OTHER FACTORS INFLUENCING WATER REQUIREMENT. 
69 
per unit of dry matter produced, and that grassland can produce dry 
matter more economically when allowed to continue its growth 
uncropped for a longer period. 
Table LIX. — Relative water requirement of pasture and grassland, according to Yon 
Seelhorst (1910, pp. 84-87)} 
Pasture. 
Grassland. 
Period of growth. 
Dry 
matter. 
Water re- 
quirement. 
Dry 
matter. 
Water re- 
quirement. 
1908. 
Apr. 1 to May 16 
Grains. 
150.6 
248 
Grams. 
Apr. 1 to June 13 
512.5 
370 
May 16 to June 20 . . . 
156.0 
715 
June 13 to July 29 
253.7 
733 
June 20 to July 29 
100.5 
135.0 
i,i30 
546 
July 29 to Sept. 16 
206.3 
513 
542.1 
620 
972.5 
495 
1909. 
325.1 
429 
Apr. 6 to June 28 
584 
451 
56.0 
845 
381.1 
490 
584 
451 
i Determinations were made in large pots, shown in figure 4 and described by Von Seelhorst (1902). 
Ordinary grassland and pasture plants were used. The experiment was continued until Sept. 27, 1909, 
but no comparable data are given after June 28. 1909. 
EFFECT OF DEFOLIATION ON THE WATER REQUIREMENT. 
sorauer's experiments. 
Sorauer (1880) determined the effect of defoliation upon the 
water requirement of a grapevine grown in distilled water. The 
experiment was continued from July 14 to September 14. The 
results (Table LXIX) indicate that the removal of the leaves at the 
beginning of the experiment increased the water requirement over 
50 per cent. 
Table LX. 
-Effect of defoliation on the water requirement of a grapevine, according to 
Sorauer (1880, p. 461). 
In leaf. Defoliated at start. 
Plant. 
Number of 
determina- 
tions. 
Water re- 
quirement. 
Number of 
determina- 
tions. 
Water re- 
quirement. 
2 
122±13 
2 
186±8 
285 
