HORTICULTURE 151 



done in the way of generalizing on the question of simultaneous 

 blooming for cross pollination is to make a chart for each well marked 

 geographical district. Until more definite knowledge is available, 

 each orchardist should learn how varieties bloom in his own neigh- 

 borhood before planting them for cross-pollination. It is better, but 

 not always necessary, that the two should bloom exactly together; if 

 they overlap two or three days that is often enough. 



It is sometimes desirable to plant varieties of different botanical 

 species together for cross-pollination, but this will often be imprac- 

 ticable because of the difference in their blooming seasons. 



The Mutual Affinity of Varieties. Another point to be looked 

 after when selecting a pollinizer for any self-sterile variety, is the 

 mutual affinity of the two. That is, will the pollen of the pollinizer 

 fertilize the pistils of the self-sterile variety readily and also develop 

 them into high grade fruit? 



It is necessary to study not only the mutual affinity of varieties 

 belonging to different species, but also of varieties of the same species. 

 Some varieties will not fertilize each other, though blossoming at the 

 same time. 



Some of the combinations which have been very successful in 

 the commercial orchards of the country are: Bartlett with Nelis, 

 Flemish Beauty, Easter, White Doyenne, Idaho with Bartlett ; Kief- 

 fer with LeConte, Garber; Coe Golden Drop with French Prune, 

 Green Gage, Italian Prune (Fellenburg) ; Statsuma with Abundance, 

 Burbank, Red June; Miner with DeSoto, Forest Rose, Wild Goose; 

 Wild Goose with DeSoto, Newman, Miner. 



Does Crossing Change the Appearance of the Fruit? In con- 

 nection with the mutual affinity of varieties which are selected for 

 cross-pollination, there comes the question of the "immediate influ- 

 ence" of pollen. For instance, if Seckel pollen is put on Kieffer pis- 

 tils, will it impart the Seckel flavor, color and characteristic shape 

 to the resulting fruit? The characters of both may be united in the 

 seeds, and the trees which come from these seeds may be expected 

 to be intermediates; but is the flesh of the fruit ever changed by 

 foreign pollen? 



The increase in size which often follows crossing cannot be called 

 a true immediate influence, for the foreign pollen generally stimu- 

 lates the fruit to a better growth because it is more acceptable to the 

 pistils, not because it carries over the size-character of the variety from 

 which it came. Setting aside the usual gain in size resulting from 

 crossing, will there be any change in the shape, color, quality and 

 season of ripening of the fruit? 



Most of the changes in fruit which are attributed to the influ- 

 ence of cross-pollination are due to variation. Every bud on a tree 

 is different in some way from every other bud on that tree and may 

 develop unusual characters, independent of all the other buds, ac- 

 cording to the conditions under which it grows. The best way to 

 determine whether there is an immediate influence of pollen is by 

 ihand crossing. 



Most of the evidence supporting the theory that there is an im- 



