JAPAN LILY DISEASE 57 



JAPAN LILY DISEASE 

 (Rhizopus necans, Massee.) 



During recent years a destructive wave of fungous disease 

 almost completely ruined the crop of lily bulbs (Lilium 

 speciosum, and L. auratum) raised in Japan for exportation 

 to Europe. 



The bulb is the part attacked, which in the earliest con- 

 dition shows a slight discoloration at the base when cut 

 open. The disease extends rapidly, the entire bulb 

 becoming discoloured, and finally soft and rotten. 

 Numerous experiments proved the disease to be caused 

 by a parasitic fungus called Rhizopus necans. This fungus 

 can live as a saprophyte on the humus in the soil, and 

 attacks the bulbs when lifted. It is a wound-parasite, 

 and usually obtains access to the bulb through broken 

 roots. 



Diseased bulbs that have become rotten show a white 

 weft of mycelium, from which numerous clusters of fruit 

 resembling miniature pins with black heads stand erect; 

 these are the conidial or summer fruit of the fungus. 

 Resting-spores are produced in the tissues of the decayed 

 bulb. 



PREVENTIVE MEANS. In most cases inoculation takes 

 place when the bulbs are taken up for exportation. If 

 submerged in a one per cent, solution of salicylic acid for 

 twenty minutes, and afterwards thoroughly dried, the 

 spores of the fungus are destroyed. The bulbs should be 

 thoroughly dry before packing, otherwise if there is the 

 least tendency to 'sweating,' and there happens to be any 

 diseased bulbs present, the disease spreads rapidly. The 

 fungus is presumably abundant as a saprophyte in the soil 



