16 N. H. Agricultural Experiment Station [Bulletin 274 



Fig. 12. Cross section of ovary (20x). Note locule or cavity in which 

 the ovule is located, a. Base of pistil. 



setting time. The flower parts become progressively more susceptible to 

 low-temperature injury as they approach the stage when the ovule becomes 

 fertilized. The advantage of an elevation is well known with regard to 

 lessening damage from spring frosts. 



Location as affected by climate causes variations in the time that various 

 varieties come into bloom. Varieties that coincide in time of bloom in one 

 place may bloom on different dates elsewhere. This same variation may also 

 occur in the same location in different seasons. 



Tests for Self -unfruitful Orchards: 



It is easy to test whether or not a lack of fruitfulness which has persisted 

 year after year in an orchard is due to lack of pollenizers. If some blossoms 

 of the variety are hand pollinated with pollen of a known good poUenizer 

 and a liigh percentage of set occurs while the usual unfruitfulness of the 

 remainder of the blossoms persists, then it may be concluded that either 

 bees or pollenizers are lacking. If bees had also been provided in the 

 orchard without increasing the set, then the conclusion would be justifiable 

 that pollenizers were absent. 



Another method to test whether the cause of unfruitfulness is lack of 

 pollenizers, would be to introduce some branches of a good known poUen- 

 izer into the orchard at blossom time. If plenty of bees are also present 

 and a set of fruit is obtained, this is proof of the lack of pollenizers. 



For such reasons as these the recommendation is always made to inter- 

 plant varieties in the apple orchard to insure a good set of fruit. 



