386 Bulletin 181. 



The same variety may be self-sterile in one place and nearly self- 

 fertile in another. 



11. Poorly nourished trees are more likely to be sterile with their 

 own pollen than well fed trees are. 



12. The loss of fruit from self-sterility usually may be prevented 

 by planting other varieties among the self-sterile trees. 



13. The European and Oriental pears can fertilize each other, 

 and many varieties of the domestica, Japanese and native plums 

 are likewise inter-fertile, provided they bloom together. 



14. The pollen of some varieties will give larger fruit than that 

 of others when it falls qn or is applied to the pistils of either self- 

 sterile or self-fertile varieties. 



15. Among our common orchard fruits cross-pollination seldom 

 has an immediate influence on the fruit itself. 



16. Cross-pollination probably gives better results than self-polli- 

 nation with nearly all varieties. 



17. It is advisable and practicable to plant all varieties of 

 orchard fruits, be they self-sterile or self-fertile, with ref^^rence to 

 cross-pollination. 



18. Insects are probably more important than wind for carrying 

 pollen from tree to tree. 



19. Final suggestions. — a. When setting out new orchards do 

 not plant a solid block of each variety, but mix them intelligently. 



b. If established orchards are unfruitful because of self-sterility 

 it may be profitable to put a few grafts of another variety in each 

 tree. 



c. Keep fruit trees well nourished but do not stimulate them to 



an over-vigorous growth. 



S. W. FLETCHER 



