12 
H. C. Agricultural Experiment Station 
Growers of dewberries might well take more than a passing notice of 
this fact of sterility in dewberries, and make ample provision for cross¬ 
pollination of varieties to insure a bountiful crop of fruit. 
Blackberries .—The self-sterility work with the blackberries began in 
the spring of 1910 and was continued through three successive seasons, 
ending with the year 1913. The tabulated results give a pretty clear 
idea as to which varieties are self-fertile and which are self-sterile. 
Table No. 3 
BLACKBERRIES. 
Variety 
Number of 
Bags 
Recovered 
Bags with 
Perfect 
Fruits 
Bags with 
Imperfect 
Fruits 
Bags 
with No 
Fruits 
Blowers . . 
41 
38 
3 
0 
Dallas.- -. . __- 
39 
32 
6 
1 
E. Cluster_ .. . 
34 
33 
1 
0 
E. Harvest _ - .. . 
39 
39 
0 
0 
Eldorado_ 
32 
32 
0 
0 
Illinois _ 
31 
30 
1 
0 
Kenoyer_ . . 
21 
15 
2 
4 
King- 
31 
30 
1 
0 
McDonald (hybrid) 
45 
0 
0 
45 
Mersereau _ _ 
31 
31 
0 
0 
Minnewaski _ _ - 
31 
29 
2 
0 
Rathbun (hybrid) .. . 
181 
41 
85 
55 
Snyder. __ 
30 
28 
0 
2 
Sorsby (hybrid)_ . 
28 
0 
0 
28 
Spalding (hybrid)_ _ . . 
40 
0 
0 
40 
Wilson (hybrid) _ _ 
41 
40 
0 
1 
Upon examination of the tabulated results, obtained under the same 
identical conditions of control as in the case of the dewberries, namely, 
the absolute exclusion of all foreign pollen from the bagged clusters, 
we notice that nearly all of the varieties are self-fertile, that one is 
imperfectly self-fertile, and that three are absolutely self-sterile. 
Among the self-sterile varieties are Spalding, Sorsby, and McDonald; 
all three of which are hybrids between blackberries and dewberries. 
The imperfectly self-fertile variety, Rathbun, we also find to be a hybrid. 
All the rest of the varieties that are mentioned above are true black¬ 
berries and are self-fertile. 
It may be said by way of explanation that in the above table those 
bags of blackberries that are listed as containing imperfect fruits differ 
essentially from similarly listed bags in the case of the dewberries in 
Table Ho. 1. The difference consists in the fact that in the case of the 
former the bags contained whole clusters of fruits which, although im¬ 
perfect, were oftentimes large enough to be utilized in the harvesting 
and marketing of a crop. In the case of the dewberries, however, the 
bags contained fruits which, in number, averaged less than 10 per cent 
