HORTICULTURE. 241 



pollinated together or by inclosing the variety furnishing pollen with 

 the variety to be pollinated in a paper bag and shaking the 2 together. 

 Paper bags were used in each instance to prevent cross fertilization by 

 foreign pollen. 



" Twelve nearly or quite self -sterile varieties were treated with pollen from 1 or 

 more of 24 varieties ranging from perfectly self-fertile to self-sterile. The results are 

 ,<j;iven in the body of the bulletin, both in detail and summarized. 



"The use of self-sterile varieties as pollenizers for other self-sterile varieties resulted 

 in failure. iSelf-sterile varieties fertilized with varieties not strongly self-fertile pro- 

 duced clusters varying in compactness about as did the bunches of the iJoUinating 

 variety. Self- fertile sorts, with rare exceptions, gave good results when used as 

 fertilizers for either partially self-sterile or completely self-sterile varieties. From 

 study of the effect of pollen from different varieties upon the same self-sterile variety, 

 it seems probable that failure to set fruit may be due to several causes, such as 

 dropping off of blossom buds before they open or poor condition of the vine; but the 

 most common cause is imperfect pollination due to impotent pollen. 



" Lists are given of varieties, both strongly self-fertile and imperfectly self-fertile 

 or self-sterile, which blossom very early, medium early, in mid-season, medium late, 

 late, and very late." 



Bench grafting resistant vines, F. T. Bioletti and A. M. dal Piaz 



( California Sta. Bui. I'BJ^ pp. 38, figs. 10). — The gradual spread of the 

 phylloxera in California vineyards, necessitating their reestablishment 

 on resistant roots, has led the authors to carry out extensive investi- 

 gations as to the most suitable varieties for this purpose, the best 

 methods of grafting the same, and the grafting of vinifera varieties 

 upon various resistant stocks. Cuttings imported from France were 

 so damaged during transportation as to make desirable the use of only 

 California-grown cuttings in the experiments. 



The 3 most resistant stocks used in 1898 were Riparia Gloire de 

 Montpellier, R. grande glabre, and Rupestris St. George. Twelve 

 vinifera varieties grew well and made good unions on the first, 14 on 

 the second, and 13 on the third. Brief detailed notes on the growth 

 in 1899 of each of these varieties are given, as well as of the growth 

 of some other varieties and of certain crosses of Rupestris on its own 

 roots. 



In 1899 the experiments consisted chiefly of tests of methods of 

 grafting and of planting in the nursery. Ten varieties of American 

 grapes were used as stocks, the varieties Zinfandel, Mondeuse, Tokay, 

 and Ferrara as scions, and 3 varieties for rooting experiments. 



The proportion of successful unions obtained by the ditierent methods 

 of grafting and with the different stocks is shown in the following tab- 

 ular summary. 



8058— No. 3 4 



