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UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



This starvation of the canes and buds may be brought about in 

 another way, namely, by the production of too large a crop. It is 

 often possible, by excessively long pruning, to cause a vine to produce 



an abnormally large crop of 

 grapes. The larger the crop the 

 more material it takes from the 

 vine, and if too large, the vine is 

 unable to support it and at the 

 same time lay up reserve mate- 

 rials in its canes and buds. In 

 consequence, an extra large crop 

 is often followed by weak growth 

 in the spring, and a consequent 

 small crop the following autumn. 

 Vines of heavy bearing varieties 

 may even be killed in this way, 

 by repeated long pruning. 



This fact has been long recog- 

 nized by practical grape-growers. 

 Lately, Professor L. Ravaz, 1 of 

 the National School of Agricul- 

 ture at Montpellier, France, has 

 advanced the opinion that the 

 death of vines, as a consequence 

 of overbearing, is much com- 

 moner than is usually supposed. 

 This overbearing may occur as a 

 consequence of various condi- 

 tions other than long pruning. 

 Some seasons are peculiarly 

 favorable to heavy crops. Cer- 

 tain diseases and injuries induce 

 temporary heavy bearing. What- 

 ever the cause of abnormally 

 heavy crops, Professor Ravaz 

 believes that they may result in 

 the death of vines. This is the 

 FIG. IG. Biaek Knot on 2-year-oid zinfandei. explanation he gives of the death 



of large numbers of vines in southern France, Algeria, and other 

 countries, and he ascribes our so-called Anaheim disease to the same 

 cause. 



1 "Influence de la Surproduction sur la Vegetation de la Vigne," by L. Ravaz, 

 Coulet et fils, Montpellier, 1906. 



