84 



PEACH LEAF CURL". ITS NATURE AND TREATMENT. 



action of the fungus at first, but were not sufficient!}^ active or per- 

 sistent to prevent its gradual increase upon the trees. An apparent 

 exception to this in the case of the sulphide of potassium appears to 

 arise from the fact that the disease was never greatlv checked by this 

 fungicide, the amount of healthy foliage being onl}" 3jJ per cent April 

 23. Another and more marked exception is seen in the trees sprayed 

 with lime and salt in solution. It is thought, however, that the true 

 explanation of this exception is that given in the preceding paragraph. 



What has been stated will be sufficient to indicate the comparative 

 value of the main classes of sprays used in these experiments. It is 

 shown that the highest degree of effectiveness in saving foliage is 

 possessed by the copper sprays, that the sulphur sprays also possess a 

 high degree of fungicidal activity, and that where Bordeaux mixture 

 is added to the sulphur sprays the effectiveness of the latter is some- 

 what increased. It is also made clear that sulphide of potassium, 

 sulphate of iron, and several other sprays, as tested, are of secondary 

 value in this work. It should be noted that the average saving- 

 obtained from the use of the sulphui- sprays is sufficiently high to well 

 warrant the use of these sprays, either in coml)ination with Bordeaux 

 mixture or alone, in cases where it is desired to use a spray having 

 both fungicidal and insecticidal qualities. 



It will now be advantageous to briefly consider the leading indi- 

 vidual sprays composing the classes of sprays already discussed, in 

 respect to their action on peach foliage and peach leaf curl. The fol- 

 lowing table gives a compact presentation of the number and nature 

 of these sprays, as well as their action in controlling curl: 



Table S. — Nature and composnlion of sprays applied. 



1 

 3 

 6 



7 

 9 



10 

 16 

 57 

 12 

 51 



36 

 18 

 19 



15 



Sulphur, lime, and salt : 



15 lbs. sulphur. 30 lbs. lime, 10 lbs. salt 



10 lbs. sulphur, 20 lbs. lime, 5 lbs. salt 



5 lbs. sulphur, 10 lbs. lime, 3 lbs. salt 



Sulphur and lime : 



15 lbs. sulphur, 30 lbs. lime 



10 lbs. sulphur, 20 lbs. lime 



10 lbs. sulphur, 8 lbs. lime 



6 lbs. sulphur, 4 'bs. lime 



5 lbs. sulphur, 15 lbs. lime 



5 lbs. sulphur, 10 lljs. lime 



5 lbs. .sulphur, 5 lbs. lime 



Bordeaux mi.xture and sulphur .spravs combined : 



3 lbs. copper sulphate, 10 lbs. sulphur, 20 lbs. lime 

 3 lbs copper sulphate, 5 lbs. sulphur, 10 lbs. lime 

 2 lbs. copper sulphate, 5 lbs. sulphur, 10 lbs. lime 

 Bordeaux mixture : 



6 lbs. copper sulphate, 15 lbs. lime 



92. 

 H. 

 76. 



85. 

 83. 



85. 

 82. 

 74. 

 81. 

 68. 



78. 

 84. 

 83. 



90.0 



607 

 549 



488 



554 

 536 

 554 

 528 

 473 

 520 

 424 



499 

 549 

 637 



589 



80 

 60 

 60 



60 

 60 

 60 

 80 

 60 

 60 

 60 



70 

 80 



100 



