48 The Horticulturist's Rule-Book. 



Grape (Downy Mildew), continued. 



leaves, finally causing yellowish discoloration on the upper 

 surface. It also causes a rot of the fruit. The berries 

 remain small and firm, usually not wrinkled, and become 

 brown in color. The disease is worst on thin and smooth 

 leaved varieties, as the Delaware and others. It extends 

 generally throughout the Union. Of American origin. 



Preventive. A wide board nailed flatwise on the top of 

 the trellises so as to somewhat protect the vines, as with a 

 roof, is a considerable protection, as it tends to keep the 

 vines dry. Vines trained against a building rarely suffer. 



Remedies. Spray with Bordeaux mixture every week or 

 ten days from the time the leaves appear until late in July. 

 Eau celeste may be used. 



POWDERY MILDEW (Uncinula spiralis, B. & C.). Appears 

 early in the season as delicate dust-like patches or 

 covering on the leaves, mostly on the upper surface, and 

 on shoots and fruits. Berries attacked by it become 

 checked in growth, and may remain small and die, or 

 they sometimes grow and crack before death ensues. 

 It attacks grapes in vineries which are not properly venti- 

 lated and managed. Occurs generally throughout the 

 Union, but is less destructive than the downy mildew 

 American origin. 



Remedy. Dry sulphur applied to the vines, two or 

 three times once when the shoots just begin to push 

 again when in blossom, and usually again shortly before 

 the grapes begin to turn. Apply :n warm and bright 

 weather, after the dew is off. In vineries, the sulphur 

 may be scattered on the hot pipes. 



Hollyhock. RUST {Puccinia Malvacearum, Mont.). Ap- 

 pears upon leaves of hollyhocks and a few related plants 

 in small, light brown patches. Introduced from Europe, 

 and not yet common in this country. 



Remedies. Destroying the plants is the only general 

 method yet known to prevent the spread of the disease 

 but some of the fungicides should be tried. 



