GRAPE DISEASES 259 



(1) Vines which exhibit a dwarfed, yellowed foliage during 

 the early part of the season (in June) may be regarded with 

 suspicion ; it is probably a case of dead-arm. Diseased plants 

 are thus located. 



(2) About this time the ground is being cultivated frequently ; 

 vines may then be marked and at trimming time may be re- 

 moved. In two or three seasons all affected plants may be 

 eliminated. 



(3) The disease affects the heart-wood. If vines show this, 

 they should be removed and the cut should be made at some 

 point below the last indications of dry-rot. Often this is at the 

 ground, in which case renewals come from below the surface. 



(4) Renewals must be carefully inspected, for they may be- 

 come infected from some outside source. 



(5) At trimming, reddish elevated lesions should be watched 

 for. More than passing attention must be given when dead- 

 arm is present in the vineyard. 



(6) Vines may be brought quickly into profitable bearing 

 by the renewal system. 



(7) It has been shown that the fungus may be carried by 

 pruning tools. 



Healthy vines may be protected from new infections by the 

 application of bordeaux mixture. This should be done at the 

 time recommended for the first black-rot spraying, that is, 

 when the shoots are eight to ten inches long. The application 

 should be made every year, regardless of the weather. For 

 while practically no infections occur in certain years, yet such 

 conditions cannot be safely forecasted by the grower. Nursery- 

 men should take cuttings from vineyards which receive this 

 early application or which are known to be free from dead-arm. 



REFERENCES 



Reddick, Donald. Dead-arm disease of grapes. New York (Geneva) 



Agr. Exp. Sta. Bui. 389 : 463-490. 1914. 

 Reddick, Donald. Necrosis of the grape vine. Cornell Univ. Agr. 



Exp. Sta. Bui. 263 : 323-343. 1909. 



