MISCELLANEOUS CROPS. 155 



plants with soft soap and water, or even with pure water, 

 as a remedy for these mites. Washing the plants with 

 ' sulphur-water ' is also an effectual remedy." 



The Hop Mildew (Podosphcera castagnei). This 

 fungus attacks the hops of England, France, Germany, 

 Austria, Belgium, Holland, and the United States. It 

 " frequently destroys the crop of hops entirely in some 

 grounds ; and this is often accomplished with wonderful 

 celerity. A few mildewed cones may be noticed in a 

 plantation ; and before the crop is ripe, or can be picked, 

 the whole may be reduced to mere blackened lumps of 

 rubbish by the work of the fungus." P. castagnei belongs 

 to the group Ascomycetes,^ and De Bary {Vergleichende 

 Morphologie und Biologie der Pilze) refers it to the 

 division ErysiphecR. Therefore it is closely allied to the 

 pea mildew {Erysiplie Martii) described in chapter ii., 

 and has a somewhat similar life-history. 



Prevention. — (1) Destroy dandelion, groundsel, daisy, 

 and other weeds belonging to the Compositoe, as Podo- 

 sphcera lives upon these plants, as well as upon hops. (2) 

 " Hop bines from infested plants should be burnt, in order 

 to destroy the resting-spores upon them." (3) Mr. White- 

 head recommends dressing the land with quicklime or 

 soot after an attack of mildew. (4) Avoid plantiug " sets " 

 from mUdewed plantations ; but if infection is suspected, 

 the " sets " should be dipped in a solution of iron sulphate 

 (2 per cent, solution). 



Cure. — (1) A solution of iron sulphate has been used 

 in France ^ as a remedy for the vine-disease caused by 

 Oidium Tuckeri (the vine mildew). As the vine mildew 



' The spores are in an ascas. 



^ Bulletin de la Societe Agronomique (Gironde), 1888. 



