June, 1933 J Pollination and Fruit Setting in the Apple 37 



only variety which has sufficient data tn recommend it in this case. The 

 capability of untested varieties as poUenizers for Rhode Island Greening 

 can only be conjectured. 



Usually it is advisable to interplant three varieties, or one variety and 

 enough trees of two other varieties to insure cross-pollination and set of 

 fruit^ 



Some of the better combinations and the reasons for choosing them are 

 given below : 



Earlier-blooming desirable orchard varieties capable of poUenizing 

 Mcintosh are not easy to find. Wagener blossoms early enough and the 

 period of l^loom is ample so that one need not worry about the blooming 

 periods not coinciding. Delicious is a desirable second sort because it will 

 pollenize both Mcintosh and Wagener. Another good triple combination is 

 Mcintosh, Cortland and Delicious. These combinations satisfactorily over- 

 come any possible difficulty due to lack of coincidence of l)loom or ability 

 to pollenize. 



When Northern Spy is desired in the orchard, the latest blooming sorts 

 are necessary as poUenizers. Under New Hampshire conditions Mcintosh, 

 although known to be able to cause a set of fruit on Spy, is not practical 

 as a poUenizer for this variety under orchard conditions because Mcintosh 

 bloom is usually over before Spy buds begin to open. The same may be 

 said for Delicious bloom. 



The extended period of bloom of Wealthy, however, normally makes it 

 dependable for pollenizing Northern Spy. The two are inter-fruitful. 

 Golden Delicious also blooms late enough to reach Spy and fortunately the 

 two are inter-fruitful. Since Mcintosh and Wealthy are inter-fruitful, a 

 combination of Northern Spy, Mcintosh and Wealthy might under some 

 conditions prove a favorable one. Baldwin and Delicious might also be in- 

 troduced to make the harvest season more continuous. 



Where Gravenstein is a profitable variety, Oldenburg and Wagener are 

 good poUenizers. Mcintosh would also fit well into such an orchard. 



Many other combinations are possible, but the following questions should 

 be remembered and considered in choosing poUenizers : 



1. Do the known statistics indicate that the varieties desired as poUeniz- 

 ers are able to cause a set of fruit on the commercial sort to be planted ? 



2. How well do the periods of bloom of varieties and poUenizers overlap ? 



3. Is it important to consider the commercial value of the poUenizers ? 



4. Are the poUenizers regular annual bearers ? 



5. Are they hardy and highly resistant to frost damage? 



6. Are they free from and resistant to such diseases as canker, apple 

 scab, blight, etc. ? 



7. Are the poUenizer varieties suspectible to railroad worm ? 



Reworking Orchards to PoUenizers: 



After one finds that an older orchard contains certain varieties which 

 have become unprofitable, their replacement by better sorts is desired. Be- 

 fore top-working the undesirable sorts one should consider whether their 

 disappearance will constitute at the same time the removal of necessary pol- 



