THE KIND OF POLLINATION GIVING BEST RESULTS 53 
when self-pollinated. Many of our Pears, such as the Anjou, 
Bartlett, Pound, Lawrence, Jones, Howell, Sheldon, Wilder, and 
some others will not produce much fruit unless pollinated with 
pollen from other varieties, while the Kiefer, Buffum, Seckel, and 
some others known as self-fertile varieties set fruit well when 
self-pollinated. Moreover, some trees which are self-fertile 
develop larger and better fruit when cross-pollinated. (Fig. 58.) 
Many of our Apple trees and Cherry trees are known to require 
cross-pollination. 
Furthermore, some varieties of fruit trees! which require cross- 
— 
Fic. 59. — Results of cross-pollination with different varieties in the 
Sweet Cherry. A, fruit obtained by pollinating a cluster of flowers of the 
Bing with pollen from the Black Republican. B, fruit obtained by polli- 
nating a cluster of flowers of the Bing with pollen from the Knight. After 
V. R. Gardner. 
pollination will not do equally well when crossed with all varieties. 
In Apples, Pears, and Cherries better results have been obtained 
1 The pollination of pear flowers. Bulletin 5, Div. of Veg. Path., U. S. 
Dept. of Agr., 1894. 
Pollination of the apple. Bulletin 104, Oregon Agr. College Exp. Sta., 1909. 
Pollination of the Sweet Cherry. Bulletin 116, Oregon Agr. College Exp. 
Sta., 1913. 
Read Pollination in Orchards. Bulletin 187, Cornell University Exp. Sta., 
1909. Also Pollination of Bartlett and Kiefer Pear. Ann. Report, Virginia 
Agr. Exp. Sta., 1911. 
