20 



N. H. AGR. EXPERIMENT STATION. 



[Bulletin 157 



effective for leaf spot. Sprayings made at various times in 

 the summer have had little or no effect upon the number of spots 

 of rot on the fruit at picking time. The destruction of the 

 affected fruit seems to be the most efficient treatment for this 

 form of disease. All cankered limbs should be cut out and 

 l)urned. Large wounds should be protected by a covering of 

 paint. Thoro spraying is of value in protecting the limbs. 

 Heavy a])plications made when the trees are in a dormant 

 condition are probably especially efficacious. (See page 32.) 



Fig. 24. — Unsprayed tree defoliated by Leaf Spot. 



BITTER ROT OF THE APPLE. 



Glomerella riifomaculans (Berk.) Spauld & Von Sch. 



The bitter rot fungus produces cankers on the limbs as well 

 as a rot on the fruit. The rot develops much earlier in the year 

 than the black rot, and the adjacent tissue of the apple has a 

 bitter taste. In the South and the Central West the bitter rot 

 is the most destructive apple disease. It is of very rare occur- 

 rence in New Hampshire, and it is probable that the climatic 

 conditions will prevent it from ever becoming serious here. 



