CHAPTEE XI 

 FRUIT SETTING AND POLLINATION 



One of the most important phases of the orchard prob- 

 lem is pollination. Without this, fruit does not set and 

 crops are impossible. Broadly speaking, there are two 

 phases of the problem: (1) The primary effect of pollin- 

 ation, that is the fertilization of the pistils of the flower so 

 that the bloom is capable of setting fruit; and (2) the 

 secondary effect of cross-pollination about which much has 

 been written, but about which there is still little definite 

 information. In a study of the secondary effect of pollin- 

 ation such questions arise as what effect Baldwin pollen 

 will have on the Mcintosh apple or how the cross-pollina- 

 tion among certain varieties will affect the form, size, 

 flavor or color of the fruit. 



Many varieties are known to be self -sterile. This term 

 is applied to varieties which are unable to set fruit without 

 the aid of pollen from another variety. Here attention is 

 called to the fact that pollen from a different tree of the 

 same variety does not constitute cross-pollination. An 

 indication of self-sterility is the continued dropping of 

 young fruit from isolated trees or from trees in solid 

 blocks of the same variety. Self-sterility is not a constant 

 character with any variety. The same variety may be 

 self-sterile in one region and nearly self-fertile in another. 

 Emphasis is placed on the fact that local conditions greatly 



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