17 



fall off, and the seeds are clearly seen under the skin which be- 

 come drawn and ridged. 



Treatment — Bordeaux mixture should be used, first before the 

 buds open, a second time when the leaves are one-third grown, a 

 third time just before flowering, a fourth time two weeks later. 

 The fifth application two weeks later should be the ammoniacal 

 copper carbonate solution, and a sixth application of the same may 

 be necessary. If the weather is dry, the number of sprayings may 

 be less. 



DOWNY MILDEW, BROWN ROT. 

 (Peronospora viticola, De Bary.) 



Description — Although this downy mildew, attacks all parts of 

 the vine, the chief mischief is when the leaves are diseased, as 

 then not only the present, but next year's crop is in danger. 



The leaf first turns lighter green where diseased, then yellow, 

 and lastly brown, while if the under surface is examined when 

 the upper has begun to turn yellow, it will be found to be covered 

 with minute threads growing out from the substance of the leaf. 



The grapes are usually attacked before they are half-grown, 

 first turning brown (brown rot), and afterwards grayish (downy 

 mildew). 



Treatment — If the downy mildew is feared the shoots should be 

 first sprayed with Bordeaux mixture when they are only from six 

 to ten inches long, and afterwards on flowering and at intervals 

 of from 2 to 4 weeks. 



POWDERY MILDEW. 



(Uncinula spiralis, B. & C.) 



Description — This fungus spreads only on the outside surface of 

 the vine though it sends suckers into the cells immediately below, 

 feeding on their contents and changing the green colour into 

 brown. The fungus itself is of a grayish white colour, and easily 

 rubs off the leaf, shoot, or grape, when the destruction of the 

 green colour is very noticeable. It is generally found on the 

 upper surface of the leaves, which distinguishes it from the 

 Downy Mildew. It develops best during dry weather. 



Treatment — As this is only a surface fungus, not penetrating be- 

 yond the outer cells, it is not so dangerous as those previously 

 mentioned, and the vines do not require treatment for it, until it 

 has actually made its appearance. 



Sulphur is applied either dry or mixed with water, but this 

 remedy is not considered so valuable as spraying with carbonate 

 of copper dissolved in ammonia. 



EUROPEAN MILDEW. 

 (Oidium Tuckeri, Berkl.) 

 Description— This mildew resembles the Powdery Mildew in 



