Cranberry. 



279 



CRANBERRY. 

 FUNGOUS DISEASES. 



Gall Fungus ; Red Rust (Synchytrium Vaccinii, Thomas). 

 Description. The presence of this fungus in the cranberry 

 plant irritates the latter to such an extent that it forms the 

 excrescences or galls which have given the popular names to the 

 disease. These galls are of a red color, and in New Jersey 

 they generally appear upon the young stems, leaves, flowers, 

 and fruit, about the first of May. They are quite small, being 

 no larger than one twenty-fifth of an inch, both in length and 

 in thickness, but they are frequently so numerous that they 

 give to the plant or even to a bog a de- 

 cided red color. In such cases the 

 affected portions are frequently dwarfed 

 and misshapen. Some of the spores 

 seem to ripen during the winter or early 

 spring, and infection takes place during 

 the early growing months of the year. 



Treatment. It has been recommended 

 to burn affected parts ; and the sugges- 

 tion has also been made to keep the bog 

 dry during winter and spring. As the 

 disease apparently progresses by means 

 of new infections, as do most of the fungous diseases which are 

 under control, it seems reasonable to expect that application of 

 such fungicides as the Bordeaux mixture or the ammoniacal 

 carbonate of copper will prove beneficial if made as soon as 

 growth begins in the spring. It would probably be necessary 

 to make several such treatments, but the flowering time of the 

 plants should be avoided if possible. 



Scald ; Rot. Description. Scald of cranberries is produced 

 by a fungus which attacks the fruit during July and August 

 (Fig. 51). The first sign of the disease is the formation of a 

 small, soft spot upon one side of the berry ; or the disease may 

 appear in different places at the same time. This affected part 

 soon extends throughout the entire berry, giving the latter the 

 appearance of having been cooked. It is soft and of a light 

 brown color, but the skin remains unbroken. Later in the 

 season the berry shrivels and may fall to the ground or remain 



FIG. 51. Cranberry scald. 



