382 Bulletin 74. 



Black-spot. — Another surface fungus which is well known and 

 which has a preference for certain varieties, particularly Hill's 

 Chili, is the black-spot {Cladospormm carpophiluni) . It is usually 

 most serious upon the later varieties. It appears as sooty-black 

 patches of greater or less size, and when the attack is severe the 

 fungus may cover the entire side of the fruit. This side is dwarf- 

 ed, the flesh becomes hardened, ripens slowly, and deep fissures 

 or cracks appear, sometimes extending through to the pit (Fig. 

 10). This fungus is usually not sufficiently troublesome in New 

 York to excite general attention, except in certain years and upon 

 particular varieties. 



In would seem that the two last diseases should be very easily 

 held in check by a few sprayings with Bordeaux mixture, but the 

 experience of those who have tried it this year has not been reas- 

 suring. The chief trouble has been that the fungicide injured 

 the peach foliage. It is well known that peach leaves are very 

 susceptible to any caustic property in spraying mixtures. It is 

 possible that the trouble has been the use of the ferro-cyanide 

 test for making the Bordeaux mixture. This test indicates when 

 sufficient lime has been added to correct the present inj urious effects 

 of the sulphate of copper ; but in wet seasons — if, in fact, not in 

 all seasons — an extra amount of lime may be needed to neu- 

 rtalize subsequent changes in the compound. I am strongly of 

 the opinion that the regular formula for Bordeaux mixture — 6 lbs. 

 lime, 4 lbs. sulphate of copper — is the safest and best one. The 

 mixture may be diluted to any strength required, but for the peach 

 I should not use less than 40 to 50 gallons of water for the above 

 formula. 



The leaf curl has been the subject of more concern amongst 

 New York peach growers during the past few years than any 

 other disease, save the yellows. This trouble is fully discussed 

 in reference to its botanical features in Bulletin 73, p. 324. It 

 certainly has a decided preference for some varieties, particularly 

 those with large, soft and dark-colored leaves. It is also in- 

 fluenced greatly by the season, although it is never wholly absent. 

 A moderate attack does not perceptibly injure trees in full vigor. 

 In many cases, however, the larger part of the leaves fall from 



