevent infected, that is diseased plants, from being 

 brought in and planted among healthy ones of the same kind. 



Fames semitastus is not yet recorded for Cochin China, but the 

 mycology of that country is quite unknown at present, and it may be 

 there all the while. However the agriculturists of Cochin China are 

 taking care not to let it or any other fungus-pest be imported which 

 is prudent. For this object the importation of Hevea-plants is 



