INVESTIGATIONS CONCERNING] Ss 
SELEPERTIBILY,) «OFs .sDHE. »G RAs 
1900-1902.” 

S. A. BEACH. 

SUMMARY. 
I. POTENCY OF POLLEN OF SELF-STERILE GRAPES. 
In previous experiments varieties of grapes which are self- 
sterile or nearly so have shown about as little ability to fertilize 
other self-sterile sorts as they have for fertilizing themselves. 
In the tests here reported they have usually likewise failed to 
fertilize self-fertile varieties. Indications are seen, however, 
that the pollen in some instances is not altogether impotent but 
that its own pistils are less congenital than those of some other 
varieties. Further investigation is needed to learn whether or 
not this self-sterility arises because the pollen is deficient in 
amount, or is not well developed, or is uncongenial to its own 
variety. 
II. INFLUENCE ON SELF-FERTILITY OF GIRDLING OR BENDING 
THE FRUITING CANES BEFORE THE BLOOMING SEASON. 
Girdling or bending sharply the fruiting canes of imperfectly 
self-fertile or self-sterile grapes before their blossoms open in 
some cases has stimulated them to increased productiveness. 
In other cases it has not. 
Further tests are needed to learn whether such practice may 
under any circumstances be profitably followed with any Amer- 
ican varieties in commercial vineyards. 
* A reprint of Bulletin No. 223. 
