26 CRANBERRY DISEASES. 



experiments were made with Bordeaux mixture only. In the spray- 

 ing work of 1904 -'' the resuhs showed an average of 21.7 j^er cent of 

 diseased fruit on the sprayed plats, while on the unsprayed check 

 plat there was an average of 76. 8 per cent diseased. The circum- 

 stances under which this was done were such, however, that the appli- 

 cations could not be made at proper intervals. During the next 

 season (1905 -'') the work was done more thoroughly and the results 

 were far more satisfactory. As a result of five applications the 

 sprayed plats averaged 2.36 per cent of rotten berries, while the un- 

 sprayed check plats averaged 92.6 per cent of rotten fruit. The 

 6-6-50 formula for Bordeaux mixture was used and 4 poimds of 

 resin-fishoil soap were added. It was found that the plain Bordeaux 

 mixture did not spread properly over the surface of the fruit and 

 foliage, and also did not adhere well. In order to correct these 

 defects the soap was added and was found to give most satisfactory 

 results. The cost of spraying as done in these experiments averaged 

 from $15 to $20 per acre, the mixture being applied at the rate of 

 4 barrels, or 200 gallons, at each application. Success in preventing 

 this disease by spraying depends largely upon the care and thorough- 

 ness with which the ]3reparation is made and applied. In our last 

 experiments the 5-5-50 formula was used, and w^th thorough work 

 it has been found to give as satisfactory results as the 6-6-50 mixture. 



ROT. 



The term " rot " is here applied to a decay of the cranberry caused 

 by a fungus which we have recently described as a new genus and 

 species {Acanthorhyiichvs raccinii Shear).-* The appearance of the 

 fruit attacked by this disease is not sufficiently peculiar or character- 

 istic to satisfactorily distinguish it from scald or anthracnose by its 

 external or internal appearance. The rot first appears as a small, 

 light-colored, soft spot on the berry, finally softening and destroying 

 the whole fruit. In the later stages of its development it very fre- 

 quently produces small, dark-colored blotches on the inner surface 

 of the skin. So far as has been observed, the fungus never produces 

 spore-bearing fructifications upon the berries. The only wa}^ in 

 which this disease can be positively diagnosed is by making a culture 

 from the mycelium of the fungus taken from the interior of the 

 affected fruit. 



The disease attacks the leaves also, but the fungus js very rarely 

 found in a fruiting condition except on those which have fallen to 

 the ground. Judging from the frequency with which this fungus 

 appears in cultures made by transplanting the fungous hyphse from 

 decaying berries, the injury caused by it is second only to that pro- 

 duced by the scald. Though this disease is most frequent and destruc- 

 Jio 



