72 



ELEMENTS OF AGRICULTURE 



3. Account for the sweet taste of germinating corn. 



4. What difference in composition would you expect to find between 

 wheat of the semi-arid regions and of the humid regions? Why? 



6. Which most frequently limits the size of the crop in your com- 

 munity, water or one of the other plant foods? 



7. Which would be better for feed, the straw of oats cut when 

 somewhat green or when ripe? Why? 



8. Following a dew, a wilted plant often "freshens." Why? 



9. Why should orchards be well cared for in the years when no crops 

 are borne? 



10. What allowance is made for water in buying ear corn in the 

 early winter? 



11. Why do stored potatoes shrink so much more than grain? 



12. Explain the comparative effect of plants and animals on the 

 amount of carbon dioxid in the air. 



13. Of two seeds the same size, one an oily seed and one a starchy 

 seed, which would probably grow more rapidly? Why? 



LABORATORY EXERCISES 



24. The Percentages of Water, Dry Matter and Ash in Plants. 



Materials. Balances weighing to centigrams, crucible or other 

 small dish that will stand heating, corn grain, potatoes, some growing 

 plant. 



Place each one in a weighed dish, heat a little above the boiling 

 temperature for one hour or more. If the school has a drying oven, 

 run it at 110 C. Weigh again, then burn by heating very hot and* 

 weigh. Record the results as follows: 



