11 



CHAPTER II. 



THE CALIFORNIA VINE OR ANAHEIM DISEASE. 



It is generally admitted that the disease is caused by a minute 

 living parasitic organism and is therefore contagious. But as long 

 as the organism is not found, an exact idea in regard to its nature 

 and manner of attack on the grape vine can not be formed. It is 

 only from its visible effect on the vine, the ensuing consequences 

 and other signs and symptoms, that we can draw our conclusions. 

 My observations during the last few years have led me to be 

 convinced that two kinds of infections may occur, through the 

 root and through parts of the foliage, and that the disease may 

 appear in five different forms or manners in which it affects the 

 vine. 



Form I, the latent or incipient form. I am not entirely con- 

 vinced that it is proper and accurate to call this form latent. It 

 may be simply the first imperceptible attack on the root of the 

 vine by the disease, having so little consequence, that the vine 

 does not show any of its effect. But I am convinced that in 

 some cases Viniferas on their own roots in the Santa Cruz Moun- 

 tains, having obtained full size before the disease germs entered the 

 tissue of their wood and on favorable soil, may have this form 

 for ten years and show perfect health and thriftiness. 



Form II. As soon as the vine is exposed to adverse con 

 ditions of one kind or another, weakening its vitality, Form I de- 

 velopes more or less rapidly into the more acute Form II. This 

 form in its beginning causes the vine sometimes to bear a heavier 

 crop as the first symptom of diminishing vigor. The heavier crop 

 in turn weakens the vine and favors the further development of 

 the disease. Form II generally shows itself in an unthrifty growth 

 of the vine, the latter setting a heavier crop than it can develop 

 properly, the grapes apparently mature, but are low in sugar. 

 The vines sometimes fail to make growth fr,om some spurs or 

 only short growth. Some which seemingly have made healthy 

 growth, occasionally die all at once during the latter part of the 

 summer or the following spring. 



It appears that in this form the disease germs do not enter 

 the top of the vine, the latter probably dies from want of nourish- 

 ment, without showing any of the characteristic spots on the leaves 

 or showing only very indistinct ones late in the season. Young 

 vines which had the disease as Form I from the time they were 



