32 PLANT BREEDING 



hills from the most productive row, and continue the project for one or more 

 seasons. 



7. Corn Improvement. — Select the best ears of corn in the field or garden. 

 Plant the seed from each ear in a row by itself. Again select the best ears from 

 the most productive row. Continue the project as long as desired. This is 

 called the ear-row system of corn improvement. 



8. Improving Peaches. — In the peach orchard select a tree that produces 

 better fruit than any others of its variety. Use buds from this tree in propa- 

 gating new peach trees, as described in Chapter VI. Some of the buds may be 

 used on trees of bearing age. They may yield fruit sooner than those budding 

 on young stocks. Compare the fruits thus produced with others. If the im- 

 provement is pronounced, and is thus shown to be well fixed, the strain may be 

 given a new name. 



9. Weight of Seeds. — Visit an implement house or seed store where a fan- 

 ning mill may be studied. If possible obtain permission to run a peck or a 

 bushel of seeds through the machine. Weigh the sample before and after. 

 Note the- difference in weights of a, quart of uncleaned and cleaned seeds. 

 Study the cleanings. This exercise may be continued as a project by growing 

 a sample of the cleaned and uncleaned seeds and comparing the yields. Calcu- 

 late the advantage to the whole state if seed cleaning were practiced by all. 



10. Discussions and Debates. — o. Each student should discuss at home 

 what varieties of garden and field crops could be improved by home selection. 



6. Discuss the probable need of a hive of bees in pollinating orchard 

 fruits and small fruits. 



c. Will it be advisable to have a distinct seed-corn plot on the home farm 

 this year? 



d. Shall we try to improve our potato yield by hill selection of seed? 



QUESTIONS 



1. What are the most important causes of variation among plants? 



2. What is meant by heredity? State the law briefly. 



3. What is meant by the term "sports" in plant breeding? 



4. What is De Vries' teaching regarding their use? 



5. What are the effects of reversion in plant breeding? 



6. Explain the meaning of prepotency. 



7. How would you explain the importance of careful selection? 



8. What are hybrids? 



9. What is Mendel's law of fixation of type? 



10. In what way is this law limited in use? 



11. Give an example of the resuts of Mendel's law. 



12. Give some advantages of using pedigreed seed. 



13. Give an example of the value of attention to improvement. 



14. How could the peach be improved by a plant breeder? 



15. State the same for the tomato. 



16. Describe the hill-row system of improving Irish potatoes. 



17. Outline a plan for improvement of corn. 



18. Explain the use of a fanning mill in improving yields of crops. 



References. — U. S. Farmers' Bulletin, 884, Saving Vegetable Seeds; Cor- 

 nell Reading Courses No. 38, Principles and Methods of Plant Breeding; Im- 

 provement of Cotton Seed by Selection, Year Book, U. S. Dept. Agriculture, 

 1902, pp. 363-386. 



