19 iS 



this period except the number of speci- 

 mens studied, in which case the num- 

 ber given for each cross represents all 

 of the specimens secured. 



The measurement in millimeters ran 

 fairly constant each year for the same 

 crosses. All crosses ran slightly larger 

 in 1915, a wet year. 



The form of all crosses consistently 

 each year was that of the female parent. 

 Differentiation of the ground colors 

 was impractical, as all of the specimens 

 possessed the common greenish-yellow 

 ground color at picking time. This 

 gradually changed according to the 

 degree of maturity that the specimens 

 reached by the date that they were 

 described. It was impossible to detect 

 any variation of the ground color of 

 any of the crosses which would indi- 

 cate the action of any particular pol- 

 len. The ground color is, therefore, 

 that which is characteristic of the 

 female parent for each variety. 



The per cent of over-color in 1915 

 was decidedly higher than for 1916 or 

 1917, thus indicating that heat and 

 moisture conditions play an important 

 part on size and color. It was notice- 

 able that self-pollinated specimens of 

 Winesap contained practically 100 per 

 cent red, or over-color, while in 1917 

 they contained only 60 per cent over- 

 color. This held true for all self- 

 pollinated specimens. 



The per cent of over-color of each 

 cross fluctuated from year to year. It is 

 particularly noticeable that the use of 

 other pollen did not increase the per 

 cent of over-color over the self-polli- 

 nated specimens. The self-pollinated 

 Grimes possessed no over-color, as 

 might be expected. Neither did any of 

 the other crosses with Grimes possess 

 over-color. It is noticeable that when 

 Grimes pollen was used on Ben Davis 

 that the Ben Davis apples possessed 54 

 per cent over-color, while the Winesap 

 pollen, a red variety, used on Ben 

 Davis, produced Ben Davis apples with 

 only 52 per cent over-color. This 

 would seem to prove that the influence 

 of the pollen of the male parent is nil 

 on the color of the fruit of the female 

 parent. In the case of self-pollinated 

 Jonathan these apples possessed 43 per 

 cent of over-color, while the Jonathan 

 crossed with Grimes, a yellow variety, 

 contained 6 per cent more over-color. 

 It does not seem probable that the 

 Grimes, carrying practically no over- 

 color itself, as grown in this com- 

 munity, and shown by its own per- 

 formance record, would have the 

 ability to increase color on Jonathan 

 when the Grimes is used as a male 

 parent. The same condition holds true 

 by the use of Grimes on Winesap, where 

 such crosses were 5 per cent more 

 colored than self-pollinated Winesap. 

 The Winesap-Jonathan cross was 17 

 per cent lower than self-pollinated 

 Winesap and 32 per cent lower than 

 ^Vinesap crossed with Grimes. The 

 difference in per cent of over-color is 

 due to the form of growth of tree, the 

 type of pruning, the location of the 

 hand-pollinated specimens on the tree, 

 and particularly to the environmental 

 conditions of the year. It is significant 

 to note in Table II the average per cent 



BETTER FRUIT 



of color of all crosses in 1915 is 75 as 

 compared with 22 per cent for 1916 and 

 30 per cent for 1917. This would indi- 

 cate the influence of other factors on 

 color instead of pollen, as the same 

 parents were used each year. 



The estimation of quality of all 

 crosses varied according to the maturity 

 of the specimens and the influence of 

 storage factors, but particularly varied 

 according to the judgment of the indi- 

 viduals testing the specimens for this 

 character. It is thought best not to list 

 this factor in such terms as fair, good 

 or excellent, as they are only relative 

 terms. Each year it was distinctly 

 noticeable that the quality of all crosses 

 was that of the female parent, making 

 allowances for the influence of the 

 above factors. It is, therefore, believed 

 to be most satisfactory to record 

 quality for the female variety which is 

 possessed as a variety characteristic. 



Summary 



1. This article contains data col- 

 lected in 1915-16-17, of the effect of 

 cross-pollination on size, color, shape 

 and quality of the apple. 



2. Ben Davis, Jonathan, Winesap and 

 Grimes were selected for this study. 



3. Data collected during this work 

 shows the necessity of cross-polli- 

 nation. 



4. The commercial value of this study 

 is based upon the detriment or advan- 

 tage of the pollen of any variety in- 

 creasing or detracting from the size, 

 color, shape or quality of the fruit of 

 the female parent. 



5. Recognized practices of emascula- 

 tion and hand-pollination were main- 

 tained each year. 



6. A total of 11,290 pollinations were 

 made, which produced 773 apples. 



7. The apple when grown under dif- 

 ferent conditions varies in all of the 

 characters mentioned. 



8. A resume of the work of investi- 

 gators conducting experiments related 

 to this subject confirms the data in this 

 article. 



9. Improper pollination will cause 

 abnormal development of the apple, 

 but other causes may also cause the 

 apple to develop improperly. 



10. A distinct color band as found 

 on apple occasionally did not occur 

 among any of the hand-pollinated 

 specimens. 



11. Light is the most important factor 

 on color. Color may be hastened by 

 mechanical, insect or disease injury. 

 Date of picking influences the color of 

 the apple. 



12. Plant food, temperature and 

 moisture are important factors in modi- 

 fying size and shape. 



13. Self-pollinated apples of Grimes, 

 Ben Davis, Jonathan and Winesap were 

 similar in every respect to cross-polli- 

 nated specimens. 



14. In self-pollinated specimens both 

 the striped and the solid type of color- 

 ing is found. Similar coloring is found 

 in orchards where pollination is not 

 under control. 



15. A two-year survey of twenty or- 

 chards in Washington County pro- 

 duced evidence that environment is 

 responsible for modification of size, 



Pase II 



BEST SERVIC 

 QUALITY a PRIC 



PERFECTION IN 



Simpson a DoEf 



portlano.oregom'^ 

 E.SHELLJEYttdHOAN 



NORTH W EStERN f^ANA GER 



: WE CARRY -AND CAN SttIP IN 24 

 HOURS-STOCK LABELS FOR PEARS. 

 . APPLES.CHERRIES a STRAWBERRIf 



color, shape and quality of the apple. 

 Also a study of 94 specimens, including 

 14 varieties, from the Idaho Experiment 

 Station. 



16. The apple when grown under 

 different conditions varies in all of the 

 characters mentioned. 



17. The total per cent of fruit set for 

 the three years for Grimes, as a female, 

 was 49.26, Ben Davis 32.71, Jonathan 

 18.67, and Winesap 9.42. 



18. The greatest mutual affinity ex- 

 ists between varieties as follows: Ben 

 Davis (female) x Grimes, Grimes 

 (female) x Jonathan, Grimes (female) 

 X Ben Davis, Ben Davis (female) x 

 Jonathan. 



19. The commercial and practical 

 application of the facts obtained by this 

 study justify apple growers in planting 

 varieties primarily for the benefit of 

 cross-pollination to secure the normal 

 development of the apple. 



20. No influence of the male pollen 

 of any variety can be detected on size, 

 color, shape and quality of the fruit of 

 the female parent. 



Conclusions 

 The results of this study for the 

 three years seem to justify the follow- 

 ing conclusions: 



1. No influence of the male pollen of 

 any variety can be detected on size, 

 color, shape and quality of the female 

 parent. 



2. The commercial and practical ap- 

 plication of the facts obtained by this 

 study justify apple growers in planting 

 varieties primarily for the benefit of 

 cross-pollination to secure the normal 

 development of the apple. 



