566 



Missouri Agricultural Report. 



It is somewhat more difRciilt to suggest a satisfactory treat- 

 ment for apple blotch than for apple scab, owing to the fact that 

 as yet lime-sulphur solution has not proven to be a satisfactory 

 preventive. Bordeaux mixture will very effectually control the 

 blotch, but its use involves the liability of injury to the fruit. 



BITTER ROT. 



This is perhaps the most sporadic disease that has ever in- 

 vaded the apple orchards of Missouri. Occasionally the entire 

 crop of an orchard is destroyed in the course of a very few days. 

 Its ravages are confined largely to the more southern counties of 

 the State. It is rarely observed as far north as the counties border- 

 ing on the Missouri river. Fortunately serious outbreaks occur 



only occasionally and then 

 usually only on certain 

 varieties and in certain 

 localities. There has 

 been perhaps but one or 

 two really serious general 

 outbreaks of this trouble 

 during the history of com- 

 mercial apple growing in, 

 Missouri. The disease 

 occurs on the fruit, also 

 on the twigs, in the form 

 of small cankers. It 

 passes the winter either 

 in the mummied fruit or 

 in the small cankers on 

 twigs from which it spreads the following season. The infections 

 begin to take place in late June and extend on into September. 

 Damp, sultry, cloudy and hot weather furnish the conditions favor- 

 able to its development. With the beginning of the cool days and 

 nights in the fall infections usually cease. 



This disease may be controlled by either lime-sulphur or 

 Bordeaux mixture, although the Bordeaux mixture is more effec- 

 tive and is generally to be preferred to lime-sulphur, as it is less 

 likely to cause serious foliage injury which may result from mak- 

 ing repeated applications during the intensely hot summer weather. 

 On the other hand, under our climatic conditions, Bordeaux mixture 

 frequently interferes materially with the development of color and 



Bitter rot. 



