38 N. H. Agriculture Experiment Station [Bulletin 274 



lenizers. In such a case, the data previously presented may be consulted in 

 selecting suitable pollinating sorts to topwork in the orchard. 



In many cases the varieties are interplanted in such a way that the 

 permanent rows consist entirely of one variety, no recognition having been 

 taken at the time of planting of the necessity for permanent pollenizers. 

 After removal of the other semi-permanent pollinating varieties, such an 

 orchard will usually be found to set little fruit. The remedy then is to top- 

 work certain of the trees to pollenizers. It will still be several years, how- 

 ever, before the grafts bloom. 



In top working an orchard, it is advisable eventually to work over a tree 

 completely to the pollenizing variet}', rather than to graft only a portion of 

 the tree permanently. When a tree is only partially worked over, either 

 through accident or neglect, the pollenizing section of the tree may be lost. 



Temporary Relief from Lack of Pollenizers: 



As soon as one learns that lack of pollenizers accounts for the failure of 

 an existing orchard, a crop may be obtained if bees are present, by placing 

 blossoming branches of pollenizing varieties in buckets or tubs of water 

 throughout the orchard or near the hives of bees. Foreign pollen is thus 

 available for the flowers on the trees and will tide the orchardist over the 

 period during which grafts are becoming old enough to produce bloom. 



Summary 



1. The increasing importance of planting only certain varieties of apples 

 in orchards has led to the problem of cross-pollination. 



2. Flower-bud formation and the relation of various flower parts to suc- 

 cessful fruit setting are important. 



3. Under New Hampshire conditions where Mcintosh is a leading com- 

 mercial variety, pollination has become important because of the self- 

 unfruitfulness of this variety. 



4. The position of the flower in the cluster has a profound efifect on the 

 percentage of flowers that set fruit and on the size and shape of the result- 

 ing apples. 



5. Competition between flowers and fruits for food and water has a pro- 

 found effect on the number of fruits reaching maturity. The nutrition of 

 the tree is very important in this respect. 



6. Certain varieties such as Baldwin, Gravenstein and Rhode Island 

 Greening are rather poor pollenizers, partly because of the low germinating 

 power of the pollen of these sorts. 



7. Certain varieties do not make good pollenizers for other varieties 

 when their dates of bloom are widely separated. 



8. Bees are of inestimable value to the orchardist. 



9. For economy, a careful consideration of the arrangement and distri- 

 bution of pollenizers is important. 



10. When orchards have proven unfruitful because they have been 

 planted in solid blocks, pollenizers should be grafted into some of the trees. 



11. Temporary relief from a lack of pollenizers is available through the 

 introduction of bouquets of other varieties at blossom time. 



