374 



STATE BOARD OF AGRICULTURE. 



WHERE THE FUNGUS COMES FROM EACH YEAR. 



The fungus lives over wiuter on the trnsh from diseased plants. Nearly 

 all samples of celery seed carry the fungus. The old seed hull is carried 

 above the ground by the growing leaves, and spores from diseased seeds 

 wash to the young leaflets. In this way some plants in the seed bed 

 may have diseased spots and carry the fungus to the field. A fcAV heart 

 leaves may be infected by splashings of rain from the trash of last year's 

 crop. 



Fig. 4. Celery seed showing fruiting bodies of the fungus; seed at left, healthy. 

 now THE DISEASE SPREADS IN THE FIELD. 



The spores from these diseased plants are splashed by rain down to 

 (he heart leaves and to neighl)oring plants and thus a "nest" of the dis- 

 ease arises. Ciillirdlioii. ir/tcn ilic plants arc wet icill spread the dis- 

 ease aJoiKj the roir. The spores are not killed by several days drying, so 

 that when spread (hey may remain alive until (he leaves are wet again. 

 A heavy dew that is sIoav drying, may keep the plants wet long enough 

 to allow the spores to sprout and get into the celery leaves. Fields that 

 are sheltered from the wiml, or poorly drained, or with rows extremely 

 close, invariably sutler most from this disease. Any voiidition that keeps 

 the plants from dnjing qnickli/ or causes tJic soil to slay wet long favors 

 the leaf spot. 



SEPTORIA LEAF SPOT AND THE WEATHER. 



Many growers believe that the weather causes this disease. If this 

 were true we conld not hope to do anything to fight the disease, since we 

 cannot control the weather. TJtc fact is, that without the fungus, no 

 matter what the weather, wc would not hare this disease. The proof 

 of this is simple. If Ave ])ut two healthy celery plants nnder wet condi- 

 tions and on one put some si)ores of this fungus, while the other is mere- 

 ly kept wet, 0}tli/ the plant icitli the spores becomes diseased. If wet 

 conditions caused the disease, both should become sick. Wet weather 

 makes this disease severe by allowing the spores to be spread over the 

 Held and by giving the right conditions for (he spores to sprout and bore 

 into the plant, "Weather does not cause this kind of a plant disease. 

 Growers must learn to get a crop iil spite of the weather. 



HOW TO FIGHT CELERY BLIGHT. 



Disinfect the seed 'before planting. SoaJc the seed % hour or longer hi 

 tcarm, but not hot^ water. Then soak I/2 hour in corrosive sublimate 1 



