CHAPTER IV. 



Plant-Diseases: 



WITH PREVENTIVES AND REMEDIES. 



Apple. Blight. — Tlie same disease as pear-bligM, which see. 

 Brown-Rot.— See under Cherry. 



Powdery Mildew {Podosplicera oxycanthce, DeBary). — Attacks 

 nursery stocks, covering leaves with a grayish and powdery 

 meal-like mildew. 



Remedy. — Ammoniacal carbonate of copper, applied four or 

 five times. 

 RiPE-RoT OR Bitter-Rot. {Glocosporium friictigenum. Berk.). — 

 A rot which attacks ripe apples and gi'apes. 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. 



Remedies.— Spray the fruit late in the season (beginning 

 early in August) with ammoniacal carbonate of copper, or 

 potassium sulphide (}4 ounce to gallon of water) . 

 Rust (species of Rocstelia) . — 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. 



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. 



Remedy. — Spray early with ammoniacal carbonate of cop- 

 per, 



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