54 CORN . 



These self -fertilized kernels probably- account for many of the small 

 or barren stalks in fields. It has often been found to increase the yield 

 to cross two varieties, as illustrated by the following data taken from 

 the Illinois Experiment Station. The. table gives the yield of the 

 two parent varieties and then the yield of the hybrid of these varieties. 



Yields from Crossing 



Variety . Bushels per acre of corn 



Burrs White 64.2 



Cranberry - 61.6 



Average 62.9 



Cross 67.1 



Burrs White 64.2 



Helm's Improved 79.2 



Average 71.7 



Cross 73.1 



Burrs White 64.2 



Edmonds 58.4 



Average 61.3 



Cross 78.5 



Learning 73.6 



Golden Beauty 65.1 



Average 69.3 



Cross 86.2 



Champion White Pearl 60.6 



Learning 73.6 



Average 67.1 



Cross . : 76.2 



QUESTIONS 



1. Where is -the " corn belt " and why is so much corn grown here? 



2. Where was corn first grown? 



3. Does it have wild relatives ? 



4. Name and distinguish the six principal types of corn. 



5. What type is most important? 



6. What conditions affect the production of tillers? 



7. Does depth of planting affect depth of permanent roots? 



8. How are roots distributed in the soil? 



9. What is pollen ? How does it fertilize the ear ? 



10. What part of the ear silks first? 



11. Explain hybridizing. 



12. What effects are noted from hybridizing, on the kernels ? On the vigor 



of plant? 



