1904.] 



Powdery Mildew of the Vine. 



497 



In some parts of the Continent it is the practice to plant fruit 



trees in suitable positions along the roadside in place of the 



ornamental or forest trees more usually 



Roadside employed. The subject was discussed 

 Planting- of , T . _ 



Fruit Trees. at tne international Congress on Arbori- 

 culture of 1900, and a resolution was 

 passed to the effect that in view of the injury which is caused 

 to adjoining lands by the presence along the roads of large 

 trees with their far-reaching roots, the planting of fruit trees 

 in their place should be encouraged. In France, during the 

 past fifteen years, pear and apple trees have been planted in 

 places along the national roads, and in 1901 it was stated that 

 there were half a million fruit trees planted along French roads. 

 As an example, it may be mentioned that in the Department of 

 l'Oise a distance of 182 j miles has been planted with 57,795 

 trees, the total length suitable for fruit trees being 257I miles. 

 The cost of planting and purchasing the trees is about the same 

 as that of ornamental trees, and the sale of the fruit yields 

 a small annual return. Apart, however, from the return, it is 

 contended that the fruit tree serves equally well for shade, 

 that its appearance when in flower is picturesque, while it 

 serves the subsidiary purpose of interesting the population in 

 the growth of fruit. The employment of the less edible varieties 

 of fruit is recommended, and the cider apple is, perhaps, the most 

 commonly used. The practice prevails also in parts of Ger- 

 many. In Hanover there were in 190 1 189,586 trees planted on 

 the roadside by the Provincial Government, which produced a 

 revenue of £8,386, although a considerable proportion ot the 

 trees were not in full bearing. 



Powdery mildew of the vine is a destructive disease caused by 



a minute parasitic fungus — Uncinula spiralis. The conidial stage 



of this fundus has been known in this 

 Powdery Mildew . 0 , . , - , 



of the Vine country since 1845, when it was described 



by the Rev. M. J. Berkeley under the name 

 Oidhim tuckeri. It is probably a native of the United States, 

 where it is common on both wild and cultivated vines. 



The vines should be sprayed with a solution made by dis- 

 solving one ounce of potassium sulphide in three gallons of 



S S 



