COPPEE SULPHATE (BLUE VITEIOL). 225 



blue vitriol solution of 0*5 per cent, and they recommend the disinfec- 

 tion of the buds of the vine against black rot by total or partial 

 immersion in a 1 per cent solution for one hour. Their experiments 

 succeeded perfectly, and proved also that the steeping of the buds for 

 an hour in 1 per cent, 5 per cent, and even 10 per cent solutions of 

 blue vitriol, did not lower their vitality ; the lower section seems as if 

 it could no longer form a cushion to remedy this drawback : it suffices 

 to cut I of an inch below the buds before transplanting them. 



Gloeosporium ampelophagum, Sacc. (grape rot). — Sorauer recom- 

 mends blue vitriol in place of green vitriol to combat this fungus in 

 winter. Instead of coating the stock with a 50 per cent solution of 

 green vitriol a 20 per cent solution of blue vitriol is used. This 

 practice is excellent, but more costly than Slavinsky's. 



Gloeosjiorium nervisequum, Sacc. (disease of the leaves of the 

 plane-tree). — Nobele recommends, to prevent this disease, to spray 

 with a 3 per cent solution of blue vitriol in the month of April and in 

 the month of May before the tree is in leaf. 



Fusicladiuvi pirimmi, Fuckel (pear scab) ; Fusicladium dentri- 

 ticiim, Fuckel (apple scab). — These diseases may be combated by 

 spraying with blue vitriol solutions. By judicious spraying at the 

 right moment the conidia formed on the cushion of the conidiophores 

 of the leaf are destroyed, and prevented from planting themselves 

 on the fruits. Oliver found that the spores were destroyed by blue 

 vitriol. Used on large scale in 0-5 per cent solution by Goff, he 

 greatly diminished these diseases. Mohr recommends a 3 per cent 

 solution for the same purpose. These sprayings should be done 

 before spring, in the month of April. Blue vitriol has not such a 

 radical action as bouillie bordelaise. The latter may, if used before 

 the expansion of the buds, completely prevent these diseases. 



Morthiera Mespili, Fuckel ; Entomospiorium macidakmi, Lev. (lea£ 

 scald). — This disease of the leaves of the pear may be prevented,, 

 according to Mohr, by spraying with a 3 per cent solution of blue vitriol 

 before the formation of the leaf in April and May. 



Disease of the Popipy (oeillet). — Mangin advises to prevent this 

 disease to steep the buds in a 0"l-2 per cent solution of blue vitriol 

 before transplanting. 



Beet Diseases. — To prevent these diseases, transmitted by spores 

 infecting the seed, disinfect the seed with blue vitriol, which gives good 

 results against — 



Pleospora putrefaciens, Franck (rot of the heart of the beet) and 

 Phoma tahifica, Prill, et Dell. {Phoma Betce, Franck), (disease of the 

 leaf-stalk of the beet). — Carlson advises washing the seed in a 1-2 

 per cent solution of blue vitriol. Linhart advises steeping for twenty- 

 four hours in a 2 per cent solution ; although this diminishes the 

 germination of the seed a little, yet Franck recommends it. It also re- 

 moves the larvae of Agriotes lineatus, Hypomyces 7nag7i2is (mole disease 

 of the mushroom). It requires three to seven days' steeping in a 

 2 per cent blue vitriol solution to kill the spores. This disease is not 

 cu'cumscribed by this salt. 



Black Disease of the Clematis. — To prevent this disease produced 

 15 



