35 



fortunately has not caused any great general loss. It should be care- 

 fully watched, however, as, when once well established under favorable 

 conditions, its eradication is very difficult. 



Certain varieties, such as Diamond, Brighton, Agawani, and Salem, 

 are especially susceptible to this disease. 



Treatment. 



All diseased shoots should be cut and burned, as it is believed that 

 it is through these that the disease is chiefly transmitted each season. 

 Spraying with Bordeaux mixture, as rec- 

 ommended for black-rot, when accom- 

 panied by thorough cutting and burning 

 of diseased parts, is likely to prove suffi- 

 cient, except where the disease is unus- 

 ually severe, in which case the treatment 

 which has been adopted and found very 

 successful in Europe may be followed. 

 This consists of the application of the 

 following mixture: 



Sulphate of iron (copperas) . . . .pounds. . 110 



Sulphuric acid, commercial quart. . 1 



Hot water gallons. . 26 



First pour the acid upon the copj>eras 

 and then add the water. This mixture 

 should be prepared and handled with great 

 care, as it is exceedingly caustic and will 

 injure the skin, clothing, and almost 

 everything with which it comes in con- 

 tact. On this account it can not be ap- 

 plied with a common spray pump. A 

 swab, made by attaching a bundle of rags to a stick, may be used 

 in applying the mixture. All portions of "the vines should be thor- 

 oughly covered with this preparation just before the buds begin to 

 swell in the spring. 



RIPE -ROT. 



Ripe-rot (Glomerella rufo- 

 maculans (Berk.) Spauld. & 

 von Schrenk) has also been 

 called bitter-rot. The name 

 bitter-rot is, however, ap- 

 plied to another fungous dis- 

 ease of the grape, caused by 

 Melanconium fuligineum. As 

 the present name indicates, 

 the disease usually appears 

 on the fruit when the latter is 

 nearly mature, and under fa- 

 vorable conditions continues its development and destruction after 

 the grapes are picked. It also attacks the leaves and stems, but is 

 most noticeable and injurious on the fruit. The first indication of the 

 disease is the appearance of reddish-brown discolored spots (fig. 19), 



284 



Fig. 19.— Grapes attacked by the ripe- 

 rot (Glomerella rufomaculans) . 



Fig. 20.— The fungus producing ripe-rot (Glomerella 

 rufomaculans): a, Summer spores, showing the man- 

 ner in which tliey are borne; 6, the same spores, more 

 highly magnified; c, a sac containing winter spores. 



