PLANT-DISEASES. 53 



Bemedies. — Spray with ammoniacal carbonate of cop- 

 per, or modified eau celeste (ammonia is added before 

 sal-soda) . 

 Apple. Blight. — The same disease as pear-blight, which see. 

 Brown-Rot. — See under Cherry. 



Powdery-Mildew (Podosphcera Oxycanthce, DeBary), — At- 

 tacks nursery stocks, covering leaves with a grayish and 

 powdery meal-like mildew. 



Bemedies. — Bordeaux mixture, or ammoniacal car- 

 bonate of copper, applied four or five times. 

 RiPE-RoT or BiTTER-RoT (Gloeospoi'ium fructigenum, 

 Berk.). — A rot which attacks ripe apples and grapes. It 

 attacks the fruit before it is picked, usually, although it 

 may not become apparent until it is stored. Many of the 

 culls in packed fruit are due to this fungus. 



Bemedies. — Spray the fruit late in the season (begin- 

 ning early in August) with ammoniacal carbonate of 

 copper, or potassium sulphide (\ ounce to gallon of water). 

 Rust (Species of Boestelici). — Bright yellow rust appearing 

 on the young leaves and fruit, causing the whole tree to 

 become enfeebled. It is now known that one stage of this 

 fungus is the "cedar-apple" which grows on red cedars 

 and junipers, where it is known as Gymnosporangium. 

 Several species have been described. Also attacks quince. 



Preventive. — Destroy the cedars or keep them free from 

 the "apples." Destroy hawthorns and escaped apples, 

 which are liable to be infested. Some varieties of apples 

 appear to be more susceptible to injury than others. 



Bemedy. — Spray early with Bordeaux mixture, as for 

 apple-scab. 

 Scab (Fusicladium dendriticum, Fckl.). — Olive green, brown 

 or blackish sooty and scab-like spots on the leaves and 

 fruit, arresting growth and causing the parts to become 

 distorted, and often causing the very young fruit to fall. 

 Very common. When bad, the foliage looks brown and 

 dry. 



Bemedies. — Spray with sulphate of copper while the trees 



