APPLE DISEASES 



445 



fungus should now be Xeofabraea mali- 

 corticis (Cordley). 



9. The conidial stage has been found 

 commonly causing a rot of the fruit of 

 the apple and the quince, both in the 

 orchard and in storage. 



10. Both the conidial and ascosporic 

 stages have been found in nature on the 

 pear. Cankers have been produced on 

 this host by inoculation with the coni- 

 dial stage of the fungus isolated from 

 the apple. 



11. Cankers have also been produced 

 by Inoculation with the fungus isolated 



_ from the apple, on peach, prune and 

 cherry branches, but no spores have 

 been observed to be matured in these 

 cankers. The occurrence of such cankers 

 in nature has not been proved. 



12. No evidence has been secured 

 that new cankers are formed by the 

 spread of the fungus in the tissues from 

 old cankers. The fungus has, however, 

 been isolated from the heart wood be- 

 neath cankers on branches of the apple, 

 two years after the maturation of the 

 conidial stage. The extent and impor- 

 ance of the fungus as a heart rot has, 

 however, not been investigated thor- 

 oughly. 



Reeommeudntions 



1. Where orchards are only slightly 

 affected with anthracnose, or where it 

 is considered advisable to spray as a 

 matter of general orchard practice, grow- 

 ers are advised to spray once each year 

 in the fall as soon as possible after the 

 fruit is picked, using Bordeaux mixture 

 6-6-50, or try in a part of the orchard 

 the use of the combination spray of 

 Bordeaux mixture 4-4-50 and arsenate of 

 lead, two pounds to 50 gallons, in the 

 last codling moth spray as suggested 

 above. 



2. In orchards where the disease is 

 on the increase and it is desired to 

 make a special effort to prevent any 

 further spread, growers should spray 

 twice with Bordeaux mixture, 6-6-50, 

 after the fruit is picked. The two 

 applications should be about two or 

 three weeks apart. If desired one appli 

 cation may be made before the fruit is 



picked, using Bordeaux 4-4-50 and the 

 other after the fruit is picked, using 

 Bordeaux 6-6-50. 



3. Where the disease is abundant and 

 is seriously interfering with the growth 

 and productiveness of the orchard and 

 it Is desired to clean up the disease in 

 the shortest time possible, then it is ad- 

 vised to spray at least once before the 

 fruit is picked with Bordeaux mixture, 

 4-4-50. This application should be made 

 about the middle of September or before 

 the first fall rains. If desired the com- 

 bination spray suggested under (1) 

 above may be used instead of the appli- 

 cation in the middle of September. In 

 addition, such an orchard should be 

 sprayed twice with Bordeaux after the 

 fruit is picked, using the 6-6-50 formula, 

 as recommended in (2) above. 



4. Growers who desire to spray be- 

 fore the fruit is picked but who object 

 to the Bordeaux at that time should try 

 the ammoniacal solution of copper car- 

 bonate, or some other copper compound 

 which does not leave a deposit upon 

 the fruit. It should be pointed out. how- 

 ever, that the efficiency of these sprays, 

 as a control of apple tree anthracnose 

 has not been thoroughly demonstrated. 



5. It is advisable, where possible, to 

 prune out all the more seriously infected 

 branches before the spraying is done. 

 The spraying is more important, how- 

 ever, and should be given the prefer- 

 ence. The pruning may follow the spray- 

 ing, especially if the work is done as 

 soon as possible afterwards. All affected 

 branches which are cut out should be 

 immediately removed from the orchard 

 and burned, since they would be a source 

 of infection if allowed to remain on the 

 ground. 



6. In so far as it is practical it 

 would be advisable whenever cankers 

 are formed, to clean out the dead bark, 

 and where the wounds are large to pro- 

 tect the exposed wood with grafting wax 

 or paint. It has been shown that bark 

 in cankers may be a source of infection 

 for at least three years. The removal 

 of the dead bark is further advisable, 

 since, if allowed to remain, it offers pro- 



