464 INSECTS AFFECTING VEGETATION 



of 70 pounds is essential, and one of 100 pounds or over is very de- 

 sirable. 



In looking for a solution of the problem various kinds and 

 strengths of Bordeaux have been tested. While weaker solutions 

 may produce less injury, they do not obviate the trouble. The use 

 of an excess of lime has had little or no effect upon the amount of 

 injury. The 3-3-50 formula seems to produce as little injury as 

 any, and is most satisfactory for the majority of apple diseases. The 

 patent Bordeauxs which are on the market have not been shown to 

 be any less liable to produce injury than the home-made mixtures, 

 and many of them have proven quite inefficient in controlling dis- 

 eases. (N. H. E. S. B. 144.) 



Other Apple Diseases. Brown Kot (See page 476) ; Pear 

 Blight (See page 464) ; Texas Koot-Rot (See page 602). 



QUINCE DISEASES. 



Anthracnose. The fruits and possibly the branches of quince 

 are attacked by an anthracnose fungus (Glomerella rufoma- 

 culans) which is the same as that causing bitter-rot in apple. Ac- 

 cording to our knowledge of the survival of this fungus, attention 

 must be given to gathering and burning of mummy fruits and to 

 the cankers produced, if any, upon the branches. The spraying 

 treatment necessary is the same as that for apple bitter-rot. 



Black-Rot. The fruit and foliage of the quince are at- 

 tacked by black-rot. The black-rot multiplies very rapidly in the 

 fruit of quince and often causes loss of much of that produced. This 

 fungus (Sphaeropsis malorum) also develops as a leaf-spot upon the 

 foliage causing defoliation. It is liable to attack the branches after 

 the manner determined for apple. To hold this fungus in check 

 very careful spraying is required at times, but as a rule it is easier 

 to keep down the black-rot on fruit and foliage of quince than to 

 keep it down on susceptible apples. The spray used is Bordeaux 

 mixture. 



Leaf-Spot. This is identical with that upon pear, and is 

 found at times formed upon the quince. It is controlled by the 

 same treatment as the black-rot. 



Blight. The blight upon quince (Bacillus amylovorus) is 

 slightly less destructive than that upon pear. It is caused by the 

 same bacterium and requires the same watchful care and attention as 

 in the case of pear. 



Pale-Rot. This (Phoma cydonise) is reported from some 

 of our states and may occur in Ohio. There is no evidence to indi- 

 cate that it will require more prolonged treatment than black-rot or 

 leaf-spot. (Col. E. S. B. 218.) 



Other Quince Diseases. Cankers (See pages 453-455 and 

 459) ; Bitter Rot (See Apple) ; Rust (See pages 453-455 and 

 459). 



PEAR DISEASES. 



Pear Blight. The disease usually attracts most attention 

 in the spring about three weeks or so after the blossoming period, 

 when many of the flower clusters shrivel and die and the infected 



