388 
Journal of Agricultural Research 
Vol. VIII, No. io 
The differences noted in the moisture contents of diseased and healthy 
spots were less concordant, as shown by Table IV. 
Table IV .—Moisture in diseased and in healthy portions of vineyard (from Table II) 
Vineyard and character of attack. 
Percentage of moisture. 
Diseased. 
Healthy. 
D-*-H. 
M, Attack diffusive; severe...,. 
4 - 25 
4- 62 
5 - 8 9 
4- 88 
2.67 
7- 61 
7 * 93 
3-99 
iS 9 *o 
60. 7 
74. 2 
122.3 
S. Attack intermediate; moderately severe. 
W. Attack diffusive; not severe. 
K. Attack intensive; very few vines affected, but these badly. 
In the S. and W. vineyards the moisture contents were notably lower 
in the diseased spots than in the healthy, but in the other vineyards they 
were higher in about the same proportion. The most weight should be 
given to the results in vineyard S. on account of the large number (108) 
of determinations made. In every case in this vineyard, at all depths, 
the soil in diseased spots was drier than in healthy spots. The same is 
true of the W. vineyard. In the M. and the K. vineyards this condition 
is reversed. In M. the soil is excessively sandy, of the type known as 
“blow sand,” and in K. the soil is the least sandy of all. Both these 
vineyards were irrigated, and the moisture conditions observed may not 
be typical of the whole year. The S. vineyard was not irrigated, and the 
observations cover the greater part of the year, from March to November. 
It seems fair to conclude, therefore, that a lack of moisture is a charac¬ 
teristic of affected soils. 
ANNUAL, AND SEASONAL, VARIATIONS 
The disease does not seem to be progressive—that is, it does not neces¬ 
sarily increase with succeeding years. A vineyard may be sufficiently 
affected one year to lose most of its crop and show practically no sign 
of the disease the next. The trouble returns, however, in subsequent 
years. In most affected vineyards it is noticeable every year, but with 
varying degrees of intensity. Very badly diseased vines seem never to 
recover, and they finally die. The annual variation in a moderately 
affected vineyard (St. vineyard) and in a badly affected vineyard 
(F. vineyard) are shown in Table V. 
Table V .—Percentage of annual variations of attack in the St. and F. vineyards 
Condition. 
St. vineyard. 
F. vineyard. 
1905 
1906 
1910 
1911 
1912 
1915 
Vines dead or missing .... 
0 
0 
20. 5 
79-5 
0 
10. 5 
17. 7 
71. 8 
9 - 7 
56.8 
29*9 
12.6 
0 2. 5 
29.9 
34 - 9 
38- 7 
2 - 5 
33*3 
21. 2 
43 *o 
3 * 2 
4a 1 
18. 7 
38.1 
Vines badly affpf'tpH . 
Vines slightly affected,...* ■ ■ 
Vines healthy ... 
a Missing vines ol 1910 replaced with new plantings. 
