TESTING GEAPE VARIETIES IN THE VINIFERA REGIONS. 155 

 CONCLUSIONS AND SUGGESTIONS. 



Varying soil, climatic, and other conditions complicate the success- 

 ful establishment of vineyards on resistant stocks. 



The adaptability of varieties to soil, climatic, and other conditions 

 can be closely forecasted, but congeniality has to be determined by 

 actual test. 



The best results are obtained where the scion and stock are con- 

 genial and both are suited to all the conditions of the environment. 



When both scion and stock varieties are suited to the conditions 

 but do not thrive, congeniality is probably lacking. 



The ideal vine is one having a most resistant root which is congenial 

 to a top that produces the best fruit abundantly. 



Different species used as stocks with the same variety grafted on 

 them (Table VII) may increase or diminish its vigor and productive- 

 ness; increase or diminish the quality, size, and appearance of the 

 fruit ; cause it to ripen earlier or later ; and bring about results varying 

 from perfect success to almost complete failure. 



Extensive saccharine and acid determinations made (Table VII) of 

 varieties grafted on resistant stocks and contrasted with the con- 

 geniality and growth ratings made of the same vines the same season 

 show a close correspondence between these important chemical 

 constituents of the fruit and the congeniality of graft and stock. 

 Similar growth ratings of a variety grafted on various stocks are 

 found to be accompanied by fairly definite percentages of sugar and 

 acid. The congeniality of the variety to the stock materially affects 

 the resistant qualities of the stock. 



The quantity and quality of the fruit are usually in opposition on 

 the soils and vines producing most abundantly; the fruit is usually 

 not of as much value per given unit as it is on vines that are rela- 

 tively less productive. 



Most vine varieties making perfect growth on resistant stocks 

 are found to yield heavier crops than the same variety when grown 

 on its own roots. 



The best results can be obtained only when the varieties are placed 

 under soil, climatic, and other conditions to which they are adapted 

 and by using the methods of pruning, training, and culture best 

 suited to each one. 



A number of the new grape introductions of the Department of 

 Agriculture are proving to be superior to the varieties that are now 

 commercially grown for certain purposes. 



The relative rooting qualities of resistant varieties are an important 

 consideration in the cost of establishing resistant vineyards. 



Some stocks are suited for bench grafting, while others are especially 

 valuable for vineyard grafting. 



