FARM DEVELOPMENT 



passes to the leaves from which it is transpired into the 

 air. The plant food from the soil is usually in very 

 dilute solutions. All the cells are kept charged full of 

 water, which holds the soft parts of the plant rigid and 

 upright. The water is given off through the same open- 

 ings in the leaves 

 which take in the car- 

 bonic acid gas, and on 

 warm days the evapo- 

 ration of this tran- 

 spired moisture helps 

 to keep the leaves cool. 

 Since the quantity of 

 water transpired 

 through the leaves 

 amounts to from 200 

 to 800 pounds for each 

 pound of dry matter 

 produced by the plant, 

 a good crop of grain 

 or of forage will 



Figure 17. Corn accurately drawn from meas- exhale from its 

 urements made in 1886 representing corn (1) at . . ., 



ten, (2) twenty, (3) thirty and (4) forty days after during the SCaSOn SCV- 

 plantmg. The drawing represents a width of 4 



feet 6 inches. The whorl of roots which spring eral inches of rainfall '. 

 from the seed or seminal whorl, as at 1, and the 

 whorls which arise from the bases of the sheaths that 1<> 

 of the first, second and even the third and fourth LliaL 13 > 

 leaves or blades, strike out through the soil in the f n mvpr tVi<= Qnil tr 

 early, cool, moist spring season in a nearly hori- LU <-UVC] 

 zontal direction. Those springing from the fourth, 

 fifth, sixth and later nodes or joints go nearly 

 downward, so as to hunt better for water in the 

 drier, warmer midsummer. The early and espe- 



f enr<=t-o1 i 

 I SCVCral i 



Extent of roots 



of 



cially the later roots springing from the stem j-pi , r 



stem roots send out many branches with sub- Crops. 1 hC TOOtS OI 



branches reaching every part of the soil. The -. . - 



roots of corn planted in hills 4 feet apart each OUr field CrOOS are 



way, even in the young stage, as at 4. have no , , - 



trouble in reaching all parts of the soil between mUCh longer. mUCh 

 the rows, often overlapping 1 or 2 feet with the 



roots of the adjacent rows. more numerous, spread 



farther, and penetrate into the soil to greater depths 

 than is generally realized. On fairly open, easily pene- 

 trable soils, where the upper portion of the earth is too 

 dry for the plant to obtain sufficient food, roots are sent 



