June 15,1925 Environme nt and Chemical Composition of Grape Juices 1169 
Alwood (#, 3) notes in connection 
with his studies of the development of 
sugar and acid in grapes during ripen¬ 
ing, which were carried on in the Lake 
Erie district in 1908, 1909, and 1910, 
that the crop of 1908 was one of very 
exceptional quality, while that of 1909 
was remarkably heavy, but that cold, 
rainy weather extended over the whole 
ripening period, some late varieties 
being partially defoliated and failing 
to ripen as a result. The crop of 1910 
was reduced by May frost to about 40 
to 60 per cent of normal. Alwood re¬ 
marks that the sugar content of several 
varieties was 1 to 4 per cent lower, and 
the acidity was higher, in 1909 than in 
INCHES 
8 -- 
of all these effects can be obtained. 
Hedrick (29 > 30) has summarized 
climate, as it affects grape growing, in 
these six essentials: Length of season, 
seasonal sum of heat, amount of 
humidity in summer, dates of spring 
and autumn frosts, winter temperature, 
and air currents. While this basis 
holds good when distinct areas differing 
materially one from another in some 
of these factors are being compared, it 
does not apply to the present case. 
The climatic conditions at Vineland 
are such as to permit annual bearing 
of crops of normal size by a large num¬ 
ber of varieties of early, medium, and 
late grapes. None of the elements of 
Rainfall and Sunshine Record, 
at 
Vineland, New Jersey 
for 
1923 
Jan. Feb. Mar. Apr. May June July Aug-. Sept. Oct. Nov; 
Q Clear Days ^ Partly Cloudy Days ^ Cloudy Days | Days of 
Fig 13.—Rainfall and sunshine at Vineland, N. J., in 1923, with 50-year average for comparison. 
on which a trace, 0.1 inch or less, was recorded are included) 
1908, but does not present data as to 
the seasonal conditions prevailing dur¬ 
ing the other years of the study. The 
work of Kelhofer (38) and of Miiller- 
Thurgau (48) on this point has already 
been mentioned (p. 1153). 
The five crop years in which analyti¬ 
cal data was secured have been roughly 
compared with one another in the dis¬ 
cussion of the climatological data in a 
preceding section. Such a comparison 
involves a consideration of the varying 
factors—amount and distribution of 
rainfall and humidity, temperature, 
and sunlight—which enter into the 
makeup of a crop season, to the end 
that each may be evaluated with 
respect to its effect upon the plant, 
before any definite picture of the sum 
climate as enumerated by Hedrick is 
sufficiently variable to become a 
limiting factor upon fruitfulness. The 
analysis necessary here is upon a finer 
scale, since the variations encountered 
are such as merely to modify the crop 
in quality and chemical composition 
without markedly affecting the growth 
or vigor of the plants. As has been 
pointed out by Livingston and McLean 
(44) , the growth of the plant automati¬ 
cally integrates all the fluctuating 
elements of the environmental com¬ 
plex, and the growth of a selected plant 
has been used as a means of measuring 
climatic conditions in different parts 
of an area, as in the work of McLean 
(45) and Hildebrandt (31). In the 
work of these writers the climatic 
