THE JHAWAIIAN 



rOR£8T£R I AGRICULTURIST 



Vol. IV AUGUST, 1907 No. 8 



REPORT ON THE GERMINATION OF THE SEEDS OF 



RUBBER PRODUCING PLANT. 



By N. A. Cobb. 



Recently a number of instances of failure in the germina- 

 tion of rubber seeds have been called to my attention. These 

 failures occurred in connection with plantations in various 

 parts of the Islands. In some cases the seed was derived 

 from foreign sources, in others the seed was grown in Ha- 

 waii. 



In one case seed obtained from Brazil gave germination 

 results at 33 per cent. The seed appeared to be sound when 

 opening and examining the cotyledons. These latter were 

 white and were not in the least discolored. When the seeds 

 were filed and placed in germination chambers, it swelled and 

 for the most part appeared to make a proper start, that 

 is, the point of the plumule appeared at the end of the seed. 

 Soon, however, the plumule and the ends of the cotyledons 

 next to it acquired a yellowish color and later on a fungus 

 appeared, described by the manager as a mildew. At the time 

 these seeds were received at my laboratory, a whitish colr)r 

 was apparent on the outside of the seed where it had been 

 filed and covering most of the germination end of the seed. 

 An examination of this m}xelium showed that it had not yet 

 formed spores. On being placed in the Petri dish with moist, 

 sterilized blotting paper, the fungus fructified and proved to be 

 Mucor iniicedo, one of the most common moulds. This would 

 indicate that the trouble was not one inherent in the seed, but 

 one that had been introduced by the treatment. In moisc con- 

 ditions the seed may have been subjected to what would tend 

 to bring about infestation by this almost omnipresent fungus. 

 It may be that if the seeds were filed less it would be better 

 as I observed that it is for the most part on the disclosed 

 cotyledon that the fungus starts. If the mucor alone is to 

 be blamed, then the difficulty is one that can be overcome 

 by the observation of sterile conditions. Horse manure is 

 particularly liable to growths of Mucor mucedo. When placed 

 in a moist, warm place, horse manure almost always gives 

 rise to a rich growth of this fungus. 



