594 ANNUAL REPORT OF THE Off. Doc. 



of the fi-nit. The spots here are larger and less dofinilely bounded 

 than Fruit Spot, are more sunken, suggesting finger print bruises; 

 the deadened tissue usually extends deeply into the flesh and is rather 

 dry and spongy, and there may be discolored areas as well toward 

 the interior of the flesh. It cannot be controlled by spraying, and 

 the only suggestion that can be made is to practice a system of culti- 

 vation that will tend to equalize soil moisture conditions as much 

 as may be. 



Two other diseases that can be controlled by midsummer spray- 

 ing are Bitter Rot and Blotch, both of which, fortunately, are as 

 yet of rare occurence in Pennsylvania. But we must be on the 

 alert, lest they gain a foothold unnoticed. Both require midsummer 

 or later spray applications, and for them, Bordeaux mixture gives 

 decidedly better results than lime-suli)hur preparations, and should 

 by all means be used where these diseases are to be combated. 



There are several Bipe Eots of fruit* that midsummer spraying 

 tends to check, although control of insects and care in handling are 

 of prime importance in their prevention. There is good evidence 

 that the keeping quality of apples is increased by spray treatment in 

 midsummer. 



Several fungous diseases of limbs, twigs or trunk, such as Twig 

 Bligut and Blight Canker, Black Rot Canker, Collar Rot and Root 

 Rot, cannot be directly controlled by spraying, although the use 

 of these disinfecting materials, or other stronger ones, may be help- 

 ful. The most important thing for these is to watch closely and 

 recognize the trouble early; to remove the affected parts promptly 

 and thoroughly so that they may not spread farther on the same tree 

 or to other trees; and to protect all wounds made in the operation 

 against possibilities of later infection by swabbing them with a good 

 disinfectant, such as 1 to 1,000 corrosive sublimate, and painting the 

 larger ones with asphaltum or pure lead and raw oil paint. Large 

 and valuable limbs may be lost from infection that has extended 

 down a watersprout or fruit spur, when early removal of these last 

 would have prevented the loss. 



Last year 1 spoke to this Association about the trouble known 

 as Apple Collar Rot. Continued attention has been given since then 

 to the question of its causation and cure. I have seen cases of this 

 sort of general trouble that could apparently be attributed to such 

 causes as freezing, improper use of paint on trunks, borer attack, 

 attack by the Blight bacterium, by the Black Rot fungus, by the 

 Amillaria Root Rot fungus, and by the Schizophyllum Wood Rot 

 fungus; but when all is said, there remain a majority of cases for 

 which I have not yet been able to satisfactorily account. This work 

 will be continued until we do reach some conclusion in the matter. 

 Meanwhile, I am more than ever srrre that these cases of Collar Rot 

 require prompt and careful individual attention at an early stage, 

 in the way of cutting away affected bark to a clean-cut, living edge, 

 disinfecting the wound .irh r-orrosive sublirriate or other good dis- 

 infectant, painting Avith asphaltum or coal tar or paint, and in 

 severe cases covering the denuded area with a sheet of grafting wax 

 to prevent drying and promote healing. Tlie affected trees should, 

 be pruned to reduce leafage, and they should not be allowed to carry 

 a full crop of fruit for a year or two, while the root-system is re- 



