1152 
Journal of Agricultural Research 
Vol. XXX, No. 12 
tawba, Diogenes, Franklin, Isabella, 
Lucile, Noah, Pocklington, Rommel, 
Salem, Wilder, and Worden. The 
analyses for three of the five years 
were made upon previously pasteurized 
juices and the negative results for cane 
sugar were obtained with pasteurized 
samples in which there is a possibility 
of inversion of cane sugar during pas¬ 
teurization. This indicates strongly 
that cane sugar may be normally pres¬ 
ent in the fresh juices of these va¬ 
rieties. Franklin may be an exception, 
as the fresh juice in 1922 gave negative 
results for cane sugar. 
The presence of cane sugar in those 
varieties in which it only occasionally 
occurs is in some degree, though not ab¬ 
solutely, correlated with immaturity. 
N ineteen hundred and twenty was a year 
of very unfavorable weather conditions 
during the ripening period—little rain 
but much cool, foggy weather. In Camp¬ 
bell Early, Catawba, Goethe, Isabella, 
Jefferson, King Philip, Lady, Noah, 
Rommel, Salem, Ulster, Yergennes, 
Wilder, and Worden the cane-sugar 
content found in 1920 was in each case 
the maximum found for the variety. 
In a number of these—Campbell 
Early, Goethe, King Philip, Rommel, 
Salem, Ulster, Vergennes and Wilder— 
the total sugar content is compara¬ 
tively low as compared with other 
years. In Salem, Wilder, and Worden 
acid content is also high. In this 
group it would appear that unfavora¬ 
ble conditions for photosynthetic activ¬ 
ity had resulted in low sugar content 
and had been accompanied by a partial 
failure of conversion of cane sugar into 
hexoses during the ripening period. 
On the other hand no cane sugar was 
found in Brilliant, Diamond, Elvira, 
Gaertner, Merrimac, and Woodruff, 
although all these varieties failed to 
develop full normal color or to mature 
properly, as is further indicated by 
their low total sugar content. To fur¬ 
ther complicate the case, 1923 was a 
year of unusually favorable seasonal 
conditions in which a number of varie¬ 
ties which occasionally fail to fully 
mature were able to do so, yet seven 
varieties (Brighton, Canada, Centen¬ 
nial, Delaware, Dutchess, Early Daisy, 
and Early Victor), unquestionably 
fully ripe, showed the presence of cane 
sugar in that year and at no other 
time, and the quantity present in a 
number of others (Agawam, Clinton, 
Concord, Dakota, “ Dutchess Seed¬ 
ling,” Eaton, Eumelan, Hartford, 
Ives, Lenoir, Niagara, and Pockling¬ 
ton) equaled or exceeded that found in 
other years. Consequently the pres¬ 
ence of cane sugar can not be consid¬ 
ered as positive proof of the immaturity 
of the fruit, as a larger number of 
varieties showed its presence under the 
exceptionally favorable conditions for 
ripening in 1923 than in any other 
year. Nor can it be definitely corre¬ 
lated with any other factor, such as 
temperature, insolation, water supply, 
or load of fruit on the vines. 
ACID CONTENT 
Examination of Tables III and IV 
will at once show that varieties differ 
greatly in the amount of fluctuation in 
acid content occurring from year to 
year when grown side by side over a 
number of years. Thus Brighton, 
Brilliant, Canada, Diamond, Delaware, 
Eumelan, Herbemont, Lindley, Mar¬ 
tha, Niagara, and Noah show a range 
of variation of less than 0.30 per cent 
during the period, while Agawam, 
Clevener, Diogenes, Isabella, Ives, 
Lenoir, Montefiore, and Norton have a 
range of 0.60 per cent or more. Yet 
both groups' contain midseason and 
late-maturing varieties and neither can 
be said to have an advantage in adapta¬ 
tion to the soil or locality. The fact 
that the experimental period included 
exceptionally favorable and decidedly 
unfavorable years with intermediate 
conditions has probably resulted in the 
inclusion in the data of the extremes 
likely to be encountered in this par¬ 
ticular region in a long period of years. 
Comparison with the data obtained by 
Alwood in the study of grapes from a 
number of States indicates that the 
fluctuation in acid content of a variety 
grown year after year in the same vine¬ 
yard, even with very wide differences 
in seasonal conditions, are much nar¬ 
rower than those encountered in the 
same variety grown over a wide area 
with a diversity of soils and cultural 
conditions. 
The extent to which variations in 
acid and sugar content in the grape are 
related has been the subject of consid¬ 
erable discussion in the European liter¬ 
ature of wine making under the title of 
“Acid-sugar ratio.” The value of a 
grape variety for wine making depends 
to a considerable degree upon this 
ratio, a high acid content resulting in a 
sour wine. Consequently varieties 
which were characterized by a fairly 
constant ratio, low in acid and high in 
sugar, were most desired, while those 
which showed widely fluctuating ratios 
or were high in acidity were less valu¬ 
able. Alwood in his various publica¬ 
tions has devoted some attention to the 
acid-sugar ratio in American grapes 
from the same point of view. Very 
little attention has been given to the 
question whether sugar and acid con- 
