396 
Journal of Agricultural Research 
Vol. VIII, No. 10 
Examinations made during the following seasons failed to show any 
difference in the amount of disease between the fertilized and the un¬ 
fertilized portions of the patch. 
It had been suggested by Mr. Frank Swett, of Martinez, and Prof. E. H. 
Twight that the trouble might be due to a deficiency of lime. Tests on 
nursery vines by Mr. Swett showed improvement in vines where lime had 
been used. Applications to old vines by Mr. Swett and others showed 
little or no effect. A test of the effect of gypsum was made by the Cali¬ 
fornia Agricultural Experiment Station on a small vineyard of 176 old 
Tokay vines, half of which was badly affected and half healthy or only 
FIRST YEAR 
(before treatment) 
• • 
SECOND YEAR 
(after treatment) 
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A A 
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B 
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♦ 
• HEALTHY 
# 5U6HTLY DISEASED 
• MORE DISEASED . DISEASED 
Fig. 2.—Graph showing the results of application of gypsum for the control of little-leaf. Gypsum was 
applied to the portion marked “ B ” during the winter of the first year. During the summer of the first 
year A was but slightly affected, B badly. During the summer of the second year A was a little worse, 
but B was almost free from disease symptoms. 
slightly affected. The condition of the vines the year before the applica¬ 
tion was made and at a corresponding date of the year following the 
application is shown in figure 2 and Table VII. 
The beneficial effect of the application of gypsum seems very apparent 
in this case. Block B, of which 83 per cent of the vines were diseased the 
year before the gypsum was applied, had only 5.8 per cent the following 
year—that is to say, the disease had almost disappeared. Block A, which 
had only 20.5 per cent of diseased vines the first year, had 29.6 per cent 
the second, showing that the improvement of block B was not due to the 
season. Unfortunately, this vineyard was close to a town, and was 
uprooted before further observations could be made. 
