SUSCEPTIBILITY AND RESISTANCE TO CROWN-GALL. 



17 



Table 11.— Percentage of diseased vines of each variety of grapes grown in the experi- 

 mental vineyard at Bernalillo, N. Mex., in infected soil. 



Variety. 



Ru oestris St. George.. . 



Feher Szagos 



Sweetwater 



Golden Chasselas 



Seedless Sultana 



Carlgnane 



Grenache 



Gros Colman 



Mataro 



Sauvignon Vert 



Black Malvoisie 



Burger 



Lenoir 



Zinfandel 



Purple Damascus 



Thompson Seedless. . . 



Riesling 



Burgundy 



Malaga 



Rose of Peru 



Mission (New Mexico). 



Flame Tokay 



Muscat of Alexandria.. 

 Mission (California) . . . 



Number 



of 



vines 



grown. 



300 

 500 

 400 

 500 

 300 

 100 

 200 

 50 

 300 

 200 

 500 

 200 

 500 

 200 

 100 

 100 

 300 

 300 

 100 

 50 

 1,000 

 300 

 650 

 300 



Age. 



Years. 

 3 

 5 

 3 

 3 

 5 

 3 

 3 

 5 

 3 

 3 

 3 

 3 

 5 

 5 

 5 

 5 

 5 

 3 

 5 

 3 

 5 

 3 

 3 

 5 



Proportion 



of 



diseased 



plants 



resulting. 



Per cent. 



1.0 



5.0 



5.4 



7.2 



8.1 



9.0 



10.0 



11.0 



12. 



13.3 



14.0 



17.0 



18.7 



22.3 



24.0 



24.0 



36.0 



46.0 



52.0 



64.0 



75.0 



70.0 



72.5 



95.0 



Growth of 



plants. 



Very good. 



Do. 



Do. 

 Uneven. 

 Good. 



Do. 



Do. 



Do. 



Do. 

 Uneven. 

 Good. 



Do. 

 Very good. 

 Good. 

 Uneven. 



Do. 

 Good. 

 Uneven. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



It will be seen from the table that the varieties showing the least 

 disease are headed by the hybrid Rupestris St. George, which shows 

 a resistance of 99 per cent. The vines of this variety that were dis- 

 eased showed only traces of the crown-gall and no effects whatever. 

 Other promising varieties are Feher Szagos, Sweetwater, Seedless 

 Sultana, Carignane, Grenache, Gros Colman, Mataro, Black Malvoisie, 

 Burger, and Lenoir. The affected vines of these varieties were, as a 

 rule, but slightly diseased, and have shown a good growth. 



The most diseased vines, viz, Mission, Muscat of Alexandria, 

 Flame Tokay, Rose of Peru, Malaga, Burgundy, Thompson Seedless, 

 and Purple Damascus, will not prove profitable in infected soil in 

 conditions similar to those at Bernalillo. 



The land upon which these vines were grown is a sandy, alluvial 

 deposit of the Rio Grande River, underlain chiefly by sand and 

 gravel. It was examined by Mr. W. W. Mackie, of the Bureau of 

 Soils, October 22, 1906, and samples were taken for a test for alkali. 

 In a report dated November 12, 1906, to the Chief of the Bureau of 

 Soils, Mr. Mackie reported alkali in injurious amount in only three 

 very small areas of the vineyard. This shows that in the greater por- 

 tion of the vineyard there was not sufficient alkali in the soil to hasten 

 the death of the vines, as is often the case in the arid regions. 



The experiment was also not complicated by the presence of 

 phylloxera. The vines were carefully examined each year, but no 

 evidence of their presence was found. 

 40702— Bui. 183—10 2 



