PROCEEDINGS OF THIRTY-THIRD FRUIT-GROWERS ' CONVENTION. 239 



fomia which make it possible to achieve such wonderful results in 

 various lines of horticulture make the adjusting and proper selection 

 of resistant stocks a complicated and difficult problem. 



As far back as 1876 introductions and plantings of resistant vines 

 were made by some of the more intelligent growers in the State, and 

 some very good results were achieved on Riparia stock, because the 

 soils and conditions where these plantings were made happened to be 

 favorable. On account of these few good results, the Riparias as a stock 

 were planted indiscriminately in high and low localities and on various 

 soils. Unfortunately, in most instances the conditions were adverse to 

 Riparias and failures predominated. Again, some thought the Califor- 

 nica was a resistant, and by 1883 at least 300,000 vines of it had been 

 planted as grafting stock. Later on its resistance to phylloxera was 

 ascertained to be very low.. In the meantime, the Lenoir had given 

 good results on some soils and all who could planted Lenoir, and more 

 would have been planted had more cuttings or vines of it been avail- 

 able. Of late years just such a stampede has occurred to the Rupes- 

 tris St. George, and similar mistakes are being made with it. These 

 and other resistant stocks are good where conditions are suited to 

 them, but are worthless where such is not the case. Had a systematic 

 study of the wild-grape species and the soil and climatic conditions 

 where they grow been applied in resistant stock plantings from the 

 start, most of these disastrous results would have been prevented. 



Resistance to the phylloxera or the ability of the vine to overcome 

 the injury of the insect is influenced greatly by whether or not the vine 

 is in soil, climatic and other conditions suited to it. A vine otherwise 

 rated lower as resistant, under conditions congenial to it will often 

 prove more resistant than one whose resistant qualities are rated higher 

 but for which the conditions are not suited. Thus, the Lenoir, which 

 in California on deep and loose soils has given excellent results and is 

 the vine on which some base hopes of its resistance to the California 

 vine disease, is not much thought of by the French as a resistant. The 

 Concord, a Labrusca, the principal grape grown east of the Rocky 

 Mountains, is only rated by French authorities as 5 in resistance out of 

 a possible 20. Nevertheless, it thrives under conditions suited to it 

 right where the phylloxera is at home. Instances like this, and the 

 fact that in France much of the resistant work is as much directed 

 toward resistance to calcareous conditions as to phylloxera, make it plain 

 that resistant standards established by the French should not be 

 accepted as infallible, but can perhaps only serve to indicate what 

 might reasonably be expected here. 



"Were not other conditions involved to complicate matters, the simple 

 determination of what resistant stock to use on any given soil need not 

 of necessity be such a difficult problem. A study of the native species, 



