PLANT-DISEASES. 71 



tation after the disease appears — is a most satisfactory 

 procedure. 



Remedies. — Spray before the buds swell with sulphate 

 of iron, and follow later with Bordeaux mixture or ammo- 

 niacal carbonate of copper. Spraying has never been very 

 successful with this disease, but frequent applications ought 

 to keep the fungus off. Burn all canes that are past re- 

 covery. 

 Red or Orange-Rust {Cceoma luminatum, Link).— Attacks 

 the under surface of the leaves of black and sometimes red 

 raspberries, and of blackberries, in patches of whitish yel- 

 low, but the fungus finally covers the whole under surface 

 with an orange-red coating. One form of the fungus is a 

 leaf-rust generally known as Puccmia Peckiana. 



Preventives. — Plant such varieties as are least susceptible 

 to attack. Among blackberries, Kittatinny is particularly 

 susceptible. Rotation. 



Remedy. — Burn the plants, roots and branch, as soon 

 as the disease appears. 

 Rose. Leaf-Blight or Black-Spot {Actinonema Boscb, Fries). 

 — Attacks the full-grown leaves, first appearing as small 

 black spots, but later covering nearly or quite the whole 

 surface with blotches. The spots have frayed edges. Com- 

 mon in outdoor and house culture. 



Remedies. — In the house, fumes of sulphur or copper 

 sprays. Outdoors, burn the affected leaves and spray with 

 Bordeaux mixture or ammoniacal carbonate of copper. 

 Spray before the leaves unfold. 

 Leaf-Spot (Cercospora roscecola, Pass.). — Black or reddish 

 black spots on the leaves, shading into red at the definite 

 edges. Later the centre of the spot becomes light brown 

 or gray. Attacks plants growing outdoors. 



Remedies. — Burn diseased parts. Spray with copper 



fungicides. 



]\[iLDEw (SjJhcerotheca pannosa, Lev.). — Whitish mildew 



attacking roses. It is brought on, according to Maynard, 



by exposure to drafts of extremely cold air when the 



