160 PRODUCTIVE FARMING 



REVIEW. 



1. Where was the Irish potato first found ? 



2. What kinds of soils are best suited to potato growing ? 



3. Describe the growing of a green manure crop for a potato field. 



4. Give directions for plowing for potatoes. 



5. Tell of the times for planting early and late potatoes. 



6. Give depths for planting; also distances for planting. 



7. Give directions for treating potato seed to keep scab disease 

 out of the soil. 



8. What is the legal weight for a bushel of potatoes in your State ? 



9. What is the usual yield in bushels per acre ? 



10. In what cUmates and on what soils are sweet potatoes chiefly 

 grown? 



11. Describe the starting of sweet potato plants for a large field. 



12. Give directions for setting them in the field. 



13. Tell how sweet potatoes are stored for winter. 



References. — U. S. Farmers' Bulletins: 35, Potato Culture; 91, 

 Potato Diseases; 324, Sweet Potatoes; 365, Farm Management in 

 Northern Potato-growing Sections; 386, Potato Culture on Irrigated 

 Farms; 407, The Potato as a Truck Crop; 342, Potato Breeding, pp. 10-14. 



CHAPTER XVI. 

 THE PRINCIPLES OF FORESTRY. 



Forest products in America are not as generally con- 

 sidered a part of the permanent resources of the farm as 

 they should be. The chief products are lumber, posts, poles, 

 railroad ties, and fuel. Thus far lumber, ties, and poles have 

 been obtained mainly from native forests. These are rapidly 

 becoming exhausted. In the prairie States firewood and 

 posts are obtained from plantings made by man, but else- 

 where chiefly from the native woods. 



Forestry should become a systematic part of many farms 

 in all the prairie States as well as in the States where tim- 

 ber was originally found. 



Tree planting is naturally considered under two heads: 

 (1) Prairie planting may be for ornament, windbreaks, 

 shelter-belts, and wood-lots or groves for wood, posts and 



