New York Agricultural Experiment Station. 525 



occur. Plate LIU shows clusters of fruit thus produced by self- 

 sterile varieties. Compare also Figure 1 of Plate LI with Figure 2 

 of the same plate. Figure 1 shows the best clusters and, excepting 

 one berry, all of the fruit which Brighton has produced on covered 

 clusters in these experiments. Figure 2 shows a cluster of the 

 same variety which was exposed to cross-pollination. 



Whenever self-sterile or nearly self-sterile varieties have pro- 

 duced a good yield from uncovered clusters it shows that the vine 

 was in good condition for testing. On the other hand a s ant yield, 

 or even a total failure to produce fruit from uncovered cluster! 

 cannot be accepted as proof that the vine was in an abnormally 

 unproductive condition and not suitable for testing because the 

 prevalence during the blooming season of a damp, cold atmosphere 

 or of other conditions unfavorable to cross-pollination would mani- 

 festly interfere with the setting of the fruit and reduce the yield. 

 Moreover, either the tendency to great productiveness or the op- 

 posite tendency appears as a varietal characteristic among self- 

 sterile as among self-fertile sorts. For example, Elvibach and Red 

 Eagle are both self-sterile. In 1894 and again in 1895 Elvibach 

 gave a very light crop, although located in a mixed vineyard where 

 the clusters were exposed to cross-pollination. Red Eagle, in the 

 same vineyard, and under similar treatment, gave a fair yield in 

 1894 and a very good yield in 1895. The Elvibach vines being 

 mature and apparently in good health their failure to produce 

 even a fair crop under the' circumstances, together with the gen- 

 eral record of the variety here, indicate that even were it not self- 

 sterile it would be habitually a poor cropper. 



The following table gives a list of varieties tested as to self- 

 fertility and shows for each variety the kind of stamens, the num- 

 ber of clusters tested, the character of the covered fruit clusters 

 and the character of the uncovered clusters of self-sterile varieties. 



