4 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



resistance of less than 14, but as the vines become old the lack of 

 resistance is generally shown by a weakening of the vine and a falling 

 off of the crop. Many vineyards in the south of France grafted on 

 Lenoir which formerly bore well, have now to be doctored with injec- 

 tions of bisulfid. For this reason it is advisable to reject all vines 

 with a resistance of 13 or under, especially as v^ines with greater 

 resistance can now be obtained for practically all conditions. 



Resistant vines are of two kinds: (a) those which are grown for the 

 grapes they produce, and (b) those which are useful only as stocks on 

 which to graft the non-resistant varieties. The former are called 

 " direct producers" the latter, " resistant stocks." 



(a) Direct Producers. When the phylloxera commenced to destroy 

 the vineyards of Europe, the natural attempt was made to replace them 

 with the varieties of vines which had proved successful in the United 

 States, where the insect was endemic. These varieties, however, all 

 proved unsatisfactory. Some, like the Concord and the Catawba, were 

 insufficiently resistant, and although they could be grown where the 

 severe cold of winter impeded the prolificness of the phylloxera, they 

 quickly succumbed in the milder grape-growing sections of Europe.* 

 Most of them were poor bearers compared with the prolific European 

 vines, and finally the character of their fruit differed so widely from 

 what Europeans were accustomed to that there was little sale for the 

 fruit, and the wine could compete with only the very poorest quality of 

 Vinifera wines, and brought a very inferior price. A few of the varieties 

 introduced during that first period are still grown to a limited extent in 

 France, chiefly the Othello and the Lenoir. They are being gradually 

 abandoned, however, as their crops are unsatisfactory, and in many 

 localities can be maintained only by the aid of injections of bisulfid. 

 For some years the search for a suitable direct producer was almost 

 abandoned by practical men, the use of resistant stocks having been so 

 fully successful. Lately, however, renewed efforts have been made and 

 several new direct producers are being advocated and planted to some 

 extent. The merit of these new varieties, however, is chiefly their 

 resistance to Peronospora and Black Rot. Phylloxera-resistance is con- 

 sidered of much less importance by their most ardent advocates, and 

 indeed the advice is given to graft some of the best of these direct pro- 

 ducers upon phylloxera-resistant stock. The main importance of these 

 facts to California grape-growers is that they hold out hopes of perma- 

 nent prosperity for the wine-making industry here, where, owing to the 

 dryness of the climate, there is no likelihood of trouble from these 

 serious fungous diseases of the grape, which threaten to make the grow- 

 ing of Vinifera varieties impossible in many parts of Europe. 



*\n California, these and other Labrusca varieties and hybrids resist very little longer 

 than Vinifera vines. 



