190 



Bulletin 252. 



Scab. 



Fig. 162. Alfalfa leaf -spot. 



APPLE. 



Commonly known among growers as " the fungus." Usually 

 most evident on the fruit. Spray with Bordeaux 5--5"50 o^ 

 3-3-50; first, just before the blossoms open; second, just as 



the blossoms fall; third, 10 to 14 days after 



the hlossoms fall. The second spraying 



seems to be the most important. Spray 



thoroughly. For the use of insect poisons 



with Bordeaux mixture, see codling- moth 



and BUD-MOTH. See also Cornell Bulle- 

 tins 84 and 226. (Fig. 163.) 



This is the same as Pear 

 Fire-blight, blight. It usually makes 

 itself manifest on the ap- 

 ple trees in three forms, blossom blight, 



twig blight, and blight cankers on limbs and 



body (Fig. 164). This disease is caused by 



bacteria which are distributed by bees and 



flies and is not controlled by spraying. Cut- 

 ting out and destroying the diseased parts 



are the chief measures to be taken. Cut out 



blighted twigs in young trees as fast as they appear. The bacteria of this disease 



are carried over winter in cankers on the main limbs and bodies of the trees. 



Remove all sucli cankers with sharp knife cutting well into the healthy bark and 



wash the wound with corrosive sublimate, i part 



to loco of water. Then paint the wound with 



heavy lead oil paint. See Cornell Bulletin, 236. 



Destroy or clean up all old pear and apple tree's 



about the premises because such trees harbor 



the disease. 



This important fungous dis- 

 ease should not be confused 

 with the "blight canker." 

 Cankers arc usually found on 

 the main limbs of old trees, 



black and rough (Fig. 165). Canker is very 



common on Twenty Ounce. Since the fungus 



enters through wounds, avoid breaking the bark. 



All wounds made in pruning should be promptly 



painted over. Cut out cankers and treat as for 



"blight cankers." Spray early in spring before 



the buds start with Bordeaux, 10-10-50, or soak the body and the limbs when 



making first application for scab. See Geneva Bulletins 163 and 185. 



ASPARAGUS. 



The most common and destructive disease of asparagus rust 



Rust. produces reddish or black pustules on the stems and branches. 



Late in the fall, burn all affected plants. Fertilize liberally and 



cultivate thoroughly. During the cutting season, permit no plants to mature and 



New York 



apple-tree 



canker. 



Fig. 163. Apple-scab. 



