11 



GIRDLING GRAPES. 



BY JABEZ FISHER. 



I send you the details and results of a repetition of the experiment 

 furnished a year ago in girdling grapes. The same vines were 

 treated as last year with some additional ones. The operation was 

 performed July 18th and 19th, when the berries were as large as 

 peas. The tool used was the small blade of an ordinar}' jackknife 

 and it required fourteen hours' service by a fifteen years old boy to 

 complete 648 girdles, the particular spots being marked in advance. 

 A part of them were upon one of the two arms forming each vine, 

 but the larger portion included both arms, leaving a few central 

 shoots only, untreated. The ring of bark removed was from one- 

 half to three-fourths of an inch in length. 



The girdled grapes showed color Aug. 17th, and the ungirdled 

 Aug. 25th. Those girdled were first sent to market Sept. 22d, and 

 the others Oct. 3d, eleven days later, against ten days in 1889. 



The analysis as made by Dr. C. A. Goessmann is here given : 



Gathered Sept. 22d. Girdled. Not Girdled. 



Moisture at 100° C, 84.93 86.49 



Ash, .48 .47 



Grape sugar, 9.29 7.36 



Acid (Tartaric), 1.17 1.15 



At this time the girdled grapes were fairly vrell ripened, very 

 nearly as good as they became a week later, and better than those 

 gathered Oct. 8th. They were sweet with about the right propor- 

 tion of acid, while those not girdled were quite sour and uneatable. 



The second gathering took place Oct. 8th near the close of the 

 harvesting and the analysis follows : 



Gathered Oct. 8th. Girdled. Not Girdled. 



Moisture at 100° C, 85.16 85.38 



Ash, .54 .59 



Sugar, 9.12 6.65 



Acid (Tartaric), .74 .51 



At this date the girdled grapes had lost a little of their sparkle, 

 and the others had attained an apparently satisfactory amount of 

 sugar with very little undue acid, and yet the analysis tells us that 

 while the former had lost two per cent, of sugar with thirty-seven 

 per cent, of acid, the latter had lost nearly ten per cent of the sugar 

 that they held Sept. 22d when uneatable, but had also lost more than 

 fifty per cent, of their acid. This would indicate that the absence 

 of acid* is of more importance in rendering grapes palatable than 

 the presence of sugar in excess, and it would seem that the ripening 



