478 REPORT OF THE HORTICULTURAL DEPARTMENT OF THE 
TABLE X.— Continued. 


a a | er | | ES | ee | ES | ge | 
1899 te alae e ereua re tite nds ie eee ee 1.12 | 1:69.) 1.71] 4.15") 2 OSmimee 
LODO SERIE Le OCR PARE ae Ov95. | dew | 1.2454) 165539) Ton ORO ree 
ROOTS es scusteeet RES fue oy cosnens nome ee 4,43:..| 3,30°1°2.07 4 3.97 15.620) eee eee 
1902 4 te Rie eh: Ae he wes coe 1.92.1) 27842) 4..33)). 5.259) 62.415) See 
1 SOBe wm eee ke psceneiete es sie tenes fearon 2.60 7) °0.223°) 0.77 4) 4.86" 7.209) 1 ee 
1 OO Bical ive heleo iinibe-coihcs epee cleat: i true leer 1,67} 4.04)) 3.37) 5.73.) 2./66.4) 3.260 eee 
A OOS eee eee ee ete oo rel ice > eee 2.05 1°2.01 [8.78 | 3.39 5:44: | 01 S905 eee 
OO Giksce Ss wh tease pau elem crm 2.08 | 4.2414 °5.31 42.37 103,689) 216i eee 
1 GOT EE Bee A Cit athe el Re ee eee 2 (424 158275172. 3845) 1286 11 860) 2S eee 
OO Sot eee ue mutes ide cca ei toes Gite ee 8528.13.07 1 1,96 A AGT 2 17 9: OG mene 
Average 1on 20 yedrous ans ie 2.06 |'°2.70 3.61 153.69 | 3. 35.4) 23 cee 
Average for 5 years — 1904 to 
TGOS See el. tals Deke eae ee ee 2630 |S. a) ae 3.81. | 2°96") 2334 geese 
Let us now consider the disposition of the 11.46 inches of 
rainfall that remains after the grass has had its supply. We 
have no data for this piece of land as to the amount of surface 
evaporation, run-off, and subterranean percolation. But using 
figures somewhat below the average as obtained by soil physi- 
cists in various experiments we may put the evaporation at 4 
inches of rainfall, the run-off at 1 inch and the downward seep- 
age at 1 inch, leaving 5.46 inches for the apple tree and_ its 
crop. But few data are at hand as to the water requirements 
of apples but since the apple plant begins growing early and 
continues until late fall, since it has an enormous leaf surface 
and a relatively large number of stomata, and since the yield of 
fruit is six tons or more to the acre, it may be assumed that the 
apple needs a large amount of water. This assumption is sup- 
ported by the work of Loughridge® in California who found that 
of the apricot, olive, peach, citrus fruits, fig, almond, plum, 
grape and apple among fruits the last is least resistant to 
drought, requiring three times as much water as the apricot, 
olive or peach; twice as much as the citrus fruits or fig, one and 
a half times as much as the almond «and. plum; and one and one 
fifth times as much as the grape. These considerations must 

°Cal. Exp. Sta. Rpt., 1897-98: 95. 
