290 



THE GARDENER'S ASSISTANT. 



bunches, stopping those retained at the first 

 leaf beyond the bunch. Keep the air rather 

 dry when the plants are in flower, and fertilize 

 with a camel-hair pencil. Reduce the number 



Fig. 1071.— Fruiting Pot Vine. 



of bunches as soon as the fruit is set and swell- 

 ing, and then start thinning. 



The number of bunches to leave on each 

 Vine must be governed by its strength. As a 



Fig. 1072.— o, Mildew of Grapes; b, Oidium Tuckeri with conidia germinating (x 200), 



rule six bunches are sufficient, and on the 

 strongest canes the number should never ex- 

 ceed eight. By this time the roots will require 

 plenty of moisture and rich food, both liquid 

 and solid, applying the latter in the form of 

 top-dressings. In all other respects the cultural 

 treatment is the same as that recommended for 

 Vines in borders. A good example of a single 



pot-grown specimen in fruit is shown at fig. 

 1071. 



Diseases. — Grown under favourable circum- 

 stances, the Vine is not particularly subject to 

 disease. Mildew (Oidium Tuckeri, fig. 1072) 

 was at one time very prevalent, and its first 

 appearance in England was reported by Mr. 

 Tucker of Margate about 1847. It has since 

 proved very destructive both in vineries and in 

 the open air not only in this country but in 

 France, Germany, Italy, and the Greek Archi- 

 pelago, where, in some seasons, the crops have 

 been almost destroyed by it. The mildew 

 appears to the naked eye like a white powder, 

 but seen under the microscope it consists .of a 

 net-work of white branching filaments, from 

 which others, either resembling a club or neck- 

 lace in shape, arise, almost in a perpendicular 

 direction; and by the spores and utricles of 

 these the fungus is rapidly propagated. 



When the disease becomes visible to the 

 naked eye there is no effectual remedy. If 

 allowed to vegetate for the short space of three 

 days on berries, it renders them incapable of 

 a natural distension, but the pulp and seeds 

 continue to increase in bulk, and the conse- 

 quence is that the berry cracks, so that the 

 seeds are exposed. This being the case, pre- 

 vention should be aimed at by the cultivator. 

 The chief cause of mildew in vineries is a too 

 low temperature, accompanied by a damp, 

 stagnant atmosphere. In vineries which 

 are liable to attacks of this disease, the 

 hot-water pipes should be kept warmed, 

 and air admitted whenever it is safe to 

 do so, damping down only when it is 

 absolutely necessary. 



The most effectual agent for the de- 

 struction of mildew is sulphur, and this 

 is best applied with a pair of Malbec 

 Bellows, and the leaves and branches 

 should be well dusted completely over 

 with it, and washed off with a copious 

 syringing of clean soft water as soon as 

 it is seen the fungus has been killed. 

 Sulphur may also be advantageously 

 applied in the form of a vapour. This 

 is best done by heating the pipes to such 

 a degree that the hand can hardly be held on 

 them. Then take some flowers of sulphur, add 

 enough water to make a thick paste, and smear 

 the hot-water pipes with it. Allow the heat to 

 continue for an hour, and then shut it off. This 

 may be done three evenings in succession. 



By the liberal use of sulphur in one year 

 there is little danger of an attack in the follow- 



