38i 



STATE BOARD OF AGRICULTURE. 



leading to a one sided fruit wiiich sometimes crarks open exposing the seeds. The 

 diseased spots are dry and do not extend deejily into the fruit but somewhat 

 resemble the spots of apple scab in their nature. 



The spores are produced on the surface of the central portions of the dis- 

 eased spots. They may be disseminated by rain or currents of air and when 

 lodged on healthy berries in a drop of water soon give rise to the spots char- 

 acteristic of the disease. "While it is not definitely known as to how the fungus 

 passes the winter it is possible that the diseased portions of plants may be 

 the means by which this is effected. 



Fig. 32. — Grapes affected with anthracnose. 



Treatment. — Removal and burning of affected portions of the vine are to be 

 accompanied by spraying with some of the standard fungicides as for black 

 rot. Treating the vines during the winter with a solution of sulphate of iron 

 to which has been added a portion of sulphuric acid, is also recommended. 



RIPE ROT. 



(Glomerella rufomaculans) (See on apple.) 

 Grape diseases of uncommon occurrence in Michigan. 



Bitter rot (Melanronium fuUgineum (Scrib. & Vial.) Car.) has been noted 

 as occurring in some of the eastern states. It resembles in appearance and effects 

 the ripe rot fungus but imparts a very bitter taste to the diseased fruit. 



White rot (Coniotlujrium fliplodielki (Speg. ) Saoc.) has been found in Mis- 

 souri on young shoots and fruit of the grape. The latter assumes somewhat 

 the appearance of that affected with black rot except the color, which does 

 not darken. 



Root rot (Armillaria meUea (Wall".) Fr. and Dematophora necatrix Hartig.). 

 These two fungi which cause the rotting of the roots of the vine in Europe 

 have also been found, but to a less extent, in this country. The former is a 

 mushrooms of common occurrence in this state in woods and clearings or where 

 there is decaying wood in the soil. So far as the writer is aware it has not 

 been noticed in connection with the rotting of grape roots in this state. The 

 latter fungus is mold-like in its fruiting or spore stage. Both fungi form 

 root-like strands or cords of mycelium l)ut those of the latter fungus are light in 



